ARTICLE INFO | ABSTRACT | |
ORIGINAL ARTICLE | Background: Obesity and overweight are important public health problems which are rapidly growing throughout the world. This study aims to provide 10-year incidence estimates of obesity and overweight in adults along with their risk factors in an Iranian adult population. Methods: This cohort study was conducted within the framework of the Yazd Healthy Heart Project (YHHP) throughout phases from 2005-2006 to 2015-2016 among urban adult population. The participants comprised of 1000 males and 1000 females aged 20-74 years from urban areas of Yazd. Cox proportional hazards model was used to examine the potential risk factors for obesity and overweight. Results: A total of 2000 participants aged 47.09 ± 16.97 years and body mass index (BMI) of 21.99 ± 2.21 kg/m2 were entered in this study at baseline. After 10 years of follow-up, the cumulative incidence of overweight for the entire population was 38.6% (41.6% in women and 36.8% in men). Furthermore, the 10-year cumulative incidence of obesity was 14.8% in the population (20.8% for women and 10.5% for men). Female participants showed a significantly higher incidence rate compared to males either for obesity or overweight. Regarding risk factors, there was a significant association between non-smoking (HR= 1.54, 95% CI: 1.06-2.25), socio-economic status (HR= 1.82, 95% CI: 1.13-2.94), and education (HR= 1.56, 95% CI: 1.14-2.13) with overweight (P < 0.05). Conclusion: This study revealed the incidence rate of obesity and overweight is significantly high in adult population of Yazd, Iran especially in women. The most important predictors of overweight seem to be smoking, lower socio-economic status, and education. Keywords: Overweight; Obesity; Incidence; Cohort; Risk factors |
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Article history: Received: 25 Sep 2021 Revised: 30 Nov 2021 Accepted: 15 Dec 2021 |
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*Corresponding author: mtsareban@gmail.com Yazd Cardiovascular Research Center, Afshar hospital, Jomhouri Blvd., Yazd, Iran. Postal code: 8917945556 Tel: +983535231421 |
Missing data
n= 22 |
Overweight [n= 199(38.6%)]
Obese n= 158(14.8%) |
Non-overweight [n= 317(61.4%)]
Non-obese [n= 910(85.5%)] |
Overweight [n= 1168 (59%)]
Obese [n= 376(19%)] |
Non-overweight [n= 810 (41%)]
Non-obese [n= 1602(81%)] |
Baseline (2005-2006)
n= 1978 |
Repeated measurement (2015-2016)
|
Loss to follow-up for overweight [n= 294(36.3%)]
Loss to follow-up for obesity [n= 534(33.3%)] |
Follow-up for overweight [n= 516(63.7%)]
Follow-up for obesity [n= 1068(66.7%)] |
Table 1. Characteristics of the follow-up and lost to follow-up in non-overweight participants at the baseline. | ||||
Variables | Follow-up | Lost to follow-up | Total | P-valuea |
Age (year) | 44.09 ± 15.47b | 52.35 ± 18.20 | 47.09 ± 16.97 | <0.001 |
Weight (kg) | 62.80 ± 9.34 | 59.43 ± 9.31 | 61.57 ± 9.46 | <0.001 |
BMI (kg/m2) | 22.14 ± 2.17 | 21.73 ± 2.26 | 21.99 ± 2.21 | 0.11 |
Systolic blood pressure (mmHg) | 123.58 ± 14.66 | 127.23 ± 16.58 | 124.90 ± 15.47 | 0.002 |
Diastolic blood pressure (mmHg) | 80.37 ± 8.54 | 81.15 ± 8.85 | 80.65 ± 8.66 | 0.218 |
Fasting blood glucose (mg/dl) | 95.45 ± 40.36 | 99.50 ± 46.69 | 96.92 ± 42.77 | 0.214 |
Triglyceride (mg/dl) | 150.27 ± 96.15 | 149.00 ± 86.82 | 149.81 ± 92.83 | 0.851 |
HDL-cholesterol(mg/dl) | 53.62 ± 14.60 | 55.38 ± 14.66 | 54.26 ± 14.64 | 0.100 |
Waist circumference (cm) | 84.76 ± 9.60 | 84.26 ± 9.37 | 84.58 ± 9.51 | 0.476 |
Gender | ||||
Male | 326 (63.2) c | 166(56.5) | 492(60.7) | 0.062 |
Female | 190 (36.8) | 128(43.5) | 318(39.3) | |
Current smokers | 110 (21.3) | 78(26.5) | 188(23.2) | 0.100 |
Socioeconomic status | ||||
Low | 70 (28.7) | 52(42.3) | 122(33.2) | 0.006 |
Moderate | 106 (43.4) | 52(42.3) | 158(43.1) | |
High | 68 (27.9) | 19(15.4) | 87(23.7) | |
Physical activity | ||||
Low | 225 (62.3) | 146 (70.5) | 371 (65.3) | 0.095 |
Moderate | 118 (32.7) | 50 (24.2) | 168 (29.6) | |
Vigorous | 18 (5.0) | 11 (5.3) | 29 (5.1) | |
Education | ||||
Low | 249 (51.2) | 198 (68.5) | 447 (57.7) | <0.0001 |
Moderate | 173 (35.6) | 70 (24.2) | 243 (31.4) | |
High | 64 (13.2) | 21 (7.3) | 85 (11.0) | |
a:Chi-square used for categorical variables and ANOVA test used for quantitative variables ; b: mean ± SD; c: n (%) |
Table 2. Hazard ratio of overweight after a 10-year follow-up. | ||||||
Variables | At risk (n) | Person year | Cases (n) |
Incidence/1000 person-year | Hazard ratio HR(95%CI) | |
Age groups (y) |
20-30 | 126 | 1260.60 | 50 | 39.66 | 1 |
30-39 | 90 | 898.66 | 44 | 48.96 | 0.99(0.65-1.49) | |
40-49 | 102 | 1005.86 | 46 | 45.73 | 1.35(0.90-2.03) | |
50-65 | 135 | 1327.71 | 43 | 32.38 | 0.77(0.51-1.17) | |
≥65 | 63 | 637.51 | 16 | 25.09 | 0.50(0.28-0.88) | |
Gender |
Male | 326 | 3223.54 | 120 | 37.22 | 1 |
Female | 190 | 1906.80 | 79 | 41.43 | 1.03(0.78-1.37) | |
Smoking |
Smoker | 110 | 1097.32 | 33 | 30.07 | 1 |
Non-smoker | 406 | 4033.02 | 166 | 41.16 | 1.54(1.06-2.25) | |
Socioeconomic status |
Low | 70 | 721.02 | 28 | 38.83 | 1 |
Moderate | 106 | 1067.30 | 48 | 44.97 | 1.82(1.13-2.94) | |
High | 68 | 682.46 | 20 | 29.30 | 0.98(0.55-1.74) | |
Physical activity |
Low | 225 | 2235.13 | 81 | 36.23 | 1 |
Moderate | 118 | 1169.35 | 44 | 37.62 | 1(0.69-1.44) | |
Vigorous | 18 | 180.34 | 9 | 49.90 | 1.36(0.68-2.73) | |
Education |
Low | 249 | 2490.48 | 93 | 37.34 | 1 |
Moderate | 173 | 1694.08 | 74 | 43.68 | 1.56(1.14-2.13) | |
High | 64 | 644.62 | 20 | 31.02 | 0.79(0.48-1.29) | |
Total | 516 | 5130.34 | 199 | 38.37 | - |
Table 3. Hazard ratio of overweight based on gender after a 10-year follow-up. | ||||||||||
Variables | Men | Women | ||||||||
At risk (n) |
Person year |
Cases (n) |
Incidence/1000 person-year | Hazard ratio HR(95%CI) | At risk (n) | Person year | Cases (n) |
Incidence/1000 person-year | Hazard ratio HR(95%CI) | |
Age groups (y) | ||||||||||
20-30 | 78 | 778.47 | 32 | 41.10 | 1 | 48 | 482.13 | 18 | 37.33 | 1 |
30-39 | 56 | 561.50 | 26 | 46.30 | 0.88(0.52-1.49) | 34 | 337.17 | 18 | 53.38 | 1.23(0.64-2.39) |
40-49 | 66 | 652.68 | 26 | 39.83 | 1.12(0.66-1.89) | 36 | 353.17 | 20 | 56.62 | 1.80(0.95-3.42) |
50-65 | 86 | 828.77 | 28 | 33.78 | 0.91(0.54-1.51) | 49 | 498.94 | 15 | 30.06 | 0.58(0.29-1.16) |
≥65 | 40 | 402.12 | 8 | 19.89 | 0.44(0.20-0.97) | 23 | 235.39 | 8 | 33.98 | 0.52(0.22-1.22) |
Smoking | ||||||||||
Yes | 108 | 1075.78 | 33 | 30.67 | 1 | - | - | - | - | - |
No | 218 | 2147.75 | 87 | 40.50 | 1.57(1.05-2.36) | - | - | - | - | - |
Socioeconomic status | ||||||||||
Low | 46 | 466.23 | 17 | 36.46 | 1 | 24 | 254.79 | 11 | 43.17 | 1 |
Moderate | 78 | 782.18 | 36 | 46.02 | 1.68(0.93-3.01) | 28 | 285.12 | 12 | 42.08 | 2.22(0.91-5.39) |
High | 49 | 490.60 | 13 | 26.49 | 0.80(0.38-1.65) | 19 | 191.87 | 7 | 36.48 | 1.61(0.60-4.29) |
Physical activity | ||||||||||
Low | 159 | 1564.40 | 60 | 38.35 | 1 | 66 | 670.73 | 21 | 31.30 | 1 |
Moderate | 79 | 781.38 | 28 | 35.83 | 0.91(0.58-1.43) | 39 | 387.97 | 16 | 41.24 | 1.23(0.64-2.37) |
Vigorous | 16 | 159.40 | 7 | 43.91 | 1.06(0.48-2.34) | 2 | 20.94 | 2 | 95.51 | 4.03(0.92-17.61) |
Education | ||||||||||
Low | 134 | 1331.64 | 50 | 37.54 | 1 | 115 | 1158.84 | 43 | 37.10 | 1 |
Moderate | 118 | 1147.14 | 46 | 40.09 | 1.38(0.92-2.07) | 55 | 546.94 | 28 | 51.19 | 2.03(1.23-3.35) |
High | 51 | 517.05 | 16 | 30.94 | 0.67(0.38-1.18) | 13 | 127.58 | 4 | 31.35 | 1.74(0.61-4.94) |
Total | 326 | 3223.54 | 120 | 37.23 | - | 190 | 1906.8 | 79 | 41.43 | - |
Table 4. Baseline characteristics of the follow-up and lost to follow-up participants in obese and non-obese participants. | ||||
Variables | Follow-up | Lost to follow-up | Total | P-valuea |
Age (year) | 46.5 ± 14.4b | 51.9 ± 17.1 | 43.8 ± 15.4 | 0.001 |
Weight (kg) | 68.9 ± 11.0 | 65.1 ± 11.3 | 48.3 ± 15.5 | 0.001 |
Body mass index (kg/m2) | 24.8 ± 3.1 | 24.2 ± 3.3 | 24.6 ± 3.2 | 0.004 |
Systolic blood pressure (mmHg) | 126.7 ± 15.3 | 129.1 ± 6.9 | 127.5 ± 15.9 | 0.007 |
Diastolic blood pressure (mmHg) | 82.0 ± 8.8 | 82.2 ± 9.1 | 82.1 ± 88.9 | 0.569 |
Fasting blood glucose (mg/dl) | 99.1 ± 40.5 | 106.7 ± 54.1 | 101.6 ± 45.6 | 0.004 |
Triglyceride (mg/dl) | 171.1 ± 106.1 | 171.3 ± 114.7 | 171.2 ± 109.0 | 0.983 |
HDL-cholesterol(mg/dl) | 53.5 ± 13.6 | 54.3 ± 13.8 | 53.8 ± 13.6 | 0.267 |
Waist circumference (cm) | 90.9 ± 10.6 | 89.6 ± 10.8 | 90.5 ± 10.7 | 0.020 |
Gender | ||||
Male | 621 (58.1)c | 260 (48.7) | 881 | 0.001 |
Female | 447 (41.9) | 274 (51.3) | 721 | |
Current smokers | 205 (19.2) | 110 (20.6) | 315 | 0.627 |
Socioeconomic status | ||||
Low | 134 (26.5) | 84 (40.2) | 218 | 0.001 |
Moderate | 207 (41.0) | 81 (38.8) | 288 | |
High | 164 (32.5) | 44 (21.1) | 208 | |
Physical activity | ||||
Low | 498 (66.0) | 267 (73.0) | 765 | 0.062 |
Moderate | 219 (29.0) | 84 (23.0) | 303 | |
Vigorous | 38 (5.0) | 15 (4.1) | 53 | |
Education | ||||
Low | 561 (54.4) | 355 (67.5) | 916 | 0.001 |
Moderate | 353 (34.2) | 132 (25.1) | 458 | |
High | 118 (11.4) | 39 (7.4) | 157 | |
a:Chi-square used for categorical variables and ANOVA test used for quantitative variables ; b: mean ± SD; c: n (%) |
Table 5. Cumulative and annual risk of overweight and obesity based on gender and total population. | |||||
Variables | At risk (n) |
Loss to follow-up (n) |
Cases (n) |
9.9-yr cumulative incidence rate (%) | Annual incidence rate (%) |
Overweight | |||||
Men | 492 | 166 | 120 | 36.8 | 3.7 |
Women | 318 | 128 | 79 | 41.6 | 4.2 |
Total | 810 | 294 | 299 | 38.6 | 3.9 |
Obesity | |||||
Men | 621 | 260 | 65 | 10.5 | 1.06 |
Women | 447 | 274 | 93 | 20.8 | 2.1 |
Total | 1068 | 534 | 158 | 14.8 | 1.49 |
Table 6. Hazard ratio of obesity after a 10-year follow-up. | |||||
Variables | At risk (n) |
Person year | Cases (n) |
Incidence/1000 person-year | Hazard ratio HR(95%CI) |
Age groups (year) | |||||
20-30 | 177 | 1778.81 | 20 | 11.24 | 1 |
30-39 | 190 | 1884.75 | 42 | 22.28 | 2.07(1.21-3.54) |
40-49 | 243 | 2407.73 | 34 | 14.12 | 1.44(0.83-2.51) |
50-59 | 219 | 2148.87 | 35 | 16.28 | 1.62(0.93-2.81) |
≥60 | 239 | 2392.73 | 27 | 11.28 | 1.03(0.57-1.84) |
Gender | |||||
Male | 621 | 6142.5 | 65 | 10.58 | 1 |
Female | 447 | 4470.38 | 93 | 20.80 | 1.77(1.28-2.44) |
Smoking | |||||
Yes | 205 | 2049.26 | 20 | 9.75 | 1 |
No | 862 | 8554.48 | 138 | 16.13 | 1.74(1.09-2.79) |
Socioeconomic status | |||||
Low | 134 | 1361.8 | 21 | 15.42 | 1 |
Moderate | 207 | 2068.01 | 29 | 14.02 | 1.01(0.57-1.78) |
High | 164 | 1644.38 | 29 | 17.63 | 1.39(0.79-2.44) |
Physical activity | |||||
Low | 498 | 4951.97 | 78 | 15.75 | 1 |
Moderate | 219 | 2192.03 | 28 | 12.77 | 0.82(0.53-1.26) |
Vigorous | 38 | 381.76 | 5 | 13.09 | 0.82(0.33-2.02) |
Education | |||||
Low | 561 | 5592.9 | 90 | 16.09 | 1 |
Moderate | 353 | 3479.83 | 52 | 14.94 | 1.004(0.71-1.41) |
High | 118 | 1176.07 | 12 | 10.20 | 0.6(0.33-1.1) |
Total | 1068 | 10612.88 | 158 | 14.88 |
Table 7. Hazard ratio of obesity based on gender after a 10-year follow-up. | |||||||||||
Variables | Men | Women | |||||||||
At risk (n) | Person year | Cases (n) |
Incidence/1000 person-year | Hazard ratio HR(95%CI) | At risk (n) |
Person year | Cases (n) |
Incidence/1000 person-year |
Hazard ratio HR(95%CI) | ||
Age groups (year) 20-30 |
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101 | 1013.29 | 20 | 19.73 | 1 | 76 | 765.52 | 8 | 10.45 | 1 | ||
30-39 | 104 | 1036.03 | 19 | 18.33 | 1.55(0.75-3.3.19) | 86 | 848.71 | 23 | 27.09 | 3.02(1.34-6.79) | |
40-49 | 144 | 1426.31 | 12 | 8.41 | 0.91(0.40-2.05) | 99 | 981.42 | 22 | 22.41 | 2.33(1.03-5.24) | |
50-59 | 127 | 1242.23 | 12 | 9.66 | 0.89(0.39-2.02) | 92 | 906.64 | 23 | 25.36 | 2.78(1.24-6.26) | |
≥60 | 145 | 1426.64 | 10 | 7 | 0.72(0.31-1.69) | 94 | 968.09 | 17 | 17.56 | 1.45(0.62-3.37) | |
Smoking | |||||||||||
Yes | 199 | 1987.26 | 17 | 8.55 | 1 | 6 | 62 | 3 | 48.38 | 1 | |
No | 422 | 4155.24 | 48 | 11.55 | 1.47(0.84-2.57) | 441 | 4408.38 | 90 | 20.41 | 0.53(0.16-1.68) | |
Socioeconomic status | |||||||||||
Low | 79 | 797.08 | 9 | 11.29 | 1 | 55 | 564.71 | 12 | 21.24 | 1 | |
Moderate | 147 | 1453.91 | 18 | 12.38 | 1.59(0.68-3.68) | 60 | 614.10 | 11 | 17.91 | 0.71(0.30-1.68) | |
High | 112 | 1114.29 | 14 | 12.56 | 1.39(0.58-3.32) | 52 | 530.09 | 15 | 28.29 | 1.59(0.74-3.43) | |
Physical activity | |||||||||||
Low | 324 | 3181.72 | 34 | 10.68 | 1 | 174 | 1770.25 | 44 | 24.85 | 1 | |
Moderate | 133 | 1327.75 | 12 | 9.03 | 0.66(0.33-1.31) | 86 | 864.27 | 16 | 18.51 | 0.89(0.49-1.59) | |
Vigorous | 30 | 302.97 | 2 | 6.60 | 0.45(0.10-1.91) | 8 | 78.79 | 3 | 38.07 | 2.27(0.69-7.42) | |
Education | |||||||||||
Low | 268 | 2661.81 | 26 | 9.76 | 1 | 293 | 2931.09 | 64 | 21.83 | 1 | |
Moderate | 228 | 2235.04 | 25 | 11.18 | 1.12(0.64-1.96) | 125 | 1244.80 | 27 | 21.69 | 1.05(0.67-1.65) | |
High | 98 | 975.90 | 12 | 12.29 | 0.95(0.47-1.91) | 20 | 200.16 | 0 | - | - | |
Total | 621 | 6142.50 | 65 | 10.58 | 447 | 4470.38 | 93 | 20.80 |
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