BUSAN, SOUTH KOREA – Whether cardiovascular disease risk reduction efforts should be more aggressive in women than men with diabetes depends on how you interpret the data.
Two experts came to different conclusions on this question during a heated, but jovial, debate last week here at the International Diabetes Federation 2019 Congress.
Endocrinologist David Simmons, MB, BChir, Western Sydney University, Campbelltown, Australia, argued that diabetes erases the well-described life expectancy advantage of 4-7 years that women experience over men in the general population.
He also highlighted the fact that the heightened risk is of particular concern in both younger women and those with prior gestational diabetes.
But Timothy Davis, BMedSc, MB, BS, DPhil, an endocrinologist and general physician at Fremantle (Australia) Hospital, countered that the data only show the diabetes-attributable excess cardiovascular risk is higher in women than men, but that the absolute risk is actually greater in men.
Moreover, he argued, at least in type 1 diabetes, there is no evidence that more aggressive cardiovascular risk factor management improves outcomes.
Yes: Diabetes eliminates female CVD protection
Dr. Simmons began by pointing out that, although on average women die at an older age than men, it has been known for over 40 years that this “female protection” is lost in insulin-treated women, particularly as a result of their increased risk for cardiovascular disease.
In a 2015 meta-analysis of 26 studies, women with type 1 diabetes were found to have about a 37% greater risk of all-cause mortality, compared with men with the condition when mortality is contrasted with that of the general population, and twice the risk of both fatal and nonfatal vascular events.
The risk appeared to be greater in women who were younger at the time of diabetes diagnosis. “This is a really important point – the time we would want to intervene,” Dr. Simmons said.
In another meta-analysis of 30 studies including 2,307,694 individuals with type 2 diabetes and 252,491 deaths, the pooled women-to-men ratio of the standardized mortality ratio for all-cause mortality was 1.14.
In those with versus without type 2 diabetes, the pooled standardized mortality ratio in women was 2.30 and in men was 1.94, both significant, compared with those without diabetes.
And in a 2006 meta-analysis of 22 studies involving individuals with type 2 diabetes, the pooled data showed a 46% excess relative risk using standardized mortality ratios in women versus men for fatal coronary artery disease.
Meanwhile, in a 2018 meta-analysis of 68 studies involving nearly 1 million adults examining differences in occlusive vascular disease, after controlling for major vascular risk factors, diabetes roughly doubled the risk for occlusive vascular mortality in men (relative risk, 2.10), but tripled it in women (3.00).
Women with diabetes aged 35-59 years had the highest relative risk for death over follow-up across all age and sex groups: They had 5.5 times the excess risk, compared with those without diabetes, while the excess risk for men of that age was 2.3-fold.
“So very clearly, it’s these young women who are most at risk, “emphasized Dr. Simmons, who is an investigator for Novo Nordisk and a speaker for Medtronic, Novo Nordisk, and Sanofi.