Factors predicting improvements in lipid values following cardiac rehabilitation and exercise training

Abstract

Background: Cardiac rehabilitation and exercise training improve prognosis following major cardiac events, partly by improving coronary risk factors, including plasma lipids. Only limited data are available to define predictors of lipid improvements following aggressive nonpharmacologic therapy with cardiac rehabilitation.

Methods: We studied 237 consecutive patients from two institutions who were enrolled in outpatient phase 2 cardiac rehabilitation and exercise programs. By univariable and multivariable analyses, we assessed the impact of numerous clinical variables, including indexes of obesity, age, gender, lipid concentrations, exercise capacity, and psychological factors, on improvements in plasma lipid values with cardiac rehabilitation.

Results: Coronary risk factors improved following cardiac rehabilitation, including levels of low-density lipoprotein cholesterol (-4%; P < .05), high-density lipoprotein cholesterol (7%; P < .0001), and triglycerides (-13%; P < .0001); body mass index (-2%; P < .0001); percentage of body fat (-5%; P < .0001); and exercise capacity (26%; P < .0001). By both univariable and multivariable analyses, corresponding dyslipidemic baseline values were the strongest predictors of improvements in levels of low-density lipoprotein cholesterol (univariable: r = .51, P < .0001; multivariable: t = 8.5, P < .0001), high-density lipoprotein cholesterol (univariable: r = .37, P < .0001; multivariable: t = 6.6, P < .0001), and triglycerides (univariable: r = .36, P < .0001; multivariable: t = 6.8, P < .0001). By multivariable analyses, reductions in body mass index (t = 4.6, P < .0001) and older age (t = 4.0, P < .0001) were strong independent predictors of reduction in triglyceride values following cardiac rehabilitation. However, low baseline triglyceride values were independently associated with improvements in both low-density and high-density lipoprotein cholesterol levels. Using a model incorporating 13 clinical variables, improvements in lipid values with cardiac rehabilitation were only modestly predictable with the variables assessed, accounting for only 30% to 40% of the improvements in lipid values.

Conclusions: (1) Coronary risk factors markedly improved following cardiac rehabilitation and exercise training. (2) Improvements in lipid values are modestly predictable. (3) Those patients with the worst baseline lipid values had the most improvements in lipid values following cardiac rehabilitation. However, patients with combined hyperlipidemia and low levels of high-density lipoprotein cholesterol are likely to require drug treatment.