Table 1.
Baseline characteristics of the Diabetes Prevention Program population by metabolic syndrome status
| Characteristic | Overall cohort | Metabolic syndrome absent | Metabolic syndrome present | P-value1 |
|---|---|---|---|---|
| Number of participants | 2000 | 578 | 1422 | |
| Age, mean (SD), years | 51.0 (10.8) | 51.8 (11.5) | 50.7 (10.6) | 0.0392 |
| Gender, No. (%) women | 1337 (66.9) | 379 (65.6) | 958 (67.4) | 0.4385 |
| Race, No. (%) | ||||
| White | 1142 (57.1) | 313 (54.2) | 829 (58.3) | 0.0091 |
| African-American | 405 (20.3) | 142 (24.6) | 263 (18.5) | |
| Other (Hispanic, Asian, American Indian) | 453 (22.7) | 123 (21.3) | 330 (23.2) | |
| Weight, mean (SD), kg | 94.5 (20.5) | 86.2 (18.6) | 97.9 (20.3) | <0.0001 |
| Body mass index, mean (SD), kg/m2 | 34.0 (6.7) | 31.3 (6.1) | 35.1 (6.7) | <0.0001 |
| Waist circumference, mean (SD), cm | 105.1 (14.7) | 97.6 (13.3) | 108.1 (14.1) | <0.0001 |
| Annual UV index, mean (SD), 90J/m2/hour 2 | 4.6 (1.4) | 4.5 (1.3) | 4.7 (1.4) | 0.0135 |
| Hypertension, No. (%) 3 | 975 (48.8) | 131 (22.7) | 844 (59.4) | <0.0001 |
| Physical Activity, mean (SD), MET-hours 4 | 15.9 (25.6) | 17.4 (22.2) | 15.2 (26.9) | 0.0004 |
| Smoking status, No. (%) | ||||
| Never | 1145 (57.3) | 333 (57.6) | 812 (57.1) | 0.0085 |
| Past | 715 (35.8) | 220 (38.1) | 495 (34.8) | |
| Current | 140 (7.0) | 25 (4.3) | 115 (8.1) | |
| Alcohol consumption, mean (SD), g/day | 2.2 (5.6) | 2.6 (6.1) | 2.1 (5.4) | 0.0050 |
| Total energy intake, mean (SD), kcal/d | 2091.0 (1027.8) | 1978.7 (946.5) | 2136.6 (1056.0) | 0.0009 |
| Calcium intake, mean (SD), mg/day | 1102.2 (724.3) | 1086.2 (681.4) | 1108.7 (741.2) | 0.7559 |
| Systolic blood pressure, mean (SD), mmHg | 124.0 (14.6) | 118.5 (13.3) | 126.3 (14.5) | <0.0001 |
| Diastolic blood pressure, mean (SD), mmHg | 78.4 (9.1) | 75.2 (7.8) | 79.7 (9.3) | <0.0001 |
| Fasting plasma glucose, mean (SD), mg/dL | 106.8 (8.1) | 104.3 (8.4) | 107.8 (7.7) | <0.0001 |
| Fasting insulin, mean (SD), μU/mL | 26.4 (15.1) | 20.2 (10.7) | 28.9 (15.9) | <0.0001 |
| Insulin Sensitivity | ||||
| Insulin sensitivity, mean (SD), (μU/mL)−1 | 0.05 (0.03) | 0.06 (0.04) | 0.05 (0.03) | <0.0001 |
| Insulin sensitivity index (ISI), mean (SD), (μnU/mL)*( mg/dL)]−1 | 0.20 (0.14) | 0.25 (0.16) | 0.18 (0.12) | <0.0001 |
| Insulin Secretion | ||||
| Insulinogenic Index (IGI), mean (SD), (μU/mL)/(mg/dL) | 1.22 (0.88) | 1.12 (0.87) | 1.26 (0.89) | <0.0001 |
| Corrected insulin response (CIR), mean (SD), [(μU/mL)/(mg/dL)2] | 0.62 (0.40) | 0.57 (0.41) | 0.64 (0.40) | <0.0001 |
| Disposition Indices (DI) | ||||
| DI 1: IGI * Insulin sensitivity, mean (SD) | 0.05 (0.04) | 0.06 (0.05) | 0.05 (0.04) | <0.0001 |
| DI 2: CIR * ISI, mean (SD) | 0.10 (0.07) | 0.12 (0.08) | 0.10 (0.07) | <0.0001 |
| Total Cholesterol, mean (SD), mg/dL | 204.5 (36.2) | 204.5 (35.8) | 204.5 (36.4) | 0.9882 |
| Triglycerides, mean (SD), mg/dL | 165.6 (95.4) | 113.0 (48.8) | 186.8 (101.3) | <0.0001 |
| HDL cholesterol, mean (SD), mg/dL | 45.5 (12.1) | 54.0 (12.2) | 42.1 (10.2) | <0.0001 |
| LDL cholesterol, mean (SD), mg/dL | 125.6 (32.8) | 127.4 (32.7) | 124.9 (32.9) | 0.1250 |
| C-reactive protein, mean (SD), mg/L | 5.8 (6.9) | 5.0 (7.3) | 6.1 (6.7) | <0.0001 |
| 25-hydroxyvitamin D, mean (SD), ng/mL | 21.6 (9.7) | 23.2 (10.3) | 20.9 (9.4) | <0.0001 |
Values are means (standard deviation) for continuous variables or n (%) for categorical variables. To convert plasma 25OHD concentration from ng/mL to nmol/L multiply by 2.459; to convert triglycerides from mg/dL to mmol/L multiply by 0.0113; to convert glucose from mg/dL to mmol/L multiply by 0.0555; to convert cholesterol from mg/dL to mmol/L multiply by 0.0259.
P values for differences between metabolic syndrome status (present vs. absent) for continuous variables are based on t-tests. For categorical variables, the p value is based on chi-square tests.
Average ultraviolet index at participants’ clinical site.
Hypertension defined as blood pressure ≥ 130/85 mmHg or the use of antihypertensive medication.
MET denotes metabolic equivalent. MET-hours represent the average amount of 588 time engaged in specified physical activities multiplied by the MET value of each activity.