One-Year Trajectories of Peripheral and Inspiratory Muscle Strength in Critical Illness Survivors: The Impact of ICU-Acquired Weakness

Objective: This prospective cohort study evaluated one-year trajectories of age-and sexnormalized handgrip strength and maximal inspiratory pressure in intensive care unit (ICU) survivors and examined the impact of ICU-acquired weakness (ICUAW) on recovery.Methods: ICU survivors from six medical ICUs in Taiwan were enrolled.ICUAW was identified at ICU discharge using the Medical Research Council sum score (MRC-SS).Peripheral and inspiratory muscle strength were assessed by handgrip strength (HGS) and maximal inspiratory pressure (MIP) at ICU discharge and 1, 3, 6, and 12 months, and expressed as age-and sex-specific normative values.Trajectories were analyzed using Generalized Estimating Equations.Results: 275 ICU survivors completed the MRC-SS assessment at ICU discharge; 166 (60.4%) required mechanical ventilation, and 62 (22.5%) screened positive for ICUAW.In the ICUAW group, mean HGS improved from 30.0% to 56.1% and MIP from 15.4% to 36.5% of normative values over one year.In contrast, non-ICUAW survivors improved from 70.2% to 97.5% for HGS and from 35.4% to 63.1% for MIP.Both groups showed significant improvements in HGS and MIP (p < .001),while ICUAW survivors exhibited lower muscle strength than those without ICUAW (HGS: = -36.8;MIP:J o u r n a l P r e -p r o o f = -23.1;p < .001).Group-by-time interactions were non-significant, indicating parallel improvements with a persistent deficit in the ICUAW group.Conclusions: Survivors with ICUAW improved over time but remained consistently below non-ICUAW peers, particularly because of early respiratory weakness.Early screening, reassessment, and targeted peripheral and inspiratory muscle strengthening may help optimize recovery after ICU discharge.