Objectives: We evaluated exercise capacity and other exercise parameters in patients with metabolic syndrome and angiographically normal coronary arteries.
Study design: Sixty-one patients with angiographically normal coronary arteries were evaluated in two groups according to the presence (n=32; 24 females, 8 males; mean age 59+/-10 years) or absence (n=29; 18 females, 11 males; mean age 59+/-9 years) of metabolic syndrome as proposed by the International Diabetes Federation. All the patients underwent exercise treadmill testing with the modified Bruce protocol, whereby the following variables were determined: workload achieved in metabolic equivalents, total exercise time, percentage of target heart rate achieved, double product, heart rate recovery, chronotropic response and incompetence. The relationships between exercise parameters and echocardiographic and clinical variables were evaluated.
Results: The two groups were similar with respect to age, left ventricular dimensions, left ventricular mass index, ejection fraction, and left atrial diameters. The incidence of diastolic dysfunction was significantly higher in patients with metabolic syndrome (71.9% vs 41.4%; p=0.016). The maximum workload achieved was significantly lower (10+/-2 ml/kg/min vs 12+/-2 ml/kg/min; p=0.024) and the initial double product was significantly higher (11.6x10(3) mmHg.pulse/min vs 10.1x10(3) mmHg.pulse/min, p=0.04) in patients with metabolic syndrome. Hypertensive patients exhibited significantly lower maximum workload and total exercise time (p<0.05). Hyperglycemic subjects had significantly lower maximum workload (p<0.05).
Conclusion: Metabolic syndrome is associated with decreased exercise capacity and each component of this syndrome affects exercise test parameters individually.