Respiratory muscle strength in relation to sarcopenia in elderly cardiac patients

Background and aims: Little information exists on the relation between respiratory muscle strength such as maximum inspiratory muscle pressure (MIP) and sarcopenia in elderly cardiac patients. The present study aimed to determine the differences in MIP, and cutoff values for MIP according to sarcopenia in elderly cardiac patients. Methods: We enrolled 63 consecutive elderly male patients aged ≥65 years with cardiac disease in this cross-sectional study. Sarcopenia was defined based on the European Working Group on Sarcopenia in Older People algorithm, and, accordingly, the patients were divided into two groups: the sarcopenia group (n = 24) and non-sarcopenia group (n = 39). The prevalence of sarcopenia in cardiac patients and MIP in the patients with and without sarcopenia were assessed to determine cutoff values of MIP. Results: After adjustment for body mass index, the MIP in the sarcopenia group was significantly lower than that in the non-sarcopenia group (54.7 ± 36.8 cmH₂O; 95 % CI 42.5–72.6 vs. 80.7 ± 34.7 cmH₂O; 95 % CI 69.5–92.0; F = 4.89, p = 0.029). A receiver-operating characteristic curve analysis of patients with and without sarcopenia identified a cutoff value for MIP of 55.6 cmH₂O, with a sensitivity of 0.76, 1-specificity of 0.37, and AUC of 0.70 (95 % CI 0.56–0.83; p = 0.01) in the study patients. Conclusion: Compared with elderly cardiac patients without sarcopenia, MIP in those with sarcopenia may be negatively affected. The MIP cutoff value reported here may be a useful minimum target value for identifying elderly male cardiac patients with sarcopenia.