Effects of Inspiratory Muscle Strength Training on Cognitive and Motor Function in Middle‐Aged and Older Adults with Above‐Normal Systolic Blood Pressure

Abstract

Aging and above normal systolic blood pressure (SBP) are independently and additively associated with decreased cognitive and motor function, which increase the risk of developing dementia and physical disabilities, respectively. Traditional aerobic exercise regimens may reduce the risk of cognitive and physical decline with aging. However, they are associated with relatively poor adherence among older adults, and only modest reductions in SBP (e.g., ≤5mmHg). As such, there is an unmet need for novel exercise modalities with improved adherence and SBP‐lowering effects. High‐intensity inspiratory muscle strength training (IMST) is a time‐efficient (~5 min/day) form of exercise with excellent adherence and strong SBP‐lowering effects in select groups. Whether IMST improves cognitive and motor function and/or lowers SBP in middle‐aged and older adults is unknown. The purpose of this study was to determine if 6‐weeks of IMST improves cognitive and motor function, while lowering SBP in middle‐aged to older adults with above‐normal SBP (≥120 mmHg).MethodsMiddle‐aged and older adults (50–79 years) with above‐normal SBP were recruited. Subjects were randomly allocated to perform 6‐weeks of IMST (30 breaths/day; 6 days/week; 75% maximum inspiratory pressure [PIMAX]) (n=7 age: 68±2, SBP: 137±3 mmHg) or sham (15% PIMAX) training (n=7; age: 67±3, SBP: 134±5 mmHg). Motor and cognitive function was measured at baseline and post‐intervention with the NIH Toolbox cognitive and motor battery of tests and other standardized measurements, including trail making test (TMT) parts A and B.ResultsNeither treatment altered body weight, body composition or blood clinical markers (all p>0.05). 6‐weeks of IMST significantly reduced SBP (−10±2 mmHg, p=0.001) compared with sham training (−4±2 mmHg, p=0.13). Selective domains of fluid cognition, including episodic memory (picture sequence memory test; +11±2 AU, p=0.04) and processing speed (TMT‐A; −6±1 sec, p=0.02) were improved after 6‐weeks of IMST, as was overall fluid cognition (composite score; +7±2 AU, p=0.02). The improvement in episodic memory was inversely related to changes in SBP (R2=0.40, p=0.01). Crystallized cognition (e.g., verbal knowledge) was unchanged with IMST (composite score; +2±2 AU, p=0.37). No domains of cognitive function changed in the sham group (all p>0.05). There was no effect of IMST on any measures of motor function, while gait speed improved slightly in the sham group (+0.22±0.07 m/s; p=0.002).ConclusionsThese data suggest IMST improves processing speed and episodic memory in middle‐aged to older adults, and the improvements may be related to IMST‐induced reductions in SBP.Support or Funding InformationAHA 18POST33990034, T32 DK007135, UL1 TR002535, R25 HL115473This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.