Modest effects of exercise training alone on coronary risk factors and body composition in coronary patients.

BACKGROUND: Cardiac rehabilitation programs have evolved to become secondary prevention centers. However, the independent effect of exercise alone on coronary risk factors and body composition in patients with coronary artery disease has not been well studied. OBJECTIVE: The aim of this study was to determine the effect of exercise training alone, without modification of dietary intake, on coronary risk factors and body composition in a coronary population. METHODS: The authors studied 82 coronary patients (23 females and 59 males) aged 61.2 +/- 12.2 years (mean +/- SD) before and after a 3-month exercise training program. Outcome variables included serum lipid values, glucose, insulin, body composition, body fat distribution, macronutrient intake, and peak aerobic capacity. RESULTS: Neither male nor female patients experienced a significant overall improvement in plasma cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, glucose, or insulin levels after the 3-month exercise training program. Dietary macronutrient intake was unaltered during the study period. Peak aerobic capacity increased by 3.4 +/- 4.7 ml/kg/min (17%, P < 0.0001) and high-density lipoprotein (HDL)-cholesterol increased from 38 +/- 10 to 41 +/- 11 mg/dL (8%, P < 0.001) after the rehabilitation program. Patients with baseline triglyceride levels over 200 mg/dL experienced a 22% decrease (from 374 +/- 205 to 293 +/- 190 mg/dL; P < 0.05) after conditioning. Patients with baseline HDL-cholesterol levels under 35 mg/dL also improved overall by 17% (from 29 +/- 3 to 34 +/- 5 mg/dL; P < 0.0001). Exercise-induced changes in plasma HDL-cholesterol were more related to changes in body composition and/or body fat distribution, rather than changes in peak aerobic capacity. CONCLUSION: Exercise conditioning alone resulted in relatively modest risk factor improvements in coronary patients after 3 months. High-density lipoprotein cholesterol measures increased by 3 +/- 8 mg/dL (8%). Patients with baseline triglyceride elevations experienced a 22% decrease. On the other hand, there were no overall effects on body weight, total cholesterol, LDL-cholesterol, triglycerides, glucose, or insulin levels. For most patients, exercise effects were minimal and nutritional and medical therapy will need to be used more aggressively to attain nationally recognized risk factor goals.

Lipid lowering in the cardiac rehabilitation setting.

PURPOSE: The authors determined the frequency and effectiveness of pharmacologic lipid lowering, guided by the recommendations of the National Cholesterol Education Program (NCEP) before and after institution of a systematic lipid assessment performed at the time of the cardiac rehabilitation entry evaluation. METHODS: The systematic lipid evaluation included a full lipid profile and a dietary evaluation at which time an active approach to pharmacologic lipid therapy was taken. Therapy was guided by the NCEP guidelines, with the collaboration of the referring physician. The frequency of lipid therapy change (starting or changing therapy) from the baseline evaluation to a 3-month follow-up visit was the primary study outcome variable. The control group consisted of 51 patients with coronary heart disease (CHD) seen in 1995 at cardiac rehabilitation, who agreed to have their serum lipids measured in a double-blinded fashion. There was no systematic lipid lowering intervention. The intervention group consisted of 187 patients with CHD who participated in cardiac rehabilitation in 1996 to 1997. RESULTS: At baseline, a similar percentage of patients in each group were on lipid lowering therapy: 38% (19/51) in controls versus 35% (65/187) in intervention patients. Among patients with a baseline low-density lipoprotein (LDL) cholesterol of > or = 130 mg/dL, therapy was modified in 18% (4/22) of control patients compared with 52% (35/68) of intervention patients (P < 0.05). Among patients with a baseline LDL cholesterol of > or = 160, therapy was altered in 22% (2/9) control patients compared with 72% (18/25) intervention patients (P < 0.01). In both risk strata of > or = 130 mg/dL and > or = 160 mg/dL, LDL cholesterol measures were lowered to a greater degree in the intervention group. CONCLUSIONS: The performance of a systematic lipid review at the time of cardiac rehabilitation entry, with an active stance toward pharmacologic therapy, results in a threefold increase in pharmacologic modifications and lower LDL cholesterol values for cardiac rehabilitation participants.

Combined resistive-aerobic training in older patients with coronary artery disease early after myocardial infarction.

BACKGROUND AND PURPOSE: Older patients with artery disease have higher rates of disability than younger coronary patients, partly based on lower levels of skeletal muscle strength. We compared the effect of a combined resistive-aerobic training program on muscular strength in older and younger coronary patients early after myocardial infarction. METHODS: The study population included 45 patients who had recently (4-12 weeks) suffered a myocardial infarction; 19 were age > or = 62 years (mean 68 +/- 3 years) and 25 were < 60 years of age (mean 48 +/- 7 years). Muscle strength was measured by single repetition maximum lifts for leg extension and bench press, before and after the 12-week conditioning program. Body composition was measured in a subset of 16 patients by dual x-ray absorptiometry. RESULTS: At baseline, the older population demonstrated lower strength measures than the younger patients. With conditioning, both groups improved strength similarly with leg-extension and bench press measures increasing by 35% and 14% respectively in the older patients and 39% and 14% in the younger patients (both P < 0.05, NS between groups). Within the older patient group, the men were significantly stronger than the women at baseline yet the women tended to improve their strength measures to a greater degree than the men, increasing leg strength by 66% and bench press by 29% versus 29% and 10% in older men (P < 0.10 between groups). In the overall study population, body composition measures showed a slight decrease in body weight, a decrease in fat mass, and a maintenance of lean body mass and bone mineral content with no difference in response between older and younger patients. CONCLUSIONS: Older coronary patients can effectively increase body strength with a combined resistive-aerobic exercise program in the early post-myocardial infarction period.