Assessment of patients with acanthosis nigricans skin lesion for hyperinsulinemia, insulin resistance and diabetes risk.

Acanthosis nigricans is a skin lesion characterized by thickening and apparent darkening of the keratin layer of the skin, usually on the neck and axillae. Recent studies reveal that this disorder is directly associated with hyperinsulinemia. A major implication of hyperinsulinemia is insulin resistance--a primary factor in the development of type II diabetes mellitus. Prolonged hypersecretion of insulin presumably leads to pancreatic exhaustion and subsequent glucose intolerance that can progress to type II diabetes. Prospective studies of individuals with acanthosis nigricans have shown very high prevalence rates of type II diabetes. Prevalence studies among adolescents have shown that the lesion appears early in life and is a common finding in some ethnic groups. These data suggest that acanthosis nigricans is an easily detected empirical marker for elevated risk of type II diabetes. The lesion can appear long before the onset of glucose intolerance. Thus, including acanthosis nigricans screening in a comprehensive disease-prevention program can help identify people at risk for type II diabetes prior to the actual onset of glucose intolerance, as well as individuals with undiagnosed diabetes. Interventions that reduce insulin resistance include weight loss and regular physical activity.