Epidemiology

Epidemiological studies published over the last 50 years have shed light on the many factors that increase cardiovascular disease (CVD) risk. It is now widely accepted that an altered lipid profile including high cholesterol, LDL cholesterol (bad cholesterol), and triglyceride concentrations as well as low HDL cholesterol (good cholesterol), high blood pressure, smoking, and a sedentary lifestyle all increase one’s risk of CVD. Also considered a major CVD risk factor, type 2 diabetes is defined by high blood glucose levels. Though obesity is an acknowledged health hazard and a risk factor for CVD and type 2 diabetes, physicians have long been puzzled by the remarkable heterogeneity seen in clinical practice among individuals with similar excess body weight. Some obese patients have no clinical signs of CVD or type 2 diabetes, whereas other patients—who may be only slightly or moderately overweight—have a metabolic profile that predisposes them to CVD and/or type 2 diabetes. Studies have shown that the risk of CVD and type 2 diabetes does not depend on excess body weight per se, but rather on the location of this excess weight. Excess abdominal fat plays the greatest role in this regard.

Coronary heart disease (CHD) is a major cause of death among adults in most regions of the world. Among adults over 40 years of age, almost half of men and one-third of women will develop CHD in their lifetime. CHD causes half of all cardiovascular events in men and women under 75 years of age. There is now considerable evidence to suggest that most coronary events may be preventable. For instance, the relationship between CHD and traditional risk factors, such as cholesterol and lipid levels, blood pressure, smoking, and a sedentary lifestyle, is well established and has been reported in several populations. Aggressive efforts to assess and control/prevent these major risk factors can significantly reduce CHD morbidity and mortality, increase overall longevity, and ultimately lower healthcare costs.

Read more on Traditional Modifiable CVD Risk Factors.

More and more people are developing diabetes worldwide, and the most common form of diabetes (over 97% of all cases) is type 2 diabetes. A high percentage of patients (65 to 80%) with type 2 diabetes will die from cardiovascular disease (CVD). Although mortality from CVD has been declining in some countries, such has not been the case for diabetic patients. Overall, the absolute risk of coronary heart disease death is roughly three times higher in diabetic patients than in non-diabetic patients. In diabetic patients, heart disease manifests as macrovascular and microvascular complications as well as a series of metabolic abnormalities such as impaired plasma glucose-insulin homeostasis. In this regard, although elevated fasting blood glucose is strongly indicative of type 2 diabetes risk, it plays a lesser role in predicting CVD risk. Evidence available suggests that the clustering risk factors observed in type 2 diabetic patients largely account for their high rates of cardiovascular morbidity and mortality.

Read more on Type 2 Diabetes.

Though most experts agree that soaring obesity rates have played a key role in the rise of chronic complications such as type 2 diabetes, hypertension, and cardiovascular disease (CVD), obesity continues to confound clinicians from both an assessment and management standpoint. One of the main reasons why is obesity’s remarkable heterogeneity. For example, some very obese individuals have normal blood pressure, a normal plasma lipid profile, and normal blood glucose despite having a large amount of fat. However, other individuals with an apparently “healthy” body weight sometimes have a disturbed metabolic risk factor profile. In light of this, it is important to stress the importance of abdominal obesity as the form of overweight/obesity most likely to entail the highest risk of CVD.

Read more on Abdominal Obesity vs. CVD: Beyond Body Weight.

Obesity is frequently linked to metabolic complications that increase the risk of type 2 diabetes and cardiovascular disease. However, obesity is a very heterogeneous condition as not every overweight/obese patient develops metabolic complications leading to type 2 diabetes. Conversely, some individuals with a normal weight and body mass index can nevertheless be at high risk of type 2 diabetes because of their abdominal obesity and the metabolic abnormalities it causes. In this regard, several epidemiological studies in the last decades have stressed that body fat distribution plays a greater role in obesity-related complications than excess body fatness per se. The specific location of body fat is more important than the overall quantity of body fat. In light of this, most experts now agree that a high amount of abdominal fat—visceral fat in particular—increases the risk of type 2 diabetes, cardiovascular disease, and related mortality.

Read more on Abdominal Obesity vs. Type 2 Diabetes: Beyond Body Weight.