Diabetes increases heart failure risk, particularly in women

The study, published in the European Association for the Study of Diabetes journal Diabetologia, found that the risk of heart failure associated with diabetes is significantly greater in women.

The large-scale research from The George Institute for Global Health involved a review of 14 studies linking diabetes and heart disease published between 1966 and 2018. In total, the review involved 12 million people and 253,260 cases of heart failure. The researchers found that diabetes was a much greater risk factor for heart failure in women than in men.

Diabetes is one of the leading causes of cardiovascular disease, blindness, kidney failure and lower limb amputation.

Type 1 typically presents in children or young adults, affecting around 1 in 300 people in the UK. It is thought to be an autoimmune disease in which the pancreas stops producing insulin and blood sugar levels go very high. It is treated with insulin injections and a healthy lifestyle.

Type 2 diabetes occurs mostly in people over 40, and mostly in people who are overweight or obese. Unlike in type 1 diabetes, you still make insulin, either not enough for your body's needs or your body does not use insulin properly. Nine in 10 people with diabetes have type 2. The first-line treatment is diet, weight control and exercise. Of the 415 million adults living with diabetes worldwide, 199 million are women.

In the study, type 1 diabetes was associated with a 47% increased risk of heart failure for women compared with men. Women with type 2 diabetes saw a smaller increased risk of 9%.

Scientists have long been aware of the heightened risk of heart failure for people with diabetes but this research suggests that the link between sex and risk should also be taken into account in research and treatment. The research did not explain the reason for the difference in risk between diabetes types. Women with type 1 diabetes are over five times more likely to have heart failure than those without diabetes. For men, the risk is 3.5 times higher than the general population.

Of the reasons cited for the gap in the risk of heart failure for diabetic women, were later diagnosis and lower levels of treatment, explained co-author of the study, Dr Sanne Peters, of The George Institute for Global Health at the University of Oxford.

"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. 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," said Peters.

The International Diabetes Foundation has also found that inequalities such as gender roles, power imbalance and socio-economic disparities can result in poor diet and decreased physical activity, making them more vulnerable to diabetes.

Lead author and research fellow Dr Toshiaki Ohkuma from The George Institute encourages further research into heart failure in diabetic women. "The increased risk of heart failure following a diabetes diagnosis is significantly greater in women than men which highlights the importance of intensive prevention and treatment of diabetes in women. Further research is required to understand the mechanisms underpinning the excess risk of heart failure conferred by diabetes [particularly type 1] in women and to reduce the burden associated with diabetes in both sexes."

This study was published in Diabetologia.