Prevalence and Factors Associated with Subclinical Hypothyroidism in Major Depressive Disorder Patients with Dyslipidemia

BACKGROUND: Major depressive disorder (MDD) is a common psychiatric disorder with a high prevalence of comorbidity with subclinical hypothyroidism. The aim of this study was to investigate the prevalence and factors influencing the comorbidity of subclinical hypothyroidism in patients with dyslipidemic MDD who were hospitalized for the first time in a Chinese population. METHODS: The study incorporated 708 first-time hospitalized MDD patients, all with dyslipidemia. Data collection encompassed socio-demographic information, blood pressure, fasting blood glucose (FBG), lipid, and thyroid hormone levels. Participants were evaluated using the Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), and Positive Symptom Subscale (PSS). RESULTS: The prevalence of subclinical hypothyroidism in dyslipidemic MDD patients with the first hospitalization was 39.97%. The course of the disease, age at onset, HAMA score, and low-density lipoprotein cholesterol (LDL-C) were risk factors for subclinical hypothyroidism in dyslipidemic MDD patients. The course of disease, age at onset, HAMA score, HAMD score, FBG, and systolic blood pressure (SBP) levels were observed to influence serum Thyroid Stimulating Hormone (TSH) levels. CONCLUSION: MDD patients with dyslipidemia have a high prevalence of subclinical hypothyroidism, and the outcome is associated with anxiety, fasting glucose, and lipids. This study provides a potential biomarker for the identification of co-morbid subclinical hypothyroidism in MDD patients with dyslipidaemia.