Abstract
Objective: To examine the cross-sectional association between trunk fat mass index (TFMI) and diabetes across individuals within the same body mass index (BMI [calculated as the weight in kilograms divided by the height in meters squared]) categories in a multinational population.
Participants and Methods: We harmonized and pooled data on 57,764 individuals aged 40 years and older from the United Kingdom, the United States, and South Korea. Trunk fat mass imaging was performed using a dual-energy X-ray absorptiometry device during 2015-2023 in the United Kingdom, 2011-2018 in the United States, and 2008-2011 in South Korea. The prevalence of diabetes was derived from the self-reported medical history. Additionally, plasma biochemistry analyses were conducted to update the number of participants with diabetes.
Results: Among participants classified as having a normal weight based on BMI, the relative risks (RRs) of diabetes increased from TFMI quintiles 1 to 5 with the linear trend (P<.001). The risk of diabetes among individuals in TFMI quintile 5 was around 3 times greater than those in quintile 1 (men-RR, 3.06; 95% confidence interval [CI], 2.17-4.34; women-3.35; 95% CI, 2.08-5.39). This significant linear trend (P<.001) in RRs was also present in overweight and obese individuals (overweight men-RR, 1.92; 95% CI, 1.50-2.47; overweight women-RR, 2.25; 95% CI, 1.73-2.91; obese men-RR, 2.47; 95% CI, 1.83-3.35; obese women-2.79; 95% CI, 2.04-3.83).
Conclusion: Within a specific BMI category, individuals with a high trunk fat mass are more likely to experience diabetes compared with those with lower levels of central fat.