Background: Changes in skin color are common among dialysis patients. They are associated with urochrome pigments, hemoglobin, and changes in cutaneous vasculature. Insulin resistance (IR) is strongly linked to cutaneous vascular dysfunction and is prevalent in dialysis patients. We postulated skin color may be associated with IR in dialysis patients because of the alternation in cutaneous vasculature.
Methods: 50 nondiabetic peritoneal dialysis (PD) patients were recruited for measurements of skin color by the Commission Internationale de I'Eclairage (CIE; International Commission on Illumination) system ("L" "a" "b" system). The "L" values represent skin brightness, "a" redness, and "b" yellowness. Correlation analysis between skin color, homeostatic model assessment (HOMA(IR)), high-density lipoprotein cholesterol (HDL-C), and adiponectin was performed.
Results: We divided patients (age 45 +/- 13 years, 31 women) into 3 groups according to tertiles of HOMA(IR). Patients with higher HOMA(IR) had a trend to have poor skin color (lower "a" and "b" values; p = 0.038 and 0.064). HOMA(IR), adiponectin, and HDL-C levels were correlated with "a" and "b" values in logarithm (all p < 0.05). After adjustments for age, hemoglobin level, duration of PD, and residual renal glomerular filtration rate, only HOMA(IR) was associated with "a" values (p = 0.038) and HDL-C was associated with "b" values (p = 0.048) in logarithm.
Conclusions: Skin color, measured noninvasively, is associated with HOMA(IR) and HDL-C. Nondiabetic PD patients that had more severe IR had worse skin color.