Beyond biology: Physical and mental health predictors of mortality in the sydney memory and ageing study

This study aimed to investigate the relevance of various predictors of mortality in late life. Additionally, it explored whether mental health indicators such as depressive symptoms, and cognitive ability, which are known predictors of healthy ageing, are also important markers of mortality. By examining both physical and mental health indicators, we aimed to gain a more comprehensive understanding of the factors that contribute to mortality.

The ability of physical health markers including high and low-density lipoprotein cholesterol, triglycerides, waist-hip ratio, body mass index, glucose, uric acid, creatinine clearance, and a cardiovascular disease (CVD) risk variable; depressive symptoms; cognitive ability; and peripheral blood inflammatory biomarkers to predict mortality was examined using survival analysis in a sample of older Australians (mean age = 77.99, SD = 4.71 at baseline) from the Sydney Memory and Ageing Study, followed biannually from 2005 (n = 901) to 2020 (n = 329).

Age (Wald = 19.63, p < .001), depressive symptoms (Wald = 8.16, p = .004), inflammation (interleukin 8; Wald = 5.73, p = .017), high density lipoprotein cholesterol levels (Wald = 4.27, p = .039), and waist-hip ratio (Wald = 4.04, p = .045) were significant predictors of mortality in this population.

While maintaining physical health is important for survival, addressing mental health issues such as depressive symptoms may in fact be equally important. Our findings contribute to future experimental and clinical research focused on developing strategies to enhance survival and mental health in the ageing population.