Table 1 Baseline characteristics of study participants^a

Leukocyte mitochondrial DNA copy number, median (interquartile range)

72.00 (59.00–87.25)

73.00 (60.00–88.50)

68.00 (56.00–83.50)

.0094

High-sensitivity C-reactive protein, median (interquartile range), mg/L

0.39 (0.16–0.83)

0.38 (0.16–0.80)

0.46 (0.17–0.94)

 < .0001

Age, years

69.1 (8.1)

67.4 (7.3)

75.4 (7.9)

 < .0001

Women, n (%)

2060 (52.4)

1728 (55.9)

332 (39.7)

 < .0001

Education

 Illiteracy, n (%)

370 (9.4)

243 (7.9)

127 (15.2)

 < .0001

 Elementary school, n (%)

1667 (42.4)

1264 (40.9)

403 (48.2)

 Junior high school

447 (11.4)

355 (11.5)

92 (11.0)

 ≥ High school, n (%)

1444 (36.8)

1229 (39.8)

215 (25.7)

Smoking

 Never, n (%)

2830 (72.1)

2337 (75.6)

493 (58.9)

 < .0001

 Former smoker, n (%)

634 (16.1)

434 (14.0)

200 (23.9)

 Current smoker, n (%)

464 (11.8)

320 (10.4)

144 (17.2)

Body mass index, kg/m²

24.2 (3.3)

24.3 (3.3)

24 (3.6)

.0089

Serum triglycerides, mg/dL

119.1 (78.8)

120 (81.4)

115.9 (68.4)

.1822

Serum high-density lipoprotein cholesterol, mg/dL

53.5 (13.9)

53.9 (13.7)

52.2 (14.4)

.0013

Serum low-density lipoprotein cholesterol, mg/dL

116.6 (32.0)

118.2 (31.4)

110.4 (33.4)

 < .0001

Hypertension, n (%)

1988 (50.6)

1443 (46.7)

545 (65.1)

 < .0001

Diabetes mellitus, n (%)

1021 (26.0)

708 (22.9)

313 (37.4)

 < .0001

Cardiovascular disease, n (%)

799 (20.3)

577 (18.7)

222 (26.5)

 < .0001

Stroke, n (%)

188 (4.8)

100 (3.2)

88 (10.5)

 < .0001

Lung disease, n (%)

116 (3.0)

72 (2.3)

44 (5.3)

 < .0001

Chronic kidney disease, n (%)

559 (14.2)

295 (9.5)

264 (31.5)

 < .0001

Years of observation, years, median (interquartile range)

10.6 (9.1–11.6)

11.1 (9.6–12.0)

7.0 (4.7–9.1)

 < .0001