Add-on Protective Effect of Pentoxifylline in Advanced Chronic Kidney Disease Treated with Renin-Angiotensin-Aldosterone System Blockade - A Nationwide Database Analysis

Risks of Topical Carbonic Anhydrase Inhibitors in Glaucoma Patients With Chronic Kidney Disease: A Nationwide Population-Based Study

PURPOSE

To investigate the risks of metabolic acidosis and renal outcomes after topical carbonic anhydrase inhibitor (CAI) use in patients with both primary open-angle glaucoma (POAG) and advanced chronic kidney disease (CKD).

DESIGN

Nationwide, population-based cohort study.

METHODS

This study was conducted with population data from Taiwan's National Health Insurance (NHI) Research Database between January 2000 and June 2009. Patients with advanced CKD who were diagnosed with glaucoma (International Classification of Diseases, Ninth Revision [ICD-9] code 365) and had been receiving eye drops for glaucoma (including carbonic anhydrase inhibitors selected by NHI drug code) were enrolled. Using Kaplan-Meier methods, we compared the cumulative incidence of mortality, long-term dialysis, and cumulative incidence of metabolic acidosis over time between CAI users and CAI non-users. Primary outcomes comprised mortality, renal outcome (progression to hemodialysis), and metabolic acidosis.

RESULTS

In this cohort, topical CAI users had a higher incidence of long-term dialysis than non-users (incidence = 1,216.85 vs 764.17 events per 100 patient-years; adjusted hazard ratio = 1.17, 95% CI = 1.01-1.37). Hospital admissions due to metabolic acidosis were higher in CAI users compared with non-users (incidence = 21.54 vs 11.87 events per 100 patient-years; adjusted hazard ratio = 1.89, 95% CI = 1.07-3.36).

CONCLUSIONS

Topical CAIs may be associated with higher risks of long-term dialysis and metabolic acidosis in patients with POAG and pre-dialysis advanced CKD. Therefore, topical CAIs should be used with caution in advanced CKD patients.

Effects of Pentoxifylline on Serum Markers of Diabetic Nephropathy in Type 2 Diabetes

OBJECTIVE

To investigate the effects of pentoxifylline (PTX) in combination with losartan compared to the high dose of losartan alone on serum markers of diabetic nephropathy such as HSP70, copeptin, CRP, and TNFα in patients with type 2 diabetes and nephropathy.

METHODS

A single-center, randomized, double-blind, open-label clinical trial was conducted. Sixty-two patients were eligible and allocated to "PTX + losartan" and "high-dose losartan" arms of the trial using software for random number generation. The first arm received 400 mg PTX two times a day (BD) plus 50 mg losartan daily, while the second arm received 50 mg losartan two times a day (BD) for 12 weeks. Comparison of the biomarkers' levels before and after treatment was done using paired sample t test variance. ANCOVA was applied to evaluate the comparative efficacy of the two interventions. The effect size was calculated and reported for each biomarker.

RESULTS

Urine albumin excretion (UAE), hs-CRP, and HbA1c significantly decreased in both trial arms compared to the baseline measures. Copeptin and TNFα showed significant differences (after vs before) only in the losartan group (p = 0.017 and p = 0.043, respectively). The losartan arm was more successful in reducing TNFα, copeptin, HSP70, systolic blood pressure (SBP), and diastolic blood pressure (DBP) values (p = 0.045, effect size = 7.3%; p = 0.018, effect size 10.1%; p = 0.046, effect size 4.7%, p = 0.001, effect size 23%; p = 0.012, effect size 10.2%, respectively) and the PTX arm was associated with a superior reduction of UAE and hs-CRP levels (p = 0.018, effect size 9.1%; p = 0.028, effect size 9.2%, respectively).

CONCLUSION

Add-on PTX to losartan may have more effective anti-inflammatory and anti-albuminuric roles and therefore may be more applicable in the management of diabetic nephropathy compared with high-dose losartan alone.

TRAIL REGISTRATION

Trial number IRCT 20121104011356N10.

Four prescribed Chinese herbal medicines provide renoprotection and survival benefit without hyperkalemia risk in patients with advanced chronic kidney disease: A nationwide cohort study

BACKGROUND

Chinese herbal medicine (CHM) has been used as adjuvant treatment of chronic kidney disease (CKD) for years. Astragalus membranaceus (A. membranaceus, Huangqi [A]), Angelica sinensis (Oliv.) Diels (Danggui [S]), Rheum palmatum L. (Dahuang [R]), and Salvia miltiorrhiza Bunge (Danshen [D]) are considered as potentially renoprotective CHMs. However, there is limited evidence on whether ASRD use affects outcomes and causes hyperkalemia in patients with stage 4 and stage 5 advanced CKD.

PURPOSE

To investigate between ASRD use (vs. nonuse) and risks of end-stage renal disease (ESRD), death, and hyperkalemia in patients with advanced CKD.

STUDY DESIGN

Retrospective nationwide cohort study using claims data from the Taiwan's 2005 Longitudinal Generation Tracking Database in 2000-2016.

METHODS

A total of 24,572 patients with advanced CKD were identified and 15,729 eligible patients were enrolled in the propensity score matching, with 1,401 incident ASRD users (8.9%) and 14,328 nonusers (91.1%). Finally, 1,076 ASRD users and 4,304 matched nonusers were subjected to analysis. We used Cox proportional hazards regression model to estimate the hazard ratios for ESRD and death and Poisson regression to estimate incidence rate ratio of hyperkalemia. The additive effect of one to four ASRD and the pooling effect of individual ASRD on risks of ESRD and death were also addressed.

RESULTS

In a total follow-up of 15,740 person-years, 2,703 patients (50.2%) developed ESRD and 499 (9.3%) died before progression to ESRD. As compared with nonusers, ASRD users were associated with adjusted hazard ratios of 0.83 (95% confidence interval, 0.76-0.91) for ESRD and 0.78 (0.30-0.93) for death, as well as adjusted incidence rate ratios of 0.54 (0.48-0.60) for inpatient hyperkalemia and 0.44 (0.42-0.46) for total hyperkalemia. The renal and survival benefits of ASRD use were consistent across almost patient subgroups on multivariate stratified analyses. Using all four ASRD provided the lowest risks of ESRD (0.30; 0.71-0.52) and death (0.32; 0.17-0.63). Individual use of ASRD also demonstrated comparable renal and survival benefits.

CONCLUSION

ASRD use was associated with lower risks of ESRD and death among advanced CKD patients. This benefit did not increase hyperkalemia risk.

Symptomatic menopausal transition and risk of subsequent stroke

Objective

To examine the long-term risk of stroke in women who have experienced symptomatic menopausal transition.

Methods

In this nationwide, population-based cohort study conducted from January 1, 2000 to December 31, 2013, we identified 22,058 women with no prior history of stroke, who experienced symptomatic menopausal transition at ≥45 years of age. Moreover, 22,058 women without symptomatic menopause were matched by propensity scores and enrolled as a comparison group. The propensity score was calculated by using all characteristic variables of each subject, including demographics (age and monthly income), comorbidities (hypertension, hyperlipidemia, diabetes mellitus, obesity, chronic kidney disease, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, dysrhythmia, peripheral artery occlusive disease), Charlson’s comorbidity index score, clinic visit frequency, and long-term medications (antihypertensives, antidiabetic agents, statins, antiplatelets, aspirin, warfarin, and hormone replacement therapy). The primary endpoint was the development of stroke after the onset of symptomatic menopausal transition. The Fine and Gray’s proportional subhazards model was performed to assess the association between symptomatic menopausal transition and subsequent stroke. All subjects were followed up until December 31, 2013.

Results

During a mean follow-up of 8.5 years (standard deviation 4.7 years, maximum 14 years), 2,274 (10.31%) women with symptomatic menopausal transition, and 1,184 (5.37%) matched comparison participants developed stroke. The incidence rates were 11.17 per 1,000 person-years in the symptomatic menopausal transition group compared with 8.57 per 1,000 person-years in the comparison group. The risk of developing stroke was significantly higher in women with symptomatic menopausal transition (crude subhazard ratio, 1.31; 95% confidence interval (CI) [1.22–1.41]; P < 0.001). After adjusting for demographics, comorbidities, clinic visit frequency, and long-term medications, the risk of stroke remained statistically significant (adjusted subhazard ratio, 1.30; 95% CI [1.21–1.40]; P < 0.001). Moreover, subgroup analyses revealed no evidence for inconsistent effects for symptomatic menopausal transition on subsequent risk of stroke across all subgroups except age, comorbidities, hypertension, and use of antihypertensives. Women with early menopausal transition (before age 50), without comorbid condition, without hypertension, or without use of antihypertensives are at a higher risk of stroke. The longer duration of symptomatic menopausal transition was associated with higher risk of stroke (P for trend < 0.001).

Conclusion

In this large-scale retrospective cohort study, symptomatic menopausal transition was statistically significantly associated with a 30% increased risk of stroke. Further prospective studies are required to confirm our findings.

Comparing the Effect of Folic Acid and Pentoxifylline on Delaying Dialysis Initiation in Patients with Advanced Chronic Kidney Disease

Background: We hypothesized that the nutrient loss and chronic inflammation status may stimulate progression in advanced chronic kidney disease. Therefore, we aimed to generate a study to state the influence of combined nutritional and anti-inflammatory interventions. Methods: The registry from the National Health Insurance Research Database in Taiwan was searched for 20–90 years individuals who had certified end-stage renal disease. From January 2005 through December 2010, the diagnosis code ICD-9 585 (chronic kidney disease, CKD) plus erythropoiesis-stimulating agent (ESA) use was defined as entering advanced chronic kidney disease. The ESA starting date was defined as the first index date, whereas the initiation day of maintenance dialysis was defined as the second index date. The duration between the index dates was analyzed in different medical treatments. Results: There were 10,954 patients analyzed. The combination therapy resulted in the longest duration (n = 2184, median 145 days, p < 0.001) before the dialysis initiation compared with folic acid (n = 5073, median 111 days), pentoxifylline (n = 1119, median 102 days, p = 0.654), and no drug group (control, n = 2578, median 89 days, p < 0.001). Lacking eGFR data and the retrospective nature are important limitations. Conclusions: In patients with advanced CKD on the ESA treatment, the combination of folic acid and pentoxifylline was associated with delayed initiation of hemodialysis.

Evolving spectrum of diabetic nephropathy

Diabetes remains an important health issue as more patients with chronic and uncontrolled diabetes develop diabetic nephropathy (DN), which classically presents with proteinuria followed by a progressive decrease in renal function. However, an increasing proportion of DN patients have a decline in kidney function and vascular complications without proteinuria, known as non-proteinuric DN (NP-DN). Despite the increased incidence of NP-DN, few clinical or experimental studies have thoroughly investigated the pathophysiological mechanisms and targeted treatment for this form of DN. In this review, we will examine the differences between conventional DN and NP-DN and consider potential pathophysiological mechanisms, diagnostic markers, and treatment for both DN and NP-DN. The investigation of the pathophysiology of NP-DN should provide additional insight into the cardiovascular factors influencing renal function and disease and provide novel treatments for the vascular complications seen in diabetic patients.

Association and risk factors of chronic kidney disease and incident diabetes: a nationwide population-based cohort study

AIMS/HYPOTHESIS

Chronic kidney disease (CKD) is a known complication of diabetes mellitus, and insulin resistance is a well-known complication of CKD. However, there is no consensus in the published data on the association of CKD with incident diabetes.

METHODS

A total of 15,403 people with CKD were identified from the Taiwan National Health Insurance Research Database to determine their risk of incident diabetes compared with that of 15,403 matched individuals without CKD. Fine and Gray regression models using death as a competing risk were performed to calculate adjusted HRs and 95% CIs. Risk factors for incident diabetes in people with CKD were also determined.

RESULTS

The CKD cohort had a higher incidence rate of diabetes compared with the non-CKD cohort (11.23/1000 person-years vs 8.93/1000 person-years). In the fully adjusted model, CKD was a significant and independent predictor of incident diabetes (adjusted HR 1.204; 95% CI 1.11, 1.31). The influence of CKD on incident diabetes showed consistent results in three levels of sensitivity analysis. In the CKD cohort, the significant risk factors for incident diabetes included increased age, geographical location, hypertension, hyperlipidaemia and gout. Of these, hypertension was associated with the highest risk of developing incident diabetes (adjusted HR 1.682; 95% CI 1.47, 1.93).

CONCLUSIONS/INTERPRETATION

People with CKD were at higher risk of developing incident diabetes. People with CKD and hypertension, hyperlipidaemia, increased age or gout and who lived in certain geographical regions of Taiwan were more likely to develop diabetes as a complication compared with people without those characteristics.

Urinary angiotensinogen as a biomarker for acute to chronic kidney injury transition - prognostic and mechanistic implications

Accurate biomarkers that both predict the progression to, and detect the early stages of chronic kidney disease (CKD) are lacking, resulting in difficulty in identifying individuals who could potentially benefit from targeted intervention. In a recent issue [Clinical Science (2018) 132, 2121-2133], Cui et al. examine the ability of urinary angiotensinogen (uAGT) to predict the progression of acute kidney injury (AKI) to CKD. They principally employ a murine ischaemia reperfusion injury model to study this and provide data from a small prospective study of patients with biopsy proven acute tubular necrosis. The authors suggest that uAGT is a dynamic marker of renal injury that could be used to predict the likelihood of structural recovery following AKI. Here we comment on their findings, exploring the clinical utility of uAGT as a biomarker to predict AKI to CKD transition and perhaps more controversially, to discuss whether the early renin-angiotensin system blockade following AKI represents a therapeutic target.

A blockade of PI3Kγ signaling effectively mitigates angiotensin II-induced renal injury and fibrosis in a mouse model

Chronic kidney disease (CKD) poses a formidable challenge for public healthcare worldwide as vast majority of patients with CKD are also at risk of accelerated cardiovascular disease and death. Renal fibrosis is the common manifestation of CKD that usually leads to end-stage renal disease although the molecular events leading to chronic renal fibrosis and eventually chronic renal failure remain to be fully understood. Nonetheless, emerging evidence suggests that an aberrant activation of PI3Kγ signaling may play an important role in regulating profibrotic phenotypes. Here, we investigate whether a blockade of PI3Kγ signaling exerts any beneficial effect on alleviating kidney injury and renal fibrosis. Using a mouse model of angiotensin II (Ang II)-induced renal damage, we demonstrate that PI3Kγ inhibitor AS605240 effectively mitigates Ang II-induced increases in serum creatinine and blood urea nitrogen, renal interstitial collagen deposition, the accumulation of ECM proteins and the expression of α-Sma and fibrosis-related genes in vivo. Mechanistically, we reveal that AS605240 effectively inhibits Ang II-induced cell proliferation and phosphorylation of Akt in fibroblast cells. Furthermore, we demonstrate that Ang II-upregulated expression of IL-6, Tnf-α, IL-1β and Tgf-β1 is significantly attenuated in the mice treated with AS605240. Taken together, our results demonstrate that PI3Kγ may function as a critical mediator of Ang II-induced renal injury and fibrosis. It is thus conceivable that targeted inhibition of PI3Kγ signaling may constitute a novel therapeutic approach to the clinical management of renal fibrosis, renal hypertension and/or CKD.

Deleting Death and Dialysis: Conservative Care of Cardio-Vascular Risk and Kidney Function Loss in Chronic Kidney Disease (CKD)

The uremic syndrome, which is the clinical expression of chronic kidney disease (CKD), is a complex amalgam of accelerated aging and organ dysfunctions, whereby cardio-vascular disease plays a capital role. In this narrative review, we offer a summary of the current conservative (medical) treatment options for cardio-vascular and overall morbidity and mortality risk in CKD. Since the progression of CKD is also associated with a higher cardio-vascular risk, we summarize the interventions that may prevent the progression of CKD as well. We pay attention to established therapies, as well as to novel promising options. Approaches that have been considered are not limited to pharmacological approaches but take into account lifestyle measures and diet as well. We took as many randomized controlled hard endpoint outcome trials as possible into account, although observational studies and post hoc analyses were included where appropriate. We also considered health economic aspects. Based on this information, we constructed comprehensive tables summarizing the available therapeutic options and the number and kind of studies (controlled or not, contradictory outcomes or not) with regard to each approach. Our review underscores the scarcity of well-designed large controlled trials in CKD. Nevertheless, based on the controlled and observational data, a therapeutic algorithm can be developed for this complex and multifactorial condition. It is likely that interventions should be aimed at targeting several modifiable factors simultaneously.

Beneficial Effects of Pentoxifylline Plus Losartan Dual Therapy in Type 2 Diabetes with Nephropathy

BACKGROUND

This study was designed to comparatively assess the effects of add-on pentoxifylline to losartan versus increasing the dose of losartan on serum N-terminal pro-brain natriuretic peptide (NT-proBNP), serum highly sensitive C-reactive protein (hsCRP) and the urinary albumin excretion (UAE) rate in patients with type 2 diabetes and nephropathy.

METHODS

In an open-label, single-center, parallel-group, randomized clinical trial (NCT03006952), 30 patients received b.i.d. dose of pentoxifylline 400mg plus daily dose of losartan 50mg (pentoxifylline arm) and 29 patients received b.i.d. dose of losartan 50mg (losartan arm) during a 12-week follow-up period.

RESULTS

Serum NT-proBNP, serum hsCRP and UAE levels all significantly decreased from baseline in both trial arms. The pentoxifylline and losartan trial arms were equally effective in reducing serum NT-proBNP levels during the course of trial (multivariable adjusted model P value = 0.864, effect size = 0.2%). There was a greater decrease in UAE and serum hsCRP levels in the pentoxifylline arm (P = 0.034, effect size = 7.8%; P = 0.009, effect size = 11.7%, respectively). Conversely, patients in the losartan arm achieved better systolic and diastolic blood pressure control (P < 0.001, effect size = 25.4%; P = 0.010, effect size = 11.3%, respectively).

CONCLUSIONS

Circulating NT-proBNP levels equally and significantly reduced from baseline in the pentoxifylline and losartan treatment arms, in parallel with comparatively superior decreases of UAE and serum hsCRP in the pentoxifylline arm, and larger decreases of systolic and diastolic blood pressures in the losartan arm.

Migraine and subsequent chronic kidney disease risk: a nationwide population-based cohort study

OBJECTIVE

We compared the incidence and risk of chronic kidney disease (CKD) between subjects with new-onset migraine and matched controls without migraine in this large-scale retrospective cohort study.

DESIGN

Population-based cohort study.

SETTING

8880 subjects with migraine and 503 070 subjects without migraine were enrolled between January 1, 2000 and December 31, 2013, all diagnosed to be without kidney disease. All the participants were registered in the National Health Insurance Research Database.

PARTICIPANTS

Finally, data from 7156 subjects with migraine and 7156 propensity-score-matched control subjects were analysed.

PRIMARY OUTCOME MEASURE

We used Cox proportional hazards regression to estimate adjusted HRs for incident CKD; subgroup analyses were performed to assess the interactive effects of migraine with demographics, comorbidities and long-term medications.

RESULTS

The incidence of CKD was higher in the migraine group than in the control group. The risk of developing CKD was significantly higher in subjects with migraine than without migraine (P=0.031). Subjects with migraine aged <65 years (age 40-64 (adjusted HR (aHR) 1.35; 95% CI 1.05 to 1.73); age <40 (aHR 1.55; 95% CI 1.02 to 2.36)), with ≥1 comorbid diseases (1-2 diseases (aHR 1.30; 95% CI 1.01 to 1.68); ≥3 diseases (aHR 1.45; 95% CI 1.01 to 2.07)), and not receiving anti-migraine agents (aHR 1.26; 95% CI 1.04 to 1.54) were at a higher risk of developing CKD compared with the control subjects. The interaction between migraine and comorbidities was not significant; age, male gender and long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) were independent risk factors for CKD in subjects with migraine.

CONCLUSION

Migraine may be an independent risk factor for CKD. Young subjects with migraine, and those with comorbid conditions or without medical control, are likely to be at higher risk for CKD. Ageing, male sex and NSAIDs tend to have an association with CKD in subjects with migraine.

Therapeutic efficacy of pentoxifylline on proteinuria and renal progression: an update

Blood pressure control with renin-angiotensin system (RAS) blockade has remained the gold standard for treating patients with proteinuric chronic kidney disease (CKD) up to date. Nevertheless, RAS blockade slows but does not halt the progression of kidney disease, thus highlighting the need to search for additional therapeutic approaches. The nonselective phosphodiesterase (PDE) inhibitor pentoxifylline (PTX) is an old drug that exhibits prominent anti-inflammatory, anti-proliferative and anti-fibrotic activities both in vitro and in vivo. Studies in human subjects have shown that PTX monotherapy decreases urinary protein excretion, and add-on therapy of PTX to background RAS blockade additively reduces proteinuria in patients with CKD of various etiology. More recent studies find that PTX combined with RAS blockade delays the decline of glomerular filtration rate in diabetic patients with mild to moderate CKD, and reduces the risk of end-stage renal disease in diabetic and non-diabetic patients in late stage of CKD with high proteinuria levels. In this review, we update the clinical trial results of PTX as monotherapy, or in conjunction or in comparison with RAS blockade on patients with proteinuria and CKD, and propose a mechanistic scheme explaining the renoprotective activities of this drug.

Pentoxifylline plus ACEIs/ARBs for proteinuria and kidney function in chronic kidney disease: a meta-analysis

Objective

This meta-analysis aimed to investigate the efficacy and safety of pentoxifylline (PTF) plus angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) for proteinuria and kidney function in chronic kidney disease (CKD).

Methods

CENTRAL, EMBASE, Ovid-MEDLINE, PubMed, and CNKI were searched for relevant, randomized, controlled trials (RCTs). A meta-analysis was performed to review the effect of PTF plus ACEIs/ARBs vs. ACEIs/ARBs alone on proteinuria and kidney function in CKD.

Results

Eleven RCTs including 705 patients were retrieved. PTF plus ACEI/ARB treatment significantly decreased proteinuria in patients with CKD within 6 months (standard mean difference [SMD] −0.52; 95% CI −0.90 to 0.15; I²= 68%) and significantly attenuated a decrease in estimated glomerular filtration rate (eGFR) in patients with stages 3–5 CKD after 6 months of treatment (standard mean difference [SMD] 0.30; confidence limit [Cl] 95% CI 0.06 to 0.54; I²= 0%). PTF plus ACEIs/ARBs for 9 to 12 months significantly reduced albuminuria in patients with CKD (SMD−0.30, 95% CI −0.57 to 0.03; I²= 0%) and alleviated the decline in eGFR in patients with stages 3–5 CKD (SMD 0.51; 95% CI 0.06 to 0.96; I²= 61%).

Conclusion

The combination of an ACEI or ARB and PTF has a protective effect in reducing proteinuria by ameliorating the decline in eGFR in patients with stages 3–5 CKD.