Managing Cardiometabolic Risk

Foreword

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Diet and physical activity are the cornerstones of weight loss therapy. Despite longstanding evidence from intervention studies that it is possible to lose weight through a standardized and well-supervised program featuring moderate caloric restriction and regular physical activity (1, 2), this approach calls for significant material and human resources as well as close patient supervision with regular follow-up (3). The literature is unequivocal in this regard: the more systematic and frequent the patient supervision, the greater the compliance with and efficacy of treatment (3). Though weight loss is possible as part of well-supervised clinical studies, this situation rarely applies to day-to-day clinical practice, where family physicians often work on their own and do not have access to a multidisciplinary team of health professionals such as dietitians and kinesiologists. This gap between our understanding of obesity’s etiology and treatment and the limited means of everyday clinical practice helps explain the rise of obesity and the medical community’s inability to treat obesity efficiently. This relative failure largely justifies the development of pharmacological means to treat obesity, not to meet aesthetic goals but to manage at-risk obesity. A wide array of pharmaceuticals products to manage the metabolic complications of intra-abdominal (visceral) obesity (hypertension, type 2 diabetes, dyslipidemia) has been available for a long time. However, drugs capable of treating the problem at its source (i.e., by reducing at-risk obesity through mobilization of intra-abdominal adipose tissue that causes such complications) have come to light only recently.

Patients must be properly selected for weight management medications, and health improvement should be the goal of therapy. It is generally accepted (4) that body mass index (BMI) should be 30 kg/m² or greater for pharmacological treatment of obesity to be considered. If there is a comorbid condition (hypertension, type 2 diabetes, hyperlipidemia), BMI should be 27 kg/m² or greater. Many experts recommend that the metabolic syndrome should also be included as a comorbid condition (5, 6). As an indication for pharmacotherapy, the metabolic syndrome diagnosis may be useful because the criteria identify individuals with levels of lipids, blood pressure, and fasting glucose that are somewhat lower than the traditional values used to identify risk for individual diseases, and because weight loss is likely to reduce overall risk for type 2 diabetes and cardiovascular disease (CVD) (7). The metabolic syndrome also includes waist circumference, an important criterion to consider (5, 7-10). However, because clinical diagnosis of the metabolic syndrome relies on variable criteria and because the underlying cause(s) of this condition is (are) poorly understood, it has been justifiably claimed that such a diagnosis cannot currently be considered an indication for pharmacotherapy (10). There is an obvious need for further research aimed at identifying individuals most likely to benefit from pharmacological treatment of obesity.

This section reviews the three major drugs currently approved by major supervising bodies for long-term treatment of obesity: orlistat, sibutramine, and rimonabant. The reader is referred elsewhere for review of additional drugs approved for short-term use or early-phase investigational agents (11-18).

Reference

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