Associations of vitamin D receptor activators and calcimimetics with falls and effect modifications by physical activity: A prospective cohort study on the Japan Dialysis Outcomes and Practice Patterns Study.

INTRODUCTION: This study aimed to examine the associations of vitamin D receptor activators (VDRA) and calcimimetics use with falls. METHODS: This is a prospective cohort study on hemodialysis patients in the Japan Dialysis Outcomes and Practice Patterns Study. We excluded those who were unable to walk. The associations of VDRA or calcimimetics use with falls and effect modifications by physical activity were analyzed using marginal structural models. RESULTS: In total, 1875 patients were included. VDRA and calcimimetics use was not associated with falls (risk ratio [95% CI]: 1.13 [0.84-1.51] and 1.02 [0.72-1.44]). The risk ratio for falls associated with VDRA use was lower among those with poor physical activity (p for interaction <0.1). CONCLUSIONS: Although vitamin D receptor activators and calcimimetics use was not associated with falls, the lower risk ratio for falls with vitamin D receptor activators use among those with poor physical activity suggests that vitamin D receptor activators use might be beneficial among these patients.

Serum total indoxyl sulfate and clinical outcomes in hemodialysis patients: results from the Japan Dialysis Outcomes and Practice Patterns Study.

BACKGROUND: Uremic toxins are associated with various chronic kidney disease-related comorbidities. Indoxyl sulfate (IS), a protein-bound uremic toxin, reacts with vasculature, accelerating atherosclerosis and/or vascular calcification in animal models. Few studies have examined the relationship of IS with clinical outcomes in a large cohort of hemodialysis (HD) patients. METHODS: We included 1170 HD patients from the Japan Dialysis Outcomes and Practice Patterns Study Phase 5 (2012-15). We evaluated the associations of serum total IS (tIS) levels with all-cause mortality and clinical outcomes including cardiovascular (CV)-, infectious- and malignancy-caused events using Cox regressions. RESULTS: The median (interquartile range) serum tIS level at baseline was 31.6 µg/mL (22.6-42.0). Serum tIS level was positively associated with dialysis vintage. Median follow-up was 2.8 years (range: 0.01-2.9). We observed 174 deaths (14.9%; crude rate, 0.06/year). Serum tIS level was positively associated with all-cause mortality [adjusted hazard ratio per 10 µg/mL higher, 1.16; 95% confidence interval (CI) 1.04-1.28]. Association with cause-specific death or hospitalization events, per 10 µg/mL higher serum tIS level, was 1.18 (95% CI 1.04-1.34) for infectious events, 1.08 (95% CI 0.97-1.20) for CV events and 1.02 (95% CI 0.87-1.21) for malignancy events after adjusting for covariates including several nutritional markers. CONCLUSIONS: In a large cohort study of HD patients, serum tIS level was positively associated with all-cause mortality and infectious events.

The effect of transportation modality to dialysis facilities on health-related quality of life among hemodialysis patients: results from the Japanese Dialysis Outcomes and Practice Pattern Study.

BACKGROUND: For hemodialysis (HD) patients, travel to the dialysis facility is an issue that can affect their quality of life (QOL), both physically and mentally. However, evidence on this association of transportation modality with health-related QOL (HRQOL) is scarce. METHODS: We conducted a cohort study among maintenance HD patients participating in the Japanese Dialysis Outcomes and Practice Pattern Study Phase 5. The study included patients who were functionally independent and able to walk. The primary exposure was the means of transportation to the dialysis facility, categorized into three groups, namely transportation by other drivers (Group 1), transportation via self-driving (Group 2) and transportation by bicycle or walking with or without public transportation (Group 3). The primary outcomes were physical and mental health composite scores (PCS and MCS) in the 12-item Short Form at 1 year after study initiation. RESULTS: Among 1225 eligible patients (Group 1, 34.4%; Group 2, 45.0%; Group 3, 20.7%), 835 were analyzed for the primary outcomes. Linear regression analyses revealed that patients in Groups 2 and 3 had significantly higher PCS and MCS at 1 year than those in Group 1 {adjusted mean differences of PCS 1.42 [95% confidence interval (CI) 0.17-2.68] and 1.94 [95% CI 0.65-3.23], respectively, and adjusted mean differences of MCS 2.53 [95% CI 0.92-4.14] and 2.20 [95% CI 0.45-3.95], respectively}. CONCLUSIONS: Transportation modality was a significant prognostic factor for both PCS and MCS after 1 year in maintenance HD patients.