The Relationship Between Dysglycemia and Dyslipidemia in First-Episode, Untreated Chinese Patients With Major Depressive Disorder at Different Ages of Onset.

PURPOSE: Dysglycemia, a common ailment in MDD patients, lacks research regarding its variance across the age of onset (AOO). Therefore, we investigated the correlation between fasting blood glucose (FBG) abnormalities and blood lipids in first-onset, untreated patients with MDD and to determine the factors that influence glycemic abnormalities in patients differentiated by age of onset. PATIENTS AND METHODS: The study enrolled 1718 Han Chinese outpatients with drug-naïve, first-episode MDD from a general hospital. Anxiety, depression, and psychotic symptoms were evaluated using the Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Clinical Global Impression of Severity Scale (CGI-S), and Positive and Negative Syndrome Scale (PANSS) positive subscale, respectively. we divided patients into early age of onset (EAO, < 45 years) and middle age of onset (MAO, ≥ 45 years) groups. RESULTS: MAO patients, compared to EAO patients, displayed higher scores on the HAMD, HAMA, CGI-S, and PANSS positive scales. Furthermore, they exhibited elevated serum levels of thyroid stimulating hormone (TSH), FBG, total cholesterol (TC), and low-density lipoprotein (LDL-C). In MAO patients, FBG correlated with TSH, triglycerides (TG), and TC, while only TSH correlated with FBG in EAO patients. Path analysis revealed a significant indirect effect of FBG on lipid levels through depressive symptoms, accounting for 35.46% of the total association in EAO patients and 16.22% in MAO patients. CONCLUSION: Age-stratified analyses revealed that MDD-associated metabolic dysregulation in younger patients (< 45 years) was mediated by psychiatric symptoms, warranting depression-focused interventions, whereas older patients (≥ 45 years) demonstrated direct metabolic dysfunction, necessitating integrated psychiatric-metabolic management.