Abstract
Background: Acanthosis nigricans (AN), a dermatological condition, is characterized by dark velvety discoloration and thickening of the skin. It has been known to be associated with various insulin-resistant conditions; however, risk factors of AN are not fully established. Methods: We conducted a systematic search of the literature using various combinations of specific keywords. The odds ratio (OR) and their 95% CI were used to draw forest plots. Results: In total, 37 studies were included in this meta-analysis. The combined meta-analysis yielded an OR of 0.35 with a 95% CI of 0.19-0.64 and a P value of .0006. The type 2 diabetes mellitus (T2DM)-related studies had an overall effect size of OR 0.24 with a 95% CI of 0.10-0.59 and a P value of .002. For obesity-related studies, the overall effect size was OR 0.62 with a 95% CI of 0.23-1.63 and a P value of .33. PCOS-related studies yielded an OR of 0.34 with a 95% CI of 0.07-1.59 and a P value of .17. Finally, the studies on acromegaly had an effect size of -0.17 with a 95% CI varying from -0.42 to 0.008 and a P value of .19. Conclusion: Insulin-resistance conditions such as T2DM, obesity, PCOS, and acromegaly are important risk factors for the development of AN when their effect size is combined with strong statistical significance. However, only T2DM shows a strong statistical significance; as a risk factor for AM when these conditions are taken individually.