Table 2.
Demographic, lifestyle and clinical characteristics of subjects by tertiles of irisin
| Variables | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | Total | P value |
|---|---|---|---|---|---|---|
| Irisin (ng/mL) | 0.13 (0.02, 1.56) | 4.73 (3.83, 5.97) | 10.38 (8.67, 12.17) | 23.05 (17.73, 31.28) | 7.26 (2.75, 14.72) | <0.001‡ |
| Demographics | ||||||
| N (%) | 279 (25.0%) | 279 (25.0%) | 279 (25.0%) | 278 (25.0%) | 1115 (100.0%) | |
| Sex | ||||||
| Male (n, %) | 94 (33.7%) | 100 (35.8%) | 85 (30.5%) | 70 (25.2%) | 349 (31.3%) | 0.039* |
| Female (n, %) | 185 (66.3%) | 179 (64.2%) | 194 (69.5%) | 208 (74.8%) | 766 (68.7%) | |
| Age (years) | 53.2 ± 7.4 | 52.6 ± 7.4 | 53.4 ± 7.1 | 53.5 ± 7.0 | 53.2 ± 7.2 | 0.7 |
| Education categories, (n, %) | 0.4 | |||||
| Illiteracy | 66 (23.7%) | 70 (25.1%) | 91 (32.6%) | 75 (27.0%) | 302 (27.1%) | |
| Elementary school | 87 (31.2%) | 77 (27.6%) | 77 (27.6%) | 89 (32.0%) | 330 (29.6%) | |
| Middle school | 67 (24.0%) | 77 (27.6%) | 52 (18.6%) | 60 (21.6%) | 256 (23.0%) | |
| High school | 35 (12.5%) | 33 (11.8%) | 38 (13.6%) | 36 (13.0%) | 142 (12.7%) | |
| College or above | 24 (8.6%) | 22 (7.9%) | 21 (7.5%) | 18 (6.4%) | 85 (7.6%) | |
| Life style | ||||||
| Ever smoking (n, %) | 82 (29.4%) | 81 (29.0%) | 73 (26.2%) | 59 (21.2%) | 295 (26.5%) | 0.1 |
| Ever drinking (n, %) | 37 (13.3%) | 27 (9.7%) | 36 (12.9%) | 30 (10.8%) | 130 (11.7%) | 0.4 |
| Physical activity (MET-h/week) | 84.0 (46.2, 158.2) | 84.0 (46.2, 140.0) | 87.3 (46.2, 152.4) | 100.3 (56.0, 154.0) | 84.0 (51.6, 148.4) | 0.4 |
| Body composition indices | ||||||
| BMI (kg/m2) | 27.5 ± 3.1 | 27.3 ± 3.1 | 27.7 ± 3.3 | 27.2 ± 2.8 | 27.5 ± 3.1 | 0.2 |
| Waist circumference (cm) | 94.1 ± 7.3 | 93.8 ± 7.2 | 93.4 ± 7.1 | 93.1 ± 6.6 | 93.6 ± 7.1 | 0.4 |
| Waist hip ratio | 0.940 ± 0.049 | 0.943 ± 0.050 | 0.933 ± 0.050 | 0.930 ± 0.049 | 0.937 ± 0.049 | 0.006† |
| Body fat mass (kg) | 24.0 ± 5.4 | 23.3 ± 5.3 | 24.1 ± 5.6 | 24.0 ± 5.1 | 23.9 ± 5.3 | 0.2 |
| Body fat rate (%) | 34.6 ± 6.6 | 34.0 ± 6.9 | 35.1 ± 7.0 | 35.3 ± 6.3 | 34.7 ± 6.7 | 0.1 |
| Body fat free weight (kg) | 46.7 ± 9.2 | 46.2 ± 8.4 | 45.8 ± 8.5 | 44.8 ± 7.5 | 45.9 ± 8.4 | 0.1 |
| Muscle mass (kg) | 44.1 ± 8.8 | 43.7 ± 8.1 | 43.2 ± 8.1 | 42.2 ± 7.2 | 43.3 ± 8.1 | 0.048* |
| Clinical characteristics | ||||||
| Systolic blood pressure (mmHg) | 133.9 ± 17.5 | 133.1 ± 17.6 | 135.7 ± 20.1 | 133.1 ± 16.0 | 134.0 ± 17.9 | 0.3 |
| Diastolic blood pressure (mmHg) | 80.1 ± 10.7 | 80.0 ± 10.8 | 80.4 ± 12.1 | 79.0 ± 9.6 | 79.9 ± 10.8 | 0.4 |
| Serum albumin (g/L) | 49.1 ± 2.4 | 48.9 ± 2.4 | 49.0 ± 2.3 | 49.2 ± 2.5 | 49.0 ± 2.5 | 0.8 |
| Serum glubulin (g/L) | 25.0 ± 3.2 | 25.7 ± 3.4 | 26.5 ± 3.7 | 26.8 ± 3.4 | 26.0 ± 3.4 | <0.001‡ |
| Triglyceride (mmol/L) | 1.94 ± 1.44 | 1.98 ± 1.34 | 1.81 ± 1.16 | 1.77 ± 1.15 | 1.87 ± 1.28 | 0.2 |
| Total cholesterol (mmol/L) | 5.83 ± 1.10 | 5.77 ± 1.00 | 5.91 ± 1.11 | 5.95 ± 1.13 | 5.87 ± 1.09 | 0.2 |
| HDL-cholesterol (mmol/L) | 1.36 ± 0.30 | 1.35 ± 0.31 | 1.36 ± 0.28 | 1.39 ± 0.30 | 1.37 ± 0.30 | 0.6 |
| LDL-cholesterol (mmol/L) | 3.59 ± 1.02 | 3.54 ± 0.96 | 3.73 ± 1.03 | 3.76 ± 1.03 | 3.65 ± 1.01 | 0.022* |
| Fasting glucose (mmol/L) | 6.22 ± 1.95 | 6.09 ± 1.69 | 6.23 ± 1.95 | 6.09 ± 1.35 | 6.16 ± 1.75 | 0.6 |
| Glucose 120 min OGTT (mmol/L) | 9.11 ± 4.17 | 8.93 ± 4.09 | 9.16 ± 4.24 | 9.01 ± 3.90 | 9.05 ± 4.10 | 0.9 |
| Fasting insulin (mIU/L) | 13.2 ± 7.2 | 12.6 ± 6.8 | 12.5 ± 6.4 | 12.7 ± 6.6 | 12.7 ± 6.8 | 0.6 |
| HOMA-IR (*10-6 mol*IU*L-2) | 3.68 ± 2.37 | 3.49 ± 2.59 | 3.51 ± 2.22 | 3.50 ± 2.21 | 3.54 ± 2.35 | 0.7 |
| HbA1c | 6.27 ± 1.25 | 6.17 ± 0.97 | 6.23 ± 1.06 | 6.16 ± 0.85 | 6.21 ± 1.04 | 0.6 |
| Hyperuricemia, (n (%)) | 120 (43.0%) | 103 (36.9%) | 104 (37.3%) | 103 (37.1%) | 430 (38.6%) | 0.4 |
| eGFR <60 mL/min/1.73 m2, (n (%)) | 9 (3.2%) | 13 (4.7%) | 11 (3.9%) | 7 (2.5%) | 40 (3.6%) | 0.6 |
| Albumin creatinine ratio > =30 mg/g, (n (%)) | 57 (20.4%) | 52 (18.6%) | 70 (25.1%) | 47 (16.9%) | 226 (20.3%) | 0.1 |
| CKD, (n (%)) | 64 (22.9%) | 62 (22.2%) | 80 (28.7%) | 52 (18.7%) | 258 (23.1%) | 0.046* |
*p < 0.05, †p < 0.01, ‡p < 0.001.
All percentages are column percentage; except for percentages, all values are mean ± s.d. or median(25th, 75th) for non-normal distribution data.
Abbreviations: ACR albumin creatinine ratio, BMI body mass index, CKD chornic kidney disease, eGFR estimated glomerular filtration rate, HDL high-density lipoprotein cholesterol, HOMA-IR homeostasis model assessment insulin resistance index, LDL low-density lipoprotein cholesterol, MET-h/week metabolic equivalent hours per week.