Early menarche is associated with insulin-resistance and non-alcoholic fatty liver disease in adolescents with obesity

Objectives: Recent evidence linked early menarche to a higher risk of insulin-resistance (IR) and nonalcoholic fatty liver disease (NAFLD) in adulthood. We aimed to evaluate the impact of early menarche on glucose derangements and NAFLD in a sample of Italian adolescents with obesity. Methods: Anthropometric and biochemical evaluations were conducted in all the enrolled 318 obese patients (mean age 12.31 +/- 2.95 years). NAFLD was defined by the presence of ultrasound detected liver steatosis and/or alanine transaminase (ALT) levels >40 IU/L. Results: Patients with early menarche showed both higher homeostasis model assessment of insulin-resistance (HOMA-IR) (p=0.008) and ALT (p=0.02) values, an increased prevalence of NAFLD (p=0.001), and lower Matsuda and Insulinogenic Index (IGI) values than the other obese patients. The association between early menarche and both ALT and Matsuda Index remained significant in General Linear Models (GLMs) in which respectively body mass index standard deviation score (BMI-SDS) and Matsuda Index, and BMI-SDS were included as covariates. Patients with early menarche also showed a higher risk of both HOMA-IR>3 (OR 1.69, CI 1.05-2.70, p=0.02) and NAFLD (OR 1.10, CI 1.01-1.21, p=0.03). Conclusions: Girls with obesity presenting early menarche showed higher HOMA-IR levels, lower Matsuda Index and IGI values, and higher risk of NAFLD compared to girls without early menarche.