Table 1.
Characteristics of Participants in Quartiles Based on IGF-1 Levels
| Variables | All | Level of IGF-1 (ng/mL) | p Value | |||
|---|---|---|---|---|---|---|
| Q1, ≤82 | Q2, 83–100 | Q3, 101–119 | Q4, ≥120 | |||
| Age, y | 71.8±5.4 | 74.2±6.1 | 71.8±5.3 | 71.0±4.8 | 70.2±4.5 | <.001 |
| Sex, % (women) | 52 | 64 | 56 | 48 | 41 | <.001 |
| BMI, kg/m2 | 23.4±3.1 | 22.8±3.3 | 23.4±3.1 | 23.5±2.9 | 24.1±2.9 | <.001 |
| Chronic diseases,* number | 1.0±0.8 | 0.9±0.8 | 1.0±0.8 | 1.0±0.8 | 1.1±0.8 | <.001 |
| Medications used, number | 1.9±2.0 | 2.0±2.1 | 1.9±2.0 | 1.8±1.9 | 1.9±1.9 | .018 |
| Education, y | 11.4±2.5 | 10.8±2.5 | 11.3±2.5 | 11.5±2.4 | 11.8±2.6 | <.001 |
| Smoking, % (current) | 10 | 8 | 9 | 13 | 11 | <.001 |
| Drinking alcohol, % (current) | 46 | 38 | 45 | 50 | 52 | <.001 |
| Habit of physical exercise, % (no) | 63 | 67 | 63 | 60 | 61 | .029 |
| Sleep duration, h | 7.7±1.3 | 7.8±1.4 | 7.7±1.2 | 7.7±1.2 | 7.8±1.2 | .068 |
| GDS, score | 2.8±2.6 | 3.1±2.6 | 2.7±2.6 | 2.7±2.6 | 2.6±2.4 | <.001 |
| MMSE, score | 26.3±2.7 | 25.9±2.9 | 26.3±2.7 | 26.3±2.7 | 26.5±2.5 | <.001 |
| Gait speed | 1.3±0.2 | 1.2±0.2 | 1.3±0.2 | 1.3±0.2 | 1.3±0.2 | <.001 |
Notes: BMI = body mass index; GDS = Geriatric Depression Scale; IGF-1 = insulin-like growth factor-1; MMSE = Mini Mental State Examination. Data are shown as mean ± SD or %. Variables were compared among IGF-1 levels (Q1–Q4).
*Chronic diseases included hypertension, hyperlipidemia, and diabetes.