The results come from the largest meta-analysis of heart disease in male and female diabetics ever reported.
Rachel Huxley, DPhil, of the University of Queensland in Sydney, Australia, and colleagues found that data from 64 studies with both male and female participants yielded a 44% greater multiple-adjusted relative risk ratio (RRR) for incident coronary heart disease (CHD) in women compared with men (RRR 1.44, 95% CI 1.27-1.63).
Pooled data from 52 studies indicated that women also had a 44% greater chance than men of dying from fatal CHD associated with diabetes, Huxley and colleagues reported.
The finding are similar to those seen in a smaller analysis of 37 studies reported by the researchers in 2006. In that study, women with diabetes had a 46% excess risk for fatal CHD compared with men with the disease.
And in a separate analysis published in The Lancet in March, Huxley, co-author Sanne Peters, PhD,of the University of Cambridge, UK, and colleagues found female diabetics to have a 25% greater risk of stroke than male diabetics.
When the studies are combined, the data offer convincing evidence that diabetes poses a greater relative risk for cardiovascular disease and death from cardiovascular causes for women than men.
She said there is growing evidence to support the hypothesis that women have to become sicker than men to be diagnosed with diabetes; specifically that their metabolic and vascular risk factor profiles must deteriorate to a greater extent. Excess body weight is the main risk factor for diabetes. Men have to put on less weight than women to develop diabetes -- on average about 120% of their ideal body weight compared with 160% for women.
This may be because men tend to put on weight around the belly, which is known to be metabolically risky, while women tend to accumulate fat in the thighs and hips. "It may be that women are living in a prediabetic state much longer than men, but because they are not considered to be diabetic their risk factors are not managed as soon."
"We propose that a greater deterioration in cardiovascular risk profile combined with more prolonged exposure to adverse levels of cardiovascular risk factors among prediabetic women compared with their male equivalents, possibly driven by greater levels of adiposity, may be responsible for the excess risk of diabetes-related CHD in women," the researchers concluded. But, "the news is not all bad for women," she said. "We know that small interventions can have a big impact in prediabetes. Losing some weight, adding some exercise, and changing the diet can all stop the progression to type 2 diabetes."
- A systematic review and meta-analysis found that women with diabetes have a significantly greater risk of incident coronary heart disease compared with men with diabetes.
- The explanation of the excess risk in women is not known but it does not appear to be sex disparities in pharmacotherapy.
- Clinicians should closely follow their female patients with prediabetes and encourage them to make the lifestyle changes that can keep them from progressing to diabetes.
Peters SAE, et al "Diabetes as risk factor for incident coronary heart disease in women compared to men: a systematic review and meta-analysis of 64 cohorts including 858,507 individuals and 28,203 coronary events" Diabetologia 2014.