Albuminuria and Mental Illness Risk: Results From National Health and Nutrition Examination Survey 2005–2018 and Mendelian Randomization Analyses

BACKGROUND: Recent evidence suggests a link between albuminuria and mental illness. However, whether this association is stable, and its specific mechanisms remain unclear. METHODS: The cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Weighted multivariable-adjusted logistic regression, subgroup analysis, interaction tests, and restricted cubic spline (RCS) were conducted to assess the correlation between albuminuria and the risk of mental illness (depression). Subsequently, two-sample Mendelian randomization analyses were performed to investigate the relationship between albuminuria and various mental illnesses (anxiety disorder, persistent delusional disorder, schizophrenia, schizotypal personality disorder, panic disorder, post-traumatic stress disorder [PTSD], obsessive-compulsive disorder, bipolar I disorder, bipolar II disorder, depression, autism, social anxiety disorder). RESULTS: Albuminuria was consistently found to have a significant association with the risk of depression, regardless of its classification as a continuous or outcome variable. A positive correlation was found between albuminuria and depression in different age groups, gender, race, education attainment, and those with hypertension, coronary heart disease, and diabetes. Further, there is a positive correlation between albuminuria and the occurrence of schizophrenia and persistent delusional disorder. CONCLUSION: There is a close association between albuminuria and mental illness, with albuminuria being a risk factor for schizophrenia and persistent delusional disorder. Further research is needed to establish the specific connections.