Anxiety disorders and age-related changes in physiology

Objective: Anxiety disorders are leading contributors to the global disease burden, highly prevalent across the lifespan, and associated with substantially increased morbidity and early mortality. The aim of this study was to examine age-related changes across a wide range of physiological measures in middle-aged and older adults with a lifetime history of anxiety disorders compared to healthy controls. Methods: The UK Biobank study recruited >500,000 adults, aged 37-73, between 2006-2010. We used generalised additive models to estimate non-linear associations between age and hand-grip strength, cardiovascular function, body composition, lung function and heel bone mineral density in cases vs. controls. Results: The main dataset included 332,078 adults (mean age = 56.37 years; 52.65% females). In both sexes, individuals with anxiety disorders had lower hand-grip strength and blood pressure, while their pulse rate and body composition measures were higher than in healthy controls. Case-control differences were larger when considering individuals with chronic and/or severe anxiety disorders, and differences in body composition were modulated by depression comorbidity status. Differences in age-related physiological changes between female anxiety disorder cases and healthy controls were most evident for blood pressure, pulse rate and body composition, while in males for hand-grip strength, blood pressure and body composition. Most differences in physiological measures between cases and controls tended to decrease with age increase. Conclusion: Individuals with a lifetime history of anxiety disorders differed from healthy controls across multiple physiological measures, with some evidence of case-control differences by age. The differences observed varied by chronicity/severity and depression comorbidity.