Lean body mass index and the risk of diabetes onset: A nationwide epidemiological cohort study.

Aims/introduction: Diabetes causes microvascular complications and cardiovascular diseases, and identifying its risk factors is a critical issue. Muscle is a primary target organ of insulin; however, previous studies on the relationship between lean body mass and the risk of developing diabetes have reported inconsistent findings. This study aimed to evaluate the association between the predicted lean body mass index (LBMI), which can be easily calculated in daily clinical practice, and the risk of developing diabetes.

Materials and methods: This retrospective study analyzed a large scale real-world database to investigate the relationship between LBMI and diabetes risk in both men and women. The incidence of diabetes was determined using ICD-10 codes from an administrative claims database, and Cox regression and cubic spline models were employed.

Results: The median age (interquartile range) was 59 (45-67) years for men and 63 (50-68) for women. Among 581,176 men and 721,605 women, a lower LBMI was associated with an increased risk of diabetes onset in both men and women (hazard ratio [95% confidence interval] (Men): Q1, 1.27 [1.23-1.32]; Q2, 1.07 [1.04-1.10]; Q3, 1.02 [0.99-1.04]; Q4. 1 [reference value], HR [95% CI] (Women): Q1, 1.10 [1.06-1.15]; Q2, 1.00 [0.97-1.03]; Q3, 0.99 [0.96-1.02]; Q4. 1 [reference value]). The restricted cubic spline regression model revealed that the risk of diabetes onset increased as LBMI decreased in both men and women.

Conclusions: We demonstrated that a lower LBMI was associated with a higher risk of diabetes onset in both men and women.