Handgrip strength is not correlated with the five-times sit-to-stand test in kidney transplant patients

Low muscle strength is the primary criterion proposed by the European Working Group on Sarcopenia in Older People (EWGSOP2) for diagnosing sarcopenia, a prevalent condition in the kidney transplant population. The EWGSOP2 recommends either handgrip strength (HGS) or the five-times sit-to-stand test (5TST) to evaluate muscle strength. However, it remains unclear whether these tests are equivalent for assessing muscle strength in kidney transplant patients (KTPs).

This study aimed to evaluate the correlation between HGS and the 5TST in KTPs.

A cross-sectional study was conducted with 127 KTPs. Muscle strength was assessed using HGS and 5TST. HGS was measured using a dynamometer on the dominant hand, with the highest recorded value used for analysis. The 5TST was conducted by instructing participants to sit and stand from a chair five times as quickly as possible without using their hands. Pearson's correlation was conducted to assess the relationship between HGS and 5TST. In addition, odds ratio analyses were performed to evaluate the likelihood of inadequate 5TST in relation to inadequate HGS. Cohen's kappa (κ) test was also performed to determine the level of agreement between HGS and 5TST.

No correlation was observed between HGS and 5TST (r = 0.093; p = 0.295). After adjusting for BMI, sex, age and glomerular filtration rate, the results remained uncorrelated (r = 0.025; p = 0.777). Individuals with inadequate 5TST did not have a higher likelihood of inadequate HGS (OR = 1.391 [0.254-7.596]). A slight agreement between HGS and 5TST was observed (k = 0.0370).

HGS is not correlated with 5TST in KTPs. These results suggest that HGS and 5TST are not equivalent measures of muscle strength in this population.