The Differential Association between Muscle Strength and Diabetes Mellitus According to the Presence or Absence of Obesity

BACKGROUND: Muscle strength can be affected by body mass index. In the present study, we compared the association between the diabetes mellitus (DM) and muscle strength according to obesity. METHODS: We analyzed the association between DM and muscle strength using the Korea National Health and Nutrition Examination Survey 2014 to 2016 data weighted to represent the Korean population aged between 30 and 79 years old. Muscle strength was classified into age- and sex-specific quartiles (Qs) of handgrip strength, with the lowest Q defined as “low muscle strength (LMS).” RESULTS: Muscle strength was positively associated with body mass index in both sexes (P<0.001); the prevalence of obesity increased by 30% in male (odds ratio [OR], 1.300; 95% confidence interval [CI], 1.231–1.373) and 12% in female (OR, 1.122; 95% CI, 1.062–1.185), respectively, per one Q of muscle strength. In contrast, the prevalence of DM decreased as muscle strength increased (OR per one Q, 0.926; 95% CI, 0.862–0.996 in male and OR per one Q, 0.917; 95% CI, 0.854–0.986 in female). LMS was significantly associated with DM even following adjustment for age, sex, family history of DM, abdominal obesity, dyslipidemia, and hypertension (OR, 1.328; 95% CI, 1.133–1.558). Stratified analysis according to obesity status showed that it remained significant only in nonobese populations (OR, 1.513; 95% CI, 1.224–1.870 in nonobese participants and OR, 1.124; 95% CI, 0.879–1.437 in obese participants). CONCLUSION: LMS was independently associated with DM in the Korean population aged between 30 and 79 years. However, obesity-stratified analysis revealed that it was significant only in the nonobese population.