By Dr. Mary O’Brien MD
Longitudinal studies clearly indicate that obesity predicts coronary atherosclerosis in men and in women. Hypertension, a leading cause of atherosclerosis, is approximately three times more common in obese individuals than in those who are of normal weight or less than normal weight.
Body mass index (BMI) is one of the most effective ways to measure obesity. Some studies show that a BMI that is between 25 and 30 confers as much as a 70 percent increased risk of coronary heart disease.
However, a high BMI may not entirely predict heart disease risk. In women, a BMI near 30 may still not be of major concern when the increase in fat tissue is distributed over the hips and not the abdomen. Accumulating evidence indicates that an increased waist circumference, or waist-to-hip ratio (WHR), predicts complications and mortality from obesity.
Weight-reduction seems to be effective in reducing risks of coronary heart disease (CHD) and congestive heart failure (CHF), potentially preventing heart disease in obese patients. Evidence indicates that, for obese patients, a reduction of only five percent to 10 percent of body weight improves lipid profiles, insulin sensitivity, and endothelial function. Such a reduction also reduces thrombosis and inflammatory markers.
Maintaining a BMI of less than 25 throughout adult life is a good strategy to reduce the risk of heart disease. For most patients with a BMI between 25 and 30, lifestyle changes in diet and exercise are appropriate.
Restricting consumption of fat to less than 30 percent of total calories should be recommended, because low-fat diets also promote weight reduction. Physical training programs can reduce body mass and help bring about gradual weight loss.
Medical therapy may be necessary in patients with a BMI higher than 30. However, the safety of long-term use of anti-obesity medications has not been established. When the BMI falls within the range of 35 to 40 (or above), bariatric surgery may be an option. Unfortunately, less than five percent of patients are able to maintain their reduced weight four years after surgery. Thus, the prevention of obesity with diet and regular physical activity appears to be the most dependable way to maintain cardiovascular health.