Sex differences in the association between serum α-Klotho and depression in middle-aged and elderly individuals: A cross-sectional study from NHANES 2007-2016

Background: Klotho is a well-known anti-aging protein that exerts pleiotropic effects; however, little is known regarding serum a-Klotho in the context of depression. Here, we evaluated the association between serum a-Klotho levels and depression in middle-aged and older individuals. Methods: In this cross-sectional study, data were collected from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2016 with a total of 5272 participants who were >= 40 years of age. Depression was evaluated using the 9-item Patient Health Questionnaire (PHQ-9). The association between serum a-Klotho levels and depression was determined on the basis of multivariable logistic regression models. Results: The mean age of the enrolled adults was 58.94 +/- 10.54 years, of which 49.5 % were female. When serum a-Klotho was log10-transformed, it was significantly inversely associated with depression in females in the final adjusted model (odds ratio [OR], 0.32; 95 % confidence interval [CI], 0.12-0.85). In the contrast, serum a-Klotho (log10) was significantly positively associated with depression in males in one of the adjusted models (OR, 3.71; 95 % CI, 1.17-11.8), and this disappeared after adjusting other covariates (all P > 0.05). Based on further stratified respective analyses of females and males, the results were stable. Limitations: The cross-sectional study could not yield any conclusions regarding causality. Conclusions: In the present study, serum a-Klotho levels were negatively related to the prevalence of depression in middle-aged and elderly women. This study provides new evidence of sex differences in the association between serum a-Klotho levels and depression.