Nearly 30% of patients with coronary artery disease have diabetes, according to a large study published on World Health Day in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).¹ That compares to a diabetes prevalence of around 9% in the general population.² There was wide geographical variation, with 60% of heart disease patients in Gulf countries having diabetes compared to 20% in Europe.

“Obesity and lack of exercise are common risk factors for both diabetes and heart disease and our results highlight the urgent need to improve nutrition and raise activity levels globally,” said study author Dr. Emmanuelle Vidal-Petiot of Bichat-Claude Bernard Hospital, Paris, France. “Countries worst affected by diabetes are also at the epicentre of the obesity epidemic, which can be in part attributed to urbanisation and associated changes in physical activity and food intake.”

This was an analysis of the CLARIFY registry, which included 32,694 patients with chronic coronary syndromes from 45 countries in Europe, Asia, America, the Middle East, Australia, and Africa. Patients were enrolled in 2009 to 2010 and followed up yearly for five years.

All adverse clinical outcomes measured in the study occurred more frequently among heart patients with diabetes compared to those without diabetes. When the researchers compared the likelihood of poor outcomes in those with diabetes compared to those without, they adjusted the analyses for multiple factors that could influence the relationship including age, sex, smoking status, body mass index, blood pressure, medications, and other conditions.

After these adjustments they found that among patients with stable coronary heart disease, those with diabetes had a 38% higher rate of death during the five-year follow-up. They also had a 28% higher risk of the combined outcome of heart attack, stroke, or death from a cardiovascular cause. Heart patients with diabetes had worse outcomes than those without diabetes regardless of geographic region and ethnicity.

Dr. Vidal-Petiot said: “Diabetes was linked with worse outcomes even in areas with the lowest prevalence. In Europe, for instance, diabetes was linked with a 29% greater risk of the combined outcome of heart attack, stroke, or cardiovascular death. This indicates that management of these very high-risk patients with heart disease and diabetes should be improved. Each country needs to identify these patients and provide tailored educational and prevention programmes.”

She concluded: “The importance of healthy eating and living cannot be overemphasised. Everyone can lower their chances of developing diabetes with weight control and exercise, and early detection is needed so that blood sugar can be controlled. Those with heart disease and diabetes also need an active lifestyle and a good diet to protect their health. Avoiding smoking is crucial, as is controlling blood pressure and cholesterol levels.”

A new biomarker of insulin resistance was tied to a 600 percent increase in risk of premature coronary heart disease

While deaths related to heart disease have declined among older people, studies suggest that death rates among younger patients have remained stagnant or increased slightly. To understand what factors put younger individuals at higher risk of premature coronary heart disease (CHD), researchers from Brigham and Women’s Hospital and the Mayo Clinic analyzed more than 50 risk factors in 28,024 women who participated in the decades-long Women’s Health Study. Notably, women under 55 with type-2 diabetes had a tenfold greater risk of having CHD over the next two decades, with lipoprotein insulin resistance (LPIR) proving to be a strong, predictive biomarker as well. Findings are published in JAMA Cardiology.

“We’re going to see, unfortunately, younger and younger people having heart attacks,” said corresponding author Samia Mora, MD, MHS, of the Brigham’s Center for Lipid Metabolomics in the Division of Preventive Medicine and an associate professor at Harvard Medical School. “When a younger individual has a cardiovascular event, it will affect their quality of life going forward, their productivity, and their contribution to society.”

“Prevention is better than cure, and many risk factors for heart disease are preventable. This study shows the impact that lifestyle has on heart health in women of all ages, and younger women in particular,” said Sagar Dugani, MD, PhD, a hospital internal medicine practitioner at Mayo Clinic in Rochester, MN. Dr. Dugani is a co-first author of the study.

The researchers analyzed approximately 50 biomarkers associated with cardiovascular health. Commonly used metrics like low-density lipoprotein (LDL) cholesterol (or “bad” cholesterol) and hemoglobin A1C (a measure of blood sugar levels) had much weaker associations with CHD onset in women younger than 55 years than LPIR, a newer metric for insulin resistance. LPIR uses a weighted combination of six lipoprotein measures and is analyzed through specialized laboratory testing. Whereas LDL cholesterol was only associated with a 40 percent increase in risk of CHD onset in women under 55, LPIR demonstrated a sixfold (600 percent) increase.

“In otherwise healthy women, insulin resistance, type-2 diabetes, and its sister diagnosis, metabolic syndrome, were major contributors to premature coronary events,” said Mora. “Women under 55 who have obesity had about a fourfold-increased risk for coronary events, as did women in that age group who smoked or had hypertension. Physical inactivity and family history are all part of the picture as well.”

The researchers acknowledged the study is limited in its generalizability — beyond its focus on women, who have been shown to have worse outcomes after premature cardiac events than men, its participants were over 95 percent white. According to Mora, findings could be even more dramatic in ethnic and racial groups that have a greater prevalence of metabolic syndrome, insulin resistance and diabetes, among other risk factors.

“Diabetes is mostly preventable, but it’s a systems-wide problem, and we urgently need further research into new strategies to address it,” Mora said. “These could be innovative lifestyle-based strategies, like community efforts, greater public health efforts, ways to medically target metabolic pathways, or new surgical approaches.”

With the prevalence of diabetes and its associated risk factors increasing dramatically, and affecting more women than men, the researchers emphasize the urgency of developing effective interventions.

We need new strategies to improve outcomes in these younger individuals and address the risk of diabetes, because we’re only seeing the beginning of this epidemic now,” said Mora.