Division of Physical Therapy, Medical School, University of Minnesota, Minneapolis, Minnesota, USA.
Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
Physiol Rep. 2022 Apr;10(8):e15277. doi: 10.14814/phy2.15277.
Facioscapulohumeral muscular dystrophy (FSHD), a common form of muscular dystrophy, is caused by a genetic mutation that alters DUX4 gene expression. This mutation contributes to significant skeletal muscle loss. Although it is suggested that cardiac muscle may be spared, people with FSHD have demonstrated autonomic dysregulation. It is unknown if baroreflex function, an important regulator of blood pressure (BP), is impaired in people with FSHD. We examined if baroreflex sensitivity (BRS) is blunted in patients with FSHD. Thirty minutes of resting BP, heart rate, and cardiovagal BRS were measured in 13 patients with FSHD (age: 50 ± 13 years, avg ± SD) and 17 sex- and age-matched controls (age: 47 ± 14 years, p > 0.05). People with FSHD were less active (Activity Metabolic Index, AMI) (FSHD: 24 ± 30; controls: 222 ± 175 kcal/day; p < 0.001) but had a similar body mass index compared with controls (FSHD: 27 ± 4; controls: 27 ± 4 kg/m ; p > 0.05). BRSup (hypertensive response), BRSdown (hypotensive response), and total BRS were similar between groups (BRSup: FSHD: 12 ± 8; controls: 12 ± 5 ms/mmHg; BRSdown: FSHD: 10 ± 4; controls: 13 ± 6 ms/mmHg; BRS: FSHD: 14 ± 9; controls: 13 ± 6 ms/mmHg; p > 0.05). Mean arterial pressure was similar between groups (FSHD: 96 ± 7; controls: 91 ± 6mmHg). Individuals with FSHD had an elevated heart rate compared with controls (FSHD: 65 ± 8; controls: 59 ± 8 BPM; p = 0.03), but when co-varied for AMI, this relationship disappeared (p = 0.39). These findings suggest that BRS is not attenuated in people with FSHD, but an elevated heart rate may be due to low physical activity levels, a potential consequence of limited mobility.
面肩肱型肌营养不良症（FSHD）是一种常见的肌肉营养不良症，由基因变异引起，这种变异会改变 DUX4 基因的表达。这种突变导致显著的骨骼肌丧失。尽管有人认为心肌可能不受影响，但 FSHD 患者表现出自主神经失调。目前尚不清楚 FSHD 患者的压力反射功能（血压的重要调节因子）是否受损。我们研究了 FSHD 患者的压力反射敏感性（BRS）是否降低。我们对 13 名 FSHD 患者（年龄：50±13 岁，平均值±标准差）和 17 名年龄和性别匹配的对照组（年龄：47±14 岁，p>0.05）进行了 30 分钟的静息血压、心率和迷走神经 BRS 测量。FSHD 患者的活动代谢指数（AMI）较低（FSHD：24±30；对照组：222±175 千卡/天；p<0.001），但与对照组相比，体重指数相似（FSHD：27±4；对照组：27±4kg/m2；p>0.05）。两组之间 BRSup（高血压反应）、BRSdown（低血压反应）和总 BRS 相似（BRSup：FSHD：12±8；对照组：12±5ms/mmHg；BRSdown：FSHD：10±4；对照组：13±6ms/mmHg；BRS：FSHD：14±9；对照组：13±6ms/mmHg；p>0.05）。两组之间平均动脉压相似（FSHD：96±7；对照组：91±6mmHg）。与对照组相比，FSHD 患者的心率较高（FSHD：65±8；对照组：59±8BPM；p=0.03），但当对 AMI 进行协方差分析时，这种关系消失（p=0.39）。这些发现表明，FSHD 患者的 BRS 并未减弱，但心率升高可能是由于活动水平低所致，这可能是运动受限的后果。
