Low muscle mass and risk of type 2 diabetes in middle-aged and older adults: findings from the KoGES

Abstract

Aims/hypothesis Asians have a propensity to develop type 2 diabetes with a lower BMI than Western populations. This discrepancy may be due to differences in body fat and muscle mass for a given BMI. However, unlike adiposity, it is unclear whether muscle mass affects the risk of type 2 diabetes in Asian populations. Methods We conducted a 2-yearly prospective assessment of 6895 participants who were free of diabetes at the baseline examination as part of the Korean Genome Epidemiology Study. The muscle mass index (MMI) was defined as the weightadjusted appendicular skeletal muscle mass. Using Cox regression models, we evaluated the association between MMI and the risk of developing type 2 diabetes across sex-specific tertiles of MMI. Low muscle mass was defined as the sex-specific lowest tertile of MMI. Main covariates included age, sex, urban or rural residence, family history of diabetes, hypertension, smoking status, education level, monthly income, physical activity, alcohol consumption and diet. In addition, body fat mass, waist circumference and BMI were controlled as categorical variables. Obesity was defined as a BMI of ≥25 kg/m 2 or a waist circumference of ≥90 cm for men and ≥85 cm for women. Results During a median follow-up of 9.06 years, 1336 participants developed type 2 diabetes. At baseline, the mean age was 52.1 years and the mean BMI was 24.4 kg/m 2 . The mean MMI for men and women was 32.1% and 26.0%, respectively. There was an inverse association between MMI and the risk of type 2 diabetes. Multivariate-adjusted HRs for the risk of developing type 2 diabetes were 2.05 (95% CI 1.73, 2.43), 1.39 (95% CI 1.17, 1.66) and 1.0 from the lowest to highest sex-specific MMI tertile, with an HR of 1.35 (95% CI 1.26, 1.45) per SD decline in MMI. Further adjustments for fat mass, waist circumference and BMI as categorical variables did not modify the relationship (each p < 0.01). In BMI-stratified analyses, the population-attributable fraction of the lowest tertile of MMI for developing type 2 diabetes was increased by 11.9% in the nonobese group and 19.7% in the obese group. Conclusions/interpretation Low muscle mass as defined by MMI was associated with an increased risk of type 2 diabetes, independent of general obesity, in middle-aged and older Korean adults.

Creatinine/(cystatin C × body weight) ratio is associated with skeletal muscle mass index

“…However, we showed that Cre/(CysC × BW) is associ- [8,[25][26][27]. In fact, weight-adjusted SMI is reported to be associated with incident diabetes [8], incident metabolic syndrome [28] and progression of NAFLD [29]. In this study, we used absolute muscle mass as numerator of formula of weightadjusted SMI.…”

Lipotoxicity plays a key role in the development of both insulin resistance and muscle atrophy in patients with type 2 diabetes

“…T2D and muscle atrophy develop hand in hand, and it has previously been speculated that muscle loss might be a cause as well as a consequence of T2D. Studies suggesting a causal role for muscle loss in the development of metabolic disturbances are relatively scarce though, and to our knowledge, there is only one study that evaluated the association between low muscle mass and incidence of T2D in a longitudinal manner . Specifically, Son et al followed 6895 participants from Asian descent for a period of approximately 9 years and observed an inverse association between muscle mass index and the development of T2D.…”

“…Main covariates included age, sex, urban or rural residence, family history of diabetes, hypertension, smoking status, education level, monthly income, physical activity, alcohol consumption, and diet. Also, additional adjustments for body fat mass, waist circumference, and body mass index (BMI) did not modify the relationship . The assumption that muscle loss may play a causal role in the development of T2D is partly based on the fact that skeletal muscle is a major determinant of total energy expenditure .…”

Low serum creatinine and risk of diabetes: The Japan Epidemiology Collaboration on Occupational Health Study

“…Thus, decreased skeletal muscle mass could potentially trigger insulin resistance, which is an underlying mechanism of diabetes. Two cohort studies from Korea have shown that low muscle mass, defined using relative muscle mass and muscle mass index (appendicular), respectively, is linked with a greater risk of incident diabetes in both young and old people.…”