Insulin Resistance and Metabolic Syndrome in Patients with Seborrheic Dermatitis: A Case-Control Study.

Background: Our knowledge of the systemic effects of seborrheic dermatitis (SD) as a chronic inflammatory skin disease remains limited. We aimed to evaluate metabolic syndrome (MS) and glucose metabolism disorders in patients with SD. Methods: The study includes 53 patients over the age of 18 diagnosed with SD and 50 age-, gender-, and body mass index-matched healthy controls. Demographic data, anthropometric measurements, blood pressure levels, family history of SD and metabolic disorder, smoking history, and severity of the disease in SD patients were obtained. Fasting plasma glucose, insulin, hemoglobin A1c, lipid profile levels, and two-hour plasma glucose in the oral glucose tolerance test (OGTT 2-h PG), homeostasis model assessment of insulin resistance (HOMA-IR), and presence of MS were determined. Results: Weight, waist circumference, family history of SD, family history of metabolic disorder, and smoking status were significantly higher in the SD group compared with the control group (P = 0.04, P = 0.007, P = 0.004, P = 0.004, and P = 0.048, respectively). The levels of fasting plasma insulin and triglyceride, HOMA-IR and OGTT 2-h PG were also significantly higher in the SD group than in the control group (P = 0.0001, P = 0.033, P = 0.0001, and P = 0.049, respectively). In addition, the number of those with insulin resistance was significantly higher in the group with SD (n = 31, 58.49%) than in the control group (n = 11, 22%) (P = 0.0001). Although the rate of MS was higher in patients with SD (n = 12, 22.64%) than the controls (n = 6, 12%), the difference was not significant (P = 0.155). Conclusion: Our findings suggest an association between SD and insulin resistance, which may be due to their common inflammatory pathogenesis. This may be an indicator of susceptibility to diabetes, and these patients can be followed up for conditions associated with insulin resistance and encouraged to adopt a healthy lifestyle.