Prevalence of acanthosis nigricans and its association with physical activity in adolescents - School-based analytical cross-sectional study from Kochi, Kerala.

INTRODUCTION: Acanthosis nigricans (AN) is a brown to black, poorly defined velvety hyperpigmentation of the skin. It is a predisposition factor for Type 2 diabetes, malignancies and various endocrinopathies. The available data regarding AN from Kerala is limited. Our study aims to estimate the prevalence of AN and to examine its association with physical activity among the adolescents of age 13-14 years.

METHODOLOGY: This analytical cross-sectional study was conducted in two grades of a school in Ernakulam district between June and December 2018 among 400 adolescents of age 13-14 years. The study proforma and the Physical activity questionnaire, Adolescents (PAQ-Adolescents), were self-administered to the students and the data were collected. The principal investigator verified the presence of AN by observation in the neck, elbow and knuckles and recorded in the study proforma. Statistical analysis of the data collected was done using SPSS Software program (version 21).

RESULTS: The mean age of the group was found to be 13.31 ± 0.46 years. The prevalence of AN was 14.5% in the study population. AN was most prevalent among obese adolescents (61.54%), adolescents with low exercise rate (23.94%), having family history of diabetes (21.18%), family history of hypertension (21.86%) and family history of both diabetes and hypertension (26.32%). The risk factors such as obesity, diabetes, hypertension, family history of diabetes, family history of hypertension and family history of both diabetes and hypertension had a positive association with AN had a negative association with physical activity with p=0.0001. In adolescents with increased exercise rate, there were no reported cases of AN.

CONCLUSION: The results of our study show that there is a strong association between AN and children with obesity, family history of diabetes mellitus, hypertension and low physical activity. Regular adequate physical activity can prevent the onset of AN and thereby reduce the early onset of diabetes, metabolic syndrome, polycystic ovarian syndrome, coronary artery diseases and certain types of malignancies.