Body Composition and Heart disease mortalityFor personal use. Mass reproduce only with permission from Mayo Clinic Proceedings a .D espite the well-known adverse affects of obesity on almost all aspects of coronary heart disease (CHD) and CHD risk factors, including hypertension (HTN), plasma lipids, inflammation, glucose abnormalities, insulin resistance, metabolic syndrome and type 2 diabetes mellitus (T2DM), as well as left ventricular hypertrophy (LVH), many studies of cohorts with established cardiovascular (CV) disease, including heart failure (HF), HTN, as well as CHD, have demonstrated an inverse relationship between obesity, generally determined by body mass index (BMI [calculated as the weight in kilograms divided by the height in meters squared]), on subsequent mortality, referred to as the obesity paradox. 1,2 The obesity paradox has also been demonstrated in non-CV studies that included patients with advanced renal disease and the elderly. 3,4 Many large studies of cohorts with CHD have demonstrated this obesity paradox, [5][6][7] which has also been demonstrated in a large meta-analysis by Romero-Corral et al 8 from Mayo Clinic, who analyzed 40 cohort studies totaling more than 250,000 patients with CHD grouped according to BMI.Although BMI is the most frequently used method to assess overweightness/obesity, especially in large epidemiologic studies, this method has been criticized because BMI does not always reflect true body fatness. 1,2,9-14 Some investigators have theorized that at least part of the inconsistent relationship between obesity and major CV disease events, including mortality, may be due to the inaccurate diagnosis of obesity by the BMI assessment and that defining obesity by other methods, including waist circumference, waist/hip ratio, as well as percent body fat (BF) may be more accurate. 2,[9][10][11][12][13] We have recently demonstrated this obesity paradox in a cohort of CHD patients using both BMI and BF determinations. 14 To our knowledge, no prior studies have determined the independent effects of both BMI and BF on mortality in a cohort of CHD patients. Therefore, in the current evaluation, we determined the combined and independent impact of both BMI and BF on mortality in a cohort with stable CHD.
PATIENTS AND METHODSWe retrospectively reviewed the case records of 581 consecutive patients with stable CHD who were referred for potential entry into formal cardiac rehabilitation programs between January 1, 2000, and July 31, 2005, and who had baseline anthropometric, lipid, and clinical data, as we have previously described. 14 Patients were divided into low (<25) and high (≥25) BMI. Elevated BF has been defined as greater than 25% in men and greater than 35% in women, 15,16 so patients were also divided into low (≤25% men and ≤35% women) and high BF (>25% men and >35% women Objective: To determine the combined effects of body mass index (BMI) and body fat (BF) on prognosis in coronary heart disease (CHD) to better understand the obesity paradox.
Patients and MethOds:We s...