Low Handgrip Strength (Possible Sarcopenia) With Insulin Resistance Is Associated With Type 2 Diabetes Mellitus

Abstract

Context: Older adults with sarcopenic obesity are at high risk for type 2 diabetes mellitus (T2DM). However, few East Asians have sarcopenic obesity. Since many East Asians have insulin resistance (IR) without obesity, it is possible that older East Asians with sarcopenia and IR might be at high risk for T2DM. However, this relationship has not been studied.

Methods: This cross-sectional study included 1629 older adults aged 65 to 84 years registered in the Bunkyo Health Study. All underwent a 75-g oral glucose tolerance test and handgrip strength measurement. Participants were classified into 4 groups by possible sarcopenia (handgrip strength <28 kg in men and <18 kg in women) and IR status (triglyceride glucose [TyG] index ≥8.79 for men and ≥8.62 for women [third quartile]). Modified Poisson regression was used to estimate relative risk (RR) and 95% CIs for T2DM with adjustment for confounding factors.

Results: The mean age was 73.1 ± 5.4 years. T2DM was diagnosed in 212 (13.0%) participants. After adjusting for age, sex, body mass index, use of lipid-lowering medications, hypertension, and cardiovascular disease, possible sarcopenia and IR were associated with T2DM, with their coexistence showing a notably stronger association (control: RR, 1.00 [Reference]; possible sarcopenia: RR, 1.55 [95% CI, 1.04-2.30]; IR: RR, 2.69 [95% CI, 1.99-3.65]; and IR possible sarcopenia: RR, 4.76 [95% CI, 3.34-6.79]).

Conclusion: Possible sarcopenia based on low handgrip strength and IR based on the TyG index are independently associated with T2DM in older Japanese individuals. Their coexistence shows a particularly strong association with T2DM.

Keywords: handgrip strength; insulin resistance; sarcopenia; triglyceride glucose index; type 2 diabetes.

Figure 1.

Associations between the prevalence of type 2 diabetes and IR-possible sarcopenia or obesity-possible sarcopenia. Fig. 1 shows relative risk (RR) and 95% CIs for type 2 diabetes across different groups. This figure represents the A, unadjusted, and B, fully adjusted models. The adjustments are made for age, sex, body mass index (BMI) (except for the group of obesity based on BMI), lipid-lowering medications, hypertension, and cardiovascular disease. In this analysis, possible sarcopenia was defined by low handgrip strength (handgrip strength <28 kg for men and <18 kg for women). In the corresponding groups, obesity was defined by BMI of 25 or greater or percentage body fat (PBF) of 30% or greater for men and 35% or greater for women. Insulin resistance (IR) was defined by homeostasis model assessment of insulin resistance index (HOMA-IR) of 1.64 or greater for men and 1.43 or greater for women, or Matsuda index of 4.30 or less for men and 4.58 or less for women. TyG index, triglyceride glucose index.