Obesity and hypertension, heart failure, and coronary heart disease-risk factor, paradox, and recommendations for weight loss

Abstract

Obesity prevalence has reached epidemic proportions and is independently associated with numerous cardiovascular disease (CVD) risk factors, including diabetes mellitus, hypertension, dyslipidemia, cancers, sleep apnea, and other major CVDs. Obesity has significant negative impact on CVD, including hypertension, coronary heart disease, heart failure, and arrhythmias via its maladaptive effects on individual CVD risk factors and cardiac structure and function. Despite this negative association between obesity and the incidence and prevalence of CVD, many studies have demonstrated that obese patients with established CVD might have better short- and long-term prognosis, suggesting an "obesity paradox." This intriguing phenomenon has been well documented in populations with heart failure, coronary heart disease, and hypertension. This review summarizes the adverse effects of obesity on individual CVD risk factors; its role in the genesis of CVDs, including heart failure, coronary heart disease, and hypertension; and the obesity paradox observed in these populations and the potential underlying mechanisms behind this puzzling phenomenon and concludes with a discussion on the potential benefits of weight reduction.

Keywords: Coronary heart disease; heart failure; hypertension; obesity; obesity paradox; weight loss.

Figure 1. Risk of heart failure in obese subjects, according to category of body mass index at the baseline examination. (Reproduced with permission from Kenchaiah S, Evans JC, Levy D, et al. N Engl J Med. 2002;347:305-313.10)

Figure 2. Sigma curve showing the probability of heart failure as a function of duration of morbid obesity. (Reproduced with permission from Alpert MA, Terry BE, Mulekar M, et al. Am J Cardiol. 1997;80:736-740.30)

Figure 3. Risk-adjusted survival curves for the 4 body mass index categories at 5 years in a study of 1,203 individuals with moderate to severe heart failure. Survival was significantly better in the overweight and obese categories. (Reproduced with permission from Horwich TB, Fonarow GC, Hamilton MA, et al. J Am Coll Cardiol. 2001;38:789-795.43)

Figure 4. Kaplan-Meier major event-free survival curves (freedom from cardiovascular death or urgent transplantation) in patients in quintiles (Q) 1 and 5 for percent body fat (upper panel) and body mass index (BMI) (lower panel). (Reproduced with permission from Lavie CJ, Osman AF, Milani RV, Mehra MR. Am J Cardiol. 2003;91:891-894.44)

Figure 5. Percentage of patients to reach primary outcome, all-cause mortality, nonfatal stroke, and nonfatal myocardial infarction according to BMI category; BMI, body mass index; CV, cardiovascular; MI, myocardial infarction. (Reproduced with permission from Uretsky S, Messerli FH, Bangalore S, et al. Am J Med. 2007;120:863-870.57)