Association Between Trunk Fat Mass Index and Diabetes in a Multinational Population

Area of Science:

• Endocrinology and Metabolism
• Public Health and Epidemiology
• Body Composition Analysis

Background:

• Body Mass Index (BMI) is a common metric for weight classification, but it doesn't differentiate fat distribution.
• Central adiposity, specifically trunk fat, is increasingly recognized as a significant risk factor for metabolic diseases.
• Understanding the independent association of trunk fat with diabetes risk across different BMI categories is crucial for public health.

Purpose of the Study:

• To investigate the cross-sectional relationship between trunk fat mass index (TFMI) and diabetes.
• To analyze this association specifically within defined body mass index (BMI) categories in a multinational cohort.
• To determine if elevated trunk fat independently predicts diabetes risk irrespective of overall BMI.

Main Methods:

• Pooled data from 57,764 individuals aged 40+ from the UK, US, and South Korea.
• Trunk fat mass assessed using dual-energy X-ray absorptiometry (DXA).
• Diabetes prevalence determined via self-reported history and confirmed with plasma biochemistry.

Main Results:

• A significant linear trend of increasing diabetes risk with higher TFMI was observed across all BMI categories (normal weight, overweight, obese).
• Individuals in the highest TFMI quintile had approximately 3 times the risk of diabetes compared to the lowest quintile in normal-weight individuals.
• Elevated TFMI consistently predicted higher diabetes risk in men and women across normal weight, overweight, and obese classifications.

Conclusions:

• High trunk fat mass is a significant predictor of diabetes, independent of overall body mass index.
• Central adiposity plays a critical role in diabetes development, even in individuals with normal or elevated BMI.
• TFMI should be considered alongside BMI for a more comprehensive assessment of diabetes risk.