Obesity and Cardiac Rehabilitation

Abstract

Obesity is a significant health burden and increasing in prevalence among patients enrolled in cardiac rehabilitation (CR)/secondary prevention programs. Strategies to address exercise and dietary needs are especially important for the obese patient, but assessing other factors that affect risk-reduction goals is also important. PURPOSE: To compare obese and normal-weight patient groups on: 1) baseline characteristics, 2) changes in exercise minutes and MET levels during CR, and 3) changes in exercise and diet related outcomes pre- to post-CR. METHODS: Between 1/96 and 9/05, 574 patients (ages 27–90, all CHD) completed our CR program. Patients were grouped by baseline body mass index (BMI): normal weight, BMI <25 kg/m2 (n = 119), overweight, BMI 25–29.9 kg/m2 (n = 211), and obese, BMI ≥30 kg/m2 (n = 244). Group comparisons were limited to the obese and normal weight groups and data analyzed with t-tests or chi-square as appropriate. RESULTS: Compared to the normal weight group, the obese group was younger (59 ±10 vs65 ±10 years, p<0.001), included more men (70% vs 66%), had poorer diet scores (33 ± 29 vs 25 ±24), a higher comorbidity index (1.8 ±1.6 vs 1.3 ±1.5) and non-HDL cholesterol level (144 ±45 mg/dl vs 129 ±43 mg/dl) and a higher prevalence of hypertension (84% vs 70%) (all p<0.01) and diabetes (48% vs 24%, p<0.001). There were no significant group differences at baseline for 6-minute walk distances, self-reported physical activity and prescribed minutes of supervised exercise minutes or MET level. At completion of CR, the obese group exercised more supervised minutes (46±10vs43 ±8, p = <0 .002), but there was no difference in MET level or self-reported weekly physical activity. Although each group made improvements from pre- to post-CR, the degree of improvement was greater in the normal-weight group for 6-minute walk distance (ft) (278 ±266 vs 217 ±266, p = 0.04) and greater for the obese group for the diet score (−15 ±28 vs −8 ±19, p <0 .001). As expected, there was a modest comparative decrease in change for the obese group in BMI (−0.8 ± 1.3 vs +0.1 ± 0.9, (p<0.001) and waist circumference (inch) (−0.9 ±2.6 vs −0.1 ±1.7, p<0.01). CONCLUSIONS:Despite the younger age, obese patients had a higher comorbidity and risk factor burden than normal weight patients that poses additional risk-reduction challenges. Although more supervised exercise minutes were logged for the obese group, the degree of improvement in functional capacity was less than the normal weight group and only modest weight-reduction benefits were achieved. More intense strategies targeting home physical activity behaviors are needed to enhance the desired outcomes among obese patients participating in CR.