Effect change of obesity on diabetes depending on measurement: self-reported body mas index from 2012 Community Health Survey vs. directly measured from the Korea National Health and Nutrition Examination Survey

Abstract

OBJECTIVES:Obesity is a well-recognized risk factor for type 2 diabetes mellitus (DM) among young and middle-aged adults in South Korea. To elaborate on the association between obesity and Diabetes mellitus (DM), subjective data from self-reporting survey or objective data from health examination is generally used. This study was conducted to validate the change of association from using these different measurements.METHODS:Community Health Survey data and Korea National Health and Nutrition Examination Survey data, as subjective and objective data respectively, were used. Population, resident in Seoul and over 45 aged, were selected for the study and the association between obesity and DM were defined by using multivariate logistic regression model.RESULTS:In subjective data, DM prevalence was 12.4% (male, 14.7; female, 10.6) and obesity prevalence was 26.0% (male, 29.2; female, 23.4). Whereas, in objective data, DM prevalence was 15.0% (male, 17.8; female, 12.9), and obese population was 32.4% (male, 34.4; female, 30.8). Based on the effect of obesity on DM prevalence from each data, using objective data increased the impact of obesity. Difference of relative risk of obesity between from subjective data and from objective was bigger in female than male and statistically significant.CONCLUSIONS:The differences of association pattern between subjective and objective data were found, due to higher obesity prevalence in objective data, and discrepancies of socio-economic status. These discrepancies could be inevitable Therefore we have to face them proactively, and understand the different aspect of various variables from different measurement.

Comparison of estimates and time series stability of Korea Community Health Survey and Korea National Health and Nutrition Examination Survey

“…This was because overestimation of height increased with age while weight was underestimated in males in their 20s and 30s and females in their 20s to 40s in KCHS [16]. In a study investigating the effects of prevalence of obesity on diabetes according to method of survey in adults aged 45 years or older, the difference of obesity prevalence by questionnaire in KCHS and that by physical examination in KNHANES was 6.4%p and the difference of diabetes prevalence was 2.6%p [17]. Other study also reported that self-reported data and actually measured data differ particularly according to sex [18].…”

“…Despite these limitations, this study clearly has strengths as well. Compared to similar Korean studies [16,17], we performed a more comprehensive comparison using six and eight variables in KCHS and KNHANES, respectively, over six years, and also analyzed the differences of estimates according to method of survey by comparing estimates taken from interviews and estimates taken from physical examinations data. Furthermore, we analyzed the time series stability of subgroup estimates and demonstrated that subgroup estimates might differ between the two surveys even with little differences in yearly estimates overall.…”