Respiratory Muscle Strength Is Related to Handgrip Performance in Community-Dwelling Persons Aged 80+ from the BUTTERFLY Study

Abstract

<b><i>Introduction:</i></b> This study aimed to evaluate the association of respiratory muscle strength with sarcopenia and its indicators in the oldest old. <b><i>Methods:</i></b> Maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), and sarcopenia-related factors (handgrip strength and appendicular lean mass) were evaluated in a cohort of <i>n</i> = 286 (45.5% female) non-frail, community-dwelling persons aged 83.6 ± 3.0 years (age range 80–97 years). <b><i>Results:</i></b> The sample presented a sarcopenia prevalence of 32.2%. Sarcopenic subjects showed comparable MIP and MEP as non-sarcopenic ones (female: MIP 43.9 ± 18.9 vs. 50.3 ± 19.5, <i>p</i> = 0.053; MEP 63.0 ± 23.0 vs. 69.2 ± 19.1, <i>p</i> = 0.067; male: MIP, 65.1 ± 24.4 vs. 64.4 ± 23.9, <i>p</i> = 0.433; MEP 87.7 ± 33.3 vs. 93.8 ± 30.9, <i>p</i> = 0.124). Statistically significant but very low associations were found between grip strength and MIP (<i>r</i> = 0.193 for male, <i>p</i> &lt; 0.05 and <i>r</i> = 0.257 for female participants, <i>p</i> &lt; 0.01) and MEP (<i>r</i> = 0.200 for male, <i>p</i> &lt; 0.01 and <i>r</i> = 0.191 for female participants, <i>p</i> &lt; 0.05). Lean mass was significantly correlated to MIP and MEP in female (<i>r</i> = 0.253, <i>p</i> &lt; 0.01 and <i>r</i> = 0.343, <i>p</i> &lt; 0.01, respectively), whereas this association was not found in male participants. Grip strength was the only statistically significant predictor of MEP (<i>r</i>² = 0.212, <i>p</i> &lt; 0.001), while MIP was independently predicted by age, male sex, and grip strength (<i>r</i>² = 0.177, <i>p</i> &lt; 0.001). <b><i>Conclusions:</i></b> 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.