The Association of Sarcopenia, Telomere Length and Mortality: Data from the NHANES 1999–2002

BACKGROUND: Sarcopenia is defined as the loss of muscle mass or function with aging and is associated with adverse outcomes. Telomere shortening is associated with mortality, yet its relationship with sarcopenia is unknown. METHODS: Adults ≥60 years from the 1999–2002 NHANES with body composition measures were identified. Sarcopenia was defined using the two Foundation for the National Institute of Health definitions: appendicular lean mass (ALM) (men<19.75; women<15.02kg); or ALM divided by body mass index (BMI) (ALM:BMI, men<0.789; women<0.512). Telomere length was assessed using quantitative PCR. Regression models predicted telomere length with sarcopenia (referent=no sarcopenia). RESULTS: We identified 2,672 subjects. Mean age was 70.9 years (55.5% female). Prevalence of ALM and ALM:BMI sarcopenia was 29.2 and 22.1%. Deaths were higher in persons with sarcopenia as compared to those without sarcopenia (ALM: 46.4 vs. 33.4%; p<0.001; ALM:BMI: 46.7 vs.33.2%; p<0.001). No adjusted differences were observed in telomere length in those with/without sarcopenia (ALM: 0.90 vs. 0.92; p=0.74, ALM:BMI 0.89 vs. 0.92; p=0.24). In men with ALM:BMI defined sarcopenia, adjusted telomere length was significantly lower compared to men without sarcopenia (0.85 vs 0.91, p=0.013). With sarcopenia, we did not observe a significant association between telomere length and mortality (ALM: HR 1.11 [0.64, 1.82], p=0.68; ALM:BMI: HR 0.97 [0.53,1.77], p=0.91), but noted significance in those without sarcopenia with mortality (ALM: HR 0.59 [0.40, 0.86], p=0.007; ALM:BMI: HR 0.62 [0.42, 0.91]; p=0.01). CONCLUSIONS: We observed a potentially inverse relationship between telomere length and mortality in those without sarcopenia but did not observe a significant relationship between telomere length and mortality in the presence of sarcopenia.