Weight Loss and Risk Factors
GEORGE L. BLACKBURN
Weight loss is the single most cost-effective treatment for obesity-related comorbid diseases, including the nation’s leading cause of morbidity, disability, hospitalization, and mortality—cardiovascular disease. Obesity is closely linked with clusters of the 20-plus identified risk factors that make up various insulin resistance syndromes that are the cornerstones of cardiovascular disease (dyslipidemia, hypertension, abnormalities of coagulation, and endothelial dysfunction) as well as type 2 diabetes (see Chapters 76, 84, and 86).
Reduction of body weight is known to improve the cluster of risk factors associated with a central metabolic syndrome characterized by hyperinsulinemia, dyslipidemia, and obesity; glucose intolerance; and hypertension (see Chapter 86). Hyperinsulinemia is associated primarily with impaired fibrinolysis in subjects with glucose intolerance. A recent study found that excess risk for cardiovascular disease associated with hyperinsulinemia and glucose intolerance may be mediated in part by enhanced potential for acute thrombosis.
Weight loss is known to improve directly or resolve risk factors of cardiovascular disease, that is, serum triglycerides; low-density lipoprotein cholesterol (LDL-C); dense LDL apolipoprotine B particles; (apo B); pattern B; high-density lipoprotein cholesterol (HDL-C); plasminogen activator inhibitor 1 (PAI-1); glucose to insulin ratio; and homeostasis model assessment of insulin resistance (HOMA-ir). Reduction in body weight is also expected to reverse metabolic defects linked to macrovascular complications and microvascular sequelae.
Weight loss as low as 5% of initial body weight can reduce or eliminate disorders associated with obesity. Weight reductions of 10% to 20%, maintained from 2 to 5 years, are known to sustain health benefits. Most obese patients can achieve these goals in 12 to 26 weeks on a balanced hypocaloric diet or on a very-low-calorie diet (VLCD), particularly when combined with regular physical activity and behavior modification. With sustained practice of this new lifestyle, long-term outcomes can be achieved.
Today, successful treatment of obesity has nothing at all to do with reduction to de