Sarcopenia, but not sarcopenic obesity, predicts mortality for older old men: A 3-year prospective cohort study

Background The prognostic significance of sarcopenia and sarcopenic obesity (SO) among older people remains controversial. The main aim of this study was to evaluate the mortality risk of sarcopenia and SO among men aged 75 years and older in Taiwan. Methods This prospective cohort study recruited all residents of the Banciao Veterans Home, a veterans retirement community in Taipei City in northern Taiwan. For all study participants, the demographic profile, comorbid medical conditions, biochemical markers, handgrip strength and gait speed, sarcopenia, SO, and all-cause mortality were collected during a 3-year follow-up period. Results In the study, 680 residents participated. The prevalence of sarcopenia and SO was 60.3% and 19.7%, respectively. During the study period, 140 (20.6%) deaths were identified. The diseased individuals were older, more prone to having diabetes mellitus and sarcopenia, had lower serum levels of total cholesterol and triglycerides, but had no difference in SO. Comparisons between different statuses of SO showed that age; diabetes mellitus; metabolic syndrome; body mass index; waist circumference; handgrip strength; gait speed; systolic blood pressure; fasting plasma glucose; serum levels of total cholesterol, triglyceride, high-density lipoprotein; and mortality were all significantly different between the groups. Sarcopenia [odds ratio (OR), 2.64; 95% confidence interval (C.I.), 1.687-4.135; p < 0.001], diabetes mellitus (OR, 1.70; 95% CI, 1.083-2.267; p = 0.021) were independent risk factors for mortality; whereas the serum level of triglyceride was protective (OR, 0.99; 95% CI, 0.989-0.997; p = 0.001). The Cox proportional hazard model confirmed that sarcopenia was significantly associated with mortality with or without obesity. Conclusion The mortality risk of sarcopenia significantly outweighed the survival benefits of obesity in old age. The unfavorable impact of SO may eventually result from sarcopenia, but not obesity.