The effects of obesity on the menstrual cycle.

The prevalence of childhood and adolescent obesity has significantly increased in the United States and worldwide since the 1970s, a trend that has been accelerated by the COVID-19 pandemic. The complications of obesity range from negative effects on the cardiovascular, endocrine, hepatobiliary, and musculoskeletal systems to higher rates of mental health conditions such as depression and eating disorders among affected individuals. Among adolescent girls, childhood obesity has been associated with the earlier onset of puberty and menarche, which can result in negative psychosocial consequences, as well as adverse effects on physical health in adulthood. The hormones leptin, kisspeptin and insulin, and their actions on the hypothalamic-pituitary-ovarian axis, have been implicated in the relationship between childhood obesity and the earlier onset of puberty. Obesity in adolescence is also associated with greater menstrual cycle irregularity and the polycystic ovary syndrome (PCOS), which can result in infrequent or absent menstrual periods, and heavy menstrual bleeding. Hyperandrogenism, higher testosterone and fasting insulin levels, and lower levels of sex hormone-binding globulin, similar to the laboratory findings seen in patients with PCOS, are also seen in individuals with obesity, and help to explain the overlap in phenotype between patients with obesity and those with PCOS. Finally, obesity has been associated with higher rates of premenstrual disorders, including premenstrual syndrome and premenstrual dysphoric disorder, and dysmenorrhea, although the data on dysmenorrhea appears to be mixed. Discussing healthy lifestyle changes and identifying and managing menstrual abnormalities in adolescents with obesity are key to reducing the obstetric and gynecologic complications of obesity in adulthood, including infertility, pregnancy complications, and endometrial cancer.