Association between allostatic load and depression in patients with sleep disorders: Evidence from national health and nutrition examination survey

Objective: Allostatic load (AL) is an indicator of cumulative wear and tear on the body's physiological systems that can predict the onset of a range of health problems. However, the relationship between AL and depression in patients with sleep disorders remains unclear. This study aimed to explore the association between AL and depression in patients with sleep disorders. Methods: Using data from the 2015-2016 National Health and Nutrition Examination Survey, a total of 4618 adults aged 18 years and older in the United States were included in this cross-sectional analysis. AL was calculated using nine biological markers, with a score of >= 3 indicating a high level. Depression was assessed using the Patient Health Questionnaire-9, and a score of 10 or higher indicated a potential risk of depression. Logistic regression models were employed to analyze the relationship between AL and depression. Results: Among the 1309 participants diagnosed with sleep disorders, 212 (16.2%) were identified as being at risk of depression. A total of 55.2% (n = 117) of the depressed persons had high AL levels. In the unadjusted model, AL levels were associated with depression in those with sleep disorders (OR:1.53, 95% CI = 1.14-2.05; P < .01). This relationship remained significant in the adjusted model (OR:1.52, 95% CI = 1.11-2.10, P < .05), after controlling for potential confounding factors. Conclusion: The findings showed that high AL levels in patients with sleep disorders were positively associated with depression, indicating that elevated AL may increase the risk of depression in this population, or alternatively, depression may increase the risk of AL.