Even prediabetics at increased risk of stroke, heart attack: Study

Key findings of the study include:

• Serious cardiovascular events occurred in 18% of people with prediabetes compared with 11% of people with normal blood sugar levels over a median of five years follow-up.
• The relationship between higher blood sugar levels and cardiovascular events remained significant even after taking into account other factors that could play a role, such as age, gender, body mass index, blood pressure, cholesterol, sleep apnea, smoking and peripheral artery disease.
• The relationship between prediabetes and events were strongest among males, Blacks and people with a family history of cardiovascular disease or personal risk factors for heart disease.
• People who were overweight had the highest rates of cardiovascular events among all patients, even more than those who were obese.

"In general, we tend to treat prediabetes as no big deal. But we found that prediabetes itself can significantly boost someone's chance of having a major cardiovascular event, even if they never progress to having diabetes," said Adrian Michel, MD, internal medicine resident at Beaumont Hospital-Royal Oak, MI, and lead author of the study, which he said is one of the largest to date. "Instead of preventing diabetes, we need to shift focus and prevent prediabetes."

"Based on our data, having prediabetes nearly doubled the chance of a major adverse cardiovascular event, which accounts for 1 out of 4 deaths in the U.S.," Michel said. "As clinicians, we need to spend more time educating our patients about the risk of elevated blood sugar levels and what it means for their heart health and consider starting medication much earlier or more aggressively, and advising on risk factor modification, including advice on exercise and adopting a healthy diet."

Of particular concern was the finding that even when patients in the prediabetes group were able to bring their blood sugar level back to normal, the risk of having a cardiovascular event was still fairly high. Events occurred in just over 10.5% of these patients compared with 6% of those with no diabetes or prediabetes.

"Even if blood sugar levels went back to normal range, it didn't really change their higher risk of having an event, so preventing prediabetes from the start may be the best approach," Michel said.

The study findings are an important reminder for adults to know their blood sugar numbers, especially as prediabetes usually has no symptoms. As with diabetes, prediabetes is diagnosed based on results from blood sugar tests, including an A1C, which reflects someone's average blood sugar for the past two to three months; a fasting plasma glucose test, which measures your blood sugar after not eating or drinking for at least eight hours beforehand; and/or an oral glucose tolerance test, which checks how well the body processes sugar after drinking a sweet drink given by the clinician.