TABLE 1

Participant characteristics at baseline and at the 3-year follow-up

VariableBaselineFollow-up% ChangeP
Vitamin D (nmol/L)58.01 ± 23.26
PTH (pmol/L)4.55 ± 1.68
Anthropometry
 Weight (kg)85.75 ± 19.7086.27 ± 19.670.9 (−2.15 to 4.20)1.060.0003
 BMI (kg/m2)30.33 (26.72–34.57)30.43 (26.93–34.58)0.39 (−0.70 to 1.56)1.23<0.0001
 Waist circumference (cm)98.43 ± 15.4399.12 ± 15.600.50 (−3.00 to 4.70)0.930.0199
Physical activity (MET h/week)19.59 (7.39–53.52)23.13 (9.62–59.66)1.56 (−10.92 to 15.29)3.940.1087
Smoking (% current)30 (6.29)25 (5.13)−5 (1.16)−16.670.09
Blood pressure
 Systolic blood pressure (mmHg)125.92 ± 16.03125.91 ± 15.020.00 (−7.5 to 9.5)0.800.79
 Diastolic blood pressure (mmHg)80.16 ± 10.3280.17 ± 10.101.00 (−5.5 to 6.5)0.860.76
Vitamin D supplement use212 (43.35)262 (53.58)50 (10.23)24.04<0.0001
Fasting glucose (mmol/L)4.95 ± 0.535.20 (4.8–5.6)0.30 (0.0–0.6)6.90<0.0001
2-h glucose (mmol/L)5.72 ± 1.376.10 (5.1–7.6)0.65 (−0.45 to 1.80)11.87<0.0001
Insulin sensitivity
 ISOGTT index13.45 (8.52–20.79)11.54 (6.89–18.85)−1.65 (−5.64 to 1.62)−16.13<0.0001
IR
 HOMA-IR1.88 (1.19–3.09)2.27 (1.41–3.76)0.34 (−0.25 to 1.00)21.42<0.0001
β-Cell function
 IGI/IR9.55 (5.43–14.94)7.41 (4.49–13.70)−1.30 (−4.62 to 1.53)−20.80<0.0001
 ISSI-2727.49 (568.74–907.48)613.51 (493.85–823.69)−93.31 (−219.93 to 27.72)−14.44<0.0001
AUCglucose13.77 ± 2.2914.82 ± 3.240.83 (−0.5 to 2.5)5.76<0.0001
  • Data are n (%) for categorical variables, means ± SD for continuous variables, or median (25 and 75% interquartiles) for non–normally distributed variables. Data are for all participants at follow-up with a baseline serum 25(OH)D measurement (n = 489). Tests of significance are the McNemar test for categorical variables, the paired Student t test for normally distributed variables, and the Wilcoxon signed-rank test for non–normally distributed variables. Percentage change was calculated as ([{follow-up – baseline}/baseline] × 100).