Body Mass Index adjustment for sitting height for better assessment of obesity risks in Maltese women

Abstract

Objective: This study is aimed to assess the influence of body shape on Body Mass Index (BMI) estimations by determining the Sitting Height to Standing height ratio.

Methods: The study population included 291 non-pregnant premenopausal Maltese women aged 20-54 years. These women were assessed using the following anthropometric measurements: Body weight (Kg), standing height (cm) and sitting height (cm). The Sitting-to-Standing Height (SH/S) ratio, the observed BMI (oBMI) based on the standing height, and the SH/S ratio-corrected BMI (cBMI) were calculated. The SPSS package version 18.0 was used for statistical calculations.

Results: The average SH/S ratio of the Maltese premenopausal women is 0.44. The mean oBMI is 25.06, while the mean cBMI is 34.49 (P value < 0.001). Applying the linear regression prediction model with either oBMI or cBMI as dependent variables and the SH/S ratio as independent variable proved that the sitting height is a significant predictor of both oBMI and cBMI (P value < 0.00001).

Conclusions: The results suggest that the cohort of this study tend to have long legs relative to torso-length (low SH/S ratio). Thus, the oBMI will underestimate the actual BMI value. The correction of BMI for the sitting height in Maltese population will more correctly identify individuals at greater risk for chronic diseases.