Obesity is an increasingly prevalent metabolic disorder affecting our population. Fatness is associated with a number of comorbidities, including several forms of heart disease, according to Dr Rupesh Singh, Specialist Cardiologist, Zulekha Hospital, Sharjah.
Heredity explains 30-70 per cent of cases of obesity and remaining are contributed by environmental factors in form of increase in total caloric intake and reduced physical activity. Body mass index (BMI) is defined as weight in kilograms divided by height in meters squared (kg/m2). A BMI above 25 is considered as marker of obesity.
Until recently the relation between obesity and coronary heart disease was viewed as indirect in form of co-morbidities like hypertension, dyslipidemia and diabetes. Studies, however, indicate that obesity as such not only relates to but independently predicts coronary atherosclerosis.
Hypertension is approximately three times more common in obese than normal-weight persons. Left ventricular hypertrophy is common in patients with obesity and to some extent is related to systemic hypertension. The changes in the left ventricle are related to sudden death in obese patients. Changes in the right heart also occur in obese people and are related to obstructive sleep apnea and/or the obesity hypoventilation syndrome which produce pulmonary hypertension.
In patients with congestive heart failure, sodium restriction and small reductions in weight may dramatically improve ventricular function and oxygenation. Several studies suggest that the more extensive weight reduction that follows gastrointestinal surgery for obesity reduces cardiovascular mortality.
Treatment of obesity should be based on its severity and presence of comorbidities eg congestive heart failure, dyslipidemia, hypertension, non–insulin dependent diabetes, and obstructive sleep apnea. Maintaining a BMI <25 throughout adult life has been recently recommended. For most patients with a BMI between 25 and 30, lifestyle modifications including diet and exercise are appropriate. Diets should be modestly restricted in calories; evidence suggests that obese patients who have slower rates of weight reduction have the same long-term outcomes as patients undergoing more rapid weight reduction.
Pharmaceuticals should be considered with a BMI >30. If the risk from obesity is sufficiently serious to indicate use of anti-obesity drugs, long-term use should be anticipated. When the BMI is >35 and comorbidities exist, gastrointestinal surgery becomes a consideration. When the BMI is >40, surgery is the treatment of choice. Prevention of obesity by diet and regular physical activity remains the highest priority for maintaining cardiovascular health. This is particularly important for small children and adolescents.