The prevalence and clinical significance of acanthosis nigricans in diabetic and non-diabetic women of mixed ancestry : research

Objectives : The purpose of this study was to improve our understanding of the prevalence of acanthosis nigricans (AN) and its clinical relevance in our mixed-ancestry population and to investigate its association with abnormal glucose metabolism, obesity and hypertension. Design : This was a cross-sectional study. Settings and subjects : A total of 390 healthy mixed-ancestry females were recruited from the dermatology outpatient clinic at Tygerberg Hospital. Outcomes measured : A short questionnaire was administered, whereafter participants were inspected for the presence and degree of AN. Height, weight, blood pressure and random fingerpick blood glucose were measured. Results : AN was observed in 30% (n = 116) of participants, and most commonly found in the nape of the neck (94%, n = 109). Participants with AN were younger (p = 0.005), and of higher body mass (p < 0.001) with a higher random blood glucose (p = 0.04). AN was more commonly seen in diabetics (p = 0.004). The presence and severity of AN in the neck correlated far better with BMI and blood glucose than other sites, including the axilla. Conclusion : AN was found to be extremely common, with a prevalence of 30% in this group. An association with blood glucose levels, diabetes and obesity was demonstrated, proving that it is not just a normal ethnic phenomenon. No association with blood pressure or hypertension was found.