Respiratory muscle strength is related to handgrip performance in community-dwelling persons aged 80+ from the BUTTERFLY study.
This study aimed to evaluate the association of respiratory muscle strength with sarcopenia and its indicators in the oldest old. Maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP) and sarcopenia related factors (handgrip strength and appendicular lean mass) were evaluated in a cohort of n=286 (45.5% female) non-frail, community-dwelling persons aged 83.6ยฑ3.0 years (age range 80-97 years).
The sample presented a sarcopenia prevalence of 32.2%. Sarcopenic subjects showed comparable MIP and MEP as non-sarcopenic ones (female: MIP 43.9ยฑ18.9 versus 50.3ยฑ19.5, p=0.053; MEP 63.0ยฑ23.0 versus 69.2ยฑ19.1, p=0.067; male: MIP, 65.1ยฑ24.4 versus 64.4ยฑ23.9, p=0.433; MEP 87.7ยฑ33.3 versus 93.8ยฑ30.9, p=0.124).
Statistically significant but very low associations were found between grip strength and MIP (r=0,193 for male, p<0.05 and r=0.257 for female participants, p<0.01) and MEP (r=0.200 for male, p<0.01 and r=0.191 for female participants, p<0.05). Lean mass was significantly correlated to MIP and MEP in female (r=0.253, p<0.01 and r=0.343, p<0.01 respectively), whereas this association was not found in male participants.
Grip strength was the only statistically significant predictor of MEP (r-square=0.212, p<0.001), while MIP was independently predicted by age, male sex and grip strength (r-square=0.177, p<0.001). Peripheral muscle strength is a statistically significant, albeit weak predictor for respiratory muscle strength in well-functioning, community-dwelling persons aged 80+.
When confronted to a low grip strength, one should be aware of concomitant respiratory muscle weakness, as this is a known risk factor for atelectasis and pneumonia. Given the relatively low association with handgrip strength, respiratory muscle strength testing might be indicated.