Creating and Evaluating a Prediction Equation for VO 2peak in Individuals with Early Stage, Never Medicated Parkinson's Disease.

Abstract

Parkinson's disease (PD) is a neurodegenerative nervous system condition causing motor and nonmotor symptoms. Endurance training is commonly prescribed in people with PD for possible slowing of disease progression. Since people with PD exhibit lower cardiorespiratory fitness, it is important to understand peak aerobic capacity (VO 2peak ) in people with PD. VO 2peak prediction equations may be used when cardiopulmonary exercise testing (CPET) is unavailable; however, exercise-based PD-specific prediction equations are lacking. The purpose of the study was to develop a PD-specific VO 2peak prediction equation and to compare this equation to published VO 2peak prediction equations. This study included N = 127 never-medicated individuals with PD, aged 40-80 yr, Hoehn and Yahr stages 1-2, within 5 yr of diagnosis, and exercising ≤3 d/wk, who completed a treadmill CPET. Linear regression analyses were performed to generate the VO 2peak equation from a validation subsample, which was applied to a cross-validation subsample. The equation was compared with two published equations for healthy adults. The PD-specific VO 2peak equation was: VO 2peak (mL/kg/min) = 12.466 + 0.149 × (treadmill speed [m/min]) + 85.7 × (treadmill grade [%, as a decimal]) - 2.383 × (sex [0 = male, 1 = female]) - 0.135 × (age [years]). There was no difference between estimated and measured VO 2peak in the cross-validation subsample. Our equation successfully predicted VO 2peak in early PD, whereas VO 2peak was over- and underestimated in people with PD by the American College of Sports Medicine and Foster equations, respectively. Clinicians can estimate VO 2peak in individuals with PD to identify those for whom endurance exercise training should be a major health priority, develop an exercise prescription, and assess changes in VO 2peak over time.