INS and polycystic ovary syndrome: The literature also shows diverse correlations; for example, Calan et al.(15) reported a positive correlation between betatrophin and HOMA-IR as well as free testosterone in PCOS patients, while Song et al.(26) and Erbag et al.(29) reported a negative correlation between serum betatrophin and BMI, fasting insulin, and HOMA-IR.