TABLE 2

Quantitative metabolic traits during an OGTT in the Danish population-based Inter99 sample of 5,553 middle-aged and nondiabetic individuals stratified according to the MTNR1B rs10830963 genotype

rs10830963CCCGGGEffect per allele (95% CI)Padd
n (men/women)2,950 (1,410/1,540)2,167 (1,101/1,066)436 (211/225)
Age (years)46 ± 846 ± 846 ± 8
BMI (kg/m2)26.1 ± 4.525.9 ± 4.326 ± 4.1−0.1 (−0.3 to 0.08)0.26
Plasma glucose (mmol/l)
    Fasting5.41 ± 0.55.48 ± 0.515.59 ± 0.540.09 (0.07 to 1.1)1 × 10−21
    30 min post-OGTT8.48 ± 1.678.62 ± 1.758.83 ± 1.630.2 (0.1 to 0.2)2 × 10−7
    120 min post-OGTT6.01 ± 1.555.83 ± 1.516.1 ± 1.56−0.03 (−0.09 to 0.03)0.35
Serum insulin (pmol/l)
    Fasting34 (24–50)33 (23–49)35 (24–52)0.3 (−2.4 to 1.9)0.81
    30 min post-OGTT251 (181–359)240 (171–343)243 (174–351)−2.4 (−4.5 to −0.3)0.025
    120 min post-OGTT155 (98–247)147 (88–234)162 (105–286)0.5 (−2.5 to 3.5)0.75
Insulinogenic index75 (47–127)71 (44–117)68 (46–106)−5.0 (−8.0 to −1.9)0.0016
BIGTT-AIR1,699 (1,342–2,160)1,576 (1,258–2,007)1,515 (1,223–1,909)−6.2 (−8.0 to −4.5)4.3 × 10−12
BIGTT-Si9.4 ± 4.09.6 ± 5.99.0 ± 3.9−0.8 (−0.25 to 0.09)0.37
HOMA-IR8.1 (5.5–12.2)8.0 (5.4–12.2)8.6 (6.0–13.4)1.3 (−0.9 to 3.6)0.23
A1C (%)5.78 ± 0.45.82 ± 0.415.82 ± 0.380.03 (0.02 to 0.05)0.00011
  • Data are means ± SD or medians (interquartile range). Type 2 diabetic patients have been excluded from the present quantitative trait analyses. Values of serum insulin, homeostasis model assessment of insulin resistance (HOMA-IR), insulinogenic index, and BIGTT-AIR were logarithmically transformed before statistical analysis, and their effect sizes are presented as the increase/decrease in percent. Calculated P values and effect sizes were adjusted for age (BIGTT-AIR and BIGTT-Si); age and sex (BMI); or age, sex, and BMI (all other traits) assuming an additive genetic model. Calculations of HOMA-IR and the insulinogenic index are described in the online appendix. BIGTT-AIR and BIGTT-Siare calculated as described elsewhere (21).