Abstract and Introduction
Abstract
Rates of obesity and overweight continue to rise and substantially increase the risk of morbidity and mortality from type 2 diabetes, coronary heart disease and stroke. On the other hand, a sustained weight loss of 5-10% in the obese confers marked health benefits. Current strategies for the management of obesity include lifestyle interventions and pharmacotherapy. At present, three drugs are approved for the medical management of obesity in the UK: orlistat, sibutramine and rimonabant. All three agents are efficacious in reducing body weight but by different mechanisms. Although weight loss is an important treatment outcome, a major goal of obesity management should be to improve cardiovascular and metabolic risk factors in order to reduce obesity-related morbidity and mortality. Given the similar levels of weight loss achievable with currently approved agents, treatment decisions should include careful assessment of the effects of these agents on cardiovascular and metabolic risk factors and on their long-term safety profiles.
Introduction
Rates of obesity have dramatically increased in the UK over the past two decades. Data from the ongoing Health Survey for England highlight the trend. In 1980, 6% of men and 8% of women were estimated to be obese (BMI > 30 kg/m). By 2005, the proportion of men and women classed as obese had increased to 22.1% and 21.9%, respectively. If no action is taken, it is estimated that 33% of men, 28% of women and 20% of children will be obese by 2010.
Obesity is responsible for more than 30,000 deaths (6% of all deaths in the UK each year). Estimates from the National Audit Office indicate that the most common health problems related to obesity are high BP, CHD, and type 2 diabetes.
It is well established that moderate weight loss has a beneficial effect on the cardiovascular risk factors associated with obesity ( table 1 ). A loss of 11% of body weight has been associated with a 25% reduction in cardiovascular disease and diabetes mortality. Intervention studies have also shown that a weight loss of 5-10% in overweight individuals has a significant impact on preventing the progression to type 2 diabetes. Data from meta-analyses show an average decrease in systolic and diastolic BP of 0.68 and 0.34 mmHg, respectively, with each 1 kg of weight loss, and a decrease in serum cholesterol, LDL-C and triglycerides of 0.06 mmol/L, 0.02 mmol/L and 0.04 mmol/L, respectively. Weight loss is also associated with a reduction in atherogenic oxidised LDL.