Table 1 The characteristics of study population in the China Health and Retirement Longitudinal Study

N

12,159

2350

895

Age

66.7 ± 5.6

69.9 ± 6.7

73.9 ± 7.2

 < 0.01

Year

 < 0.01

 2011

3604 (29.6%)

877 (37.3%)

310 (34.6%)

 2013

3846 (31.6%)

715 (30.4%)

259 (28.9%)

 2015

4709 (38.7%)

758 (32.3%)

326 (36.4%)

Sex

0.09

 Male

6303 (51.8%)

1199 (51.0%)

495 (55.3%)

 Female

5856 (48.2%)

1151 (49.0%)

400 (44.7%)

Region

 < 0.01

 Southwest

3271 (26.9%)

924 (39.3%)

322 (36.0%)

 South and central

6344 (52.2%)

1163 (49.5%)

447 (49.9%)

 North

2544 (20.9%)

263 (11.2%)

126 (14.1%)

Urban/Rural

 < 0.01

 Urban

4927 (40.5%)

604 (25.7%)

224 (25.0%)

 Rural

7232 (59.5%)

1746 (74.3%)

671 (75.0%)

Married status

 < 0.01

 Current unmarried

2021 (16.6%)

551 (23.4%)

302 (33.7%)

 Current married

10,138 (83.4%)

1799 (76.6%)

593 (66.3%)

Alcohol

 < 0.01

 More than once a month

3170 (26.1%)

605 (25.7%)

220 (24.6%)

 Less than once a month

927 (7.6%)

144 (6.1%)

48 (5.4%)

 Never

8062 (66.3%)

1601 (68.1%)

627 (70.1%)

Smoking

 < 0.01

 Never

6806 (56.0%)

1175 (50.0%)

456 (50.9%)

 Ever

1556 (12.8%)

239 (10.2%)

119 (13.3%)

 Current

3797 (31.2%)

936 (39.8%)

320 (35.8%)

Body mass index category

 < 0.01

 Underweight

76 (0.6%)

834 (35.5%)

344 (38.4%)

 Normal

5996 (49.3%)

1512 (64.3%)

549 (61.3%)

 Overweight

4460 (36.7%)

4 (0.2%)

2 (0.2%)

 Obesity

1627 (13.4%)

0 (0.0%)

0 (0.0%)

Night sleep duration

 < 0.01

  < 360 min

4000 (32.9%)

931 (39.6%)

370 (41.3%)

 360–419 min

2641 (21.7%)

459 (19.5%)

148 (16.5%)

 420–479 min

2150 (17.7%)

308 (13.1%)

107 (12.0%)

 480–539 min

2352 (19.3%)

427 (18.2%)

160 (17.9%)

  ≥ 540 min

1016 (8.4%)

225 (9.6%)

110 (12.3%)

Hypertension

 < 0.01

 No

8392 (69.0%)

1854 (78.9%)

675 (75.4%)

 Yes

3767 (31.0%)

496 (21.1%)

220 (24.6%)

Dyslipidemia

 < 0.01

 No

10,637 (87.5%)

2185 (93.0%)

828 (92.5%)

 Yes

1522 (12.5%)

165 (7.0%)

67 (7.5%)

Hyperglycemia

 < 0.01

 No

11,167 (91.8%)

2243 (95.4%)

858 (95.9%)

 Yes

992 (8.2%)

107 (4.6%)

37 (4.1%)

Cancer

0.69

 No

12,054 (99.1%)

2331 (99.2%)

885 (98.9%)

 Yes

105 (0.9%)

19 (0.8%)

10 (1.1%)

Chronic lung diseases

 < 0.01

 No

10,846 (89.2%)

1999 (85.1%)

773 (86.4%)

 Yes

1313 (10.8%)

351 (14.9%)

122 (13.6%)

Liver diseases

0.002

 No

11,608 (95.5%)

2271 (96.6%)

871 (97.3%)

 Yes

551 (4.5%)

79 (3.4%)

24 (2.7%)

Heart diseases

 < 0.01

 No

10,316 (84.8%)

2069 (88.0%)

786 (87.8%)

 Yes

1843 (15.2%)

281 (12.0%)

109 (12.2%)

Stroke

0.02

 No

11,821 (97.2%)

2308 (98.2%)

867 (96.9%)

 Yes

338 (2.8%)

42 (1.8%)

28 (3.1%)

Kidney diseases

0.48

 No

11,329 (93.2%)

2199 (93.6%)

842 (94.1%)

 Yes

830 (6.8%)

151 (6.4%)

53 (5.9%)

Digestive diseases

0.01

 No

9527 (78.4%)

1785 (76.0%)

680 (76.0%)

 Yes

2632 (21.6%)

565 (24.0%)

215 (24.0%)

Emotional, nervous, or psychiatric problems

0.10

 No

11,997 (98.7%)

2327 (99.0%)

889 (99.3%)

 Yes

162 (1.3%)

23 (1.0%)

6 (0.7%)

Memory-related diseases

0.76

 No

11,907 (97.9%)

2306 (98.1%)

875 (97.8%)

 Yes

252 (2.1%)

44 (1.9%)

20 (2.2%)

Arthritis or rheumatism

0.34

 No

8044 (66.2%)

1584 (67.4%)

607 (67.8%)

 Yes

4115 (33.8%)

766 (32.6%)

288 (32.2%)

Asthma

 < 0.01

 No

11,671 (96.0%)

2228 (94.8%)

846 (94.5%)

 Yes

488 (4.0%)

122 (5.2%)

49 (5.5%)

Depression

 < 0.01

 No

8847 (72.8%)

1551 (66.0%)

588 (65.7%)

 Yes

3312 (27.2%)

799 (34.0%)

307 (34.3%)

PEF

289.5 ± 119.5

237.5 ± 108.7

195.9 ± 105.3

 < 0.01