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Genetics/Genomes/Proteomics/Metabolomics

Assessment of MTNR1B Type 2 Diabetes Genetic Risk Modification by Shift Work and Morningness-Eveningness Preference in the UK Biobank

  1. Hassan S. Dashti1,2,3,
  2. Céline Vetter2,4,
  3. Jacqueline M. Lane1,2,3,
  4. Matt C. Smith5,
  5. Andrew R. Wood5,
  6. Michael N. Weedon5,
  7. Martin K. Rutter6,7,
  8. Marta Garaulet8,9,
  9. Frank A.J.L. Scheer10,11 and
  10. Richa Saxena1,2,3⇑
  1. 1Center for Genomic Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
  2. 2The Eli and Edythe L. Broad Institute of MIT and Harvard, Cambridge, MA
  3. 3Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
  4. 4Department of Integrative Physiology, University of Colorado at Boulder, Boulder, CO
  5. 5Genetics of Complex Traits, University of Exeter Medical School, Exeter, U.K.
  6. 6Division of Endocrinology, Diabetes and Gastroenterology, Faculty of Biology, Medicine and Health, School of Medical Sciences, University of Manchester, Manchester, U.K.
  7. 7Manchester Diabetes Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, U.K.
  8. 8Department of Physiology, University of Murcia, Murcia, Spain
  9. 9Biomedical Research of Murcia (IMIB-Arrixaca), Murcia, Spain
  10. 10Division of Sleep Medicine, Harvard Medical School, Boston, MA
  11. 11Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA
  1. Corresponding author: Richa Saxena, rsaxena{at}mgh.harvard.edu
Diabetes 2020 Feb; 69(2): 259-266. https://doi.org/10.2337/db19-0606
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Abstract

Night shift work, behavioral rhythms, and the common MTNR1B risk single nucleotide polymorphism (SNP), rs10830963, associate with type 2 diabetes; however, whether they exert joint effects to exacerbate type 2 diabetes risk is unknown. Among employed participants of European ancestry in the UK Biobank (N = 189,488), we aimed to test the cross-sectional independent associations and joint interaction effects of these risk factors on odds of type 2 diabetes (n = 5,042 cases) and HbA1c levels (n = 175,156). Current shift work, definite morning or evening preference, and MTNR1B rs10830963 risk allele associated with type 2 diabetes and HbA1c levels. The effect of rs10830963 was not modified by shift work schedules. While marginal evidence of interaction between self-reported morningness-eveningness preference and rs10830963 on risk of type 2 diabetes was seen, this interaction did not persist when analysis was expanded to include all participants regardless of employment status and when accelerometer-derived sleep midpoint was used as an objective measure of morningness-eveningness preference. Our findings suggest that MTNR1B risk allele carriers who carry out shift work or have more extreme morningness-eveningness preference may not have enhanced risk of type 2 diabetes.

Introduction

MTNR1B encodes the high-affinity melatonin receptor 1B, and the common risk single nucleotide polymorphism (SNP), rs10830963 G, has consistently been associated with fasting glucose, measures of reduced insulin secretion in response to glucose, and increased risk of type 2 diabetes in multiethnic populations (1–6). Melatonin, which is naturally secreted by the pineal gland during the biological night in humans, causes impairment of glucose tolerance in vivo (7) and inhibits baseline and glucose-stimulated insulin secretion in vitro (7). The gain-of-function common genetic variant (>30% minor allele frequency in people of European, Asian, or Native American ancestry) results in increased expression of the melatonin receptor 1B in pancreatic islets and has been shown to potentiate the inhibitory effect of melatonin on insulin release, leading to reduced insulin secretion, increased fasting glucose, and type 2 diabetes risk (7–10).

The influences of melatonin signaling, MTNR1B genetic variation, and their combined impact on glucose metabolism at different times of day have begun to be explored in experimental studies, raising the hypothesis that prolonged concurrence of elevated melatonin and food intake in MTNR1B risk allele carriers may contribute to their increased diabetes risk relative to noncarriers. A small trial in 17 women observed that exogenous melatonin more adversely affected glucose tolerance in MTNR1B risk allele carriers, particularly in the morning (11). Data from highly controlled in-laboratory protocols indicated that endogenous melatonin production may be prolonged later into the morning in MTNR1B risk allele carriers compared with noncarriers and suggested that the MTNR1B risk allele may influence type 2 diabetes risk among morning types who are likely to eat breakfast while melatonin levels are still high (12). A recent randomized crossover study of 40 overweight or obese women found that MTNR1B risk allele further impairs glucose tolerance in response to late night versus early dinners (i.e., in the presence of elevated endogenous melatonin concentrations) (13). This observation may reflect the adverse impact of food intake coincident with high melatonin levels.

Circadian misalignment between the endogenous circadian cycle and behavioral cycles also adversely impacts glucose metabolism (14). Shift work, an example of circadian misalignment that involves a drastic change in daily behavioral cycles, has also been shown to consistently increase risk of type 2 diabetes (15). Given that the MTNR1B common risk SNP links daily melatonin rhythms and food intake to type 2 diabetes, we tested the possibility that misalignment between behavioral and internal circadian rhythms may exacerbate the type 2 diabetes genetic risk conferred by the genetic variant. Specifically, we hypothesized that the type 2 diabetes risk conferred by the MTNR1B risk allele is exacerbated by 1) night shift work as a likely consequence of chronic exposure to nighttime eating and 2) morning chronotype as a likely result of breakfast intake concurrent with extended melatonin production later into the morning. Thus, the aim of the current investigation was to test the independent associations of MTNR1B risk allele, night shift work, and chronotype (self-report and accelerometer derived) on prevalent type 2 diabetes and HbA1c levels and interaction effects of MTNR1B by behavior on prevalent type 2 diabetes and HbA1c levels in a large population from the UK Biobank.

Research Design and Methods

UK Biobank

Study participants for this analysis were from the UK Biobank, previously described in detail (16). In brief, the UK Biobank is a prospective study of >500,000 people living in the U.K. All people in the National Health Service registry who were aged 40–69 years and living <25 miles from a study center were invited to participate between 2006 and 2010. In total, 503,325 participants were recruited from >9.2 million mailed invitations. Baseline data were collected at assessment centers by questionnaires as previously described (15). Height and weight were also measured, and BMI was calculated as weight in kilograms divided by the square of height in meters. Biological samples were also collected at baseline. Genotyping was performed by the UK Biobank for 488,377 participants using two similar arrays, UK BiLEVE and UK Biobank Axiom. Genotyping and quality control have been previously described in detail (15,16). Arrays included markers of known associations with, or possible roles in, phenotypic variation and disease risk, including the MTNR1B risk allele SNP, rs10830963.

A subset of 103,711 participants from the UK Biobank wore actigraphy devices (Axivity AX3) for up to 7 days ∼2.8–9.7 years after their study baseline visits. Details on quality control and data processing have been described previously (17,18). Sleep midpoint, an objective measure of chronotype (19), was derived by processing of the raw accelerometer data.

Ascertainment of Prevalent Type 2 Diabetes and HbA1c Levels

Prevalent cases of type 2 diabetes were defined based on hospital admission data and self-report. Hospital in-patient diagnoses were coded according to the ICD-10, and disease codes for type 2 diabetes (E11) prior to date of baseline assessment were used to denote type 2 diabetes cases. We also followed the algorithms described by Eastwood et al. (20) to determine additional probable prevalent type 2 diabetes cases. These cases were determined from self-report through a verbal interview by a trained nurse at the UK Biobank assessment center on past and current medical conditions and medication use. Participants with no disease codes for any other diabetes and who were determined to be unlikely have diabetes based on self-report served as control subjects. HbA1c levels in red blood cells were centrally determined by the UK Biobank using high-performance liquid chromatography using the Bio-Rad VARIANT II TURBO HbA1c analyzer (21).

Assessment of Shift Work and Morningness-Eveningness Preference

At assessment centers, participants self-reported current work schedule and morningness-eveningness preference. Employed participants were then asked to report whether their current main job involved shift work (i.e., a schedule that falls outside of the normal daytime working hours of 9:00 a.m.–5:00 p.m.; by definition, such schedules involved afternoon, evening, or night shifts or rotating through these kinds of night shifts). If yes, participants were further asked whether their main job involved night shifts, which were defined as work schedules that involve working through the normal sleeping hours, e.g., working through the hours from 12:00 a.m. to 6:00 a.m. Response options were “never/rarely,” “sometimes,” “usually,” or “always” and included “prefer not to answer” and “do not know.” We derived participants’ current shift work status, categorized as “day workers,” “shift workers, but only rarely, if ever, night shifts,” “irregular or rotating shifts with some night shifts,” “irregular or rotating shifts with usual night shifts,” and “permanent night shifts” based on responses to these questions. Participants further self-reported morningness-eveningness preference in response to the question, “Do you consider yourself to be?” Response options were as follows: “definite-morning person,” “more morning than evening,” “more evening than morning,” and “definite-evening person” and also included “prefer not to answer” and “do not know.” Participants who responded “do not know” or “prefer not to answer” were characterized as missing. This assessment question was taken from the Morningness-Eveningness Questionnaire (22) and is an accepted measure of chronotype, as it explains the highest fraction of variance in preferences in sleep-wake timing (19).

Statistical Analyses

The current analysis was restricted to employed or self-employed participants at baseline (57.0% of UK Biobank) with genetic and covariate information and to unrelated participants of European descent (67.2% of UK Biobank) to limit confounding effects by race. Our final analytic sample consisted of 189,488 participants. Participants determined to have type 2 diabetes at baseline were excluded from HbA1c analyses (n = 5,042 cases excluded). Furthermore, participants with missing or extreme HbA1c measures defined as those beyond 3 SDs from the mean were further excluded (n = 9,290 excluded). Among the 189,488 participants, a total of 169,926 responded to the morningness-eveningness preference question, of whom 157,256 participants were subsequently included in the HbA1c analysis. Missing BMI data (n = 340) and sleep duration data (n = 568) were imputed using sex-specific median values.

Associations of current shift work and morningness-eveningness preference on both prevalent type 2 diabetes and HbA1c were estimated using crude and adjusted logistic and linear regression models adjusted for age (continuous) and sex (male/female), further adjusted for sleep duration (continuous), and then further adjusted for BMI (continuous) and other previously established covariates (15) including family history of type 2 diabetes (yes/no), Townsend deprivation index (continuous [23]), alcohol consumption (never, once/week, 2–3 times/week, 4–6 times/week, or daily), physical activity (continuous, METs), hypertension (yes/no), hypertension medication use (yes/no), hypercholesterolemia (yes/no), and lipid-lowering medication intake (yes/no). The Townsend deprivation index is a measure of the level of social deprivation in which the participant lives and is based on unemployment, non–car ownership, non–home ownership, and household overcrowding calculated prior to joining the UK Biobank based on previous national census data (24). Day workers or definite morning preference participants served as the reference group. Association of MTNR1B rs10830963 risk allele on prevalent type 2 diabetes and HbA1c was estimated using logistic and linear regression models adjusted for age, sex, BMI, genotyping array, and 10 principal components of ancestry.

Interaction effects of MTNR1B risk allele and current shift work or morningness-eveningness preference on prevalent type 2 diabetes and HbA1c were tested using a log likelihood ratio test to compare models with and without cross-product interaction terms including main effect terms in logistic or linear regression models adjusted for the aforementioned covariates. Subsequently, stratified MTNR1B association analyses by current shift work or morningness-eveningness preference categories were conducted. In sensitivity analyses, we further adjusted for current shift work or morningness-eveningness preference in our interaction analyses and lastly expanded our analytical sample to include all unrelated participants of European descent regardless of employment status (n = 298,953) in all morningness-eveningness preference analyses. Lastly, we tested for MTNR1B interaction effect with accelerometer-derived sleep midpoint as an objective measure of chronotype to verify findings from the self-reported morningness-eveningness preference analyses. These analyses were limited to type 2 diabetes as an outcome. To account for the ∼10-year time period between baseline assessment when employment status was reported and the accelerometer period, we included only self-reported employed participants 55 years of age or younger at baseline in the primary analysis (n = 38,701). Accelerometer analyses were later repeated to include all unrelated participants of European descent regardless of employment status (n = 82,923). In sensitivity analysis, we further adjusted for household status: people residing in the household with the participant (husband, wife, or partner; sons or daughters; brothers or sisters; mother or father; and grandparents/grandchildren/other). Statistical analyses were conducted with R (version 3.5.1; The R Foundation for Statistical Computing, Vienna, Austria) with a two-sided significance threshold of P < 0.05.

Data and Resource Availability

The data sets generated during and/or analyzed during the current study are available from the UK Biobank. Data may be accessed by contacting the UK Biobank, but restrictions may apply to the availability of these data. No applicable resources were generated or analyzed during the current study.

Results

From a total sample of 189,488 participants, 51% were female, mean (SD) age was 53.5 (7.1) years, and mean BMI was 27.2 (4.7) kg/m2 (Table 1). We observed 5,042 prevalent cases of type 2 diabetes. The subset of 175,156 participants included in the HbA1c analyses had a mean HbA1c of 5.3% (2.5%) [34.47 (3.69) mmol/mol)]. A total of 30,649 (16.2%) current workers reported being involved in some shift work, with 15,311 (8.1%) reporting any night shift work. Among 169,926 participants who reported morningness-eveningness preference, a total of 43,369 (25.5%) reported being a definite morning person and 15,150 (8.9%) reported being a definite evening person. The minor allele frequency of the rs10830963 G risk allele was 27.5%.

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Table 1

Characteristics of employed UK Biobank participants of European descent by current shift work (n = 189,488)

We first tested associations of current shift work and morningness-eveningness preference on outcomes type 2 diabetes and HbA1c. In age- and sex-adjusted logistic and linear regression models, we observed that current shift work was associated with higher odds of type 2 diabetes and higher HbA1c levels (Table 2 and Supplementary Table 1). Compared with day workers, shift work without nights (odds ratio [OR] 1.26 [95% CI 1.15–1.39]), sometimes night shift work (OR 1.33 [95% CI 1.17–1.5]), usual night shift work (OR 1.48 [95% CI 1.18–1.86]), and always night shift work (OR 1.47 [95% CI 1.24–1.73]) were associated with higher odds of type 2 diabetes, but none retained significance upon adjustment for BMI and other established risk factors (Table 2). Compared with day workers, all categories of current shift work were associated with higher HbA1c levels, even upon adjustment for sleep duration or BMI and established risk factors (Table 2 and Supplementary Table 1). Furthermore, we observed that morningness-eveningness preference was associated with type 2 diabetes and HbA1c levels (Table 2 and Supplementary Table 1). Compared with definite morning preference, more morningness than eveningness preference (OR 0.86 [95% CI 0.8–0.93]) was associated with lower odds of type 2 diabetes, whereas definite evening preference (OR 1.30 [95% CI 1.17–1.45]) was associated with higher odds of type 2 diabetes (Table 2). Similar associations were also evident for HbA1c (Table 2). Upon adjustment for BMI and other known risk factors, association estimates were attenuated but remained significant for definite evening preference on type 2 diabetes and HbA1c (Table 2).

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Table 2

Associations of current shift work (n = 189,488) and morningness-eveningness preference (n = 169,926) on adjusted odds of type 2 diabetes and adjusted mean difference in HbA1c

We then tested whether the MTNR1B genetic risk may be exacerbated by current shift work or morningness-eveningness preference. We first observed that each additional G risk allele (rs10830963) was associated with 10% higher odds of type 2 diabetes per effect allele (OR 1.10 [95% CI 1.05–1.15]) and 0.26 mmol/mol higher HbA1c per effect allele (β 0.26 [95% CI 0.23–0.28] [mmol/mol]). No interaction effects were observed between MTNR1B risk allele and current shift work on type 2 diabetes (Pinteraction [Pint] = 0.15) and HbA1c (Pint = 0.25), with results remaining similar after further adjustment for morningness-eveningness preference (Table 3 and Supplementary Table 2). As such, the effect of MTNR1B risk allele was similar across categories of shift work on odds of type 2 diabetes (OR 1.10 [95% CI 1.05–1.15] [per effect allele]) and on HbA1c (β 0.26 [95% CI 0.23–0.28] [mmol/mol per effect allele]) (Table 3).

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Table 3

Adjusted ORs of type 2 diabetes and adjusted βs of HbA1c with each additional copy of the MTNR1B G risk allele across categories of current work schedule

We observed an interaction effect of MTNR1B risk allele and morningness-eveningness preference on type 2 diabetes (Pint = 0.04), which retained significance upon further adjustment for current shift work (Pint = 0.04) (Table 4 and Supplementary Table 3). In analyses stratified by morningness-eveningness preference, the effect of MTNR1B risk allele on odds of type 2 diabetes was stronger among definite morning participants (OR 1.17 [95% CI 1.07–1.28]), while no association was observed among definite evening participants (OR 1.02 [95% CI 0.88–1.18]) (Table 4). MTNR1B risk allele, however, had comparable effects on HbA1c levels (Pint = 0.87) across categories of morningness-eveningness preference (β 0.26 [95% CI 0.23–0.29] [mmol/mol per effect allele]).

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Table 4

Adjusted ORs of type 2 diabetes and adjusted βs of HbA1c with each additional copy of the MTNR1B G risk allele across categories of morningness-eveningness preference

In sensitivity analyses expanded to include all unrelated participants of European descent regardless of employment status (n = 298,953), association of morningness-eveningness preference on type 2 diabetes and HbA1c levels remained similar; however, no interaction effect was observed with MTNR1B (Pint = 0.10) (Supplementary Tables 4 and 5). Using a more precise objective measurement of chronotype in a subset of 38,701 employed participants of European descent with 7-day accelerometer-derived sleep midpoint data, we observed similar U-shaped associations of sleep midpoint on type 2 diabetes (Supplementary Table 6). Compared with the first quartile of sleep midpoint, both second (OR 0.64 [95% CI 0.56–0.75]) and third (OR 0.72 [95% CI 0.61–0.86]) quartiles of sleep midpoint were associated with lower odds of type 2 diabetes (Table 5), which remained similar when analyses were expanded to include all 82,923 unrelated participants of European descent regardless of employment status (Supplementary Table 7) and when people residing in the household with the participant were accounted for. We observed no interaction effects between MTNR1B risk allele and sleep midpoint on type 2 diabetes among employed participants (Pint = 0.21) and all unrelated participants of European descent regardless of employment status (Pint = 0.11).

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Table 5

Associations of quartiles of accelerometer-derived sleep midpoint (n = 38,701) on adjusted odds of type 2 diabetes in employed UK Biobank participants of European descent

Discussion

In the present analysis, we showed that among employed participants of European descent, current shift work, morningness-eveningness preference, and MTNR1B rs10830963 risk allele associated with type 2 diabetes and HbA1c levels in the UK Biobank. MTNR1B type 2 diabetes–associated risk did not appear to be modified by shift work schedules or morningness-eveningness preference.

Shift work schedules have been observed to associate with modest increases in the risk for type 2 diabetes (15,25,26), coronary heart disease (27), and cancer (28), and our present findings further support and extend our previously reported relationship with type 2 diabetes (15) to HbA1c levels in workers without diabetes in the UK Biobank. The relationships between shift work and adverse health are hypothesized to result from chronic misalignments between the endogenous biological rhythms and behavioral rhythms such as daily sleep/wake and fasting/feeding cycles (14,29–31).

In addition, while earlier studies have primarily focused on adverse health problems associated with eveningness preference (32), our observed relationship of both definite morning and definite evening preference on higher odds of type 2 diabetes and levels of HbA1c relative to moderate morningness or eveningness preferences suggests that extreme preference may be related to adverse health problems. These U-shaped association findings for type 2 diabetes were also supported by accelerometer-derived sleep midpoint as an objective measure of chronotype. Associations, however, remained significant only for definite evening preference after accounting for BMI and other risk factors, supporting higher cardiometabolic disease risk among this subgroup.

Our MTNR1B risk allele associations are similar in magnitude to two recent reports of genome-wide association studies for type 2 diabetes (5,6), suggesting ∼10% higher odds of type 2 diabetes with each additional G risk allele. Furthermore, among employed participants only, we observed a suggestive interaction effect between MTNR1B and morningness-eveningness preference on type 2 diabetes. Consistent with previous findings of MTNR1B SNP interaction effect with early wake time from actigraphy data (12), we observed that the MTNR1B risk allele association on type 2 diabetes is significant among participants self-reporting definite morning preference but not among those reporting more evening preference. This interaction effect supports our earlier hypothesis that, given the MTNR1B risk allele extends duration of endogenous melatonin production later in the morning, eating breakfast early, when melatonin levels are high, may magnify the type 2 diabetes risk conferred by the risk allele (12). In further support of these findings, morning circadian misalignment conferred by short sleep duration, rather than MTNR1B, has also been observed to elevate type 2 diabetes risk when coinciding with early morning food intake (33). In agreement with results of similar investigations in the UK Biobank (34), the interaction effect, however, was not evident when analysis was expanded to include all participants of European descent regardless of employment status and when accelerometer-derived sleep midpoint was used as a more precise objective measure of chronotype.

Despite mounting evidence indicating that night shift work, with likely concurrent chronic exposure to nighttime eating, may exacerbate the associations of MTNR1B on type 2 diabetes (14), we did not observe an interaction effect between MTNR1B and current shift work on type 2 diabetes. Our hypothesis is derived from experimental studies indicating that enhanced melatonin signaling, either from endogenous or exogenous melatonin, dysregulates glucose metabolism particularly among MTNR1B risk allele carriers (11,13). Our results suggest that additional studies in shift workers are needed before population-based recommendations can be made. Worth noting is that our assumption of the concurrence of food intake and endogenous circulating melatonin might not hold true in the night shift work population investigated herein. Furthermore, we have no information about light exposure, which is known to be a potent suppressor of melatonin secretion (35). It is possible that nighttime light exposure in various work environments may suppress endogenous melatonin secretion, which may limit the concurrency between systemic melatonin levels and food intake.

Findings reported here should also be interpreted in light of various other limitations. Lack of information on time-specific eating episodes is a limitation of the traditional 24-h diet recall utilized in the UK Biobank, which assesses for dietary quantity and composition only. The current data set also lacks data on melatonin measures and light exposure, which may be a relevant interacting factor in light of preliminary findings from a northern Sweden cohort, where daylight duration varies from 4.5 to 22 h daily depending on the season, that identified that the MTNR1B G variant associated with 0.07 mmol/L lower 2-h glucose concentrations only in participants examined during the dark season (36). In addition, as a result of limited data, we were unable to account for irregular shifts during the accelerometer period, which may have influenced our sleep midpoint estimates. Furthermore, despite our large sample size, our analysis in the UK Biobank population is limited to adults aged 40–69 years, of which only 57% are currently employed. Our findings may also be affected by misclassification of shift worker exposure as a result of sicker employees transitioning from night to day shift schedules with the onset of type 2 diabetes, thus biasing our results toward the null. Lastly, considering the cross-sectional nature of the current analysis, we are unable to infer direct causality for any of our findings. Therefore, it is plausible that the detected associations could be explained by reverse causality (type 2 diabetes onset affecting morningness-eveningness preference or influencing job options). Thus, follow-up longitudinal investigations with detailed assessment of food intake, light exposure, and melatonin levels are necessary to unravel true effects.

Type 2 diabetes, recently estimated to affect 422 million people worldwide, remains a major public health challenge imposing substantial health, societal, and economic burdens (37). Our analyses point at two modifiable lifestyle risk factors, night shift work and definite morningness-eveningness preference, that associate with type 2 diabetes prevalence and HbA1c levels and may variably affect disease risk based on genetics. Furthermore, our findings on shift work, morningness-eveningness preference, and MTNR1B may help in developing interventions and guide initiatives aimed at attenuating the further rise of type 2 diabetes prevalence.

Article Information

Acknowledgments. This project was conducted using the UK Biobank resource (project ID 6818). The authors thank the participants of the UK Biobank for their participation. The authors also thank the administrative support team at the UK Biobank for their support.

Funding. H.S.D. and R.S. are supported by NIDDK grant R01DK107859. C.V. is supported by NIDDK grant R01DK105072. M.N.W. is supported by the Wellcome Trust Institutional Strategic Support Award (WT097835MF). M.K.R. is supported by The University of Manchester Research Infrastructure Fund. M.G. is supported by the Spanish Government of Investigation, Development and Innovation (SAF2017-84135-R) including the European Regional Development Fund (FEDER) cofunding, Séneca Foundation (20795/PI/18), and National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) grant R01DK105072. F.A.J.L.S. and R.S. are supported by NIDDK grants R01DK102696 and R01DK105072. F.A.J.L.S. is further supported by NIDDK grant R01DK099512 and National Heart, Lung, and Blood Institute grants R01HL118601 and R01HL140574. R.S. is supported by MGH Research Scholar Fund. This study was supported in part by NIDDK grant R01DK105072 and National Heart, Lung, and Blood Institute grant R01HL118601 and the University of Manchester (Regional Innovation Funding).

The funding sources had no influence on study design, data analyses, or interpretation of the findings.

Duality of Interest. M.K.R. has acted as a consultant for GlaxoSmithKline (GSK), Novo Nordisk, Roche, and Merck Sharp & Dohme (MSD) and also participated in advisory board meetings on their behalf; has received lecture fees from MSD and grant support from Novo Nordisk, MSD, and GSK; reports receiving research funding from Novo Nordisk; reports receiving consultancy fees from Novo Nordisk and Roche Diabetes Care; and reports modest owning of shares in GSK. F.A.J.L.S. has received speaker fees from Bayer HealthCare, Sentara Healthcare, Philips, Kellogg Company, Vanda Pharmaceuticals, and Pfizer Pharmaceuticals. No other potential conflicts of interest relevant to this article were reported.

Author Contributions. The study was designed by H.S.D., C.V., J.M.L., F.A.J.L.S., and R.S. H.S.D., C.V., J.M.L., M.K.R., M.G., F.A.J.L.S., and R.S. participated in acquisition, analysis, and/or interpretation of data. H.S.D., C.V., and R.S. wrote the manuscript, and all coauthors reviewed and edited the manuscript before approving its submission. R.S. is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Prior Presentation. Parts of this study were presented in abstract form at the 77th Scientific Sessions of the American Diabetes Association, San Diego, CA, 9–13 June 2017.

Footnotes

  • This article contains Supplementary Data online at http://diabetes.diabetesjournals.org/lookup/suppl/doi:10.2337/db19-0606/-/DC1.

  • Received June 20, 2019.
  • Accepted November 18, 2019.
  • © 2019 by the American Diabetes Association.
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References

  1. ↵
    1. Prokopenko I,
    2. Langenberg C,
    3. Florez JC, et al
    . Variants in MTNR1B influence fasting glucose levels. Nat Genet 2009;41:77–81
    OpenUrlCrossRefPubMedWeb of Science
    1. Bouatia-Naji N,
    2. Bonnefond A,
    3. Cavalcanti-Proença C, et al
    . A variant near MTNR1B is associated with increased fasting plasma glucose levels and type 2 diabetes risk. Nat Genet 2009;41:89–94
    OpenUrlCrossRefPubMedWeb of Science
    1. Dupuis J,
    2. Langenberg C,
    3. Prokopenko I, et al
    . New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk. Nat Genet 2010;42:105–116
    OpenUrlCrossRefPubMedWeb of Science
    1. DIAbetes Genetics Replication And Meta-analysis (DIAGRAM) Consortium; Asian Genetic Epidemiology Network Type 2 Diabetes (AGEN-T2D) Consortium; South Asian Type 2 Diabetes (SAT2D) Consortium; Mexican American Type 2 Diabetes (MAT2D) Consortium; Type 2 Diabetes Genetic Exploration by Nex-generation sequencing in muylti-Ethnic Samples (T2D-GENES) Consortium,
    2. Mahajan A,
    3. Go MJ,
    4. Zhang W, et al
    . Genome-wide trans-ancestry meta-analysis provides insight into the genetic architecture of type 2 diabetes susceptibility. Nat Genet 2014;46:234–244
    OpenUrlCrossRefPubMed
  2. ↵
    1. Scott RA,
    2. Scott LJ,
    3. Mägi R, et al
    . An expanded genome-wide association study of type 2 diabetes in Europeans. Diabetes 2017;66:2888–2902
    OpenUrlAbstract/FREE Full Text
  3. ↵
    1. Zhao W,
    2. Rasheed A,
    3. Tikkanen E, et al
    . Identification of new susceptibility loci for type 2 diabetes and shared etiological pathways with coronary heart disease. Nat Genet 2017;49:1450–1457
    OpenUrlCrossRef
  4. ↵
    1. Tuomi T,
    2. Nagorny CLF,
    3. Singh P, et al
    . Increased melatonin signaling is a risk factor for type 2 diabetes. Cell Metab 2016;23:1067–1077
    OpenUrlCrossRefPubMed
    1. Lyssenko V,
    2. Nagorny CLF,
    3. Erdos MR, et al
    . Common variant in MTNR1B associated with increased risk of type 2 diabetes and impaired early insulin secretion. Nat Genet 2009;41:82–88
    OpenUrlCrossRefPubMedWeb of Science
    1. Jonsson A,
    2. Ladenvall C,
    3. Ahluwalia TS, et al
    . Effects of common genetic variants associated with type 2 diabetes and glycemic traits on α- and β-cell function and insulin action in humans. Diabetes 2013;62:2978–2983
    OpenUrlAbstract/FREE Full Text
  5. ↵
    1. Wood AR,
    2. Jonsson A,
    3. Jackson AU, et al
    .A genome-wide association study of IVGTT-based measures of first-phase insulin secretion refines the underlying physiology of type 2 diabetes variants. Diabetes 2017;66:2296–2309
    OpenUrlAbstract/FREE Full Text
  6. ↵
    1. Garaulet M,
    2. Gómez-Abellán P,
    3. Rubio-Sastre P,
    4. Madrid JA,
    5. Saxena R,
    6. Scheer FAJL
    . Common type 2 diabetes risk variant in MTNR1B worsens the deleterious effect of melatonin on glucose tolerance in humans. Metabolism 2015;64:1650–1657
    OpenUrlCrossRefPubMed
  7. ↵
    1. Lane JM,
    2. Chang A-M,
    3. Bjonnes AC, et al
    . Impact of common diabetes risk variant in MTNR1B on sleep, circadian, and melatonin physiology. Diabetes 2016;65:1741–1751
    OpenUrlAbstract/FREE Full Text
  8. ↵
    1. Lopez-Minguez J,
    2. Saxena R,
    3. Bandín C,
    4. Scheer FA,
    5. Garaulet M
    . Late dinner impairs glucose tolerance in MTNR1B risk allele carriers: a randomized, cross-over study. Clin Nutr 2018 Aug;37:1133–1140
  9. ↵
    1. Scheer FAJL,
    2. Hilton MF,
    3. Mantzoros CS,
    4. Shea SA
    . Adverse metabolic and cardiovascular consequences of circadian misalignment. Proc Natl Acad Sci U S A 2009;106:4453–4458
    OpenUrlAbstract/FREE Full Text
  10. ↵
    1. Vetter C,
    2. Dashti HS,
    3. Lane JM, et al
    . Night shift work, genetic risk, and type 2 diabetes in the UK Biobank. Diabetes Care 2018;41:762–769
    OpenUrlAbstract/FREE Full Text
  11. ↵
    1. Bycroft C,
    2. Freeman C,
    3. Petkova D, et al
    . The UK Biobank resource with deep phenotyping and genomic data. Nature 2018;562:203–209
    OpenUrlCrossRefPubMed
  12. ↵
    1. van Hees VT,
    2. Sabia S,
    3. Jones SE, et al
    . Estimating sleep parameters using an accelerometer without sleep diary. Sci Rep 2018 Aug 28;8:12975
  13. ↵
    1. Jones SE,
    2. van Hees VT,
    3. Mazzotti DR, et al
    . Genetic studies of accelerometer-based sleep measures yield new insights into human sleep behaviour. Nat Commun 2019;10:1585
    OpenUrlCrossRefPubMed
  14. ↵
    1. Taillard J,
    2. Philip P,
    3. Chastang J-F,
    4. Bioulac B
    . Validation of Horne and Ostberg morningness-eveningness questionnaire in a middle-aged population of French workers. J Biol Rhythms 2004;19:76–86
    OpenUrlCrossRefPubMedWeb of Science
  15. ↵
    1. Eastwood SV,
    2. Mathur R,
    3. Atkinson M, et al
    . Algorithms for the capture and adjudication of prevalent and incident diabetes in UK Biobank. PLoS One 2016;11:e0162388
    OpenUrlCrossRefPubMed
  16. ↵
    1. Higgins TN,
    2. Blakney GB,
    3. Dayton J
    . Analytical evaluation of the Bio-Rad variant II automated HbA(1C) analyzer. Clin Biochem 2001;34:361–365
    OpenUrlCrossRefPubMedWeb of Science
  17. ↵
    1. Horne JA,
    2. Ostberg O
    . A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms. Int J Chronobiol 1976;4:97–110
    OpenUrlCrossRefPubMed
  18. ↵
    1. Townsend P,
    2. Phillimore PBA
    . Health and Deprivation: Inequality and the North. London, Croom Helm Ltdm, 1988
  19. ↵
    1. Tyrrell J,
    2. Jones SE,
    3. Beaumont R, et al
    . Height, body mass index, and socioeconomic status: mendelian randomisation study in UK Biobank. BMJ 2016;352:i582
  20. ↵
    1. Gan Y,
    2. Yang C,
    3. Tong X, et al
    . Shift work and diabetes mellitus: a meta-analysis of observational studies. Occup Environ Med 2015;72:72–78
    OpenUrlAbstract/FREE Full Text
  21. ↵
    1. Vetter C,
    2. Devore EE,
    3. Ramin CA,
    4. Speizer FE,
    5. Willett WC,
    6. Schernhammer ES
    . Mismatch of sleep and work timing and risk of type 2 diabetes. Diabetes Care 2015;38:1707–1713
    OpenUrlAbstract/FREE Full Text
  22. ↵
    1. Vetter C,
    2. Devore EE,
    3. Wegrzyn LR, et al
    . Association between rotating night shift work and risk of coronary heart disease among women. JAMA 2016;315:1726
    OpenUrlCrossRefPubMed
  23. ↵
    1. Wang XS,
    2. Armstrong ME,
    3. Cairns BJ,
    4. Key TJ,
    5. Travis RC
    . Shift work and chronic disease: the epidemiological evidence. Occup Med (Lond) 2011;61:78–89
    OpenUrlCrossRefPubMed
  24. ↵
    1. Roden M,
    2. Koller M,
    3. Pirich K,
    4. Vierhapper H,
    5. Waldhauser F
    . The circadian melatonin and cortisol secretion pattern in permanent night shift workers. Am J Physiol Integr Comp Physiol 1993;265:R261–R267
    OpenUrl
    1. Sack RL,
    2. Blood ML,
    3. Lewy AJ
    . Melatonin rhythms in night shift workers. Sleep 1992;15:434–441
    OpenUrlPubMedWeb of Science
  25. ↵
    1. Qian J,
    2. Scheer FAJL
    . Circadian system and glucose metabolism: implications for physiology and disease. Trends Endocrinol Metab 2016;27:282–293
    OpenUrlCrossRefPubMed
  26. ↵
    1. Vera B,
    2. Dashti HS,
    3. Gómez-Abellán P, et al
    . Modifiable lifestyle behaviors, but not a genetic risk score, associate with metabolic syndrome in evening chronotypes. Sci Rep 2018;8:945
    OpenUrl
  27. ↵
    1. Eckel RH,
    2. Depner CM,
    3. Perreault L, et al
    . Morning Circadian misalignment during short sleep duration impacts insulin sensitivity. Curr Biol 2015;25:3004–3010
    OpenUrlCrossRefPubMed
  28. ↵
    1. Tan X,
    2. Ciuculete D-M,
    3. Schiöth HB,
    4. Benedict C
    . Associations between chronotype, MTNR1B genotype and risk of type 2 diabetes in UK Biobank. J Intern Med. 17 October 2019 [Epub ahead of print]. DOI: 10.1111/joim.12994
  29. ↵
    1. Phillips AJK,
    2. Vidafar P,
    3. Burns AC, et al
    . High sensitivity and interindividual variability in the response of the human circadian system to evening light. Proc Natl Acad Sci U S A 2019;116:12019–12024
    OpenUrlAbstract/FREE Full Text
  30. ↵
    1. Renström F,
    2. Koivula RW,
    3. Varga TV, et al
    . Season-dependent associations of circadian rhythm-regulating loci (CRY1, CRY2 and MTNR1B) and glucose homeostasis: the GLACIER Study. Diabetologia 2015;58:997–1005
    OpenUrl
  31. ↵
    1. NCD Risk Factor Collaboration (NCD-RisC)
    . Worldwide trends in diabetes since 1980: a pooled analysis of 751 population-based studies with 4.4 million participants. Lancet 2016;387:1513–1530
    OpenUrlCrossRefPubMed
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Assessment of MTNR1B Type 2 Diabetes Genetic Risk Modification by Shift Work and Morningness-Eveningness Preference in the UK Biobank
Hassan S. Dashti, Céline Vetter, Jacqueline M. Lane, Matt C. Smith, Andrew R. Wood, Michael N. Weedon, Martin K. Rutter, Marta Garaulet, Frank A.J.L. Scheer, Richa Saxena
Diabetes Feb 2020, 69 (2) 259-266; DOI: 10.2337/db19-0606

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Assessment of MTNR1B Type 2 Diabetes Genetic Risk Modification by Shift Work and Morningness-Eveningness Preference in the UK Biobank
Hassan S. Dashti, Céline Vetter, Jacqueline M. Lane, Matt C. Smith, Andrew R. Wood, Michael N. Weedon, Martin K. Rutter, Marta Garaulet, Frank A.J.L. Scheer, Richa Saxena
Diabetes Feb 2020, 69 (2) 259-266; DOI: 10.2337/db19-0606
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