Joint Associations of Diabetes and Sarcopenia on All-Cause Mortality among U.S. Older Adults

Background: Recent studies have shown that sarcopenia defined as the loss of muscle mass and/or strength was associated with diabetes and independently predicted all-cause mortality in older adults; however, it is unclear whether sarcopenia and diabetes synergistically affect all-cause mortality. Methods: We aimed to prospectively examine joint associations of sarcopenia (defined by either low muscle mass (LMM), low muscle strength (LMS), or both) and diabetes on all-cause mortality in a nationally representative sample of U.S. adults, including 4,449 participants aged 50 years and older from NHANES 1999-2002 with linked mortality data. Weighted multivariable logistic regression models were adjusted for age, sex, race, BMI, smoking, alcohol use, education, leisure time physical activity, sedentary time, and comorbid diseases. Results: Overall, we had 971 with diabetes and 921 with sarcopenia defined by LMM (ALM/BMI), 762 with LMS, 207 with sarcopenia defined by both LMM (ALM/BMI) and LMS. The prevalence of sarcopenia was higher in diabetic than nondiabetic individuals (23.7% vs. 14.6% for LMM, 15.8% vs. 13.8% for LMS, and 4.0% vs. 3.5% for both LMM and LMS). In the joint analyses, diabetic individuals had increased risk of all-cause mortality than those without diabetes or LMM, whether they had LMM (OR=2.79; 95% CI: 1.56-4.98) or not (OR=1.40; 95% CI: 1.02-1.92) (P for joint effect=0.001). LMS was associated with higher risk of all-cause mortality among both diabetic (OR=4.10; 95% CI: 1.59-10.55) and nondiabetic individuals (OR=2.39; 95% CI: 1.77-3.23) (P for joint effect<0.0001). Compared to those without diabetes or sarcopenia (both LMM and LMS), all-cause mortality risk was higher among individuals with sarcopenia alone (OR=1.78; 95% CI: 1.15-2.75) (P for joint effect=0.011). Conclusions: Our results suggest that LMS was independently and strongly associated with elevated risk of all-cause mortality, with additional risk synergistically with diabetes among U.S. older adults. Disclosure J. Xia: None. Y. Song: None.