In a retrospective study conducted on 18 to 80-year-old female inpatients with or without T2DM, the estrogen, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels of 964 T2DM patients and 263 controls were analyzed to conclude that the estrogen decline phase begins at the age of 40 in women with T2DM and was continuously low by the age of 45 years to show that ovarian aging was accelerated as compared to the controls thereby indicating that the aging-related changes in sex hormones of the patients accelerate ovarian aging. The gene discussed is PLOD1; the disease is type 2 diabetes mellitus.