Hideaki Ishikawa, Takashi Hibino, Yoshifumi Moriyama
Department of Nephrology, Japanese Red Cross Nagoya Daiichi Hospital, 453-8511 Nakamuraku Nagoya Aichi  Japan
DOI: 10.2340/20030711-1000013

Background: Physical impairment or frailty due to sarcopaenia is common in patients with chronic kidney disease and those receiving dialysis. This study examined the association between muscle weakness and kidney function in Japanese patients with chronic kidney disease.
Methods: A total of 23 stable outpatients were enrolled in the study. Several indices were used to assess muscle function; hand grip strength, isometric knee extension strength, Timed Up and Go test (TUG), and the short physical performance battery. The relationships between these indices and estimated glomerular filtration rate (eGFR) as a measure of kidney function were analysed statistically.
Results: Patients’ characteristics were as follows: mean age 73. 9 years (standard deviation (SD) 13); 12 males, 11 females; body mass index (BMI) 22. 5 kg/m2 (SD 3. 2); serum creatinine (sCr) 4. 6 mg/dl (SD 3. 7); estimated glomerular filtration rate (eGFR) 19. 1 ml/min (SD 16). Their physical performance indices were: hand grip strength 20. 8 kg (SD 7. 9); isometric knee extension strength 19. 1 kgf/kg (SD 10. 6); TUG 14. 9 s (SD 6. 0); and short physical performance battery score 7. 0 (SD 4. 3). Multiple regression analysis adjusted for age revealed significant associations between isometric knee extension strength/body weight and eGFR (F [2,19] = 8. 38, p = 0. 002) and TUG and eGFR (F=4. 98 [2,18], p = 0. 02).
Conclusion: Deterioration in muscle function or maintenance of posture is associated with chronic kidney disease.

Frailty due to sarcopaenia is common in patients with chronic kidney disease and those receiving dialysis. However, there is limited information available on the relationship between kidney function and such comorbidities in the Japanese chronic kidney disease population. Such comorbidities are a potential risk for poor physical activity, disability, falls, more frequent hospitalization and, especially, increased mortality. This study included a total of 23 stable outpatients, and measured several indices of muscle function, such as hand grip strength, isometric knee extension strength, Timed Up and Go test, and short physical performance battery. Relationships between these indices and kidney function, assessed by the estimated glomerular filtration rate, were then examined. Deterioration in muscle function and maintenance of posture were found to be associated with chronic kidney disease.