Impact of beta blockers on resting respiratory rate in older adults: A cross-sectional study

[Purpose] Beta blockers, commonly prescribed for older adults, affect heart rates and blood pressure and may reduce respiratory rates, which are used to evaluate patient status and predict outcomes. However, limited clinical evidence is available on the impact of beta blockers on respiratory rates. This study aimed to investigate the impact of beta blockers on respiratory rates in older adults. [Methods] This cross-sectional study included patients aged ≥60 years who underwent an annual checkup. Patients were excluded if they had a diagnosis of severe heart failure, chronic obstructive pulmonary disease, interstitial pneumonitis, severe anemia, or neurodegenerative disease. Doubly robust estimation with inverse probability weighting was applied to estimate the mean differences between beta blocker users and non-users. The dose-response relationship between the administered beta blockers and respiratory rates was examined using multivariable regression models. [Results] Of 637 participants, 108 had received beta blockers regularly. The adjusted mean differences (95% confidence interval, CI) in respiratory rates, pulse rates, systolic blood pressure, and diastolic blood pressure between beta blocker users and non-users were 0.35 (-0.68 to 1.37), -3.56 (-6.34 to -0.78), -5.53 (-8.53 to -2.52), and -4.70 (-8.27 to -1.14), respectively. The adjusted mean differences (95% CI) in respiratory rates per 1 mg of a carvedilol equivalent dose in all beta blocker users, liposoluble beta blocker users, and carvedilol users were -0.10 (-0.18 to -0.02), -0.35 (-0.59 to -0.11), and -0.29 (-0.54 to -0.06), respectively. [Conclusions] Beta blockers may dose-dependently reduce the respiratory rates of older adults. However, in clinical settings, the impact of beta-blocker use or non-use on the respiratory rate may not occur at a clinically important level. Clinicians should note the potentially suppressive impact of beta blockers on respiratory rates according to the situation.