Type 2 diabetes: losing even a small amount of weight may lower heart disease risk
People with type 2 diabetes are often encouraged to lose weight. And recent studies have shown that losing a lot of weight can reverse diabetes, meaning the person no longer has to take drugs to treat their disease. Unfortunately, most people struggle to lose large amounts of weight and keep the weight off. However, there has been little research on the impact of losing a moderate amount of weight – which would be an easier goal for most people.
Our team assessed weight change in 725 people who were newly diagnosed with type 2 diabetes. The participants had their weight measured at the time of their diagnosis and again one year later. We focused on weight loss in the year after a diabetes diagnosis, as weight loss early on may be more beneficial than weight loss later.
People who lost at least 5% of their weight in the year after they were diagnosed with type 2 diabetes had a 48% lower risk of cardiovascular disease after ten years, compared with people who kept the same weight. People who lost weight also had significantly lower blood glucose (sugar), blood pressure and cholesterol levels one year after they received a diagnosis compared with people who kept the same weight. The results couldn’t be explained by age, sex, smoking or medication as these “confounders” were taken into account in our analysis.
The sooner, the better
While our study showed potential long-term benefits of just 5% weight loss, past research has mostly focused on larger amounts of weight loss. In a US study, people with type 2 diabetes who lost 10% of their weight in one year had lower rates of cardiovascular disease after ten years compared with people who maintained their weight or gained weight.
But unlike the participants in our study, participants in the US study were not newly diagnosed with diabetes. They had, on average, been diagnosed seven years before the study started. It is possible that smaller amounts of weight loss soon after diabetes diagnosis may be just as beneficial as larger amounts of weight loss later on.
Our study participants were from the east of England and most were white, so the results may not apply to other populations. Also, most participants in the study were overweight or obese at the time of diabetes diagnosis. So the results don’t suggest that people with diabetes who are a normal weight or underweight should lose weight. However, our findings emphasise the potential benefits of even modest weight loss for people with type 2 diabetes.
Being diagnosed with type 2 diabetes may inspire some people to make changes to their lifestyle to try and lose weight. Intensive diet and exercise programmes have been shown to help people with diabetes to lose weight. Unfortunately, there are no established guidelines in the UK for doctors to provide patients with weight-loss support and most patients don’t have access to these programmes.
Yet evidence from our study suggests that some people can lose weight after being diagnosed and hence lower their risk of cardiovascular disease, even without a weight-loss support programme. So people with type 2 diabetes may want to consider focusing more attention towards setting moderate weight-loss goals.
Jean Strelitz receives funding from the Medical Research Council.