Blood pressure linked to diabetes in global study

High blood pressure sufferers have an almost 60% greater chance of developing diabetes, according to a major global study, released today.

Study author Professor Kazem Rahimi, Deputy Director of the George Institute for Global Health UK, said that in face of earlier conflicting and inconclusive reports, this study now reliably shows the connection between high blood pressure and diabetes and it could lead to new insights and strategies for treating and reducing the chances of developing diabetes.

“This is potentially a game changer in the understanding and treatment of diabetes,” Prof Rahimi said.

“Diabetes affects more than 400 million people worldwide, and we know that diabetics are more likely to suffer from cardiovascular disease such as heart attacks, stroke and heart failure.

“High blood pressure affects even more people.

“Confirming this connection reliably provides new hope for those people and new avenues for research.

“We can’t say for certain that one causes the other, but this study helps to connect the dots, showing that if you have high blood pressure there is a significantly greater chance of developing diabetes.

“Understanding the link will help us better communicate risks to patients and can provide another motivation for patients and doctors to aim for tight blood pressure control.”

Professor Rahimi said that the link between hypertension and fatal heart issues had been well documented, but the connection to diabetes had been less clear.

“Previous smaller studies have varied significantly or even found no link, but now we have something clear to go on,” he said.

The study, which has been published in the Journal of the American College of Cardiology (JACC), looked at the health records of 4.1 million adults in the UK who were initially free of diabetes and cardiovascular disease and found:

• For every 20 mm mercury increase on the measurement gauge, in systolic blood pressure there was a 58% higher risk of developing diabetes.
• For every 10 mm mercury increase in systolic blood pressure there was a 52% higher risk of developing diabetes
• Higher blood pressure was also associated with a higher risk of new onset diabetes in a wide variety of groups of individuals, including men and women, people of young (30-50), middle (51-70) and old age (71-90) as well as normal weight, overweight and obese individuals
• The relative association between blood pressure and diabetes decreased as body mass index (BMI) and age increased but absolute effects were higher in the elderly and overweight.

Professor Rahimi said the research also pooled together 30 prior studies that examined risk factors for diabetes.

“There were similar results in this section of the research with a 77% higher chance of getting diabetes for every 20 mm increase of mercury in systolic blood pressure,” he said.

“Using the two complementary approaches has given us even greater confidence in the results.”

Professor Rahimi said researchers could now examine the causal relationship between blood pressure and diabetes.

“At a minimum we know for certain that the link exists, but is high blood pressure a cause of diabetes or just a risk factor? We still don’t know,” he said.

“In particular researchers can now look at whether lowering blood pressure is an effective treatment or reduces the risk of getting diabetes.

“These are exciting results and I look forward to seeing further developments because of this research.”

The study was conducted by The George Institute for Global Health, with support from the Oxford Martin School at the University of Oxford, the NIHR Oxford Biomedical Research Centre and NIHR Career Development Fellowship.

The paper Usual blood pressure and risk of new onset diabetes: evidence from 4.1 million adults and a meta-analysis of prospective studies, can be found on the Journal of the American College of Cardiology at http://content.onlinejacc.org/journal.aspx