Introduction:
Chronic kidney disease (CKD) is associated with alterations in body composition, which appears ahead of the conventional markers of protein-energy wasting (PEW). There are no kidney-specific tools for screening sarcopenia in CKD. The European Working Group for Sarcopenia in Older Patients 2 (EWGSOP2) recommends the use of a 5-point SARC-F questionnaire as a screening tool and further testing is warranted when the SARC-F score is more than or equal to 4. However, this SARC-F questionnaire is validated in the geriatric population and the effectiveness of the SARC-F questionnaire as a screening tool for Sarcopenia in CKD has not been tested. The main aim of our study was to examine the utility of the 5-component SARC-F questionnaire as a screening tool for sarcopenia among patients with CKD.
Methods:
All patients in CKD stages 3 and 4 attending the JIPMER Nephrology Outpatient Department were recruited between June 2022 to September 2023. Evaluations were performed using the self-administered SARC-F questionnaire. Irrespective of the SARC-F score, all patients underwent muscle strength testing using Jamar’s handheld dynamometer and Chair stand test. Muscle mass (Appendicular Skeletal Muscle Index-ASMI) was measured using the 3-compartment DXA. All patients with sarcopenia (Low muscle strength and Low ASMI) performed the gait speed test for severity assessment. The level of agreement between the SARC-F questionnaire and Sarcopenia was tested using the Kappa statistic. Sensitivity and specificity with Confidence intervals were used to assess the utility of the SARC-F questionnaire as a screening tool.
Results:
A total of 190 patients were recruited. The mean age of the study population was 56.6 ± 11.6 years and 80.5 % were males. 18.4%, 37.4%, and 44.2% of the study population belonged to CKD- Stage 3A,3B, and 4 respectively. SARC-F questionnaire identified that only 11.5% of the study population had Sarcopenia. A total of 76.8% were found to have low muscle strength. ASMI was low in around 52.6% of the study population. 41.6% qualified the definition of sarcopenia (Low muscle strength and low muscle mass). Based on the kappa statistic, the inter-rater agreement for SARC-F to correctly identify Sarcopenia was poor (0.093 (p<0.076). The sensitivity and specificity of SARC-F questionnaire as a screening tool were 16.5% (CI 9.1-26.5) and 91.9% (CI 85.2-96.2) respectively. Using upper limb muscle strength as a screening tool provides a higher sensitivity of 98.73% (93.15 – 99.97) for the detection of Sarcopenia.
Conclusions:
Based on our observations, SARC-F has poor inter-rater agreement and low sensitivity. Hence, it cannot be used as a screening tool in relatively young patients with CKD. However, using hand grip strength for screening will have a higher sensitivity.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.