Weight gain and increasing diabetes prevalence are hampering efforts to reduce heart attacks and strokes, according to research published today in The Lancet Regional Health – Europe.
Researchers at the London School of Hygiene & Tropical Medicine found that between 1990 and 2014, a decrease in three main risk factors contributed to a decrease in the number of heart attacks and strokes. Progress in further reducing the number, however, has been stalled by increases in body mass index (BMI) and diabetes prevalence over the same period.
The team used Scottish health data to calculate the change in the number of heart attacks and strokes in Scotland between 1990 and 2014. It showed that the number of heart attacks has fallen from 1,069 per 100,000 inhabitants to 276 per 100,000. Ischemic strokes (a type of stroke caused by a blood clot) decreased from 608 per 100,000 to 188 per 100,000 people.
Fall in heart attack and strokes
They found that 74 percent of this decrease in heart attacks and 68 percent in stroke were due to changes in the prevalence of risk factors. This was driven by falls in blood pressure, cholesterol levels, and the rate of smoking.
The average systolic blood pressure fell from 140 mmHg to 129 mmHg, the cholesterol level fell from 6.4 mmol / l to 5.0 mmol / l and the smoking rate among adults has more than halved from 58 percent to 25 percent.
Increase in BMI and diabetes prevalence
However, the average BMI increased from 27.2 kg / m2 to 28.1 kg / m2, and the prevalence of diabetes more than doubled in Scotland during that period, from 4 to 9 percent of the population. This is estimated to have resulted in a 20 percent increase in heart attacks and a 15 percent increase in ischemic strokes due to these two risk factors.
The researchers estimate that increased diabetes prevalence contributed to almost as many heart attacks as the reduction in smoking prevented.
While the team could be confident that changes in risk factors had an impact on the frequency of heart attacks and strokes, in their analysis they looked at each risk factor in isolation, meaning that its estimated effects are likely exaggerated.
The picture is similar across the UK. Figures show that the number of people diagnosed with diabetes and developed obesity has increased over the past few decades. The analysis also shows that the contribution of diabetes to heart and circulatory diseases is increasing. In 1990, the number of deaths from cardiovascular disease-related diabetes was 19 percent. In 2019 it was 26 percent.
Slow down progress
Our Medical Director, Professor Sir Nilesh Samani, said:
“While it is great to see the positive effects public health interventions such as smoking bans have had on the number of people who have suffered heart attacks and strokes over the past 25 years, it is worrying that the rise in BMI and diabetes prevalence is now seems to be slowing progress.
“Obesity is a leading cause of type 2 diabetes, and this study shows the government must pursue the bold promises made in the 2020 obesity strategy.
“Obesity is a complex issue and we cannot rely solely on the willpower and training of individuals to solve the problem of increasing BMI across the population that has helped reduce the burden of cardiovascular disease.”
This research was also supported by the Academy of Medical Sciences.
