Sample characteristics and their associations with obesity by gender: the KNHANES V, 2010–2012, South Korea
| Distribution, N (%) | Obesity, % | |||||
| Men | Women | P value* | Men | Women | P value† | |
| BMI (kg/m2)‡ | 23.97 (3.1) | 23.43 (3.6) | <0.001 | |||
| Obesity | 2565 (35.0) | 2940 (29.7) | <0.001 | |||
| Age (years)‡ | 50.79 (16.4) | 50.48 (16.6) | <0.001 | 35.1§ | 34.7§ | <0.001 |
| Marital status | <0.001 | <0.001¶ | <0.001¶ | <0.001 | ||
| Married | 5848 (79.7) | 6887 (69.5) | 36.0 | 30.5 | ||
| Formerly married | 339 (4.6) | 1803 (18.2) | 30.1 | 37.4 | ||
| Never married | 1150 (15.7) | 1218 (12.3) | 31.0 | 13.4 | ||
| Residential area | 0.446 | 0.259¶ | <0.001¶ | <0.001 | ||
| Metro urban | 3240 (44.2) | 4404 (44.5) | 35.2 | 27.0 | ||
| Non-metro urban | 2523 (34.4) | 3471 (35.0) | 36.6 | 29.2 | ||
| Rural | 1574 (21.4) | 2033 (20.5) | 31.9 | 36.4 | ||
| Education | <0.001 | <0.001¶ | <0.001¶ | <0.001 | ||
| Elementary school or less | 1294 (17.6) | 3168 (32.0) | 26.6 | 40.2 | ||
| Junior high school | 867 (11.8) | 1024 (10.3) | 36.1 | 38.6 | ||
| Senior high school | 2617 (35.7) | 3136 (31.7) | 34.5 | 27.1 | ||
| College or more | 2559 (34.9) | 2580 (26.0) | 39.3 | 16.4 | ||
| Income, quartiles | <0.001 | 0.002¶ | <0.001¶ | <0.001 | ||
| Lowest | 1694 (23.1) | 2641 (26.6) | 28.4 | 36.8 | ||
| 2nd lowest | 1924 (26.2) | 2514 (25.4) | 36.5 | 31.7 | ||
| 3rd lowest | 1739 (23.7) | 2177 (22.0) | 34.9 | 28.0 | ||
| Highest | 1980 (27.0) | 2576 (26.0) | 39.1 | 21.8 | ||
| Occupation | <0.001 | <0.001¶ | <0.001¶ | <0.001 | ||
| Unemployed | 1878 (25.6) | 5208 (52.6) | 28.7 | 31.1 | ||
| Office worker | 1965 (26.8) | 1586 (16.0) | 42.1 | 17.5 | ||
| Manual worker | 3494 (47.6) | 3114 (31.4) | 34.3 | 33.6 | ||
| Housing status | 0.158 | 0.945¶ | 0.843¶ | 0.838 | ||
| Home owner | 5606 (76.4) | 7280 (73.5) | 35.1 | 29.5 | ||
| Renter | 1731 (23.6) | 2628 (26.5) | 34.6 | 30.1 | ||
| Universal health insurance | <0.001 | 0.020¶ | 0.004¶ | <0.001 | ||
| National Health Insurance | 7204 (98.2) | 9609 (97.0) | 35.2 | 29.4 | ||
| Medical Care Aid | 133 (1.8) | 299 (3.0) | 24.8 | 39.8 | ||
| Private health insurance | 0.181 | <0.001¶ | <0.001¶ | <0.001 | ||
| Non-holder | 2258 (30.8) | 2898 (29.3) | 29.3 | 34.9 | ||
| Holder | 5079 (69.2) | 7010 (70.7) | 37.5 | 27.5 | ||
| Survey year | 0.831 | 0.695¶ | 0.133¶ | 0.162 | ||
| 2010 | 2592 (35.3) | 3364 (34.0) | 35.2 | 28.3 | ||
| 2011 | 2494 (34.0) | 3380 (34.1) | 34.6 | 30.4 | ||
| 2012 | 2251 (30.7) | 3164 (31.9) | 35.1 | 30.4 | ||
| Current smoking status | <0.001 | 0.375¶ | 0.936¶ | 0.729 | ||
| Non-smoker | 4336 (59.1) | 9359 (94.5) | 36.1 | 29.8 | ||
| Smoker | 3001 (40.9) | 549 (5.5) | 33.3 | 27.1 | ||
| Alcohol consumption | <0.001 | <0.001¶ | 0.064¶ | <0.001 | ||
| Not excessive | 4950 (67.5) | 8689 (87.7) | 31.5 | 30.1 | ||
| Excessive | 2387 (32.5) | 1219 (12.3) | 42.1 | 26.7 | ||
| Routine physical exercise | <0.001 | 0.838¶ | <0.001¶ | 0.012 | ||
| Physically active | 1552 (21.2) | 1620 (16.4) | 35.6 | 32.8 | ||
| Physically inactive | 5785 (78.8) | 8288 (83.6) | 34.8 | 29.1 | ||
| Daily sleep duration | 0.992 | 0.150¶ | <0.001¶ | 0.007 | ||
| Non-short | 4291 (58.5) | 5717 (57.7) | 34.2 | 27.4 | ||
| Short | 3046 (41.5) | 4191 (42.3) | 36.0 | 32.8 | ||
| Daily energy intake | <0.001 | 0.818¶ | <0.001¶ | <0.001 | ||
| Not moderate | 5859 (79.9) | 8306 (83.8) | 34.9 | 28.0 | ||
| Moderate | 1478 (20.1) | 1602 (16.2) | 35.4 | 38.5 | ||
| Self-perceived stress | <0.001 | 0.969¶ | 0.031¶ | 0.236 | ||
| Not very high | 7087 (96.6) | 9421 (95.1) | 35.1 | 29.5 | ||
| Very high | 250 (3.4) | 487 (4.9) | 32.4 | 33.3 | ||
| Self-perceived health | <0.001 | 0.362¶ | <0.001¶ | 0.002 | ||
| Not very bad | 7159 (97.6) | 9467 (95.5) | 35.2 | 29.1 | ||
| Very bad | 178 (2.4) | 441 (4.5) | 24.2 | 42.4 | ||
| Hypertension | <0.001 | <0.001¶ | <0.001¶ | <0.001 | ||
| No | 5764 (78.6) | 7713 (77.8) | 32.6 | 24.3 | ||
| Yes | 1573 (21.4) | 2195 (22.2) | 43.6 | 48.5 | ||
| Dyslipidaemia | <0.001 | <0.001¶ | <0.001¶ | 0.137 | ||
| No | 6859 (93.5) | 9065 (91.5) | 33.9 | 27.8 | ||
| Yes | 478 (6.5) | 843 (8.5) | 50.6 | 49.8 | ||
| Diabetes | 0.099 | 0.858¶ | <0.001¶ | <0.001 | ||
| No | 6661 (90.8) | 9219 (93.0) | 34.8 | 28.1 | ||
| Yes | 676 (9.2) | 689 (7.0) | 36.1 | 50.4 | ||
| Number of participants | 7337 | 9908 | 7337 | 9908 | ||
*P value was estimated by using the t-test for continuous variables and χ2 tests for categorical variables.
†P value was estimated from the interaction-effects terms between gender and each characteristic by using the logistic analysis.
‡Mean (SD).
§For the continuous age variable, the proportion of obesity was obtained from people aged 50–59 years to which median age for each gender belonged.
¶P value was estimated by χ2 tests for each gender.
All P values were estimated by considering a stratified cluster sampling design.
BMI, body mass index; KNHANES V, Fifth Korea National Health and Nutrition Examination Survey; N, number