Table 5.
Subgroup analyses for odds of metabolic syndrome by tertiles of continuous plasma 25-hydroxyvitamin D concentration in the lifestyle and placebo arms of the Diabetes Prevention Program cohort by subgroups
| No. of participants | Tertile of 25-hydroxyvitamin D concentration | P value | P value for interaction | |||
|---|---|---|---|---|---|---|
| 1 (Lowest) | 2 | 3(Highest) | ||||
| Number of participants | 2000 | N = 666 | N = 667 | N = 667 | --- | --- |
| Number with MS | 2000 | N = 504 | N = 477 | N = 441 | --- | --- |
| Plasma 25-hydroxyvitamin D concentration, median (interquartile range), ng/mL | 2000 | 12.1 (9.7, 14.3) | 20.3 (18.3, 22.7) | 30.6 (27.5, 34.9) | --- | --- |
| Odds ratio (95% confidence interval) | ||||||
| Age (median, y) | 0.1190 | |||||
| < 50 | 932 | 1.00 (reference) | 0.83 (0.71, 0.96) | 0.65 (0.46, 0.92) | 0.0154 | |
| Participants (number with Metabolic Syndrome) | 359 (272) | 280 (208) | 293 (199) | |||
| >= 50 | 1027 | 1.00 (reference) | 0.79 (0.65, 0.96) | 0.59 (0.38, 0.90) | 0.0153 | |
| Participants (number with Metabolic Syndrome) | 289 (219) | 375 (260) | 363 (235) | |||
| Gender | 0.5047 | |||||
| Female | 1308 | 1.00 (reference) | 0.84 (0.71, 0.98) | 0.67 (0.47, 0.97) | 0.0317 | |
| Participants (number with Metabolic Syndrome) | 486 (369) | 412 (295) | 410 (274) | |||
| Male | 651 | 1.00 (reference) | 0.75 (0.58, 0.99) | 0.53 (0.29, 0.97) | 0.0393 | |
| Participants (number with Metabolic Syndrome) | 162 (122) | 243 (173) | 246 (160) | |||
| Race | 0.7822 | |||||
| White | 1128 | 1.00 (reference) | 0.86 (0.72, 1.02) | 0.71 (0.48, 1.05) | 0.0841 | |
| Participants (number with Metabolic Syndrome) | 242 (194) | 407 (305) | 479 (318) | |||
| Non-White | 831 | 1.00 (reference) | 0.80 (0.65, 0.99) | 0.61 (0.38, 0.98) | 0.0393 | |
| Participants (number with Metabolic Syndrome) | 406 (297) | 248 (163) | 177 (116) | |||
| Body mass index (kg/m2) | 0.0648 | |||||
| < 30 | 637 | 1.00 (reference) | 0.76 (0.58, 1.00) | 0.54 (0.29, 1.00) | 0.0503 | |
| Participants (number with Metabolic Syndrome) | 138 (79) | 221 (119) | 278 (136) | |||
| >= 30 | 1322 | 1.00 (reference) | 0.85 (0.71, 1.01) | 0.69 (0.46, 1.02) | 0.0596 | |
| Participants (number with Metabolic Syndrome) | 510 (412) | 434 (349) | 378 (298) | |||
Results are presented for tertiles of plasma 25-hydroxyvitamin D concentration at the baseline visit of the Diabetes Prevention Program cohort; odds ratio of metabolic syndrome in each of the two highest tertiles was compared with the lowest tertile by extrapolating the per unit change in estimated odds from the multivariate model; all models are adjusted for recruitment site and month of blood draw; to convert plasma 25-hydroxyvitamin D concentration from ng/mL to nmol/L multiply by 2.459. Subgroup models adjusted for recruitment location, month of blood draw, age (years), gender (male or female; except for analysis by gender), race (black, white, or other; except for analysis by race), ultraviolet radiation index at participant's study site (mean annual in 1997, 90J/m2/hour), smoking status at baseline (never, past, or currently smoking), alcohol consumption (g/day), C-reactive protein (mg/L), self-reported physical activity (MET-hours per week), total energy intake (kcal/day), and body mass index.