Obesity has most pronounced effects on the cardiovascular system. weight loss surgery is ideal in the control or resolution of many diseases of heart and blood vessels.
Hypertension is one of the commonest diseases associated with obesity and up to 70% of the patients undergoing weight loss (bariatric) surgery have hypertension. It occurs due to increased tone of blood vessels, retention of sodium and water resulting from hormonal changes and insulin resistance. The obesity surgery has been found to reduce the requirement of anti-hypertensive drugs in 18-36% cases and improves or resolves it completely in up to 50% patients.
Hyperlipidaemia is present in half of obese patients and is a risk factor for atherosclerosis and coronary disease. The triglycerides and total cholesterol reduce and there is an increase in HDL cholesterol after obesity surgery. These changes are maximal after Roux-en-Y gastric bypass.
Congestive heart failure may occur in obese patients due to high cardiac output and circulating volume of blood. After obesity surgery, the cardiac performance improves and is demonstrable by a reduction in the thickness of left ventricle of heart. The ejection fraction of left ventricle (fraction of blood ejected during contraction of left ventricle) also improves.
Coronary artery disease is more common in patients with morbid obesity. After the weight loss surgery, the blood flow in the coronary arteries improves as demonstrated by transthoracic Doppler echocardiography. The risk of coronary artery disease is reduced by 39% in men and 25% in women after weight loss surgery induced resolution of hypertension.
Atherosclerosis in obese people is related to insulin resistance, hyperglycemia, diabetes and hypertension. Obesity surgery has been proven to decrease or reverse fatty plaque deposition in the blood vessels. In a scientific study it was found that 18 months after obesity surgery, the thickness of blood vessels reduced and flow mediated dilatation improved. All these factors result in improved long term survival.
