The Association between Normal Weight Obesity and Metabolic Syndrome in Older Korean Adults

Background: Body mass index (BMI) has its drawback in that it is unable to distinguish between the distribution and quantity of fat mass and lean mass. Normal weight obesity (NWO) refers to a special phenotype of having excessive body fat despite a normal BMI. This cross-sectional study examined the association between NWO and metabolic syndrome in older Korean adults aged ³65 years. Methods: : Data for the current study (612 men and 479 women) was obtained from the 2008-2011 Korea National Health and Nutrition Examination Survey. NWO was defined as a BMI between 18.5 and 24.9 kg/m 2 and body fat of ³26.0% in men and body fat of ³36.0% in women. Metabolic syndrome was defined according to the revised National Cholesterol Education Program definition, with a modified waist circumference threshold of > 90 cm for Korean men or > 85 cm for Korean women. Results: : People with NWO had an increased risk for metabolic syndrome (odds ratio, OR=2.531, 95% confidence interval, CI=1.287~4.980, p =0.007 in men; OR=1.970, 95% CI=1.020~3.850, p =0.043 in women) compared to people with NWNO (OR=1). When all covariates, including age, sex, education, income, smoking, heavy alcohol intake, serum vitamin D, physical activity, and nutrient intake of carbohydrates, fats, and proteins, and fat-to-lean mass ratio, were controlled, however, the risk of NWO for metabolic syndrome was no longer significant in both genders. Conclusions: : The current findings suggest that older adults with NWO should be monitored in clinical settings for early intervention.