Chronic kidney disease and the aging population

Ferroptosis Activation Contributes to Kidney Aging in Mice by Promoting Tubular Cell Senescence

Kidney aging is the strongest independent risk factor for chronic kidney disease. Ferroptosis, a recently discovered form of cell death mediated by iron overload and lipid peroxidation accumulation, has an unclear role in kidney aging. To determine the pathophysiological role of ferroptosis during kidney aging, we employed immunofluorescence, Western blotting, and qRT-PCR to analyze renal cells and tissues in natural aging and accelerated aging mouse models. We investigated the activation of ferroptosis during aging and examined the effects of the ferroptosis inhibitor ferrostatin-1 and the ferroptosis inducer erastin on age-related renal interstitial fibrosis in aged model mice. We found that both naturally aged and stress-aged renal tubular cells and tissues presented extensive abnormalities in ferroptosis-related genes. This included increased expression of ACSL4 and decreased expression of GPX4. Additionally, these abnormalities were accompanied by elevated free iron concentrations; increased expression of iron import proteins, and iron storage proteins; and downregulated expression of the iron export protein Fpn. We further discovered that ferrostatin-1 inhibited, whereas erastin increased, age-related renal interstitial fibrosis in aged mouse kidneys. Finally, our study revealed that aged renal tubular cells exhibit characteristics of ferroptosis and are highly sensitive to ferroptosis, as demonstrated by the activation of ferroptosis-related genes, accumulation of lipid peroxides. Ferrostatin-1 inhibited, whereas erastin increased, D-galactose induced, renal tubular cell senescence in vitro. These findings suggest that ferroptosis exacerbates renal tubular cell senescence and age-related renal interstitial fibrosis. Managing ferroptosis may represent a novel strategy for reversing kidney aging.

Medication regimen complexity and medication adherence in elderly patients with chronic kidney disease

INTRODUCTION

Elderly patients with chronic kidney disease (CKD) stage 5 with or without dialysis treatment usually have concomitant comorbidities, which often result in multiple pharmacological therapies. This study aimed to identify factors associated with medication complexity and medication adherence, as well as the association between medication complexity and medication adherence, in elderly patients with CKD.

METHODS

This prospective study involved elderly patients with CKD stage 5 (estimated glomerular filtration rate < 15 ml/min/1.73m² ) recruited from three Norwegian hospitals. Most of the patients were receiving either hemodialysis or peritoneal dialysis. We used the Medication Regimen Complexity Index (MRCI) to assess the complexity of medication regimens, and the eight-item Morisky Medication Adherence Scale (MMAS-8) to assess medication adherence. Factors associated with the MRCI and MMAS-8 score were determined using either multivariable linear or ordinal logistic regression analysis.

FINDINGS

In total, 157 patients aged 76 ± 7.2 years (mean ± SD) were included in the analysis. Their overall MRCI score was 22.8 ± 7.7. In multivariable linear regression analyses, female sex (P = 0.044), Charlson Comorbidity Index of 4 or 5 (P = 0.029) and using several categories of phosphate binders (P < 0.001 to 0.04) were associated with the MRCI. Moderate or high adherence (MMAS-8 score ≥ 6) was demonstrated by 83% of the patients. The multivariable logistic regression analyses found no association of medication complexity, age or other variables with medication adherence as assessed using the MMAS-8.

DISCUSSION

Female sex, comorbidity and use of phosphate binders were associated with more-complex medication regimens in this population. No association was found between medication regimen complexity, phosphate binders or age and medication adherence. These findings are based on a homogeneous elderly group, and so future studies should test if they can be generalized to patients of all ages with CKD.

Bisphosphonates for Osteoporosis in Patients with Renal Insufficiency: Pharmacists' Practices and Beliefs

BACKGROUND

Clinicians often face challenges in deciding how to treat osteoporosis in patients with chronic kidney disease. As background to offering guidance to health care providers, it is important to understand their practices and beliefs.

OBJECTIVES

To describe the practices and beliefs of pharmacists regarding use of bisphosphonates for patients with osteoporosis and chronic kidney disease.

METHODS

A cross-sectional survey of pharmacists working in hospitals and related health care settings was conducted. A 34-item online questionnaire was developed consisting of 4 sections: demographic characteristics, practices, beliefs, and comfort level with making decisions about osteoporosis treatment. An e-mail invitation was sent to members of the Canadian Society of Hospital Pharmacists (n = 2499) in November 2012.

RESULTS

A total of 367 pharmacists completed the survey. Most of the respondents were women (258 [70%]), had more than 10 years in practice (213 [58%]), and were providing care to 1 or more osteoporosis patients per week (212 [58%]). Over one-third (150 [41%]) stated that they would use a bisphosphonate for patients with creatinine clearance (CrCl) of 15-30 mL/min, but more than half (207 [56%]) stated that they would avoid a bisphosphonate (and recommend another medication) for patients with CrCl below 15 mL/min. Forty-eight percent (176/363) agreed that oral bisphosphonates could be used for patients with renal failure (defined as CrCl < 30 mL/min), so long as dosage adjustments are made. More than half (206/363 [57%]) believed that the adverse effects of oral bisphosphonates increase for patients with renal failure. Respondents expressed a low level of comfort in assessing and initiating osteoporosis treatment for patients with renal failure.

CONCLUSIONS

Pharmacists had varying beliefs about managing osteoporosis in patients with chronic kidney disease. This study highlights the need for practice tools and targeted education addressing the use of bisphosphonates for these patients.