NDRI.com

Even Slightly Elevated Fasting Blood Glucose Levels Than Normal Have High Heart Risk

Glucose in the blood is produced by the liver from the foods you eat.In a healthy person, the blood glucose level is regulated by several hormones, one of which is insulin. Insulin is produced by the pancreas, a small organ near the stomach that also secretes important enzymes that help in the digestion of food.In diabetes, glucose in the blood cannot move into cells, and it stays in the blood. This not only harms the cells that need the glucose for fuel, but also harms certain organs and tissues exposed to the high glucose levels.

When you have diabetes, the sugar builds up in your blood instead of moving into the cells. Some, but not all, of the excess sugar is carried out of your body (through urine), and the energy is wasted.

Prediabetes is a condition in which your blood sugar level is higher than normal, but not high enough to be classified as type 2 diabetes. It's a condition that occurs when the blood glucose (blood sugar) levels are higher than normal but not high enough to be diagnosed as diabetes. lt's also called impaired fasting glucose or impaired glucose tolerance. Prediabetes shouldn't be taken lightly. It means that you're at risk of developing type 2 diabetes, heart disease and stroke.

Diabetes mellitus is the most prominent disease related to failure of blood sugar regulation.A fasting blood sugar test measures the amount of sugar in your blood after you fast for at least eight hours or overnight.If your fasting blood sugar level is 100 mg/dL to 125 mg/dL, you have impaired fasting glucose — commonly known as prediabetes.In fact, long-term damage to the cardiovascular system may occur while a person has prediabetes.

People with pre-diabetes can prevent the onset of diabetes with the help of exercise, weight loss and diet changes.For people with diabetes, that might be very difficult because they really need to watch portion size, when they’re drinking and how much, and pay attention to how stress affects their blood sugar levels.

Since higher glucose levels are tied to such serious health conditions, it is important that we monitor these levels in people who appear to be at higher risk, such as people whose blood pressure does not drop significantly overnight.

Heart disease isn't generally thought of as a young person's disease, but being young and physically fit is no guarantee the arteries that keep your heart pumping aren't blocked.The U.S. Department of Health and Human Services recommends that everyone who is overweight and older than 45 be tested for prediabetes. However, if you're younger than 45, overweight and have one or more other risk factors, such as high blood pressure, high cholesterol or are in one of the high risk factors.

Fasting glucose levels may independently predict the risk of being hospitalized with congestive heart failure in heart attack survivors and others who are at high risk of developing the disorder, researchers reported in Circulation: Journal of the American Heart Association.

Drawing on data from 31,546 high-risk patients participating in two international trials, researchers found that even small increases in fasting glucose raised the risk of congestive heart failure in both diabetes patients and those whose blood sugar fell within the normal range.

“This illustrates that blood glucose by itself is a continuous risk factor for developing heart failure because all of these patients were free of heart failure when they enrolled in the trials,” said Claes Held, M.D., Ph.D., lead author of the study.

“However, these are only associations,” said Held, an associate professor of cardiology at the Karolinska Institutet in Stockholm, Sweden. “They do not prove that elevated blood glucose causes heart failure. To demonstrate a causal relationship, you would have to do a study that showed lowering blood glucose levels would reduce the incidence of heart failure.”

About 5.2 million Americans evenly divided between males and females suffer from heart failure, according to the American Heart Association. Each year about 550,000 new cases are diagnosed and about 57,700 people die from it. Heart failure is a debilitating condition in which the heart fails to pump an adequate supply of blood throughout the body.

Established heart failure risks include uncontrolled high blood pressure, diabetes and heart attack.

To examine the relationship between blood glucose levels and congestive heart failure, Held and colleagues performed an interim analysis on the blinded data from the ONgoing Telmisartan Alone and in combination with the Ramipril Global Endpoint Trial (ONTARGET) and Telmisartan Randomized AssessmeNt Study in aCE intolerant subjects with cardiovascular Disease (TRANSCEND) trials. Both were randomized, controlled, parallel clinical studies testing drug regimens aimed at reducing fatal and nonfatal cardiovascular events. ONTARGET had 25,620 patients enrolled and TRANSCEND had 5,926, and both included patients with and without diabetes. Researchers obtained fasting blood glucose levels for patients when they entered the trials and periodically thereafter.

“We know that diabetes is a strong risk factor for cardiovascular disease including heart failure, but these studies included patients with and without diabetes,” Held said. “This was a great opportunity to evaluate a broad population of high-risk individuals and study the association between blood glucose and cardiovascular disease, regardless of the diabetic state.”

Patients in the two trials were average age 67 at entry, and 69 percent were men. Thirty-seven percent had been previously diagnosed with diabetes and 3.2 percent were diagnosed with the disease at the time of entry.

Patients were assigned to five groups based on their entry fasting blood glucose levels, measured in millimoles per liter of blood, or mmol/L. The lowest group had an average fasting blood glucose of 4.6 mmol/L and the highest had an average reading of 8.5 mmol/L.

The mmol/L is the international standard unit for measuring blood glucose. In the United States, blood glucose levels are usually reported in milligrams per deciliter, mg/dL. Multiplying the number of mmol/L by 18 converts the number to mg/dl.

Researchers analyzed data from patients with an average follow-up of 2.4 years. During this time there were:

1,067 cardiovascular deaths
926 heart attacks
823 strokes
668 hospitalizations for congestive heart failure

When the researchers examined fasting blood glucose levels alone as a risk factor by adjusting for other known risk factors, they found that, for all patients, an increase of 1 mmol/L above a patient’s entry glucose level increased the risk of hospitalization for congestive heart failure by 5 percent.

Similarly, a 1 mmol/L rise increased the risk of congestive heart failure hospitalization or cardiovascular death by 9 percent for all patients, by 3 percent for patients without diabetes and by 5 percent for patients with diabetes.

“Even in the normal range, our results indicate that elevated blood glucose is associated with the risk of heart failure,” Held said. “You can look at blood glucose much like blood pressure or cholesterol. Even if you have normal blood glucose, there is a gradual increase in risk wherever you start on the scale. If the blood sugar is “high normal” there is a higher risk than those with “low normal fasting blood glucose levels.”

He and colleagues suggested several potential mechanisms for rising glucose levels which increase the risk of developing congestive heart failure.

“Individuals with disturbances in their glucose regulation usually have more coronary artery disease, which is a well known underlying risk factor for heart failure,” Held said. “That is a strong explanation for our findings but the others are more speculative and hypothetical.”

Co-authors are Hertzel C. Gerstein, M.D.; Salim Yusuf, M. D., D. Phil.; Feng Zhao, M.Sc.; Lutz Hilbrich, M.D.; Craig Anderson, Ph.D.; Peter Sleight, M.D.; and Koon Teo, M.D., Ph.D.

Held did the research during a sabbatical at Population Health Research Institute at McMaster University, Hamilton, Canada who originally initiated the trials. Boehringer-Ingelheim Pharma GmbH is the main sponsor of the study, a megatrial designed to study the secondary prevention of cardiovascular events in patients at high risk.

Many people with some of the less alarming symptoms ignore them. The signs may have come on slowly, and so may have seemed like a natural part of the aging process. It's also possible that the affected person simply failed to recognize the symptoms or was in denial.

Whatever the reason, ignoring signs that suggest diabetes is risky business. Diabetes is no minor troublemaker but a really bad actor whose cumulative damage often sets the stage for amputations, blindness, kidney failure, heart disease, stroke, and death. Indeed, diabetes currently kills about two-thirds as many U.S. women as breast cancer and has become the Western Hemisphere's sixth leading cause of death.