A perspective cohort study on influence factors of survival outcome among the elderly aged ≥80 years old from longevity areas in China / 中华预防医学杂志

ABSTRACT

Objective@#To investigate the influence factors of survival outcome among elderly aged ≥80 years old.@*Methods@#In baseline survey in 2009, 930 participants aged ≥80 years old were enrolled from 7 longevity areas, to collect the information of socioeconomic factors, life style, cognitive function, activities of daily living and diseases, as well as physical examination to test biomarkers of blood and urine. The survival status was followed up at 2012 and 2014 survey. Stepwise Cox proportional hazards models were used to screen influence factors of 5-year survival.@*Results@#During 5 years of follow-up, 571 participants died, 133 participants were lost to follow up, and the all-cause mortality was 63.4%. In stepwise Cox proportional hazards models, male, unmarried, self-reported poor life quality, disability in daily life, cognitive impairment, cardiovascular and cerebrovascular diseases, chronic kidney diseases were risk factors for elderly survival outcome, with the HR (95%CI) at 1.75 (1.40-2.12), 1.49 (1.10-2.03), 1.40 (1.16-1.69), 1.37 (1.11-1.70), 1.51 (1.22-1.88), 1.62 (1.18-2.23) and 1.48 (1.23-1.77) respectively. Each 1 year increase in age corresponded to 4% increase in mortality risk (HR (95%CI)=1.04 (1.02-1.05)); each 1 kg/m2 increase in BMI corresponded to 5% increase in mortality risk (HR (95%CI)=0.95 (0.93-0.98)); each 1.0×109/L increase in total lymphocyte count (TLC) corresponded to 13% increase in mortality risk (HR (95%CI)=0.87 (0.76-0.99)). Additionally, the mortality risk decreased 19% (HR (95%CI)=0.81 (0.66-0.98)) in participants with regularly physical exercise compared to those without; and the mortality risk decreased 41% (HR (95% CI)=0.59 (0.40-0.88)) in participants with elevated triglycerides (TG, ≥2.26 mmol/L) compared to those without.@*Conclusion@#In Chinese longevity areas, some nutritional and immune indices such as relatively higher level of BMI, TLC and TG were independent protective factors for 5-year survival outcome, which was different from general adults and younger elderly.