Lifestyle modification is often not enough to treat a chronic disease like diabetes. The majority of patients need medication to maintain a healthy level of blood glucose.

A chief concern among medical practitioners, however, is a drug’s effect on the cardiovascular health of their diabetic patients. Cardiovascular disease (CVD) is a major complication of diabetes. Heart disease and stroke are the No. 1 causes of death and disability among Type 2 diabetic patients. Adults with diabetes are two to four times more likely to have a heart attack and stroke compared to adults without diabetes.

Uncontrolled blood glucose can compromise the blood vessel’s integrity, making them more prone to damage. It can also damage the nerves, producing what is called the “silent” heart attack, a myocardial infarction that does not come with the typical chest pain.

‘End of the line’

Patients with Type 2 diabetes are more likely to have a heart attack or stroke due to contributing risk factors that develop CVD, such as hypertension, high cholesterol and triglycerides, obesity, sedentary lifestyle, uncontrolled blood glucose and smoking.

“The cause of death of most diabetics is still heart disease. A third, more than 30 percent of causes of deaths in the Philippines, are diseases of the heart and vascular system. Double whammy if you’re diabetic,” said Dr. Leni Iboleon, chair of the Philippine Heart Association Council on Women’s Cardiovascular Health, during “Usapang Diabetes: Mga Kwentong Puso Atbp.,” a forum organized by the American pharmaceutical company Merck Sharp & Dohme (MSD).

Iboleon said that according to the Centers for Disease Control and Prevention, up to 20 percent of deaths from heart attack and 13 percent of deaths from stroke are related to diabetes. Heart failure, described by Iboleon as a condition that is “the end of the line” for diabetics, is also two and a half times more common in people with diabetes.

Each reduction in an HbA1c test result, which measures blood glucose of the past three months, reduces the risk for heart disease, Iboleon said. A one percent drop means 21 percent reduction in deaths related to diabetes alone other than heart attack.

“You want to make sure that the drug you use to treat for diabetes will not complicate the risks for heart attacks and stroke. Use drugs that are not only good with controlling the sugar, but also good in protecting the heart, or at least a medication that won’t cause any further damage,” Iboleon said.

‘Tecos’

Sitagliptin, a dipeptidyl peptidase-4 inhibitor introduced in 2006 to treat Type 2 diabetes, has been shown to neither carry risks nor provide benefits for CVD. The trial also demonstrated no incidence of increased hospitalization due to heart failure, compared to the placebo arm.

The study, called Tecos (Trial Evaluating Cardiovascular Outcomes with Sitagliptin), involved 14,671 patients with Type 2 diabetes from 38 countries. It was conducted in November 2008 and concluded in July last year.

The patients, all more than 50 years old, have been living with their diabetes for an average of 11.6 years, and have already experienced diseases such as heart attack, heart failure, stroke, and blockage in the lower extremities. About 22 percent of the subjects are from Asia.

Sitagliptin, a glucose-lowering drug, has been tested under the US Food and Drug Administration rules in 2008 requiring anti-diabetic drugs to be studied for cardiovascular safety. At the time, a number of antidiabetic medications were pulled out in Europe and the US for their adverse effect on the patient’s cardiovascular health.

Tecos was led by an independent academic research collaboration between the University of Oxford Trials Unit and the Duke University Clinical Research Institute, and was sponsored by MSD.

Dr. Mary Anne Lim-Abrahan, professor at the Section of Endocrinology, Diabetes and Metabolism at the University of the Philippines College of Medicine, said that 100 mg of sitagliptin was given to patients, with a corresponding dose adjusted to those with kidney problems (50 mg or 25 mg) for a period of three years, with the longest at 5.7 years.

Abrahan said outcomes included infection causing cardiovascular deaths, nonfatal heart attack, nonfatal stroke, hospitalization for chest pain, and hospitalization for heart failure.

At the conclusion of the study, however, it was demonstrated that sitagliptin caused very low incidence of heart failure, did not increase cardiovascular risk, and did not increase heart failure, infection, pancreatitis, overall cancer, kidney failure or low sugar. Abrahan said there was no difference between the sitagliptin arm and placebo arm.

“Overall, it proved that sitagliptin was better than other drugs of the same class because of the low hospitalization rate for heart failure or chest pain,” Abrahan said.

The incidence of pancreatic cancer was very low in both treatment arms, but it was less frequent among those who received sitagliptin.