Sport, Health and Performance Enhancement (SHAPE) Research Centre, Nottingham Trent University, Clifton Lane, Clifton, Nottingham, NG11 8NS, UK.
Charles Dent Metabolic Unit, The National Hospital for Neurology and Neurosurgery, London, UK.
Orphanet J Rare Dis. 2022 Jan 31;17(1):28. doi: 10.1186/s13023-022-02184-1.
Individuals with glycogen storage disease IIIa (GSD IIIa) (OMIM #232400) experience muscle weakness and exercise limitation that worsen through adulthood. However, normative data for markers of physical capacity, such as strength and cardiovascular fitness, are limited. Furthermore, the impact of the disease on muscle size and quality is unstudied in weight bearing skeletal muscle, a key predictor of physical function. We aim to produce normative reference values of aerobic capacity and strength in individuals with GSD IIIa, and to investigate the role of muscle size and quality on exercise impairment.
Peak oxygen uptake (V̇Opeak) was lower in the individuals with GSD IIIa than predicted based on demographic data (17.0 (9.0) ml/kg/min, 53 (24)% of predicted, p = 0.001). Knee extension maximum voluntary contraction (MVC) was also substantially lower than age matched predicted values (MVC: 146 (116) Nm, 57% predicted, p = 0.045), though no difference was found in MVC relative to body mass (1.88 (2.74) Nm/kg, 61% of predicted, p = 0.263). There was a strong association between aerobic capacity and maximal leg strength (r = 0.920; p = 0.003). Substantial inter-individual variation was present, with a high physical capacity group that had normal leg strength (MVC), and relatively high V̇Opeak, and a low physical capacity that display impaired strength and substantially lower V̇Opeak. The higher physical capacity sub-group were younger, had larger Vastus Lateralis (VL) muscles, greater muscle quality, undertook more physical activity (PA), and reported higher health-related quality of life.
V̇Opeak and knee extension strength are lower in individuals with GSD IIIa than predicted based on their demographic data. Patients with higher physical capacity have superior muscle size and structure characteristics and higher health-related quality of life, than those with lower physical capacity. This study provides normative values of these important markers of physical capacity.
糖原贮积病 IIIa 型（GSD IIIa）（OMIM #232400）个体在成年后会出现肌肉无力和运动受限，且病情会逐渐恶化。然而，目前对于体力能力的标志物（如力量和心血管健康）的规范数据有限。此外，在承重骨骼肌中，该疾病对肌肉大小和质量的影响尚未得到研究，而承重骨骼肌是身体功能的关键预测因素。我们旨在为 GSD IIIa 个体生成有氧能力和力量的规范参考值，并研究肌肉大小和质量对运动障碍的作用。
与基于人口统计学数据预测的结果相比，GSD IIIa 个体的峰值摄氧量（V̇Opeak）更低（17.0（9.0）ml/kg/min，53（24）%预测值，p=0.001）。膝关节伸展最大自主收缩（MVC）也明显低于年龄匹配的预测值（MVC：146（116）Nm，57%预测值，p=0.045），但与体重相比，MVC 没有差异（1.88（2.74）Nm/kg，61%预测值，p=0.263）。有氧能力与最大腿部力量之间存在很强的相关性（r=0.920；p=0.003）。个体间存在很大的差异，其中高体力能力组具有正常的腿部力量（MVC）和相对较高的 V̇Opeak，低体力能力组表现出肌肉力量受损和明显较低的 V̇Opeak。较高体力能力的亚组更年轻，拥有更大的股外侧肌（VL）肌肉，更高的肌肉质量，进行更多的身体活动（PA），并报告更高的健康相关生活质量。
与基于人口统计学数据预测的结果相比，GSD IIIa 个体的 V̇Opeak 和膝关节伸展力量更低。体力能力较高的患者具有更好的肌肉大小和结构特征以及更高的健康相关生活质量，而体力能力较低的患者则较差。本研究提供了这些重要体力能力标志物的规范值。
