Hand grip strength measurement in haemodialysis patients: before or after the session?

Background: Hand grip strength (HGS) is a key measurement in the assessment of frailty phenotype in haemodialysis
patients. However, the measurement is not very standardized, and notably, current data on the potential impact of a
haemodialysis session on the results are both limited and controversial. In the present analysis, we compared HGS results
before and after a haemodialysis session in 101 patients.
Methods: In the current observational study, HGS has been measured in adult haemodialysis patients on the same day, first
before connection to the dialysis machine and then just after disconnection. At each timing, measurements were repeated
three times with an interval of 5 s between measurements and the higher value was used for analysis.
Results: One hundred and one patients (64% men) with a median (interquartile range, 25th percentile; 75th percentile) age
of 66 (46; 76) years were included. In the whole population, a significant decline in HGS was observed after dialysis, with an
absolute median decline of 4 (0; 6) kg and a relative median difference of 11 (0; 20)%. These differences were observed
in both genders and were independent of the baseline HGS value.
Conclusions: Our results suggest that the timing (before or after the dialysis session) of hand grip assessment is clinically
relevant and should be taken into account in clinical practice and also in epidemiological and clinical studies.