Patients at a high risk of diabetes also have a greater risk of heart disease—but not because of increased sugar levels, according to a study published on Thursday.
The research led by the University of Glasgow in the UK found that higher heart disease risk in such people was largely due to a higher prevalence of other cardiac risk factors such as obesity, higher blood pressure levels and abnormal lipids.
The study, published in the journal Diabetes Care, analysed over 370,000 patients from the UK Biobank, making it the largest single cohort reported to date using patients' measurements of HbA1c average blood glucose (sugar) levels over 2-3 months.
The researchers wanted to assess whether knowing HbA1c levels -- which are increasingly measured in screening for diabetes to assess risk -- could improve heart disease risk assessment.
They found that the near two-fold higher risk for heart disease for those susceptible to diabetes was driven mainly by abnormal levels of conventional heart disease risk factors.
On average such people were around 10 kilogrammes heavier, and their blood pressure was already six units higher, the researchers noted.
They also smoked so they had many other reasons to be at higher risk, well before their sugar levels rose into the diabetes range.
The team noted that people at risk for diabetes are, on average, have 80 per cent greater risk of heart disease compared to those with normal HbA1c levels.
However, such risk is not largely driven by elevated HbA1c, but by differences in the prevalence or levels of other established heart disease risk factors, such as age, blood pressure, smoking, lipid levels, and body mass index (BMI).
"In our study, we found that whilst assessing HbA1c levels adds minimally to cardiovascular risk prediction, those patients at risk for diabetes should have their heart disease risk factors appropriately measured and managed using conventional methods," said Professor Naveed Sattar, from the University of Glasgow.
"Doctors, therefore, should make sure such patients are properly checked for all risk factors as the patients will then better know all their risks and be more motivated to make lifestyle changes which may lessen all these risks," Sattar said.
