Identification of suitable obesity-related index: from the perspective of prevalence and obesity-linked characteristics

Background Obesity is categorized as a global burden of disease and is a risk factor for several clinical conditions and early mortality. Limited studies have only investigated in identifying a suitable obesity index for assessing obesity but with inconsistent results. The present study therefore, aimed to calculate the obesity prevalence and then compare and identify the better obesity index based on the ability of those indices and respective thresholds to distinguish more obesity related characteristics in obese groups. Methods A prospective, cross-sectional study involving 300 women (20–75, 46.5 ± 13.4 years) were recruited from Kathmandu Valley, and their obesity related indices (body mass index (BMI) 27.0 ± 4.6 kg/m 2 , waist circumference (WC) 84.4 ± 10.85 cm, waist to hip ratio (WHR) 0.8 ± 0.06 and waist to height ratio (WtHR) 0.5 ± 0.07)) were calculated. Hand grip strength and physical performance measures (gait speed, one-leg standing balance test (OLST) and chair stand) were assessed from all the individuals. Blood samples from all the participants were collected and then the bone markers (calcium, alkaline phosphatase and phosphorous) and liver function test (alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. Results The prevalence of obesity was calculated as 41.0%, 68.3%, 41.0% and 80.3% with BMI, WC, WHR and WtHR, respectively. The WHR index was capable of differentiating the most, 8 (HGS, gait speed, OLST, chair stand, ALP, phosphorous, ALT and AST), of the obesity-related characteristics in obese groups, followed by the WtHR differentiating 6 (HGS, gait speed, OLST, chair stand, calcium and ALT) characteristics, 5 (gait speed, OLST, chair stand, ALT and AST) by WC and 5 (gait speed, OLST, chair stand, ALT and AST) by BMI. Conclusion The prevalence of obesity varies with obesity indices and thresholds, and WHR index is successful in differentiating more obesity related characteristics in the obese group. The current findings suggest the WHR index could be used in obesity related studies where sophisticated techniques are not available for fat quantification.