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 2 ; 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.
Bibliographical noteFunding Information:
This study was supported in part by a FLEXfund grant from Friends of FSH Research, and by the National Institutes of Arthritis and Musculoskeletal and Skin Diseases (R01 AR055685). Additional resources were provided by University of Minnesota's NIH Clinical and Translational Science Award: UL1TR002494. EL is supported by a NIA T32 (T32AG029796) and MKR is supported by a NIA K01 (AG064038‐01A1).
This study was supported in part by a FLEXfund grant from Friends of FSH Research, and by the National Institutes of Arthritis and Musculoskeletal and Skin Diseases (R01 AR055685). Additional resources were provided by University of Minnesota's NIH Clinical and Translational Science Award: UL1TR002494. EL is supported by a NIA T32 (T32AG029796) and MKR is supported by a NIA K01 (AG064038-01A1). We would like to thank all the individuals who participated in this study, particularly those who had significant travel requirements to contribute to this research.
© 2022 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.
- autonomic function
- blood pressure
- heart rate variability
- muscular dystrophy
- Blood Pressure
- Middle Aged
- Muscle, Skeletal/metabolism
- Homeodomain Proteins
- Muscular Dystrophy, Facioscapulohumeral/genetics
- Genes, Homeobox
PubMed: MeSH publication types
- Research Support, Non-U.S. Gov't
- Journal Article
- Research Support, N.I.H., Extramural