Characteristics of the study participants according to the survey time
| Variables | 1992 (N=1460) | 2000 (N=664) | 2009 (N=232) | 2012 (N=122) | 2017 (N=65) |
| Age (years) | 68.82 (8.50) | 73.62 (7.17) | 79.49 (5.04) | 82.10 (4.48) | 85.51 (3.66) |
| Male, n (%) | 733 (50.21) | 317 (47.74) | 99 (42.67) | 51 (41.80) | 30 (46.15) |
| Educational level, n (%) | |||||
| Secondary or higher | 300 (20.55) | 148 (22.29) | 54 (23.28) | 32 (26.23) | 23 (35.38) |
| Primary or lower | 1160 (79.45) | 516 (77.71) | 178 (76.72) | 90 (73.77) | 42 (64.62) |
| Residence, n (%) | |||||
| Urban | 828 (56.71) | 338 (50.90) | 94 (40.52) | 52 (42.62) | 33 (50.77) |
| Rural | 632 (43.29) | 326 (49.10) | 138 (59.48) | 70 (57.38) | 32 (49.23) |
| Smoke, n (%) | |||||
| 0 | 1008 (69.04) | 515 (77.56) | 200 (86.21) | 106 (86.89) | 57 (87.69) |
| 1–5 | 105 (7.19) | 46 (6.93) | 9 (3.88) | 3 (2.46) | 2 (3.08) |
| >5 | 347 (23.77) | 103 (15.51) | 23 (9.91) | 13 (10.66) | 6 (9.23) |
| Alcohol intake, n (%) | |||||
| Yes | 186 (12.74) | 68 (10.24) | 16 (6.90) | 8 (6.56) | 6 (9.23) |
| No | 1274 (87.26) | 596 (89.76) | 216 (93.10) | 114 (93.44) | 59 (90.77) |
| Physical activity, hours/per week, n (%) | |||||
| <3 | 592 (40.55) | 237 (35.69) | 56 (24.14) | 36 (29.51) | 30 (46.15) |
| 3–10 | 604 (41.37) | 256 (38.55) | 96 (41.38) | 51 (41.80) | 20 (30.77) |
| >10 | 264 (18.08) | 171 (25.75) | 80 (34.48) | 35 (28.69) | 15 (23.08) |
| BMI (kg/m2) | 23.13 (3.86) | 23.76 (3.86) | 22.98 (3.94) | 22.61 (4.38) | 22.63 (4.33) |
| SBP (mm Hg) | 141.2 (25.2) | 142.3 (25.0) | 143.7 (21.8) | 142.3 (22.1) | 141.4 (24.3) |
| DBP (mm Hg) | 81.5 (12.5) | 80.0 (12.0) | 76.7 (11.4) | 75.6 (11.1) | 72.3 (12.4) |
| FPG (mmol/L) | 5.17 (0.98) | 5.15 (0.94) | 5.09 (0.91) | 5.05 (0.96) | 4.94 (1.06) |
| TC (mmol/L) | 4.34 (1.02) | 5.14 (1.15) | 5.46 (1.18) | 5.27 (1.16) | 5.26 (1.18) |
| TG (mmol/L) | 1.47 (0.75) | 1.52 (0.97) | 1.54 (0.95) | 1.45 (0.80) | 1.46 (0.75) |
| LDL-C (mmol/L) | 2.99 (0.98) | 2.93 (0.86) | 2.92 (0.82) | 2.93 (0.87) | 2.90 (0.89) |
| HDL-C (mmol/L) | 1.51 (0.58) | 1.65 (0.52) | 1.46 (0.45) | 1.49 (0.37) | 1.47 (0.35) |
| TG/HDL-C | 1.13 (0.87) | 1.09 (1.03) | 1.20 (0.96) | 1.07 (0.71) | 1.10 (0.75) |
BMI, body mass index; DBP, diastolic blood pressure; FPG, fasting plasma glucose; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; SBP, systolic blood pressure; TC, total cholesterol; TG, triglyceride.