Obesity comorbidities

Body mass index (BMI), waist circumference, comorbidities, and readiness to lose weight are used in the assessment of the overweight or obese patient. 

Because of comorbidity with diabetes, dyslipidemia, hypertension, and stroke, the presence of increased serum uric acid levels or gout should prompt evaluation for cardiovascular disease and the need for appropriate risk reduction measures. Clinicians should also look for possible correctable causes of hyperuricemia (e.g., medications, obesity, and alcohol abuse). 

Surgery, which reduces the stomach volume or absorptive surface of the alimentary tract, remains the most effective intervention for obesity. Although modern techniques are safer than older procedures and have an operative mortality of 1%, there are still many potential complications. Therefore, surgery should be reserved for those with BMI greater than 35 or 40 kg/m2 and significant comorbidity. 

Circulating glucose and insulin levels are the key values for a diagnosis of type II diabetes. Obesity and elevated levels of non-esterified fatty acids (NEFA) are known to cause insulin resistance and diabetes. Comorbidity of T2DM and dyslipidemia are common in animal models and in clinical populations and therefore, cholesterol, triglycerides, inflammation markers, and blood pressure are often measured within the same experiments. However, for the purpose of this chapter, we will cover only values directly linked to T2DM. 

Lifestyle factors have been associated with ED in both cross-sectional and longitudinal studies. In particular, obesity and sedentary lifestyle are clear-cut risk factors for ED, both in men with comorbid illnesses such as hypertension and diabetes, and especially in men without overt cardiovascular disease (50). Other lifestyle factors, such as smoking and alcohol consumption, have been implicated in some, but not all, studies to date. Intervening on cardiovascular and lifestyle factors may have broader benefits beyond restoration of erectile function. This important concept needs careful consideration, as recent studies have implicated the role of the metabolic syndrome, obesity, insulin resistance, and lack of exercise as independent risk factors for both ED and cardiovascular disease (51,52). 

Excess adiposity, particularly the abdominal obesity associated with increased waist circumference, is associated with insulin resistance, hypertension, and proinflammatory states. The prevalence of this complex of comorbidities associated with obesity, now referred to as the metabolic syndrome, is reaching epidemic proportions in the United States (Grundy et al., 2004 Roth et al., 2002). Indeed, increased abdominal adiposity is one of a cluster of factors that are used in the diagnosis of metabolic syndrome. Abdominal tissue in the trunk occurs in several compartments, including subcutaneous and intraperitoneal or visceral fat. Visceral fat in particular appears to contribute to perturbed fuel metabolism by at least two mechanisms. First, hormones and free fatty acids released from visceral fat are released into the portal circulation and impact directly on metabolism of the liver. Second, the visceral adipose depot produces a different spectrum of adipocytokines than that produced by subcutaneous fat (Kershaw and Flier, 2004). 

The presence of multiple comorbid conditions (e.g., diabetes, asthma, congestive heart failure, obesity) further increases the risk of ADRs. Such patients may have altered physiology and some degree of end-organ dysfunction (e.g., renal, hepatic, cardiovascular, pulmonary). Conditions such as renal dysfunction may not be readily apparent in the elderly or in those with muscle wasting or malnutrition. 

Table 15.2 Common Comorbidities Associated with Obesity...

Ghali, P. and Lindor, K. 2003. Hepatotoxicity of drugs used for treatment of obesity and its comorbidities. Semin. Liver Dis. 24, 389-397. 

Antel, J., Gregory, P. C., Nordheim, U. CBl cannabinoid receptor antagonists for treatment of obesity and prevention of comorbid metabolic disorders. J. Med. Chem. 2006,49(14), 4008-4016. 

The importance and clinical applicability of these measurements continue to evolve as there are probably racial and ethnic differences in the relationship between BMI, WC, and risk for development of disease and enhanced comorbidity. ° Table 140-3 outlines the current classification of overweight and obesity using BMI and WC. The table identifies risk for development of type 2 diabetes, hypertension, or cardiovascular disease at various stages of BMI or WC. Note that increased WC confers increased risk even in normal-weight individuals. 

The increasing prevalence of childhood obesity has seri-ons implications for child health becanse it is associated with comorbidity, even during early childhood. This inclndes elevated BP, abnormal blood lipid concentrations, insnlin resistance, type 2 diabetes mellitns, orthopedic disorders, skin problems, and psychological problems. 

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