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

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.