Background: This study sought to determine whether health-related quality of life (HRQoL) could be related to cardiorespiratory fitness (CRF) and/or physical activity (PA) in patients with McArdle disease and to compare the CRF and HRQoL data obtained with normative data for age- and sex-matched healthy subjects.
Methods: Eighty-one adult patients with McArdle disease underwent aerobic capacity testing to determine peak oxygen uptake (V˙O2peak), among other variables. HRQoL (Short Form 36-Item Health Survey questionnaire version 2 (SF-36 version 2)) and PA (International Physical Activity Questionnaire) questionnaires were completed by 45 of the patients. HRQoL and V˙O2peak data were compared with published normative data.
Results: Positive correlations were observed between V˙O2peak and leisure time PA versus the physical component summary score and scores for several domains of the SF-36 questionnaire after adjusting for age, body mass index, and disease severity (R values, 0.42–0.68; all P < 0.01). In a regression analysis, the physical component summary score was directly linked to V˙O2peak (B = 1.28; 95% confidence interval, 0.78–1.78; P < 0.001; R2 = 0.422). The mean V˙O2peak recorded for patients with McArdle disease was 57% lower than the normative value (17.1 ± 5.3 vs 40.0 ± 9.5 mL·kg−1·min−1, respectively; P < 0.001). All patients showed a CRF below their age-/sex-matched normality value and scored clinically lower in the physical component summary and in most SF-36 domains compared with the Spanish general population.
Conclusions: Patients showed a consistent link between higher physical HRQoL scores and higher CRF. Patients fulfilling leisure time PA recommendations showed higher CRF and physical HRQoL scores than those not meeting guideline recommendations. According to normative data for healthy subjects, CRF and physical HRQoL are severely impaired in adult patients with McArdle disease.
1Department of Sport and Informatics, Section of Physical Education and Sports, Faculty of Sport, Universidad Pablo de Olavide, Sevilla, SPAIN; and 2European University and Research Institute Hospital 12 de Octubre, Madrid, SPAIN
Address for correspondence: Diego Munguía-Izquierdo, Ph.D., Departamento de Deporte e Informática, Universidad Pablo de Olavide, Carretera de Utrera Km. 1 s/n, 41013 Sevilla, España; E-mail: firstname.lastname@example.org.
Submitted for publication January 2014.
Accepted for publication July 2014.