Regional disparities in the associations of cardiometabolic risk factors and healthy dietary factors in Korean adults

Background/objectives Regional disparities in dietary factors might be related to regional disparities in cardiometabolic health. Therefore, this study investigated the associations of cardiometabolic risk factors and dietary factors with regional types in Korean adults. Subjects/methods Based on data from the 2007-2017 Korea National Health and Nutrition Examination Survey, the study included 39,781 adults aged ≥ 19 years who completed the dietary survey and a health examination. Healthy and unhealthy dietary factors (fat, sodium, fruit, and vegetable intakes) were evaluated using 1-day 24-h dietary recall method, as well as the use of nutrition labels with a questionnaire. Results Of the participants, 48.7%, 36.0%, and 15.2% lived in metropolitan, urban, and rural areas, respectively. Adults living in urban and rural had higher odds ratios (ORs) for obesity (OR for urban, 1.07; 95% confidence interval (CI), 1.01-1.14; OR for rural, 1.14; 95% CI, 1.05-1.24) than adults living in metropolitan areas; these associations were significantly observed in middle-aged adults. Compared to metropolitan residents, rural residents had lower ORs for hypertension in middle-aged (OR, 0.86; 95% CI, 0.76-0.96) and metabolic syndrome in older adults (OR, 0.78; 95% CI, 0.67-0.91). Regarding urban residents, a lower OR for diabetes in middle-aged adults (OR, 0.85; 95% CI, 0.74-0.97) and a higher OR for hypertension in older adults (OR, 1.19; 95% CI, 1.02-1.39) were observed. Overall rural residents had higher ORs of excessive carbohydrate, low fruit, and high salted-vegetable intakes than metropolitan residents. Low fruit intake was positively associated with obesity, metabolic syndrome, and hypertension, after adjustment for regional type and other confounders in total participants. Conclusions These findings indicate that cardiometabolic risk and unhealthy dietary factors differ among regional types and age groups within Korea. Nutritional policy and interventions should consider regional types for prevention and management of cardiometabolic risk factors.