Background:
Cardiac events are the predominant cause of late mortality in patients with peripheral arterial disease (PAD). In these patients,
mortality decreases with increasing body mass index ...(BMI). COPD is identified as a cardiac risk factor, which preferentially
affects underweight individuals. Whether or not COPD explains the obesity paradox in PAD patients is unknown.
Methods:
We studied 2,392 patients who underwent major vascular surgery at one teaching institution. Patients were classified according
to COPD status and BMIs ( ie , underweight, normal, overweight, and obese), and the relationship between these variables and all-cause mortality was determined
using a Cox regression analysis. The median follow-up period was 4.37 years (interquartile range, 1.98 to 8.47 years).
Results:
The overall mortality rates among underweight, normal, overweight, and obese patients were 54%, 50%, 40%, and 31%, respectively
(p < 0.001). The distribution of COPD severity classes showed an increased prevalence of moderate-to-severe COPD in underweight
patients. In the entire population, BMI (continuous) was associated with increased mortality (hazard ratio HR, 0.96; 95%
confidence interval CI, 0.94 to 0.98). In addition, patients who were classified as being underweight were at increased
risk for mortality (HR, 1.42; 95% CI, 1.00 to 2.01). However, after adjusting for COPD severity the relationship was no longer
significant (HR, 1.29; 95% CI, 0.91 to 1.93).
Conclusions:
The excess mortality among underweight patients was largely explained by the overrepresentation of individuals with moderate-to-severe
COPD. COPD may in part explain the âobesity paradoxâ in the PAD population.
body mass index
COPD
mortality
peripheral arterial disease
Increased body mass index (BMI), a parameter of total body fat content, is associated with an increased mortality in the general population. However, recent studies have shown a paradoxic relation ...between BMI and mortality in specific patient populations. This study investigated the association of BMI with long-term mortality in patients with known or suspected coronary artery disease. In a retrospective cohort study of 5,950 patients (mean age 61 ± 13 years; 67% men), BMI, cardiovascular risk markers (age, gender, hypertension, diabetes, current smoking, angina pectoris, old myocardial infarction, heart failure, hypercholesterolemia, and previous coronary revascularization), and outcome were noted. The patient population was categorized as underweight, normal, overweight, and obese based on BMI according to the World Health Organization classification. Mean follow-up time was 6 ± 2.6 years. Incidences of long-term mortality in underweight, normal, overweight, and obese were 39%, 35%, 24%, and 20%, respectively. In a multivariate analysis model, the hazard ratio (HR) for mortality in underweight patients was 2.4 (95% confidence interval CI 1.7 to 3.7). Overweight and obese patients had a significantly lower mortality than patients with a normal BMI (HR 0.65, 95% CI 0.6 to 0.7, for overweight; HR 0.61, 95% CI 0.5 to 0.7, for obese patients). In conclusion, BMI is inversely related to long-term mortality in patients with known or suspected coronary artery disease. A lower BMI was an independent predictor of long-term mortality, whereas an improved outcome was observed in overweight and obese patients.
