Mineral disorders are associated with adverse renal outcomes in chronic kidney disease (CKD) patients. Previous studies have associated hypercalcemia and hypocalcemia with mortality; however, the association between serum calcium and renal outcome is not well-described. Whether adding calcium besides phosphorus or in the form of calcium-phosphorus (Ca × P) product into the model of survival analysis could improve the prediction of renal outcomes is not known. A prospective cohort of 2144 outpatients with CKD stages 3–4 was evaluated. Cox proportional hazard analysis was performed according to calcium quartiles. The mean calcium level was 9.2 ± 0.7 mg/dL. Low serum calcium (<9.0 mg/dL) was associated with increased risk of requiring renal replacement therapy (RRT) (hazards ratio [HR]:2.12 (95% CI: 1.49–3.02, P <0.05) and rapid renal function progression (odds ratio [OR]: 1.65 (95% CI: 1.19–2.27, P 9.8 mg/dL). Adding calcium into the survival model increased the integrated discrimination improvement by 0.80% (0.12% – 1.91%) while calcium-phosphorus product did not improve risk prediction. The combination of high serum phosphorus (>4.2 mg/dL) and low serum calcium (<9.1 mg/dL) was associated with the highest risk of RRT (HR:2.31 (95% CI: 1.45–3.67, P < 0.05). Low serum calcium is associated with increased risk of RRT and rapid renal function progression in CKD stage 3–4 patients. The integration of serum calcium and phosphorus, but not calcium-phosphorus product should be considered in a predictive model of renal outcome.

Digoxin is commonly prescribed for heart failure and atrial fibrillation, but there is limited data on its safety in patients with chronic kidney disease (CKD). We conducted a population-based cohort study using the pre-end stage renal disease (ESRD) care program registry and the National Health Insurance Research Database in Taiwan. Of advanced CKD patient cohort (N = 31,933), we identified the digoxin user group (N = 400) matched with age and sex non-user group (N = 2,220). Multivariable Cox proportional hazards and sub-distribution hazards models were used to evaluate the association between digoxin use and the risk of death, cardiovascular events (acute coronary syndrome, ischemic stroke, or hemorrhagic stroke) and renal outcomes (ESRD, rapid decline in estimated glomerular filtration rate—eGFR, or acute kidney injury). Results showed that all-cause mortality was higher in the digoxin user group than in the non-user group, after adjusting for covariates (adjusted hazard ratio, aHR 1.63; 95% CI 1.23–2.17). The risk for acute coronary syndrome (sub-distribution hazard ratio, sHR 1.18; 95% CI 0.75–1.86), ischemic stroke (sHR 1.42; 95% CI 0.85–2.37), and rapid eGFR decline (sHR 1.00 95% CI 0.78–1.27) was not significantly different between two groups. In conclusion, our study demonstrated that digoxin use was associated with increased mortality, but not cardiovascular events or renal function decline in advanced CKD patients. This finding warns the safety of prescribing digoxin in this population. Future prospective studies are needed to overcome the limitations of cohort study design.

Depression is common in dialysis patients, but the clinical impact of this condition is poorly defined. Out of 57,703 patients starting dialysis during 2000–2007 recorded in the National Health Insurance Research Database of Taiwan, we identified 2,475 patients with a clinical diagnosis of depression, and compared them with 1:5 age- and sex-matched patients without a depression diagnosis (n = 12,375). Patients were followed up for hospitalisation due to severe infections, major adverse cardiovascular events (MACE) and death. Multivariable Cox regression and competing risk analyses (accounting for death when appropriate) were used to estimate risk associations. Patients with depression had a higher frequency of comorbidities. During a mean follow-up of 3.2 years, 1,140 severe infections, 806 MACE, and 1,121 deaths were recorded. Compared to controls, patients with depression were at increased risk of death (adjusted hazard ratio 1.24; 95%CI 1.16–1.33). Patients with depression were also at higher risk of severe (1.14; 1.06–1.22) and fatal infections (death within 30 days, 1.22; 1.09–1.35), attributed mainly to sepsis (1.19; 1.08–1.31), septic shock (1.36; 1.13–1.62) and pneumonia (1.19; 1.07–1.33). Conversely, no association was observed between depression and the MACE risk (1.04; 0.94–1.15). Dialysis patients with depression are associated with increased risk of infections and death.

Thiazide, a first-line therapy for hypertension, lowers blood pressure, increases bone mineral density, and reduces the risk of fractures. However, hyponatremia, an adverse effect of thiazide, is associated with increased risk of osteoporosis and fractures. It is currently unclear whether thiazide-associated hyponatremia (TAH) outweighs the protective effects of thiazide. Using data from Taiwan’s National Health Insurance Research Database, we identified patients who were prescribed thiazide between 1998 and 2010. Those diagnosed with hyponatremia within three years after initiation of thiazide were selected for the TAH group. Thiazide users without hyponatremia were selected for the control group. The association between TAH and fracture risk was further evaluated using multivariable Cox regression models adjusted for comorbidities and medications. Subjects were followed up from the index date until the appearance of a fracture, death, or the end of a 3-year period. A total of 1212 patients were included in the TAH group, matched with 4848 patients in the control group. The incidence rate of fracture was higher in the TAH group than in the control group (31.4 versus 20.6 per 1000 person-years). TAH was associated with a higher risk of total fractures (adjusted hazard ratio [aHR]: 1.47, 95% confidence interval [CI] = 1.15–1.88), vertebra fractures (aHR: 1.84, 95% CI = 1.12–3.01), and hip fractures (aHR: 1.66, 95% CI = 1.12–2.46) after controlling for comorbidities and other medications. Thiazide users with hyponatremia have a higher risk of fracture than thiazide users without hyponatremia. The fracture-protective effect of thiazide is attenuated by TAH.