Understanding risk in the oldest old: Frailty and the metabolic syndrome in a Chinese community sample aged 90+ years

Objectives: To investigate the relationship between frailty and the metabolic syndrome and to evaluate how these contribute to mortality in very old people. Design: Secondary analysis of data from the Project of Longevity and Aging in Dujiangyan. Setting: Community sample from Sichuan Province, China. Participants: People aged 90+ years (n=767; baseline age=93.7±3.4 years; 68.0% women. Measurements: After a baseline health assessment, participants were followed for four years (54.0% died). A frailty index (FI) was calculated as the sum of deficits present, divided by the 35 health-related deficits considered. Relationships between the FI and the metabolic syndrome were tested; their effect on death was examined. Results: The mean FI was 0.26 ±0.11. Higher FI scores were associated with a greater risk of death, adjusted for age, sex, education, and metabolic syndrome items. The hazard ratio was 1.03 (95% confidence interval 1.02, 1.04) for each 1% percent increase of the FI. The mortality risk did not change with the metabolic syndrome (odds ratio=0.99; 0.71-1.36). Conclusions: In the oldest old, frailty was a significant risk for near-term death, regardless of the metabolic syndrome. Even using age-adjusted models, the epidemiology of late life illness may need to account for frailty routinely.