Data from a large French cohort study suggest that women who have a hysterectomy before 40-45 years of age may be at particular risk of subsequently developing type 2 diabetes.
A 20% increase in the risk for incident diabetes was found comparing women of all ages who had and had not had a hysterectomy (P = .0003).
This risk jumped to a 52% increase when only women below the age of 45 were considered (P < .0001) and was still 38% higher if only women under 40 years were analyzed (P = .005).
“Our findings clearly show that hysterectomy is a risk marker for diabetes,” Fabrice Bonnet, MD, PhD, of Centre Hospitalier Universitaire (CHU) de Rennes (France), said at the annual meeting of the European Association for the Study of Diabetes.
Importantly, this risk appears to occur “independently of any hormonal therapy, any reproductive factors, physical activity, and diet,” Dr. Bonnet added.
Findings challenged
“I would like to challenge your findings,” said Peter Nilsson, MD, PhD, a professor at Lund (Sweden) University, during the postpresentation discussion period.
“Could there be a detection bias?” queried Dr. Nilsson. “If you undergo surgery like this, there will be several postoperative visits to a physician and there’s a higher likelihood of somebody taking blood samples and detecting diabetes.
“So, if this is true, it could mean that postoperative controls of goiter or thyroid surgery would bring the same findings,” Dr. Nilsson suggested.
“It is an epidemiological cohort of woman followed for a long time,” Dr. Bonnet responded. “So of course, there probably was more blood testing than in the usual population, but we did not observe the association for another type of surgery and type 2 diabetes.”
Clarifying further, Dr. Bonnet said that they had looked at thyroid surgery but not any other types of abdominal surgery.
Assessing the risk of incident diabetes
Hysterectomy is a common surgery among women – more than 400,000 are estimated to be performed every year in the United States, and 80,000 in France, with a rising rate in developing countries, Dr. Bonnet said in an interview.
“We don’t know exactly why that is, but it could have long-term consequences in terms of metabolic effects and the incidence of diabetes,” he said.
Prior research has linked having a hysterectomy with an increased rate of hypertension and cardiovascular risk, and there have also been a few studies linking it to diabetes.
“Our aim was to analyze the relationship between the past history of hysterectomies and the risk of incident diabetes; and specifically, we assessed the influence of age,” Dr. Bonnet said.
To do so, data on more than 83,000 women who had participated in The French E3N Prospective Cohort Study (E3N) were obtained. This large epidemiologic study is the French component of the long-running EPIC study.
For inclusion in the analysis, women had to have no diabetes at baseline, to have had their uterus, ovaries, or both removed for benign gynecologic reasons, and to have had their surgeries performed before any diagnosis of diabetes had been made. A diagnosis of diabetes was identified through the women’s responses to self-report questionnaires and prescriptions for antidiabetic medications.
In all, 2,672 women were found to have developed diabetes during the 16-year follow-up period.
The hazard ratio for the risk of diabetes in women who had and had not had a hysterectomy was 1.30 (95% confidence interval, 1.17-1.43; P < .0001), taking age into account and stratifying for birth generation.
The association held, when there was adjustment for other factors such as smoking status, physical activity, history of diabetes, weight, and adherence to a Mediterranean diet (HR 1.27; 95% CI 1.02-1.05; P = .02).
And, after adjustment for age at menarche, menopausal status, age at which menopause was reached, oral contraceptive and hormone therapy use, and the number of pregnancies, the risk for type 2 diabetes was still apparent in those who had undergoing a hysterectomy (HR, 1.20; 95% CI, 1.09-1.33; P = .0003).