Surface-Based Body Shape Index and Its Relationship with All-Cause Mortality

Area of Science:

• Anthropometry
• Public Health
• Biostatistics

Background:

• Obesity is a significant global health issue with high prevalence in the US.
• Obesity is linked to numerous health problems, including diabetes, cardiovascular diseases, and cancer.
• Current measures like Body Mass Index (BMI) have limitations in assessing health risks accurately.

Purpose of the Study:

• Introduce a novel anthropometric measure, the Surface-based Body Shape Index (SBSI).
• Evaluate SBSI's performance in predicting all-cause mortality.
• Compare SBSI's predictive power against existing obesity indices.

Main Methods:

• Analyzed data from 11,808 subjects (ages 18-85) from NHANES (1999-2004) with 8-year mortality follow-up.
• Developed SBSI using body surface area (BSA), vertical trunk circumference (VTC), height (H), and waist circumference (WC).
• Utilized Cox proportional hazards models and Kaplan-Meier curves for mortality hazard prediction.

Main Results:

• SBSI is defined as: SBSI = ((H(7/4))(WC(5/6)))/(BSA VTC).
• SBSI shows a negative correlation with BMI and weight, no correlation with WC, and a linear relationship with age.
• SBSI demonstrated superior performance in predicting all-cause mortality compared to BMI, WC, WHtR, WHR, and ABSI.

Conclusions:

• The Surface-based Body Shape Index (SBSI) is a novel measure combining body shape and size.
• SBSI is linearly associated with age and increases with mortality risk.
• SBSI offers improved predictive accuracy for all-cause mortality over conventional indices.