Association of Adiposity Indices with Hypertension in Middle-Aged and Elderly Thai Population: National Health Examination Survey 2009 (NHES-IV)

Obesity in terms of excess fat mass is associated with increased morbidity, disability and mortality due to obesity-related disorders, including hypertension. Many hypertensive individuals are overweight and often receive their advice to lose weight related to body-fat, in order to lower their blood pressure. However, it is still unclear whether there is a strong association of adipose tissue measured by adiposity indicators with hypertension in the Thai population. Various adiposity indices have been published to distinguish the distribution of body fat with disparate properties. This study examined nine adiposity markers and their association with hypertension in 15,842 Thai adults >= 35 years old. Data were obtained from the nationwide Thai National Health Examination Survey 2009. Accuracy performance and associations of indexes with hypertension were analyzed by Area Under Curve (AUC) and logistic regression analyses. Regardless of gender, the best methods to distinguish performance were waist-to-height ratio (WHtR) [AUC: 0.640 (0.631-0.649)], followed by lipid accumulation product (LAP) [AUC: 0.636 (0.627-0.645)], waist circumference (WC) [AUC: 0.633 (0.624-0.641)], and Conicity index (C-Index) [AUC: 0.630 (0.621-0.639)]. Linear regression analysis exhibited the independent association of the top four indices, WC, WHtR, C-Index, and LAP with higher systolic and diastolic blood pressure. Those indices' quartiles were graded in a dose-response manner which significantly increased at the higher quartiles. The indicator's cutoff point carried the odds ratio of presence hypertension in the range of 1.7 to 2.5 (p < 0.001). Among the nine obesity indices, WHtR (cutoff >0.52) in both genders was the simplest and most practical measurement for adiposity in association with hypertension in middle-aged and elderly Thais.