Dynamic association of mortality hazard with body shape

Area of Science:

• Public Health
• Epidemiology
• Biostatistics

Background:

• The Body Shape Index (ABSI) was developed using US NHANES data to assess abdominal obesity risks.
• The British Health and Lifestyle Survey (HALS) offers a valuable dataset for validating ABSI's predictive power for mortality.
• HALS's repeated observations allow for the analysis of ABSI changes over time.

Purpose of the Study:

• To evaluate the Body Shape Index (ABSI) as a predictor of all-cause mortality using 24-year follow-up data from the HALS.
• To compare the predictive performance of ABSI against other abdominal obesity measures.
• To investigate the impact of changes in ABSI on mortality risk.

Main Methods:

• ABSI z-scores were calculated relative to population norms (both NHANES and HALS derived).
• Survival analysis was used to assess the association between ABSI and all-cause mortality over 24 years.
• Changes in ABSI were analyzed between two HALS examinations separated by 7 years.

Main Results:

• ABSI demonstrated a strong association with mortality hazard, with a 1.13 hazard ratio per standard deviation increase.
• Individuals in the top 20% of ABSI had a 1.61 times higher mortality hazard compared to those in the bottom 20%.
• ABSI outperformed waist circumference, waist-to-height ratio, and waist-to-hip ratio in predicting mortality and remained a consistent predictor over time. Changes in ABSI also predicted mortality, with increasing ABSI indicating higher risk.

Conclusions:

• ABSI is a readily computable and dynamic health indicator.
• The correlation of ABSI with lifestyle, risk factors, and health outcomes warrants further investigation.