Inspiratory Muscle Strength Training Lowers Resting Systolic Blood Pressure and Improves Vascular Endothelial Function in Middle‐Aged and Older Adults
Authors: Craighead Daniel H , Heinbockel Thomas C , Rossman Matthew J , Jankowski Lindsey R , Jackman Rachel A , Bailey E. Fiona , Chonchol Michel , Seals Douglas R 
Published: June 2021

BackgroundThe majority of middle‐aged to older adults have above‐normal systolic blood pressure (SBP), i.e., SBP ≥120 mmHg, placing them at an increased risk for cardiovascular diseases, cognitive dysfunction, chronic kidney disease, and other chronic conditions of aging. This elevated SBP state is associated with the vascular risk factors endothelial dysfunction and stiffening of the large elastic (i.e., aorta and carotid) arteries. High‐intensity short‐duration inspiratory muscle strength training (IMST) represents a novel, time‐efficient (~5 min/day) lifestyle intervention that lowers SBP in select patient populations. However, whether IMST lowers SBP in middle‐aged to older adults with above‐normal SBP, or improves arterial function in any population, remains unknown.PurposeTo determine whether high‐intensity short‐duration IMST lowers SBP and improves arterial function in otherwise healthy middle‐aged to older adults with above‐normal SBP.MethodsThirteen middle‐aged and older (50–79 years) men and post‐menopausal women with resting SBP ≥120 mmHg underwent 6 weeks of IMST (30 breaths/day; 6 days/week; 75% maximum inspiratory pressure [PIMAX]) (n=7, 2M/5F, age: 68 ± 2 years) or sham (15% PIMAX) training (n=6, 3M/3F, age: 67 ± 3 years) in a randomized, double‐blind, sham‐controlled study. Subjects underwent testing for BP (resting and 24‐hour ambulatory [AMBP]), vascular endothelial function (brachial artery flow‐mediated dilation [FMDBA]) and arterial stiffness (carotid‐femoral pulse wave velocity [CFPWV], carotid artery compliance and β‐stiffness index) before and after the intervention.ResultsResting SBP was significantly lower after vs. before IMST (pre: 137 ± 4 mmHg, post: 127 ± 5 mmHg; p=0.001), but not sham training (pre: 134 ± 5 mmHg, post: 130 ± 5 mmHg; p=0.13). No changes in resting diastolic BP (DBP) or AMBP (24‐hour, daytime, and nighttime measures of SBP and DBP) were observed in either group (all p>0.05). FMDBA was increased after IMST (pre: 4.2 Δ%, post: 6.3 Δ%; p=0.001), but not in response to sham training (pre: 3.2 Δ%, post: 3.2 Δ%; p=0.99), such that FMDBA was significantly higher in the IMST group compared to sham post‐intervention (p=0.01). There were no changes in CFPWV, or carotid artery compliance or β‐stiffness with training in either group (all p>0.05), nor were body weight, body composition, fasting plasma lipids or fasting blood glucose concentrations altered with IMST or sham training (all p>0.05).ConclusionThese findings suggest that, independent of changes in other conventional CVD risk factors, high‐intensity short‐duration IMST may be an effective lifestyle‐based approach to lower resting (casual) SBP and improve vascular endothelial function in middle‐aged and older men and women with above‐normal initial levels of resting SBP.Support or Funding InformationAHA 18POST33990034, T32 DK007135, UL1 TR002535This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.