Diabetes-related heart failure risk greater in women than men
Women with diabetes appear to be at a greater risk of heart failure than men with diabetes, according to a recent study.
“It is already known that diabetes puts you at greater risk of developing heart failure but what our study shows for the first time is that women are at far greater risk – for both type 1 and type 2 diabetes,” said study lead author Dr Toshiaki Ohkuma from The George Institute for Global Health, New South Wales, Australia.
Ohkuma and co-authors conducted a systematic review of observational studies published between January 1966 and November 2018 that assessed the association between diabetes and heart failure with sex-specific analysis. The meta-analysis was conducted on 47 cohorts comprising 12,142,998 individuals from 10 countries. A total of 253,260 incidents of heart failure were recorded in this population. Diabetes that was not differentiated by type in the studies were categorized as type 2 diabetes (T2D).
Women with type 1 diabetes (T1D)* had a more than fivefold risk of heart failure (adjusted risk ratio [adjRR], 5.15, 95 percent confidence interval [CI], 3.43–7.74; p<0.001) compared with those without diabetes, while men had a threefold risk (adjRR, 3.47, 95 percent CI, 2.57–4.69; p<0.001). The risk of heart failure associated with T1D was 47 percent higher in women than men (women-to-men ratio [adjRRR], 1.47, 95 percent CI, 1.14–1.90; p=0.003). [Diabetologia 2019;doi:10.1007/s00125-019-4926-x]
T2D had less of an effect on heart failure than T1D, with a smaller difference in impact between sexes, though women were still at a 9 percent greater risk than men (adjRR, 1.95, 95 percent CI, 1.70–2.22; p<0.001 [women] vs adjRR, 1.74, 95 percent CI, 1.55–1.95; p<0.001 [men]; adjRRR, 1.09, 95 percent CI, 1.05–1.13; p<0.001).
Subgroup analysis showed that this increased risk among women vs men was consistent regardless of study region (Asia or non-Asia; p=0.29), year of baseline study (p=0.87), ascertainment of diabetes (self-reported or otherwise; p=0.72), or outcome (fatal or combination of fatal and non-fatal; p=0.41).
According to the authors, previous meta-analyses showed a greater risk of other diabetes-related complications among women vs men, including coronary heart disease (CHD), stroke, and cancer. [Diabetologia 2014;57:1542-1551; Lancet 2014;383:1973-1980; Diabetologia 2018;61:2140-2154]
“[The present findings] are in agreement with the previous evidence … and shed light on the importance of a routine sex-specific approach both in research and clinical practice in this field,” they said.
Among the reasons cited for the greater heart failure risk in women than men were an extended exposure to hypoglycaemia and undertreatment, said the authors.
“Women were reported to have two years’ longer duration of prediabetes than men and this increased duration may be associated with greater excess risk of heart failure in women,” said study co-author Dr Sanne Peters from The George Institute for Global Health at the University of Oxford, Oxford, UK.
“Some major concerns are that women are also being undertreated for diabetes, are not taking the same levels of medications as men, and are less likely to receive intensive care,” she added.
Another possible reason is the higher risk of CHD, “a major cause of heart failure in people with T2D”, in women than men, a factor that may also play a role in the difference in impact conferred by T1D and T2D on heart failure, the authors said, citing a previous meta-analysis which showed a stronger sex-specific effect of T1D than T2D on CHD risk (women-to-men RRR, 2.54 vs 1.44). [Lancet Diabetes Endocrinol 2015;3:198-206]
“[These results] highlight the importance of intensive prevention and treatment of diabetes in women,” noted Ohkuma.
“Further research is required to understand the mechanisms underpinning the excess risk of heart failure conferred by diabetes [particularly T1D] in women and to reduce the burden associated with diabetes in both sexes,” said the authors, highlighting that factors such as duration of diabetes, diabetes medications, glycaemic control, and heart failure phenotype will be taken into consideration in future studies.