Women with abnormally long menstrual cycles of 40 days or more, a condition known as oligomenorrhea, are at a higher risk for developing type 2 diabetes, according to a study published in the Journal of the American Medical Association.
The study followed 101 073 women from 1989 to 1997 who recorded their menstrual cycles and reported any diagnosis of type 2 diabetes. At the incipience of the study, the women ranged in age from 18 to 22 years. 507 cases of diabetes were reported.
Adjusting for body mass index, oral contraceptive use, and other variables, the researchers found that women who reported oligomenorrhea were statistically far more likely to develop diabetes than women whose menstrual cycles were normal or shorter than usual (less than 21 days), regardless of obesity or family history of the disease.
Oligomenorrhea can be a symptom of polycystic ovary syndrome (PCOS), a condition involving elevated levels of hormones and enlarged ovaries that is associated with irregular periods, obesity, infertility, glucose intolerance and insulin resistance.
Women who are not diagnosed with PCOS but still experience long menstrual cycles can still be at a greater risk for diabetes, especially if high levels of testosterone are present in the body. However, women who have irregular periods due to low body fat, poor caloric intake and intense exercise are excluded from this risk group.
Women who experience oligomenorrhea, irregular periods or who are diagnosed with PCOS should check with their doctors about diabetes screening to prevent possible complications.
Sources: Caren G. Solomon, MD et al. "Long or Highly Irregular Menstrual Cycles as a Marker for Risk of Type 2 Diabetes Mellitus." JAMA. 2001;286:2421-2426. Vol. 286 No. 19, November 21, 2001.