Long menstrual cycles may be diabetes risk
30 November 2001
Women with highly irregular or long menstrual cycles face a significantly increased future risk for developing type 2 diabetes mellitus, new research suggests.
In the study, reported in the Journal of the American Medical Association (2001; 286: 2421-2426), US researchers studied data from more than 100,000 women involved in the Nurses' Health Study, and found that women with irregular or 40-plus day cycles had about twice the future risk of type 2 diabetes compared with women with average cycles.
The risk was greatest in obese women, but was also increased in non-obese women. (Relative risk was 1.67 in average weight women with a body mass index (BMI) less than 25; 1.74 in women with a BMI between 25-29 and 3.86 in women with a BMI of 30 or above.)
This means that average weight women with long or irregular cycles had 1.67 times the future risk of developing type 2 diabetes of average weight women with average cycles. It also means that obese women (with a BMI of 30 or more) with long or irregular cycles have 3.86 times the future risk of developing type 2 diabetes of those average weight women with average cycles.
Dr Pat Phillips, senior director of endocrinology at North West Adelaide Health Service, said it was known that central obesity, or 'apple-shaped' obesity in women was associated with metabolic syndrome, also known as insulin-resistant syndrome or Syndrome X.
'It's also associated with insulin resistance, hypertension (high blood pressure), dyslipidemia (high cholesterol), polycystic ovary syndrome and increased cardiovascular risk.'
Dr Phillips said women with polycystic ovary syndrome were also very prone to developing type 2 diabetes.
'One of the most likely diagnoses in women who have irregular or long periods is polycystic ovary syndrome, and that tends to be more prevalent in overweight and obese women - both of which are a risk factor for type 2 diabetes.'
He said that lifestyle modifications such as 'walking more and eating less' could be useful for women with long or irregular periods, those with polycystic ovary syndrome, or those who were overweight or obese, to reduce future risk of type 2 diabetes.
Last Reviewed: 27 November 2001
- Medical Observer Weekly 30 November 2001
