Publication:

Acanthosis nigricans: a clinical marker of insulin resistance

Background Very little information is available regarding the association of acanthosis nigricans with insulin resistance from rural areas of India. Therefore this study was carried out with the aim and objectives to study the association between acanthosis nigricans and insulin resistance and to evaluate correlation of acanthosis nigricans severity, neck severity and neck texture severity with fasting blood sugar & serum insulin especially in this rural part of central India.

Methods In this cross sectional study with comparative group, total 162 age and sex matched subjects were divided into two groups of cases (81) with acanthosis nigricans and comparative subjects (81) without acanthosis nigricans. The severity acanthosis nigricans was assessed using the Burke’s quantitative scale. Fasting blood sugar and fasting insulin levels were estimated to know the Homeostasis model assessment of insulin resistance (HOMA-IR) values. Data was analyzed by using appropriate statistical tests.

Results The age range was 20 to 55 years with the mean of 32.82 ± 10.19 years for cases and 33.67 ± 8.09 for comparative subjects. Univariate analysis which showed significant association of acanthosis nigricans with fasting insulin and HOMA-IR with significant odds ratios and p value (p =0.0001) respectively. Fasting blood sugar showed greater risk of association in cases but it was statistically insignificant with p-value of (p =0.32). Spearman rank coefficient correlation showed weak correlation of HOMA-IR with acanthosis nigricans severity, neck severity and neck texture severity, but showed positive correlation of fasting insulin with acanthosis nigricans severity, neck severity and neck texture severity, with statistically significant P-value (p <0.05).

Conclusions Acanthosis nigricans was strongly associated with insulin resistance with significant odds ratio and statistical significant p value (P < 0.05). Acanthosis nigricans severity, neck severity and neck texture severity showed positive correlation with fasting serum insulin with statistically significant p value (P <0.05).