Table 1.
Clinical characteristics according to quartiles of year 15 serum adiponectin concentrations; CARDIA "calendar years".
| Year 15 adiponectin quartiles (Q) | Q1 (n = 565) | Q2 (n = 449) | Q3 (n = 519) | Q4 (n = 523) | p value |
|---|---|---|---|---|---|
| Age (years) | 40.2 (3.7) | 40.2 (3.6) | 40.2 (3.6) | 40.5 (3.5) | 0.51 |
| Race (% blacks) | 62 | 46 | 36 | 27 | <0.001 |
| Sex (% men) | 70 | 53 | 41 | 22 | <0.001 |
| Education level (completed high school or lower) (%) | 26 | 20 | 17 | 17 | <0.001 |
| Smoking Status | 0.003 | ||||
| Never smoker, % | 65 | 65 | 65 | 64 | |
| Former smoker, % | 14 | 14 | 19 | 21 | |
| Current smoker, % | 21 | 20 | 16 | 15 | |
| Body Mass Index (kg/m2) | 31.0 (6.1) | 29.5 (6.9) | 27.9 (6.2) | 25.3 (5.2) | <0.001 |
| Physical Activity score (exercise units) | 355 (301) | 347 (288) | 352 (286) | 369 (275) | 0.66 |
| Serum C-reactive protein (g/ml) | 3.9 (5.1) | 3.0 (3.8) | 2.8 (6.0) | 1.9 (3.2) | <0.001 |
| ln (Homeostasis Model Assessment, HOMA units) | 1.5 (0.5) | 1.3 (0.4) | 1.2 (0.4) | 1.1 (0.4) | <0.001 |
| FVC at year 10 (ml) | 4464 (1027) | 4395 (1064) | 4381 (1046) | 4204 (942) | <0.001 |
| FEV1 at year 10 (ml) | 3568 (775) | 3507 (813) | 3510 (793) | 3371 (696) | <0.001 |
| FEV1/FVC at year 10 (%) | 80.4 (5.5) | 80.3 (5.7) | 80.5 (5.5) | 80.7 (6.1) | 0.65 |
Note 1: All variables were measured at year 15 except Forced vital capacity (FVC), Forced Expiratory Volume in 1 second (FEV1) and FEV1/FVC that were measured at year 10 and are expressed as mean (standard deviation) or percent.
Note 2: Quartile cutpoints for serum adiponectin concentrations are ≤6.99, 7.00-9.59, 9.60-14.39, and ≥ 14.40 mg/l.