Combined effect of metabolic syndrome and cancer on depression

BACKGROUND: Cancer survivors frequently experience depression and metabolic dysfunction; however, the combined impact of these conditions remains understudied. AIM: This study aimed to examine the joint associations between cancer, metabolic syndrome, and depression. METHODS: Data from the 2007-2021 Korea National Health and Nutrition Examination Survey encompassed 57,176 participants aged ≥ 19 years. Cancer diagnosis and components of metabolic syndrome (waist circumference, triglycerides, high-density lipoprotein cholesterol, blood pressure, and fasting glucose) were obtained through self-report or clinical measurement. Depression was assessed using a single-item question regarding persistent sadness or hopelessness. Multivariable logistic regression models evaluated the associations among cancer, metabolic syndrome, and depression, adjusting for sociodemographic and lifestyle factors. RESULTS: Among participants, 1,691 (3.0%) had cancer, 17,510 (30.7%) met criteria for metabolic syndrome, and 7,472 (13.1%) reported depression. Cancer was independently associated with increased risk of depression (odds ratio: 1.26; 95% confidence interval: 1.10-1.45). While metabolic syndrome alone was not significantly associated with depression, patients with cancer who had elevated triglycerides (≥ 150 mg/dL) or decreased high-density lipoprotein cholesterol exhibited substantially higher risk of depression (odds ratio: 1.51; 95% confidence interval: 1.17-1.95 and odds ratio: 1.32; 95% confidence interval: 1.07-1.62, respectively). The association between elevated triglycerides in cancer survivors and depression remained robust after FDR correction. CONCLUSIONS: Specific lipid abnormalities, rather than metabolic syndrome as a whole, were significantly associated with a higher prevalence of depression among cancer survivors. These findings underscore the need for integrated screening and management that address both metabolic dysfunction and mental health in cancer survivorship care.