Influence of Malnutrition on the Improvement of Physical Function by Intradialytic Resistance Exercise in Patients Undergoing Hemodialysis

Abstract

Intradialytic exercise improves physical function. However, malnutrition may be an essential factor affecting the effectiveness of exercise to improve physical function. Few studies of the relationship between malnutrition and the effectiveness of intradialytic exercise to improve physical function exist. Therefore, this study investigated malnutrition at the beginning of intradialytic exercise and how it affects the subsequent improvement in physical function. Patients who performed intradialytic exercise for 12months were enrolled in this study. A Geriatric Nutritional Risk Index of 91.2 was defined as malnutrition. Patients were assigned to 2 groups using propensity score matching to adjust for confounding factors. Physical function outcomes were handgrip strength, isometric knee extension strength, short physical performance battery, and 10-m walking speed; these were compared at baseline, 3months, 6months, and 12months. The 2 groups were further divided into another 2 groups as per whether the nutritional status had improved after 12months; therefore, a total of 4 groups were analyzed. After matching, the data of 154 patients in each group were analyzed. During the intragroup comparison, isometric knee extension strength, short physical performance battery, and 10-m walking speed improved significantly in both groups after intradialytic exercise was started compared with before intradialytic exercise was started. However, there was no significant improvement in handgrip strength in the malnutrition group. There were no significant differences in any of the physical function measurements or changes from the baseline values among the 4 groups divided as per subsequent recovery of the nutritional status. Malnutrition may not impact the effectiveness of intradialytic exercise to improve lower-leg physical function. Its effect on the improvement of handgrip strength requires further investigation.