Characteristics of study populations without diabetes in the CARRS (2010–2011) and ARIC (1987–1989) cohorts
| Variables | South Asians (n=3136) | US blacks (n=3059) | US whites (n=9924) |
| Age, years | 52.0 (47.0, 60.0) | 52.0 (48.0, 58.0) | 54.0 (49.0, 59.0)† |
| Age categories (years), (%) | |||
| 45–49 | 36.4 | 34.6‡ | 26.0† |
| 49–54 | 22.5 | 26.8 | 26.6 |
| 55–59 | 14.2 | 21.2 | 25.1 |
| ≥60 | 26.8 | 17.5 | 22.3 |
| Men, (%) | 52.7 | 37.8‡ | 46.6† |
| Current smoker, (%) | 16.9 | 29.7‡ | 23.9† |
| Current drinker, (%) | 14.4 | 33.8‡ | 66.3† |
| Family (parental) history of diabetes, (%) | 17.2 | 24.7‡ | 21.9† |
| BMI, kg/m2 | 24.9 (21.7, 28.4) | 28.2 (25.1, 32.1)‡ | 26.0 (23.4, 29.1)† |
| BMI categories, kg/m2 (%) | |||
| <25.0 | 50.6 | 23.8‡ | 39.4† |
| 25.0–29.9 | 32.4 | 39.6 | 40.4 |
| ≥30 | 17 | 36.6 | 20.2 |
| Waist, cm | 87.5 (79.0, 96.0) | 96.0 (88.0, 106.0)‡ | 95.0 (86.5, 103.0)† |
| HbA1c, mmol/mol* | 40.0 (37.0, 42.0) | 39 (36.0, 42.0)‡ | 36 (33.0, 38.0)† |
| HbA1c, %* | 5.8 (5.5, 6.0) | 5.7 (5.4, 6.0)‡ | 5.4 (5.2, 5.6)† |
| FPG, mmol/L | 5.27 (4.94, 5.66) | 5.44 (5.08, 5.82)‡ | 5.44 (5.13, 5.77)† |
| Triglycerides, mmol/L | 1.36 (1.03, 1.85) | 1.02 (0.77, 1.40)‡ | 1.25 (0.90, 1.79)† |
| LDL-c, mmol/L | 2.98 (2.43, 3.52) | 3.45 (2.78, 4.21)‡ | 3.50 (2.91, 4.52)† |
| HDL-c, mmol/L | 1.11 (0.96, 1.32) | 1.37 (1.14, 1.70)‡ | 1.27 (1.02, 1.57) |
| SBP, mm Hg | 126.0 (114.5, 140.5) | 124.0 (113.0, 137.0)‡ | 116.0 (106.0, 127.0)† |
| DBP, mm Hg | 83.0 (76.0, 91.0) | 79.0 (72.0, 87.0)‡ | 71.0 (65.0, 78.0)† |
| Fasting insulin, pmol/L§ | 56.3 (36.8, 83.3) | 79.2 (50.0, 114.6)‡ | 57.6 (43.1, 86.1) |
| HOMA-IR, µIU/mL×mmol/L, | 1.9 (1.2, 3.0) | 2.7 (1.8, 4.3)‡ | 2.1 (1.4, 3.2)† |
| HOMA-B, µIU/mL/mmol/L, | 87.6 (59.6, 129.7) | 118.7 (78.8, 172.4)‡ | 90.1 (62.0, 127.4)† |
Data are presented as median (IQR Q1, Q3) or %.
Diabetes defined as FPG ≥7.00 mmol/L (126 mg/dL) or HbA1c ≥48 mmol/mol (6.5%) or self-reported/physician-diagnosed diabetes or medication.
P value calculated using median test for comparing median values and χ2 test for categorical variables.
HOMA-B=(20×insulin)/(glucose−3.5) or (20×I0 (µIU/mL)/G0 (mmol/L)−3.5). HOMA-IR=fasting insulin (µIU/L)×fasting glucose (nmol/L)/22.5 or (I0 (µIU/mL)×G0 (mmol/L)/22.5).
Family history=diabetes mellitus in father or mother.
*HbA1c in US blacks and whites was assessed 3 years after baseline in 1990–1992.
†Shows significant difference between South Asians versus US whites.
‡Shows significant difference between South Asians versus US blacks.
§Insulin in South Asians only in Chennai and Delhi samples (n= 1835).
ARIC, Atherosclerosis Risk in Communities; BMI, body mass index; CARRS, Center for Cardiometabolic Risk Reduction in South Asia Study; DBP, diastolic blood pressure; FPG, fasting plasma glucose; HbA1c, hemoglobin A1c; HDL-c, high-density lipoprotein-cholesterol; HOMA-B, homeostasis model assessment of β-cell dysfunction; HOMA-IR, homeostatic model assessment of insulin resistance; LDL-c, low-density lipoprotein-cholesterol; ns, not significant; SBP, systolic blood pressure.