Review on January 22, 2008
A recent study in the Journal of the American Medical Association (JAMA) suggests that irregular periods, or abnormally long and light menstrual cycles of over 40 days (oligomenorrhea) may be associated with increased risk for type 2 diabetes.
The report tracked 101 073 women from 1989 to 1997 who reported their menstrual cycles and related any diagnosis of type 2 diabetes. At the beginning of the article, the women ranged in age from 18 to 22 years. 507 cases of diabetes were confirmed. Taking into account body mass index, oral contraceptive use, and other variables, the researchers found that women who experienced 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 disorder involving elevated levels of hormones and enlarged ovaries that is associated with irregular periods, irregular menstrual cycles, 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, particularly if high levels of testosterone are present in the body. However, women who have long or light menstrual cycles due to body mass index, poor caloric intake and excessive exercise are excluded from this risk group.
Conclusion: Irregular periods thus may warrant greater attention from doctors when screening patients for diabetes.