Table 1.
Characteristics of sample at blood draw, by fasting insulin levels
| <3.3 μIU/ml | 3.3–5.9 μIU/ml | 5.9–10.3 μIU/ml | >10.3 μIU/ml | |
|---|---|---|---|---|
| Participants, n | 188 (14.3) | 557 (42.4) | 384 (29.2) | 185 (14.1) |
| Geometric mean insulin level, μIU/ml | 2.82 | 4.51 | 7.47 | 16.23 |
| Geometric mean C-peptide level, nmol/1 | 0.41 | 0.52 | 0.70 | 1.14 |
| Mean age ± SD, years | 71.5 ±5.9 | 71.1 ±5.8 | 71.5 ±5.8 | 71.2 ±5.6 |
| History of hypertension, % | 37.8 | 43.4 | 45.8 | 61.1 |
| History of elevated total cholesterol, % | 16.7 | 28.1 | 31.4 | 34.1 |
| Current smoking, % | 2.1 | 2.3 | 2.6 | 3.2 |
| Past smoking, % | 49.5 | 44.3 | 47.7 | 47.6 |
| Depression, % | 10.6 | 9.2 | 8.6 | 9.7 |
| History of cardiovascular disease, % | 6.9 | 7.9 | 10.7 | 15.1 |
| Physical activity, % | ||||
| ≥5 times per week | 16.8 | 19.6 | 19.0 | 19.7 |
| 1–4 times per week | 51.4 | 41.3 | 42.6 | 32.2 |
| Alcohol, % | ||||
| ≥1 drinks per day | 47.9 | 41.5 | 37.3 | 36.6 |
| 1–6 drinks per week | 27.7 | 31.8 | 31.3 | 33.9 |
| Mean body mass index score ± SD | 23.8 ±2.6 | 25.1 ±2.7 | 26.5 ±3.4 | 28.2 ±4.2 |
| Body mass index ≥30, % | 4.3 | 3.8 | 13.0 | 22.8 |
Groups are based on 1-SD distances from the sample log mean (geometric sample log mean = 5.9 μIU/ml), and cutoff values are presented after natural log back-transformation. Values in parentheses denote percentages.