National trends in hypertension stratified by central adiposity using waist-to-height ratio in South Korea, 2005 to 2022

Despite the growing prevalence of hypertension due to lifestyle changes and aging populations, with central obesity as a critical risk factor, there is limited research examining the association between central adiposity and hypertension trends. To address this gap, this study analyzed trends in hypertension prevalence among Korean adults categorized by healthy and increased central adiposity based on waist-to-height ratio (WHtR) and investigated the associated risk factors. We utilized data from 98,396 adults aged 30 years and older from the Korea National Health and Nutrition Examination Survey from 2005 to 2022 in South Korea. Participants were categorized into 2 groups according to central adiposity: low-WHtR group (<0.50) and high-WHtR group (≥0.50). Long-term trends in hypertension and adjusted odds ratios were analyzed, with stratified analyses by sociodemographic factors. Weighted linear regression and binary logistic regression were used to calculate β coefficients, βdiff, and adjusted odds ratios with 95% confidence intervals. From 2005 to 2019, the prevalence of hypertension increased in both low and high-WHtR groups, with a more pronounced increase in the increased central obesity group. Notably, the prevalence was higher in males than in females in the low-WHtR group (20.47% in males vs 12.33% in females), but similar in both sexes in the high-WHtR group (43.44% vs 41.74%). Furthermore, subgroup analyses showed that females aged 30-59 years in the high-WHtR group had higher odds of hypertension than males, whereas males aged 60 years and older had higher odds than females. This study suggests that the association between central obesity and hypertension risk varies significantly across age and sex categories, highlighting the necessity for age- and sex-specific prevention and management strategies.