Sex Differences in Age Trajectories of Physiological Dysregulation: Inflammation, Metabolic Syndrome, and Allostatic Load

Yang Yang, University of Chicago
Michael Kozloski, University of Chicago

Using nationally representative data on 38,000 individuals aged 17+ from the National Health and Nutrition Examination Survey (1988 – 2006), this study examined sex differences in the age trajectories of 14 markers of physiological functions that show marked sexual dimorphism and are essential to cardiovascular health and vitality including markers of inflammation, metabolic disorders, and allostatic load. We found significant sex by age interaction effects for all variables examined. The patterns of sex and age differences vary by biological functions. Differential exposures and vulnerabilities to social status and health behaviors, especially obesity and cigarette smoking, partially account for the sex differences in age patterns of various biological functions. This study provides population based evidence for the potential physiological pathways through which age changes in sex mortality gaps occur. We discuss sex-specific biological mechanisms especially reproductive physiology underlying these differences, the complexity of the measurement of phenotypic frailty, and avenues for future research.