Periorbital melanosis and its possible association with insulin resistance and vitamin D deficiency: A pilot case-control study.

Objective: To investigate the possible association of periorbital melanosis (POM) with insulin resistance (IR) and vitamin D serum levels.

Methods: In this pilot, case-control study, we included 100 adult patients with POM and 100 age- and sex-matched healthy control subjects. Vitamin D levels and IR indices (i.e., homeostatic model assessment-insulin resistance [HOMA-IR], triglycerides/high-density lipoprotein cholesterol (TG/HDL-c) ratio, adiponectin/leptin (A/L) ratio) were compared between cases and controls.

Results: Compared with controls, POM cases had significantly higher values of HOMA-IR and TG/HDL-c ratio, and significantly lower values of A/L and vitamin D. HOMA-IR and TG/HDL-c ratio were statistically significantly positively correlated with POM severity while Vitamin D and A/L ratio were statistically significantly negatively correlated.

Conclusion: POM was associated with indices of IR and vitamin D deficiency. However, the exact causal link among POM, IR, and vitamin D needs to be established. However, the results of this pilot study suggest that POM may have potential as a cutaneous non-invasive marker of these metabolic disorders which would assist in detecting and treating them at an early stage.