The impact of the combination of kidney and physical function on cognitive decline over 2 years in older adults with pre-dialysis chronic kidney disease.

BACKGROUND: No longitudinal study has investigated the impact of combination of kidney function (KF) and physical function (PF) on cognitive decline in these patients. METHODS: We conducted a 2-year prospective cohort study enrolling 131 patients ≥ 65 years with pre-dialysis chronic kidney disease (CKD). We assessed cognitive function with the Japanese version of the Montreal Cognitive Assessment (MoCA-J). We calculated %MoCA-J based on the rate of change between baseline and follow-up MoCA-J scores, and defined cognitive decline over 2 years as a %MoCA-J of less than the first quartile value. We defined eGFR ≥ 30 as mild-to-moderate and eGFR < 30 mL/min per 1.73 m2 as severe. In addition, low PF was defined as low handgrip strength (< 26 for men and < 18 kgf for women) and/or low gait speed (< 0.8 m/s). Patients were classified into four groups: group 1, patients with mild-to-moderate impairment in KF and high PF; group 2, with mild-to-moderate impairment in KF and low PF; group 3, with severe impairment in KF and high PF; and group 4, with severe impairment in KF and low PF. RESULTS: Eighty-four patients completed follow-up assessment. Multivariate logistic regression analysis showed that the combination of severe impairment in KF and low PF was significantly associated with cognitive decline (odds ratio 5.73). However, no significant cognitive decline was observed in patients with either severe impairment in KF or low PF alone. CONCLUSIONS: We may need to focus on maintaining PF in older patients with advanced CKD may help to prevent cognitive decline.

Mild cognitive impairment in older adults with pre-dialysis patients with chronic kidney disease: Prevalence and association with physical function.

AIM: Chronic kidney disease (CKD) is a risk factor for declining cognitive and physical function. However, the prevalence of mild cognitive impairment (MCI) and its relationship with physical function is not clear. Therefore, our aim was to evaluate the prevalence of MCI and the relationship between MCI and physical function among older adults with pre-dialysis CKD. METHODS: We conducted a cross-sectional study of 120 patients, aged ≥65 years (mean age, 77.3 years), with pre-dialysis CKD but without probable dementia (Mini Mental State Examination <24). MCI was evaluated using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). For analysis, patients were classified into two cognitive function groups: normal (MoCA-J ≥ 26) and MCI (MoCA-J < 26). Physical, clinical, and biochemical parameters were compared between the groups. Logistic and linear regression analyses were used to evaluate the specific association between cognitive and physical function. RESULTS: Seventy-five (62.5%) patients belonged to the MCI group. Significant differences between the two groups were identified for gait speed, balance, age, and haemoglobin concentration. After adjustment for covariates, only gait speed was significantly associated with MCI (odds ratio, 0.06; 95% confidence interval, 0.009-0,411). CONCLUSION: The prevalence of MCI among older adults with pre-dialysis CKD was as high as 62.5%. The association between MCI and reduced gait speed supports the possible interaction between physical and cognitive functions and the need for early screening.

Effects of home-based exercise on pre-dialysis chronic kidney disease patients: a randomized pilot and feasibility trial.

BACKGROUND: Only a few research is available on the effects of home-based exercise training on pre-dialysis chronic kidney disease (CKD) patients. Therefore, we aimed to elucidate the effect of home-based exercise therapy on kidney function and arm and leg muscle strength in pre-dialysis CKD patients. METHODS: Thirty-six male stage 3-4 pre-dialysis CKD patients (age, 68.7 ± 6.8 years; estimated glomerular filtration rate (eGFR), 39.0 ± 11.6 ml/min/1.73 m2) who were being treated as outpatients were included. The subjects were randomly assigned to an exercise intervention group (Ex group: 18) and a control group (C group: 18). The Ex group wore accelerometer pedometers and were instructed to perform home-based aerobic and resistance exercises, such as brisk walking for 30 min per day, for 12 months. The C group subjects wore accelerometer pedometers but received no exercise therapy guidance; the number of steps covered during normal daily activities was recorded for the C group. The outcome measures were changes in kidney function and handgrip and knee extension muscle strength. Values at the baseline (T1) and 12 months later (T2) were compared. RESULTS: There were no significant differences in baseline characteristics between the two groups; however, the C group was more physically active than the Ex group. Eight subjects dropped out, and 28 subjects (14 in each group) were included in the final analysis. Physical activity increased significantly only in the Ex group. Grip strength (F = 7.0, p = 0.01) and knee extension muscle strength (F = 14.3, p < 0.01) were found to improve only in the Ex group. Further, the changes in eGFR were not significantly different between the two groups (F = 0.01, p = 0.93). CONCLUSIONS: Home-based exercise therapy for pre-dialysis CKD patients was feasible and improved arm and leg muscle strength without affecting kidney function. TRIAL REGISTRATION: UMIN Clinical Trials Registry ( UMIN000005091 ). Registered 2/15/2011.

Knee extensor muscle strength and index of renal function associated with an exercise capacity of 5 metabolic equivalents in male chronic heart failure patients with chronic kidney disease.

BACKGROUND: The goal of the present study was to determine knee extensor muscle strength (KEMS) and degree of renal dysfunction associated with an exercise capacity of ≥5 metabolic equivalents (METs) in male chronic heart failure (CHF) patients with chronic kidney disease (CKD). METHODS: In this cross-sectional study of 75 male CHF patients with CKD (65.3 ± 11.6 years), we measured clinical characteristics, peak [Formula: see text], estimated glomerular filtration rate (eGFR), and KEMS. Patients were divided into two groups by exercise capacity: ≥5 METs group (n = 41) and <5 METs group (n = 34). Cutoff values for KEMS and eGFR resulting in an exercise capacity of ≥5 METs were selected with ROC curves. Patients were divided into four groups according to cutoff values, and numbers of patients attaining an exercise capacity of ≥5 METs were compared between groups. RESULTS: Age was significantly higher although eGFR, Hb, and KEMS were lower in the <5 METs versus ≥5 METs group (P < 0.001). Multiple logistic regression analysis revealed a positive significant relation between KEMS and eGFR and exercise capacity of ≥5 METs. Exercise capacity of ≥5 METs was associated with KEMS of approximately 1.69 Nm/kg and an eGFR of 45.7 mL/min/1.73 m(2). The number of patients attaining an exercise capacity of ≥5 METs in the patients who did not reach both cutoff values was significantly lower than that in any other patients (P < 0.001). CONCLUSION: KEMS and eGFR may be useful indices for predicting attainment of exercise capacity of ≥5 METs in male CHF patients with CKD.

Moderate-intensity single exercise session does not induce renal damage.

BACKGROUND: The aim of this study was to determine whether a single moderate-intensity exercise session induces renal injury based on various parameters that reflect kidney dysfunction, including urinary L-type fatty acid-binding protein (L-FABP). METHODS: Adult outpatients (n = 31) with chronic kidney disease (CKD) not receiving renal replacement therapy participated in this study. Urine was collected before and after a single 20-min moderate-intensity exercise session. Urinary levels of L-FABP, albumin, N-acetyl-ß-d-glucosaminidase (NAG), and α1-microglobrin (α1MG) were measured. In addition, 12 patients with estimated glomerular filtration fraction less than 30 ml/min/1.73 ml(2) were selected from all patients and evaluated using the same analysis. RESULTS: Urinary values of L-FABP, albumin, NAG, and α1MG did not increase significantly after exercise compared with before exercise (urinary L-FABP, from 8.3 to 9.4 µg/g of creatinine; urinary albumin, from 293.1 to 333.7 mg/g of creatinine; urinary NAG, from 9.2 to 8.2 U/g of creatinine; urinary α1MG, from 11.4 to 9.8 mg/g of creatinine, not significant). Similar findings were seen in all patients, regardless of degree of renal dysfunction. CONCLUSIONS: A single session of moderate-intensity exercise was not associated with an increase in renal parameters used to assess renal damage.

Decreased physical function in pre-dialysis patients with chronic kidney disease.

BACKGROUND: Patients undergoing dialysis experience decreases in physical function; however, few data exist on physical function in pre-dialysis patients with chronic kidney disease (CKD). The primary objective of this study was to clarify physical function in pre-dialysis patients according to CKD stage. METHODS: This was a cross-sectional study of 120 ambulant pre-dialysis CKD stage 2 or higher patients (85 male, 35 female; mean age 66.5 years) who visited St. Marianna University School of Medicine Hospital. Participants were grouped according to CKD stage as follows: stage 2 (n = 17), stage 3 (n = 55), stage 4 (n = 25), and stage 5 (n = 23). Handgrip strength, knee extensor muscle strength, single-leg stance time, and maximum gait speed were used to assess physical function. Clinical laboratory tests were also examined at the same time as physical function measurements. RESULTS: All indices of physical function decreased according to the progression of CKD. Each physical function index was significantly lower in CKD stage 4 or 5 patients than CKD stage 2 or 3 patients. All physical function indices showed a positive correlation with estimated glomerular filtration rate (eGFR), blood hemoglobin level, and serum albumin level, and a negative correlation with urinary protein levels. In multiple regression analysis, age, female sex, body mass index, eGFR and urinary protein were significantly correlated with indices of physical function. CONCLUSION: Physical function in pre-dialysis CKD patients decreased as the disease progressed according to stage. Early intervention in CKD patients might delay the loss of physical function.