Relation between the severity of acanthosis nigricans and metabolic syndrome components

Background Acanthosis nigricans (AN) is characterized by hyperpigmented velvety plaques of the skin. AN is caused by hyperinsulinemia, a result of insulin resistance that is associated with obesity. Objective To detect the relation between the severity of AN skin lesions and metabolic syndrome components in obese patients not fulfilling the criteria for metabolic syndrome. Patients and methods This case control study included 30 obese patients with AN and 30 overweight, age-matched and sex-matched individuals without AN as controls. For all patients, assessment of full medical history was carried out. Weight, height, and waist circumference were measured, and BMI (kg/m2) was calculated. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured. Complete blood count, liver and renal function tests, fasting blood glucose, fasting insulin levels, and lipid profile were estimated. For the patient group, the severity of AN was assessed according to a quantitative scale of AN, and patients were subdivided according to the neck severity score into mild, moderate, and severe subgroups. Results There was a significant difference between the cases and the controls in waist circumference (112.1 ± 12.9 vs. 90.2 ± 4.6, Po0.001), BMI (32.9 ± 2.9 vs. 26.6± 0.93, Po0.001), fasting blood glucose (104.6 ± 8 vs. 87.3 ± 6.9, Po0.001), total cholesterol (189.37± 22.28 vs. 144.3 ± 44.5, Po0.001), high-density lipoprotein (39.02 ±0.039 vs. 47.27± 4.39, Po0.001), low-density lipoprotein (106.43± 19.28 vs. 90.37 ±17.57, Po0.001), and fasting insulin levels (23.2 ±5 vs. 11.3± 1.4, Po0.001). Among the patient subgroups, there was a significant difference in waist circumference, BMI (Po0.001), SBP, DBP (Po0.001), and fasting insulin levels (Po0.001). There was a positive significant correlation between the neck severity score, axillary severity score, neck texture score, and each of waist circumference, BMI (Po0.001), SBP, DBP (Po0.001), fasting insulin levels (Po0.001), total cholesterol, and triglycerides (Po0.05), but a significant negative correlation with high-density lipoprotein (Po0.05). Conclusion The severity of AN skin lesions correlates positively with insulin levels and biochemical changes related to the metabolic syndrome.