Age and Outcomes Associated with BP in Patients with Incident CKD

Association of the Intensive Blood Pressure Target and Cardiovascular Outcomes in the Population With Chronic Kidney Disease: A Retrospective Study in Korea

BACKGROUND

Recently, the target systolic blood pressure (BP) <120 mm Hg was suggested in the population with chronic kidney disease. We aimed to determine the applicability of intensified BP and to assess the incidence of cardiovascular disease (CVD) in the population with chronic kidney disease.

METHODS AND RESULTS

Participants who were >20 years old and had estimated glomerular filtration rate 15 to 60 mL/min per 1.73 m2 during 2009 to 2011 were included from the database of Korean National Health Insurance Service and were followed up to 2018. Participants were categorized by BP as <120/80 mm Hg; 120 to 129/<80 mm Hg; 130 to 139/80 to 89 mm Hg; ≥140/90 mm Hg. The primary outcome was CVD risk and the secondary outcomes were all-cause mortality and progression to end-stage renal disease followed by subgroup analysis. Among the 45 263 adults with chronic kidney disease, 5196 CVD events were noted. In Cox regression analysis, higher BP was associated with a higher risk for CVD (hazard ratio [HR], 1.15 [95% CI, 1.12-1.19]; P for trend <0.001), end-stage renal disease (HR, 1.29 [95% CI, 1.22-1.37]; P for trend <0.001), and all-cause mortality (HR, 1.09 [95% CI, 1.06-1.13]; P for trend <0.001) than BP <120/80 mm Hg. In subgroup analysis, the association between BP and CVD showed a different trend in participants taking antihypertensives compared with those not using antihypertensive drugs. When comparing BP-treated individuals to untreated individuals, a significant interaction in the association between BP categories and end-stage renal disease was observed.

CONCLUSIONS

The new intensive BP target proposed by 2021 Kidney Disease: Improving Global Outcomes should be applied to patients with chronic kidney disease in a personalized and advisory manner.

Long-term Patiromer Use and Outcomes Among US Veterans With Hyperkalemia and CKD: A Propensity-Matched Cohort Study

Rationale & Objective

Patiromer is a potassium binder approved for the long-term management of hyperkalemia. Although patiromer use among patients with advanced chronic kidney disease (CKD) has been shown to reduce the discontinuation of renin-angiotensin-aldosterone system inhibition therapy, it remains unclear whether patiromer can improve clinical outcomes. The aim of this study was to examine the association of long-term patiromer use with clinical outcomes among hyperkalemic patients with CKD.

Study Design

This was a longitudinal observational study.

Setting & Participants

We evaluated a national cohort of 854,217 US Veterans who had at least 1 serum potassium measurement of ≥5.1 mEq/L and were treated at US Department of Veterans Affairs health care facilities between January 2016 and September 2019.

Exposure

The exposure was long-term patiromer use.

Outcomes

The outcomes were as follows: (1) composite endpoint of kidney failure with replacement therapy (KFRT) or all-cause death and (2) all-cause death including the post-KFRT period.

Analytical Approach

Cox proportional Fine-Gray subdistribution hazard models were used in a propensity-matched cohort.

Results

Among 2,004 patients who ever used patiromer during the study period (0.2% of the cohort), 666 met the criteria for long-term patiromer use. We matched 308 long-term patiromer users to 308 nonusers based on propensity scores. The median estimated glomerular filtration rate was 23.5 mL/min/1.73m2, and the median potassium level was 5.2 mEq/L. Approximately 45% were on renin-angiotensin system inhibitor(s) at baseline. During follow-up, 93 patients developed KFRT, and 134 patients died. Long-term patiromer users, when compared to nonusers, experienced a 26% lower risk of the composite outcome (HR, 0.74; 95% CI, 0.53-1.01; P = 0.06) and a 41% lower risk of all-cause mortality (HR, 0.59; 95% CI, 0.41-0.84; P = 0.003).

Limitations

The study cohort included mostly male veterans with relatively short follow-up periods.

Conclusions

Long-term patiromer use was associated with a lower risk of all-cause mortality among patients with CKD and hyperkalemia. Long-term potassium binder use for hyperkalemia may improve clinical outcomes in CKD.

Plain-Language Summary

Hyperkalemia is a common complication of chronic kidney disease (CKD) and can result in the discontinuation of renin-angiotensin-aldosterone system inhibition therapy, a cornerstone of CKD management. Patiromer is a new potassium binder approved for the long-term management of hyperkalemia, but it remains unclear whether patiromer can improve clinical outcomes. We examined a cohort of US Veterans with hyperkalemia between January 2016 and September 2019 and found that patiromer use was uncommon for treating hyperkalemia during this study period. We then matched 308 long-term patiromer users and 308 nonusers based on propensity scores. Long-term patiromer users, when compared to nonusers, experienced a 26% lower risk of the composite outcome and a 41% lower risk of all-cause mortality. These findings indicate that long-term potassium binder use for hyperkalemia may improve clinical outcomes in CKD.

Association of iron therapy with incidence of chronic kidney disease

OBJECTIVE

We investigated the association of oral iron replacement with the incidence of chronic kidney disease (CKD) in a population with normal kidney function to study the effects of iron replacement on the development of new onset CKD.

METHODS

In a national cohort of US Veterans with no pre-existing CKD, we identified 33 894 incident new users of oral iron replacement and a comparable group of 112 780 patients who did not receive any iron replacement during 2004-2018. We examined the association of oral iron replacement versus no iron replacement with the incidence of eGFR <60 mL/min/1.73 m2 and the incidence of urine albumin creatinine ratio (UACR) ≥30 mg/g in competing risk regressions and in Cox models. We used propensity score weighing to account for differences in key baseline characteristics associated with the use of oral iron replacement.

RESULTS

In the cohort of 146 674 patients, a total of 18 547 (13%) patients experienced incident eGFR <60 mL/min/1.73 m2 , and 16 117 patients (11%) experienced new onset UACR ≥30 mg/g. Oral iron replacement was associated with significantly higher risk of incident eGFR <60 mL/min/1.73 m2 (subhazard ratio, 95% confidence interval [CI]: 1.3 [1.22-1.38], p < .001) and incident albuminuria (subhazard ratio, 95% CI: 1.14 [1.07-1.22], p < .001).

CONCLUSION

Oral iron replacement is associated with higher risk of new onset CKD. The long-term kidney safety of oral iron replacement should be tested in clinical trials.

Relationship between the lower limit of systolic blood pressure target and kidney function decline in advanced chronic kidney disease: an instrumental variable analysis from the REACH-J CKD cohort study

Intensive antihypertensive treatment decreases cardiovascular disease and mortality risks in chronic kidney disease (CKD), whereas extremely low systolic blood pressure (SBP) is associated with worsening kidney function and poor prognosis. Although the SBP variation is particularly large in patients with CKD, the optimal lower limit of SBP target is unclear. In a nationwide, multicenter cohort study of patients with an estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m2, we evaluated the association between the eGFR slopes and the lower limit of SBP target at ≥110 mmHg using a linear mixed-effects model and an instrumental variable method. The instrumental variable was calculated as the facility-level percentage of nephrologists who answered in the survey that their lower limit of SBP target was 110 mmHg or higher. A total of 1320 patients (mean age 70 years; 66% men) were included. The mean eGFR slope ± standard deviation over the four years to baseline was -2.48 ± 2.15 mL/min/1.73 m2/year. The instrumental variable for the lower limit of SBP target at ≥110 mmHg (vs. ≤100 mmHg) was associated with less eGFR decline (coefficient: +1.05 mL/min/1.73 m2/year; 95% confidence interval: 0.33-1.77), while unassociated with a history of cardiovascular disease. The renoprotective effect was particularly larger in the subgroups of the elderly and those with a history of cardiovascular disease. In conclusion, the lower limit of SBP target at 110 mmHg or higher was associated with improved eGFR slope, suggesting the importance of aiming at avoiding excessively low SBP in patients with advanced CKD.

Association of oral iron replacement therapy with kidney failure and mortality in CKD patients

Background

Oral iron is the predominant route of iron replacement (IRT) but its benefits and safety are unclear in patients with chronic kidney disease (CKD).

Methods

We examined the association of oral IRT vs no IRT with end-stage kidney disease (ESKD) and mortality in a national cohort of US Veterans. We identified 17 413 incident new users of oral IRT with estimated glomerular filtration rates <60 mL/min/1.73 m2 and 32 530 controls who did not receive any IRT during 2004-18. We used propensity score-overlap weighting to account for differences in key baseline characteristics associated with the use of oral IRT. We examined associations using competing risk regression and Cox models.

Results

In the cohort of 49 943 patients, 1616 (3.2%) patients experienced ESKD and 28 711 (57%) patients died during a median follow-up of 1.9 years. Oral IRT was not associated with ESKD [subhazard ratio (HR) (95% confidence interval, CI) 1.00 (0.84-1.19), P = .9] and was associated with higher risk of all-cause mortality [HR (95% CI) 1.06 (1.01-1.11), P = .01]. There was significant heterogeneity of treatment effect for mortality, with oral IRT associated with higher mortality in the subgroups of patients without congestive heart failure (CHF), anemia or iron deficiency. In patient with blood hemoglobin <10 g/dL oral IRT was associated with significantly lower mortality.

Conclusion

Oral IRT was associated with lower mortality only in patients with anemia. In patients without anemia, iron deficiency or CHF, the risk-benefit ratio of oral IRT should be further examined.

Epidemiology and Risk Factors for Stroke in Chronic Kidney Disease: A Narrative Review

Patients with chronic kidney disease (CKD) have a higher risk ofboth ischemic and hemorrhagic stroke. This association appears to be partly independent from the higher prevalence of established risk factors for stroke in patients with CKD, including hypertension and atrial fibrillation. In the present review we aim to discuss the impact of CKD on the risk of stroke and stroke-related consequences, and explore the pathophysiology underpinning the increased risk of stroke in patients with CKD. We cover the clinical association between renal dysfunction and cerebrovascular disease including stroke, silent brain infarct, cerebral small vessel disease, microbleeds, and white matter hyperintensity, and discuss the underlying mechanisms.

Blood Pressure Levels, Cardiovascular Events, and Renal Outcomes in Chronic Kidney Disease Without Antihypertensive Therapy: A Nationwide Population-Based Cohort Study

BACKGROUND

High blood pressure (BP) is highly prevalent in patients with chronic kidney disease. However, the thresholds to initiate BP-lowering treatment in this population are unclear. We aimed to examine the associations between BP levels and clinical outcomes and provide evidence on potential thresholds to initiate BP-lowering therapy in people with chronic kidney disease.

METHODS

This nationwide, multicenter, prospective cohort study included 12 523 chronic kidney disease participants without antihypertensive therapy in mainland China. Participants were followed up during 2011 to 2016 for cardiovascular events (nonfatal myocardial infarction, nonfatal stroke, hospitalized or treated heart failure, and cardiovascular death) and renal events (≥20% decline in the estimated glomerular filtration rate, end-stage kidney disease, and renal death).

RESULTS

Overall, 652 cardiovascular events and 1268 renal events occurred during 43 970 person-years of follow-up. We observed a positive and linear relationship between systolic BP and risks of cardiovascular and renal events down to 90 mm Hg, as well as between diastolic BP and risks of renal events down to 50 mm Hg. A J-shaped trend was noted between diastolic BP and risks of cardiovascular events, but a linear relationship was revealed in participants <60 years (P for interaction <0.001). A significant increase in the risk of cardiovascular and renal outcomes was observed at systolic BP ≥130 mm Hg (versus 90-119 mm Hg) and at diastolic BP ≥90 mm Hg (versus 50-69 mm Hg).

CONCLUSIONS

In people with chronic kidney disease, a higher systolic BP/diastolic BP level (≥130/90 mm Hg) is significantly associated with a greater risk of cardiovascular and renal events, indicating potential thresholds to initiate BP-lowering treatment.

Association of Uric Acid-Lowering Therapy With Incident Chronic Kidney Disease

IMPORTANCE

Uric acid is a waste metabolite produced from the breakdown of purines, and elevated serum uric acid levels are associated with higher risk of hypertension, cardiovascular disease, and mortality and progression of chronic kidney disease (CKD). Treatment of hyperuricemia in patients with preexisting CKD has not been shown to improve kidney outcomes, but the associations of uric acid-lowering therapies with the development of new-onset kidney disease in patients with estimated glomerular filtration rate (eGFR) within reference range and no albuminuria is unclear.

OBJECTIVE

To examine the association of initiating uric acid-lowering therapy with the incidence of CKD.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included patients with eGFR of 60 mL/min/1.73 m2 or greater and no albuminuria treated at US Department of Veterans Affairs health care facilities from 2004 to 2019. Clinical trial emulation methods, including propensity score weighting, were used to minimize confounding. Data were analyzed from 2020 to 2022.

EXPOSURE

Newly started uric acid-lowering therapy.

MAIN OUTCOMES AND MEASURES

The main outcomes were incidences of eGFR less than 60 mL/min/1.73 m2, new-onset albuminuria, and end-stage kidney disease.

RESULTS

A total of 269 651 patients were assessed (mean [SD] age, 57.4 [12.5] years; 252 171 [94%] men). Among these, 29 501 patients (10.9%) started uric acid-lowering therapy, and 240 150 patients (89.1%) did not. Baseline characteristics, including serum uric acid level, were similar among treated and untreated patients after propensity score weighting. In the overall cohort, uric acid-lowering therapy was associated with higher risk of both incident eGFR less than 60 mL/min/1.73 m2 (weighted subhazard ratio [SHR], 1.15 [95% CI, 1.10-1.20; P < .001) and incident albuminuria (SHR, 1.05 [95% CI, 1.01-1.09; P < .001) but was not associated with the risk of end-stage kidney disease (SHR, 0.96 [95% CI, 0.62-1.50]; P = .87). In subgroup analyses, the association of uric acid-lowering therapy with worse kidney outcomes was limited to patients with baseline serum uric acid levels of 8 mg/dL or less.

CONCLUSIONS AND RELEVANCE

These findings suggest that in patients with kidney function within reference range, uric acid-lowering therapy was not associated with beneficial kidney outcomes and may be associated with potential harm in patients with less severely elevated serum uric acid levels.

Update in Hypertension

The treatment of elevated blood pressure (BP) can improve cardiovascular (CV) event rates. Current BP targets depend on expected CV event rates in individuals as assessed by concurrent medical conditions and other risk factors. Importantly, the means by which BP is measured has evolved. This evolution is driven by recognition that techniques different than routine office BP measurements can provide a better assessment of future CV risk.

Application of machine learning techniques to understand ethnic differences and risk factors for incident chronic kidney disease in Asians

INTRODUCTION

Chronic kidney disease (CKD) is increasing in Asia, but there are sparse data on incident CKD among different ethnic groups. We aimed to describe the incidence and risk factors associated with CKD in the three major ethnic groups in Asia: Chinese, Malays and Indians.

RESEARCH DESIGN AND METHODS

Prospective cohort study of 5580 general population participants age 40-80 years (2234 Chinese, 1474 Malays and 1872 Indians) who completed both baseline and 6-year follow-up visits. Incident CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² in those free of CKD at baseline.

RESULTS

The 6-year incidence of CKD was highest among Malays (10.0%), followed by Chinese (6.1%) and Indians (5.8%). Logistic regression showed that older age, diabetes, higher systolic blood pressure and lower eGFR were independently associated with incident CKD in all three ethnic groups, while hypertension and cardiovascular disease were independently associated with incident CKD only in Malays. The same factors were identified by machine learning approaches, gradient boosted machine and random forest to be the most important for incident CKD. Adjustment for clinical and socioeconomic factors reduced the excess incidence in Malays by 60% compared with Chinese but only 13% compared with Indians.

CONCLUSION

Incidence of CKD is high among the main Asian ethnic groups in Singapore, ranging between 6% and 10% over 6 years; differences were partially explained by clinical and socioeconomic factors.

Association of dyskalemias with short-term health care utilization in patients with advanced CKD

BACKGROUND: Patients with advanced chronic kidney disease (CKD) are at high risk for dyskalemias, which may induce arrhythmias that require immediate emergent or hospital care. The association of dyskalemias with short-term hospital/emergency room (ER) visits in advanced CKD is understudied. OBJECTIVE: To assess the association of dyskalemias with short-term hospital/ER visits in an advanced CKD population. METHODS: From among 102,477 US veterans transitioning to dialysis from 2007 to 2015, we identified 21,366 patients with 2 predialysis outpatient eGFR < 30 ml/min/1.73m2 90-365 days apart (with the second eGFR serving as the index date) and at least 1 potassium (K) in the baseline period (1 year before index) and 1 outpatient K (oK) in the follow-up (1 year after the index but before dialysis initiation). We examined the association of time-varying hypokalemia (K < 3.5 mEq/L) and hyperkalemia (K > 5.5 mEq/L) vs referent (3.5-5.5 mEq/L) with separate hospital and ER visits within 2 calendar days following each oK value over the 1-year follow-up period from the index. We used generalized estimating equations with binary distribution and logit link to model the exposure-outcome relationship adjusted for various confounders. We conducted various subgroup and sensitivity analyses to test the robustness of our results. RESULTS: Over the 1-year follow-up, 125,266 oK measurements were observed, of which 6.8% and 3.7% were classified as hyper- and hypokalemia, respectively. In the multivariable-adjusted model, hyperkalemia (adjusted odds ratio [aOR] = 2.04; 95% CI = 1.88-2.21) and hypokalemia (aOR = 1.66; 95% CI = 1.48-1.86) were associated with significantly higher odds of hospital visits. Similarly, hyperkalemia (aOR = 1.83; 95% CI = 1.65-2.03) and hypokalemia (aOR = 1.24; 95% CI = 1.07-1.44) were associated with significantly higher odds of ER visits. Results were robust to subgroups and sensitivity analyses. CONCLUSIONS: In patients with advanced CKD, dyskalemias are associated with higher risk of hospital/ER visits. Interventions targeted at lowering the risk of dyskalemias might help in reducing the health care utilization and associated economic burden among patients with advanced CKD experiencing dyskalemias. DISCLOSURES: This study was supported by grant 5U01DK102163 from the National Institute of Health (NIH) to Kamyar Kalantar-Zadeh and Csaba P. Kovesdy and by resources from the US Department of Veterans Affairs. The data reported here have been supplied in part by the United States Renal Data System (USRDS). Support for VA/CMS data were provided by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, Health Services Research and Development, VA Information Resource Center (project numbers SDR 02-237 and 98-004). Opinions expressed in this article are those of the authors and do not necessarily represent the opinion of the Department of Veterans Affairs or the funding institution. Kovesdy has received honoraria from Akebia, Ardelyx, Astra Zeneca, Bayer, Boehringer-Ingelheim, Cara Therapeutics, Reata, and Tricida unrelated to this study. Kalantar-Zadeh has received honoraria and/or support from Abbott, Abbvie, ACI Clinical (Cara Therapeutics), Akebia, Alexion, Amgen, American Society of Nephrology, Astra-Zeneca, Aveo, BBraun, Chugai, Cytokinetics, Daiichi, DaVita, Fresenius, Genentech, Haymarket Media, Hofstra Medical School, International Federation of Kidney Foundations, International Society of Hemodialysis, International Society of Renal Nutrition & Metabolism, Japanese Society of Dialysis Therapy, Hospira, Kabi, Keryx, Kissei, Novartis, OPKO, National Institutes of Health, National Kidney Foundations, Pfizer, Regulus, Relypsa, Resverlogix, Dr Schaer, Sandoz, Sanofi, Shire, Veterans Affairs, Vifor, UpToDate, and ZS-Pharma, unrelated to this study. Gatwood has received research support from AstraZeneca, Merck & Co., and GlaxoSmithKline unrelated to this study. Obi has received research support from Relypsa/Vifor Pharma Inc. The remaining authors declare that they have no relevant financial interests.

Association of morning blood pressure surge with chronic kidney disease progression in patients with chronic kidney disease and hypertension

Blood pressure (BP) usually rise from being asleep to awake, which is named the morning blood pressure surge (MBPS). Researches have reported that elevated MBPS was related with CV events, incident CKD in hypertensive patients. However, there have been no studies that have investigated the association between MBPS and renal or heart outcomes in patients with CKD and hypertension, in these patients, the MBPS is much lower because of high prevalence of night hypertension and reduced BP dipping. In this prospective two-center observational study, we enrolled patients with CKD and hypertension and the 24 h ambulatory blood pressure monitoring (ABPM) was conducted in all patients. Time to total mortality, CKD progression and CV events was recorded; Finally, a total of 304 patients were enrolled and 94 (30.9%) of them had elevated MBPS. After a follow-up for median 30 months, 23 (7.6%), 34 (11.2%), and 95 (31.3%) patients occurred death, CKD progression and new-onset CV events, respectively. The Cox regression analysis suggested the elevated MBPS was a strong predictor of CKD progression (HR 2.35, 95%CI 1.2 -4.63, p = .013), independent of morning BP, while no associations were found between elevated MBPS and CV events (HR 1.02, 95%CI 0.66 -1.57), as well as death (HR 1.08, 95%CI 0.46 -2.55). In conclusion, we provided the first evidence that elevated MBPS was an important risk factor of CKD progression in patients with CKD and hypertension. Appropriate evaluation and management of MBPS may be helpful to postpone CKD progression.

Association of Blood Pressure with Cardiovascular Outcome and Mortality: Results from the KNOW-CKD Study

BACKGROUND

Optimal BP control is a major therapeutic strategy to reduce adverse cardiovascular events and mortality in patients with CKD. We studied the association of BP with adverse cardiovascular outcome and all-cause death in patients with CKD.

METHODS

Among 2,238 participants from the KoreaN cohort study for Outcome in patients With CKD, 2,226 patients with baseline BP measurements were enrolled. Main predictor was SBP categorized by 5 levels: <110, 110-119, 120-129, 130-139, and ≥140 mmHg. Primary endpoint was a composite outcome of all-cause death or incident cardiovascular events. We primarily used marginal structural models using averaged and the most recent time-updated SBPs.

RESULTS

During a median follow-up of 10233.79 person-years (median 4.60 years), the primary composite outcome occurred in 240 (10.8%) participants, with a corresponding incidence rate of 23.5 (95% CI, 20.7-26.6) per 1,000 patient-years. Marginal structural models with averaged SBP showed a U-shaped relationship with the primary outcome. Compared to time-updated SBP of 110-119 mmHg, hazard ratios (95% CI) for <110, 120-129, 130-139, and ≥140 mmHg were 2.47 (1.48-4.11), 1.29 (0.80-2.08), 2.15 (1.26-3.69), and 2.19 (1.19-4.01), respectively. Marginal structural models with the most recent SBP also showed similar findings.

CONCLUSIONS

In Korean patients with CKD, there was a U-shaped association of SBP with the risk of adverse clinical outcome. Our findings highlight the importance of BP control and suggest a potential hazard of SBP <110 mmHg.

Association of Dyskalemias with Ischemic Stroke in Advanced Chronic Kidney Disease Patients Transitioning to Dialysis

INTRODUCTION

Hypo- and hyperkalemia are associated with a higher risk of ischemic stroke. However, this association has not been examined in an advanced chronic kidney disease (CKD) population.

METHODS

From among 102,477 US veterans transitioning to dialysis between 2007 and 2015, 21,357 patients with 2 pre-dialysis outpatient estimated glomerular filtration rates <30 mL/min/1.73 m2 90-365 days apart and at least 1 potassium (K) each in the baseline and follow-up period were identified. We separately examined the association of both baseline time-averaged K (chronic exposure) and time-updated K (acute exposure) treated as categorized (hypokalemia [K <3.5 mEq/L] and hyperkalemia [K >5.5 mEq/L] vs. referent [3.5-5.5 mEq/L]) and continuous exposure with time to the first ischemic stroke event prior to dialysis initiation using multivariable-adjusted Cox regression models.

RESULTS

A total of 2,638 (12.4%) ischemic stroke events (crude event rate 41.9 per 1,000 patient years; 95% confidence interval [CI] 40.4-43.6) over a median (Q1-Q3) follow-up time of 2.56 (1.59-3.89) years were observed. The baseline time-averaged K category of hypokalemia (adjusted hazard ratio [aHR], 95% CI: 1.35, 1.01-1.81) was marginally associated with a significantly higher risk of ischemic stroke. However, time-updated hyperkalemia was associated with a significantly lower risk of ischemic stroke (aHR, 95% CI: 0.82, 0.68-0.98). The exposure-outcome relationship remained consistent when using continuous K levels for both the exposures.

DISCUSSION/CONCLUSION

In patients with advanced CKD, hypokalemia (chronic exposure) was associated with a higher risk of ischemic stroke, whereas hyperkalemia (acute exposure) was associated with a lower risk of ischemic stroke. Further studies in this population are needed to explore the mechanisms underlying these associations.

BP in Young Adults with CKD and Associations with Cardiovascular Events and Decline in Kidney Function

BACKGROUND

BP is an important modifiable risk factor for cardiovascular events and CKD progression in middle-aged or older adults with CKD. However, studies describing the relationship between BP with outcomes in young adults with CKD are limited.

METHODS

In an observational study, we focused on 317 young adults (aged 21-40 years) with mild to moderate CKD enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study. Exposures included baseline systolic BP evaluated continuously (per 10 mm Hg increase) and in categories (<120, 120-129, and ≥130 mm Hg). Primary outcomes included cardiovascular events (heart failure, myocardial infarction, stroke, or all-cause death) and CKD progression (50% decline of eGFR or ESKD). We used Cox proportional hazard models to test associations between baseline systolic BP with cardiovascular events and CKD progression.

RESULTS

Cardiovascular events occurred in 52 participants and 161 had CKD progression during median follow-up times of 11.3 years and 4.1 years, respectively. Among those with baseline systolic BP ≥130 mm Hg, 3%/yr developed heart failure, 20%/yr had CKD progression, and 2%/yr died. In fully adjusted models, baseline systolic BP ≥130 mm Hg (versus systolic BP<120 mm Hg) was significantly associated with cardiovascular events or death (hazard ratio [HR], 2.13; 95% confidence interval [95% CI], 1.05 to 4.32) and CKD progression (HR, 1.68; 95% CI, 1.10 to 2.58).

CONCLUSIONS

Among young adults with CKD, higher systolic BP is significantly associated with a greater risk of cardiovascular events and CKD progression. Trials of BP management are needed to test targets and treatment strategies specifically in young adults with CKD.

On-treatment blood pressure and long-term outcomes in chronic kidney disease

BACKGROUND

The treatment BP target in CKD remains unclear, and whether the benefit of intensive BP-lowering is comparable between CKD and non-CKD patients is debated.

METHODS

Using the Korean National Health Information Database, 359,492 CKD patients who had received antihypertensives regularly were identified from 12.1 million participants of nationwide health screening. The composite risk of major cardiovascular events, kidney failure, and all-cause mortality was assessed according to timely-averaged, on-treatment systolic BP.

RESULTS

Over 9-year follow-up, the composite outcome noted in 18.4% of 239,700 participants with eGFR <60 ml/min/1.73 m2 and 18.9% of 155,004 with dipstick albuminuria. The thresholds of systolic BP, above which the composite risk increased significantly, in the reduced eGFR and the proteinuric population were 135 mm Hg and 125 mm Hg, respectively. For all-cause mortality, the respective thresholds were 145 mm Hg and 135 mm Hg. When comparing the composite risk between propensity score-matched groups, the hazard ratios of on-treatment BP of systolic 135-144 mm Hg (reference, 115-124 mm Hg) in the reduced eGFR and non-CKD pairs were 1.18 and 0.98, respectively (P = 0.13 for interaction), and those in the proteinuria and non-CKD pairs were 1.30 and 1.01, respectively (P = 0.003 for interaction).

CONCLUSIONS

The findings support the recommendation that, based on office BP, the systolic target in CKD with proteinuria is ≤ 130 mm Hg, and the target in CKD with no proteinuria is ≤ 140 mm Hg. The benefit of intensive BP-lowering may be greater in CKD patients particularly with proteinuria than in their non-CKD counterparts.

Laxative Use and Risk of Dyskalemia in Patients with Advanced CKD Transitioning to Dialysis

BACKGROUND

Patients with advanced CKD experience increased intestinal potassium excretion. This compensatory mechanism may be enhanced by laxative use; however, little is known about the association of laxative use with risk of dyskalemia in advanced CKD.

METHODS

Our study population encompassed 36,116 United States veterans transitioning to ESKD from 2007 to 2015 with greater than or equal to one plasma potassium measurement during the last 1-year period before ESKD transition. Using generalized estimating equations with adjustment for potential confounders, we examined the association of time-varying laxative use with risk of dyskalemia (i.e., hypokalemia [potassium <3.5 mEq/L] or hyperkalemia [>5.5 mEq/L]) versus normokalemia (3.5-5.5 mEq/L) over the 1-year pre-ESKD period. To avoid potential overestimation of dyskalemia risk, potassium measurements within 7 days following a dyskalemia event were disregarded in the analyses.

RESULTS

Over the last 1-year pre-ESKD period, there were 319,219 repeated potassium measurements in the cohort. Of these, 12,787 (4.0%) represented hypokalemia, and 15,842 (5.0%) represented hyperkalemia; the time-averaged potassium measurement was 4.5 mEq/L. After multivariable adjustment, time-varying laxative use (compared with nonuse) was significantly associated with lower risk of hyperkalemia (adjusted odds ratio [aOR], 0.79; 95% confidence interval [95% CI], 0.76 to 0.84) but was not associated with risk of hypokalemia (aOR, 1.01; 95% CI, 0.95 to 1.07). The results were robust to several sensitivity analyses.

CONCLUSIONS

Laxative use was independently associated with lower risk of hyperkalemia during the last 1-year pre-ESKD period. Our findings support a putative role of constipation in potassium disarrays and also support (with a careful consideration for the risk-benefit profiles) the therapeutic potential of laxatives in hyperkalemia management in advanced CKD.

Potassium Trajectories prior to Dialysis and Mortality following Dialysis Initiation in Patients with Advanced CKD

INTRODUCTION

Patients with advanced non-dialysis-dependent CKD (NDD-CKD) have a reduced ability for maintaining plasma potassium (K) in normal range. Deviation from normal plasma K ranges is associated with increased mortality; however, the average trajectory of plasma K over time in patients with advanced NDD-CKD and the outcomes associated with plasma K trajectory are unknown.

METHODS

We identified 34,167 US veterans with advanced NDD-CKD transitioning to dialysis between October 2007 and March 2015 with at least 1 K measurement each year over a 3-year period prior to dialysis transition (3-year prelude). The K trajectory defined as the change in K (slope) per year over the entire 3-year prelude was estimated using linear mixed-effects models. The association between unadjusted (crude) K slope (categorized as stable [-0.09 to 0.09 mEq/L/year], decreasing [≤-0.10 mEq/L/year], and increasing [≥0.10 mEq/L/year]) and time to all-cause and cardiovascular mortality during the 6 months following dialysis initiation was assessed using multivariable-adjusted survival models.

RESULTS

The crude and multivariable-adjusted K slopes (mean, 95% CI) over the 3-year prelude were 0.008 (0.0059, 0.0110) and -0.15 mEq/L/year (-0.19, -0.11), respectively. Decreasing K slope was associated with higher multivariable-adjusted risk of all-cause mortality (adjusted hazard ratio [95% CI] vs. stable K slope: 1.08 [1.00-1.17]). No association was observed between K slope and cardiovascular mortality.

DISCUSSION/CONCLUSION

The average intraindividual plasma K trajectory is remarkably stable in patients with advanced NDD-CKD. A decreasing K slope is associated with higher all-cause mortality risk.

Predialysis Potassium Variability and Postdialysis Mortality in Patients With Advanced CKD

Introduction

Patients with advanced non–dialysis-dependent chronic kidney disease (NDD-CKD) are prone to potassium (K) imbalances due to reduced kidney function. Both hypo- and hyperkalemia are associated with increased mortality; however, it is unclear if K variability before dialysis initiation is associated with outcomes after dialysis initiation.

Methods

We identified 34,167 US veterans with advanced NDD-CKD transitioning to dialysis between October 1, 2007, through March 31, 2015, who had at least 1 K measurement each year over a 3-year period before transition (3-year prelude). For each patient, a linear mixed-effects model was used to regress K over time (in years) over the 3-year prelude to derive K variability (square root of the average squared distance between the observed and estimated K). The main outcomes of interest were 6-month all-cause and cardiovascular mortality after dialysis initiation. Multivariable Cox and Fine-Gray competing risk regression adjusted for 3-year prelude K intercept, K slope (per year), demographics, smoking status, comorbidities, length of hospitalizations, body mass index, vascular access type, medications, average estimated glomerular filtration rate, and number of K measurements over the 3-year prelude were used to assess the association of K variability (expressed as quartiles) with all-cause and cardiovascular mortality, respectively.

Results

Higher prelude K variability was associated with higher multivariable-adjusted risk of all-cause mortality but not cardiovascular mortality (adjusted hazard/subhazard ratios [95% confidence interval] for highest quartile [vs. lowest] of K variability, 1.14 [1.03–1.25] and 0.99 [0.85–1.16] for all-cause and cardiovascular mortality, respectively).

Conclusion

Higher K variability is associated with higher all-cause mortality after dialysis initiation.

Laxative use in patients with advanced chronic kidney disease transitioning to dialysis

BACKGROUND

Constipation is highly prevalent in patients with chronic kidney disease (CKD), particularly among those with end-stage renal disease (ESRD), partly due to their dietary restrictions, comorbidities and medications. Laxatives are typically used for constipation management; however, little is known about laxative use and its associated factors in patients with advanced CKD transitioning to ESRD.

METHODS

In a retrospective cohort of 102 477 US veterans transitioning to dialysis between October 2007 and March 2015, we examined the proportion of patients who filled a prescription for any type of laxative within each 6-month period over 36 months pre- and post-transition to ESRD. Factors associated with laxative use during the last 1-year pre-ESRD period were identified by multivariable logistic regression.

RESULTS

The proportion of patients prescribed laxatives increased as patients progressed to ESRD, peaking at 37.1% in the 6 months immediately following ESRD transition, then remaining fairly stable throughout the post-ESRD transition period. Among laxative users, stool softeners were the most commonly prescribed (∼30%), followed by hyperosmotics (∼20%), stimulants (∼10%), bulk formers (∼3%), chloride channel activator (<1%) and several combinations of these. The use of anticoagulants, oral iron supplements, non-opioid analgesics, antihistamines and opioid analgesics were among the factors independently associated with pre-ESRD laxative use.

CONCLUSION

The use of laxatives increased considerably as patients neared transition to ESRD, likely mirroring the increasing burden of drug-induced constipation during the ESRD transition period. Findings may provide novel insight into better management strategies to alleviate constipation symptoms and reduce medication requirements in patients with advanced CKD.

Laxative Use and Change in Estimated Glomerular Filtration Rate in Patients With Advanced Chronic Kidney Disease

OBJECTIVES

Constipation is highly prevalent in advanced chronic kidney disease (CKD), due in part to dietary (e.g., fiber) restrictions, and is often managed by laxatives; however, the effect of laxative use on kidney function in advanced CKD remains unclear. We aimed to examine the association of laxative use with longitudinal change in estimated glomerular filtration rate (eGFR) in patients with advanced CKD.

DESIGN AND METHODS

In a retrospective cohort of 43,622 US veterans transitioning to end-stage renal disease (ESRD) from 2007 to 2015, we estimated changes in eGFR (slope) by linear mixed-effects models using ≥2 available outpatient eGFR measurements during the 2-year period before transition to ESRD. The association of laxative use with change in eGFR was examined by testing the interaction of time-varying laxative use with time for eGFR slope in the mixed-effects models with adjustment for fixed and time-varying confounders.

RESULTS

Laxatives were prescribed in 49.8% of patients during the last 2-year pre-ESRD period. In the crude model, time-varying laxative use was modestly associated with more progressive eGFR decline compared with non-use of laxatives (median [interquartile interval] -7.1 [-11.9, -4.3] vs. -6.8 [-11.6, -4.0] mL/min/1.73 m²/year, P < .001). After multivariable adjustment, a faster eGFR decline associated with laxative use (vs. non-use of laxatives) remained statistically significant, although the between-group difference in eGFR slope was minimal (median [interquartile interval] -8.8 [-12.9, -5.9] vs. -8.6 [-12.6, -5.6] mL/min/1.73 m²/year, P < .001). The significant association was no longer evident across different types of laxatives (i.e., stool softeners, stimulants, or hyperosmotics).

CONCLUSIONS

There was a clinically negligible association of laxative use with change in eGFR during the last 2-year pre-ESRD period, suggesting the renal safety profile of laxatives in advanced CKD patients.

[Evidence-Based Information Which Could Influence Arterial Hypertension Treatment Approach after Publication of SPRINT Trial Results]

The article discusses results of secondary analysis of the data obtained in the SPRINT study and published in recent years. Unresolved issues in the tactics of managing patients with arterial hypertension are discussed. One of such issues is choosing an optimum level of blood pressure (BP) for a subgroup of patients with certain characteristics, including elderly and senile patients, patients with chronic kidney disease, and patients with arterial hypertension who continue smoking. The article discusses calculation of a threshold of risk for complications of cardiovascular diseases, at which a maximum advantage of intensified regimens of antihypertensive therapy could be achieved. In addition, the article addresses approaches to selection of antihypertensive drugs in the current conditions. The authors discussed the role of candesartan in the treatment of arterial hypertension, a sartan most studied in a broad range of patients. The issue of a rapid increase in BP without a damage to target organs is addressed; evidence for the role of captopril in such clinical situation is provided.

Association between Posttransplant Opioid Use and Immunosuppressant Therapy Adherence among Renal Transplant Recipients

INTRODUCTION

Little is known about the effect of posttransplant opioid use on adherence to immunosuppressant therapy (IST) among adult renal transplant recipients (RTRs).

OBJECTIVE

The aim of this study was to examine the relationship between opioid use and IST adherence among adult RTRs during the first year posttransplant.

METHODS

Longitudinal data were analyzed from a retrospective cohort study examining US veterans undergoing renal transplant from October 1, 2007, through March 31, 2015. Data were collected from the US Renal Data System, Centers for Medicare and Medicaid Services Data (Medicare Part D), and Veterans Affairs pharmacy records. Dose of opioid prescriptions was collected and divided based on annual morphine milligram equivalent within a year of transplant. Proportion of days covered of greater than or equal to 80% indicated adherence to tacrolimus. Unadjusted and multivariable-adjusted logistic regression analyses were performed.

RESULTS

A study population of 1,229 RTRs included 258 with no opioid use, while 971 opioid users were identified within the first year after transplantation. Compared to RTRs without opioid usage, RTRs with opioid usage had a lower probability of being adherent to tacrolimus in unadjusted logistic regression (odds ratio [OR] (95% confidence interval [CI]): 0.22 [0.07-0.72]) and adjusted logistic regression (OR [95% CI]: 0.11 [0.03-0.44]). These patterns generally remained consistent in unadjusted and adjusted main and sensitivity analyses.

CONCLUSIONS

Findings indicate RTRs who use prescription opioids during the first year posttransplant, regardless of the dosage/amount, are less likely to be adherent to tacrolimus. Future studies are needed to better understand underlying causes of the association between opioid use and tacrolimus nonadherence.

Hypertension in older adults: Assessment, management, and challenges

Hypertension in older adults is related to adverse cardiovascular outcomes, such as heart failure, stroke, myocardial infarction, and death. The global burden of hypertension is increasing due to an aging population and increasing prevalence of obesity, and is estimated to affect one third of the world's population by 2025. Adverse outcomes in older adults are compounded by mechanical hemodynamic changes, arterial stiffness, neurohormonal and autonomic dysregulation, and declining renal function. This review highlights the current evidence and summarizes recent guidelines on hypertension, pertaining to older adults. Management strategies for hypertension in older adults must consider the degree of frailty, increasingly complex medical comorbidities, and psycho-social factors, and must therefore be individualized. Non-pharmacological lifestyle interventions should be encouraged to mitigate the risk of developing hypertension, and as an adjunctive therapy to reduce the need for medications. Pharmacological therapy with diuretics, renin-angiotensin system blockers, and calcium channel blockers have all shown benefit on cardiovascular outcomes in older patients. Given the economic and public health burden of hypertension in the United States and globally, it is critical to address lifestyle modifications in younger generations to prevent hypertension with age.

Association Between Income Disparities and Risk of Chronic Kidney Disease: A Nationwide Cohort Study of Seven Million Adults in Korea

OBJECTIVE

To examine the association between income level and incident chronic kidney disease (CKD) in adults with normal baseline kidney function.

PATIENT AND METHODS

We studied the association between income level categorized into deciles and incident CKD in a national cohort comprised of 7,405,715 adults who underwent National Health Insurance Service health examinations during January 1, 2009, to December 31, 2015, with baseline estimated glomerular filtration rates (eGFRs) ≥60 mL/min/1.73 m². Incident CKD was defined as de novo development of eGFR <60 mL/min/1.73 m² (model 1) or ≥25% decline in eGFR from baseline values accompanied by eGFR <60 mL/min/1.73 m² (model 2).

RESULTS

During a median follow-up of 4.8 years, there were 122,032 of 7,405,715 (1.65%) and 55,779 of 7,405,715 (0.75%) incident CKD events based on model 1 and 2 definitions, respectively. Compared with income levels in the sixth decile, there was an inverse association between lower income level and higher risk for CKD up to the fourth decile, above which no additional reduction (model 1) or slightly higher risk for CKD (model 2) was observed at higher income levels. The multivariable-adjusted hazard ratios from the lowest to fourth deciles were 1.30 (95% CI, 1.26-1.33), 1.16 (95% CI, 1.13-1.19), 1.07 (95% CI, 1.05-1.10), and 1.06 (95% CI, 1.03-1.09) in model 1 and 1.32 (95% CI, 1.27-1.37), 1.18 (95% CI, 1.14-1.22), 1.08 (95% CI, 1.04-1.13), and 1.05 (95% CI, 1.01-1.09) in model 2, respectively. These associations persisted across various subgroups of age, sex, and comorbidity status.

CONCLUSION

In this large nationwide cohort, lower income levels were associated with higher risk for incident CKD.

Blood pressure modifies outcomes in patients with stage 3 to 5 chronic kidney disease

Observational studies have demonstrated that low blood pressure is related to poor clinical outcomes in patients with chronic kidney disease (CKD). Subgroup analyses from the SPRINT trial showed that targeting systolic blood pressure under 120 mmHg is less beneficial for patients with CKD. Although malnutrition and inflammation are common in patients with advanced CKD, such patients are usually excluded from clinical trials. Therefore, we hypothesized that malnutrition-inflammation-cachexia syndrome could explain this J-shaped relationship. To test this, we studied 2441 patients with CKD stages 3-5 who received anti-hypertensive treatment for at least one year. Averaged blood pressures of the first year were used in the analyses. Fine-Gray competing risks regression showed a J-shaped relationship between continuous systolic blood pressure and end-stage kidney disease (ESKD) with a nadir risk at a systolic blood pressure of 120 mmHg. Adjusted sub-distribution hazard ratios of categorical systolic blood pressure 100-109 and 110-119 mmHg were 2.17 (95% confidence interval: 1.21-3.89) and 1.37 (0.94-1.99) for ESKD, respectively, compared with systolic blood pressures of 120-129 mmHg. Cox regression also showed J-shaped relationships between continuous systolic or diastolic blood pressures, and the composite outcomes of cardiovascular events and all-cause mortality. Logistic regression demonstrated the odds ratios of blood pressure components for Malnutrition-Inflammation Scores over 4 were J-shaped. Sub-distribution hazard ratios of systolic blood pressure 100-119 mmHg for ESKD was higher in those with a Malnutrition-Inflammation Score over 4, compared to 0.93 (0.53-1.63) in those with a score of 4 or under with significant interaction. Thus, malnutrition-inflammation-cachexia syndrome is associated with low blood pressure and modifies the J-shaped relationship in patients with advanced CKD.

Microalbuminuria and cardiorenal risk: old and new evidence in different populations

Since the association of microalbuminuria (MAU) with cardiovascular (CV) risk was described, a huge number of reports have emerged. MAU is a specific integrated marker of CV risk and targets organ damage in patients with hypertension, chronic kidney disease (CKD), and diabetes and its recognition is important for identifying patients at a high or very high global CV risk. The gold standard for diagnosis is albumin measured in 24-hour urine collection (normal values of less than 30 mg/day, MAU of 30 to 300 mg/day, macroalbuminuria of more than 300 mg/day) or, more practically, the determination of urinary albumin-to-creatinine ratio in a urine morning sample (30 to 300 mg/g). MAU screening is mandatory in individuals at risk of developing or presenting elevated global CV risk. Evidence has shown that intensive treatment could turn MAU into normoalbuminuria. Intensive treatment with the administration of an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker, in combination with other anti-hypertensive drugs and drugs covering other aspects of CV risk, such as mineralocorticoid receptor antagonists, new anti-diabetic drugs, and statins, can diminish the risk accompanying albuminuria in hypertensive patients with or without CKD and diabetes.

Prognostic significance of pre-end-stage renal disease serum alkaline phosphatase for post-end-stage renal disease mortality in late-stage chronic kidney disease patients transitioning to dialysis

Background

Higher serum alkaline phosphatase (ALP) levels have been associated with excess mortality in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) and end-stage renal disease (ESRD). However, little is known about the impact of late-stage NDD-CKD ALP levels on outcomes after dialysis initiation.

Methods

Among 17 732 US veterans who transitioned to dialysis between October 2007 and September 2011, we examined the association of serum ALP levels averaged over the last 6 months of the pre-ESRD transition period ('prelude period') with all-cause, cardiovascular and infection-related mortality following dialysis initiation, using Cox (for all-cause mortality) and competing risk (for cause-specific mortality) regressions adjusted for demographics, comorbidities, medications, estimated glomerular filtration rate and serum albumin levels over the 6-month prelude period, and vascular access type at dialysis initiation.

Results

During a median follow-up of 2.0 (interquartile range, 1.1-3.2) years following dialysis initiation, a total of 9196 all-cause deaths occurred. Higher ALP levels were incrementally associated with higher all-cause, cardiovascular and infection-related mortality. Compared with patients in the lowest ALP quartile (<66.0 U/L), those in the highest quartile (≥111.1 U/L) had multivariable-adjusted hazard/subhazard ratios (95% confidence interval) of 1.42 (1.34-1.51), 1.43 (1.09-1.88) and 1.39 (1.09-1.78) for all-cause, cardiovascular and infection-related mortality, respectively. The associations remained consistent in various subgroups and after further adjustment for liver enzymes, serum phosphorus and intact parathyroid hormone levels.

Conclusions

Higher pre-ESRD serum ALP levels are independently associated with higher post-ESRD mortality risk. Further studies are warranted to determine if interventions that lower pre-ESRD ALP levels reduce mortality in incident dialysis patients.

History of posttraumatic stress disorder and outcomes after kidney transplantation

A history of posttraumatic stress disorder (PTSD), if uncontrolled, represents a contraindication for kidney transplantation. However, no previous large study has assessed the association between pretransplant history of PTSD and posttransplantation outcomes. We examined 4479 US veterans who had undergone transplantation. The diagnosis of history of PTSD was based on a validated algorithm. Measured covariates were used to create a matched cohort (n = 560). Associations between pretransplant PTSD and death with functioning graft, all-cause death, and graft loss were examined in survival models. Posttransplant medication nonadherence was assessed using proportion of days covered (PDC). From among 4479 veterans, 282 (6.3%) had a history of PTSD. The mean age ± standard deviation (SD) of the cohort at baseline was 61 ± 11 years, 91% were male, and 66% and 28% of patients were white and African American, respectively. Compared to patients without a history of PTSD, patients with a history of PTSD had a similar risk of death with a functioning graft (subhazard ratio [SHR] 0.97, 95% confidence interval [CI] 0.61-1.54), all-cause death (1.05, 0.69-1.58), and graft loss (1.09, 0.53-2.26). Moreover, there was no difference in immunosuppressive drug PDC in patients with and without a history of PTSD (PDC: 98 ± 4% vs 99 ± 3%, P = .733 for tacrolimus; PDC: 99 ± 4% vs 98 ± 7%, P = .369 for mycophenolic acid). A history of PTSD in US veterans with end-stage renal disease should not on its own preclude a veteran from being considered for transplantation.

May Measurement Month 2017: an analysis of the blood pressure screening campaign results in Indonesia-South-East Asia and Australasia

Elevated blood pressure (BP) is a growing burden worldwide, leading to over 10 million deaths each year. Our previous primary health surveys in 2013 and 2018 show that 25.8% to 34.1% of adults have raised BP, which is associated with cardiovascular, cerebrovascular, and renovascular morbidity and mortality. May Measurement Month (MMM) is a global initiative aimed at raising awareness of high BP and to act as a temporary solution to the lack of screening programmes worldwide. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in May 2017. Blood pressure measurement, the definition of hypertension and statistical analysis followed the standard MMM protocol. We recruited 292 sites in all 34 provinces in Indonesia, and screened in public areas and offices as well as health centres. A total of 69 307 individuals were screened. After multiple imputation, 23 892 (34.5%) had hypertension. Of individuals not receiving antihypertensive medication, 20.0% were hypertensive. Among individuals receiving antihypertensive medication, 7885 (62.8%) had uncontrolled BP. MMM17 was the largest standardized screening campaign for BP measurement in our country. The proportion of individuals identified with hypertension and the percentage of those with uncontrolled BP on medication provide evidence of the substantial challenges in managing hypertension in the community. These results suggest that opportunistic screening can identify significant numbers of individuals with raised BP.

Predialysis coronary revascularization and postdialysis mortality

Objectives

Coronary artery bypass grafting (CABG) is associated with better survival than percutaneous coronary intervention (PCI) in patients with mild-to-moderate chronic kidney disease (CKD) and End-Stage Renal Disease (ESRD). However, the optimal strategy for coronary artery revascularization in advanced CKD patients who transition to ESRD is unclear.

Methods

We examined a contemporary national cohort of 971 US veterans with incident ESRD, who underwent first CABG or PCI up to 5 years prior to dialysis initiation. We examined the association of a history of CABG versus PCI with all-cause mortality following transition to dialysis, using Cox proportional hazards models adjusted for time between procedure and dialysis initiation, socio-demographics, comorbidities and medications.

Results

582 patients underwent CABG and 389 patients underwent PCI. The mean age was 66±8 years, 99% of patients were male, 79% were white, 19% were African Americans, and 84% were diabetics. The all-cause post-dialysis mortality rates after CABG and PCI were 229/1000 patient-years (PY) [95% CI: 205-256] and 311/1000PY [95% CI: 272-356], respectively. Compared to PCI, patients who underwent CABG had 34% lower risk of death [multivariable adjusted Hazard Ratio (95% CI) 0.66 (0.51-0.86), p=0.002] after initiation of dialysis. Results were similar in all subgroups of patients stratified by age, race, type of intervention, presence/absence of myocardial infarction, congestive heart failure and diabetes.

Conclusion

CABG in advanced CKD patients was associated lower risk of death after initiation of dialysis compared to PCI.

Aldosterone induces renal fibrosis by promoting HDAC1 expression, deacetylating H3K9 and inhibiting klotho transcription

Aldosterone has an important role in the progression of renal fibrosis. In the present study, the concentration of aldosterone and klotho (KL) in the serum of patients with chronic kidney disease (CKD) were analyzed. A negative correlation was observed between aldosterone and KL, suggesting that KL may serve a protective role in CKD. Subsequently, an aldosterone‑induced CKD mouse model was established using a single nephrectomy and subcutaneous osmotic pump with aldosterone and 1% high‑salt drinking water. It was demonstrated that fibronectin 1 (Fn1) expression levels were higher in high aldosterone mice, whereas KL expression levels were low. In addition, the results demonstrated that histone deacetylase 1 (HDAC1) protein expression levels were upregulated in the renal distal convoluted tubules of high aldosterone mice, whereas acetylated H3K9 (H3K9Ac) was significantly downregulated. To determine the transcriptional activation status, chromatin immunoprecipitation polymerase chain reaction (PCR) was used to validate binding of H3K9Ac to the KL gene promoter site. It was revealed that the binding product of the KL promoter could be PCR‑amplified at the H3K9Ac site from wild‑type and low aldosterone mice; however, amplification of the binding product was not observed in high aldosterone mice. In conclusion, aldosterone significantly inhibited H3K9 acetylation by upregulating HDAC1 protein expression levels in the renal distal convoluted tubule cells, resulting in its inability to bind to the KL promoter, loss of transcription of the KL gene and increased expression of the renal fibrosis gene, Fn1.

Blood pressure components and incident cardiovascular disease and mortality events among Iranian adults with chronic kidney disease during over a decade long follow-up: a prospective cohort study

Background

To explore the association between systolic and diastolic blood pressure (SBP and DBP respectively) and pulse pressure (PP) with cardiovascular disease (CVD) and mortality events among Iranian patients with prevalent CKD.

Methods

Patients [n = 1448, mean age: 60.9 (9.9) years] defined as those with estimated glomerular filtration rate < 60 ml/min/1.73 m², were followed from 31 January 1999 to 20 March 2014. Multivariable Cox proportional hazard models were applied to examine the associations between different components of BP with outcomes.

Results

During a median follow-up of 13.9 years, 305 all-cause mortality and 317 (100 fatal) CVD events (among those free from CVD, n = 1232) occurred. For CVD and CV-mortality, SBP and PP showed a linear relationship, while a U-shaped relationship for DBP was observed with all outcomes. Considering 120 ≤ SBP < 130 as reference, SBP ≥ 140 mmHg was associated with the highest hazard ratio (HR) for CVD [1.68 (1.2–2.34)], all-cause [1.72 (1.19–2.48)], and CV-mortality events [2.21 (1.16–4.22)]. Regarding DBP, compared with 80 ≤ DBP < 85 as reference, the level of ≥ 85 mmHg increased risk of CVD and all-cause mortality events; furthermore, DBP < 80 mmHg was associated with significant HR for CVD events [1.55 (1.08–2.24)], all-cause [1.68 (1.13–2.5)] and CV-mortality events [3.0 (1.17–7.7)]. Considering PP, the highest HR was seen in participants in the 4th quartile for all outcomes of interest; HRs for CVD events [1.92 (1.33–2.78)], all-cause [1.71 (1.11–2.63)] and CV-mortality events [2.22 (1.06–4.64)].

Conclusions

Among patients with CKD, the lowest risk of all-cause and CV-mortality as well as incident CVD was observed in those with SBP < 140, 80 ≤ DBP < 85 and PP < 64 mmHg.

Blood pressure parameters and morbid and mortal outcomes in nondialysis-dependent chronic kidney disease

PURPOSE OF REVIEW

Observational and interventional studies provide conflicting evidence regarding optimal blood pressure (BP) control in persons with chronic kidney disease (CKD). Recent publications provide additional information to inform therapeutic decision-making.

RECENT FINDINGS

Targeting SBP to less than 120 mmHg, versus less than 140 mmHg, decreased cardiovascular events and all-cause mortality in persons with nondiabetic CKD. A meta-analysis of trials testing blood pressure management among nondialysis-dependent CKD patients (15 924 total patients) found more intensive therapies generally reduced mortality in all subgroups. Observational studies demonstrate that low SBP is associated with higher mortality in CKD. A recent report suggests that this is because of death from cardiovascular and noncardiovascular and nonmalignant causes, whereas higher BP is associated with death from cardiovascular causes. The shape of association between BP and cardiovascular and noncardiovascular events also appears to vary depending on baseline risk factors. Furthermore, BP measurement methodology may differ importantly between observational and interventional studies.

SUMMARY

We review and summarize observational and interventional literature relating BP parameters to key clinical outcomes in persons with CKD. Apart from the inherent differences between these study designs, the disparate findings from trials and observational studies may be because of differences in patient characteristics and BP measurement techniques.

Abrupt Decline in Kidney Function Precipitating Initiation of Chronic Renal Replacement Therapy

INTRODUCTION

Abrupt declines in kidney function often occur in patients with advanced chronic kidney disease and may exacerbate the need to initiate dialysis treatment. It is unclear how frequently such events occur in patients transitioning to chronic dialysis therapy, and what outcomes they are associated with.

METHODS

We examined a national cohort of 23,349 US veterans with incident end-stage renal disease (ESRD) and with available pre-ESRD estimated glomerular filtration rate (eGFR) to identify abrupt declines in kidney function, defined as an unexpected >50% decrease in eGFR at the time of chronic dialysis transition. Associations with all-cause mortality and with renal recovery were examined in Cox proportional hazard and competing risk regression models.

RESULTS

A total of 4804 (21%) patients experienced an abrupt decline in kidney function at dialysis transition. Renal recovery occurred in 586 (12.2%) and 297 (1.6%) patients with and without an abrupt decline, respectively (adjusted subhazard ratio: 4.42; 95% confidence interval [CI]: 3.72-5.27; P < 0.001). In the first 6 months after dialysis transition 1178 patients (24.5%) with abrupt decline died (annualized mortality rate 574/1000 patient-years), compared with 2354 deaths (12.7%) in patients without abrupt decline (274 deaths/1000 patient-years). An abrupt decline was associated with 45% higher mortality after multivariable adjustments (hazard ratio: 1.45; 95% CI: 1.33-1.57).

CONCLUSION

Abrupt declines in kidney function are common in patients transitioning to chronic dialysis, and are associated with higher mortality. Patients with abrupt declines also experience a higher rate of renal recovery; hence, careful attention to residual kidney function is warranted in these patients.

Pre-end-stage renal disease visit-to-visit systolic blood pressure variability and post-end-stage renal disease mortality in incident dialysis patients

OBJECTIVES

Higher SBP visit-to-visit variability (SBPV) has been associated with increased risk of adverse events in patients with chronic kidney disease, but the association of SBPV in advanced nondialysis-dependent chronic kidney disease with mortality after the transition to end-stage renal disease (ESRD) remains unknown.

METHODS

Among 17 729 US veterans transitioning to dialysis between October 2007 and September 2011, we assessed SBPV calculated from the SD of at least three intraindividual outpatient SBP values during the last year prior to dialysis transition (prelude period). Outcomes included factors associated with higher prelude SBPV and post-transition all-cause, cardiovascular, and infection-related mortality, assessed using multivariable linear regression and Cox and competing risk regressions, respectively, adjusted for demographics, comorbidities, medications, cardiovascular medication adherence, SBP, BMI, estimated glomerular filtration rate, and type of vascular access.

RESULTS

Modifiable clinical factors associated with higher prelude SBPV included higher SBP, use of antihypertensive medications and erythropoiesis-stimulating agents, inadequate cardiovascular medication adherence, and catheter use. After multivariable adjustment, higher prelude SBPV was significantly associated with higher post-ESRD all-cause and infection-related mortality, but not cardiovascular mortality [hazard/subhazard ratios (95% confidence interval) for the highest (vs. lowest) quartile of SBPV, 1.08 (1.01-1.16), 1.02 (0.89-1.15), and 1.41 (1.10-1.80) for all-cause, cardiovascular, and infection-related mortality, respectively].

CONCLUSION

High pre-ESRD SBPV is potentially modifiable and associated with higher all-cause and infection-related mortality following dialysis initiation. Further studies are needed to test whether modification of pre-ESRD SBPV can improve clinical outcomes in incident ESRD patients. VIDEO ABSTRACT:.

Association between vascular access creation and deceleration of estimated glomerular filtration rate decline in late-stage chronic kidney disease patients transitioning to end-stage renal disease

Background

Prior studies have suggested that arteriovenous fistula (AVF) or graft (AVG) creation may be associated with slowing of estimated glomerular filtration rate (eGFR) decline. It is unclear if this is attributable to the physiological benefits of a mature access on systemic circulation versus confounding factors.

Methods

We examined a nationwide cohort of 3026 US veterans with advanced chronic kidney disease (CKD) transitioning to dialysis between 2007 and 2011 who had a pre-dialysis AVF/AVG and had at least three outpatient eGFR measurements both before and after AVF/AVG creation. Slopes of eGFR were estimated using mixed-effects models adjusted for fixed and time-dependent confounders, and compared separately for the pre- and post-AVF/AVG period overall and in patients stratified by AVF/AVG maturation. In all, 3514 patients without AVF/AVG who started dialysis with a catheter served as comparators, using an arbitrary 6-month index date before dialysis initiation to assess change in eGFR slopes.

Results

Of the 3026 patients with AVF/AVG (mean age 67 years, 98% male, 75% diabetic), 71% had a mature AVF/AVG at dialysis initiation. eGFR decline accelerated in the last 6 months prior to dialysis in patients with a catheter (median, from -6.0 to -16.3 mL/min/1.73 m2/year, P < 0.001), while a significant deceleration of eGFR decline was seen after vascular access creation in those with AVF/AVG (median, from -5.6 to -4.1 mL/min/1.73 m2/year, P < 0.001). Findings were independent of AVF/AVG maturation status and were robust in adjusted models.

Conclusions

The creation of pre-dialysis AVF/AVG appears to be associated with eGFR slope deceleration and, consequently, may delay the onset of dialysis initiation in advanced CKD patients.

History of psychosis and mania, and outcomes after kidney transplantation - a retrospective study

History of psychosis or mania, if uncontrolled, both represent relative contraindications for kidney transplantation. We examined 3680 US veterans who underwent kidney transplantation. The diagnosis of history of psychosis/mania was based on a validated algorithm. Measured confounders were used to create a propensity score-matched cohort (n = 442). Associations between pretransplantation psychosis/mania and death with functioning graft, all-cause death, graft loss, and rejection were examined in survival models and logistic regression models. Post-transplant medication nonadherence was assessed using proportion of days covered (PDC) for tacrolimus and mycophenolic acid in both groups. The mean ± SD age of the cohort at baseline was 61 ± 11 years, 92% were male, and 66% and 27% of patients were white and African-American, respectively. Compared to patients without history of psychosis/mania, patients with a history of psychosis/mania had similar risk of death with functioning graft [subhazard ratio (SHR) (95% confidence interval (CI)): 0.94(0.42-2.09)], all-cause death [hazard ratio (95% CI): 1.04 (0.51-2.14)], graft loss [SHR (95% CI): 1.07 (0.45-2.57)], and rejection [odds ratio(95% CI): 1.23(0.60-2.53)]. Moreover, there was no difference in immunosuppressive drug PDC in patients with and without history of psychosis/mania (PDC: 76 ± 21% vs. 78 ± 19%, P = 0.529 for tacrolimus; PDC: 78 ± 17% vs. 79 ± 18%, P = 0.666 for mycophenolic acid). After careful selection, pretransplantation psychosis/mania is not associated with adverse outcomes in kidney transplant recipients.

Pre-End-Stage Renal Disease Hemoglobin Variability Predicts Post-End-Stage Renal Disease Mortality in Patients Transitioning to Dialysis

BACKGROUND

Hemoglobin variability (Hb-var) has been associated with increased mortality both in non-dialysis dependent chronic kidney disease (NDD-CKD) and end-stage renal disease (ESRD) patients. However, the impact of Hb-var in advanced NDD-CKD on outcomes after dialysis initiation remains unknown.

METHODS

Among 11,872 US veterans with advanced NDD-CKD transitioning to dialysis between October 2007 through September 2011, we assessed Hb-var calculated from the residual SD of at least 3 Hb values during the last 6 months before dialysis initiation (prelude period) using within-subject linear regression models, and stratified into quartiles. Outcomes included post-transition all-cause, cardiovascular, and infection-related mortality, assessed in Cox proportional hazards models and adjusted for demographics, comorbidities, length of hospitalization, medications, estimated glomerular filtration rate (eGFR), type of vascular access, Hb parameters (baseline Hb [i.e., intercept] and change in Hb [i.e., slope]), and number of Hb measurements.

RESULTS

Higher prelude Hb-var was associated with use of iron and antiplatelet agents, tunneled dialysis catheter use, higher levels of baseline Hb, change in Hb, eGFR, and serum ferritin. After multivariable adjustment, higher prelude Hb-var was associated with higher post-ESRD all-cause and infection-related mortality, but not cardiovascular mortality (adjusted hazard ratios [95% CI] for the highest [vs. lowest] quartile of Hb-var, 1.10 [1.02-1.19], 1.28 [0.93-1.75], and 0.93 [0.79-1.10], respectively).

CONCLUSIONS

High pre-ESRD Hb-var is associated with higher mortality, particularly from infectious causes rather than cardiovascular causes. Further research is required to clarify the underlying mechanisms and true causal nature of the observed association.

Hypertension in chronic kidney disease after the Systolic Blood Pressure Intervention Trial: targets, treatment and current uncertainties

Hypertension is the number one cardiovascular (CV) risk factor, and its treatment represents one of the most important interventions in patients at high risk for CV events. Patients with chronic kidney disease (CKD) are at high CV risk, yet as a group they have been excluded from most major blood pressure (BP)-lowering trials examining CV and mortality end points. The paucity of randomized clinical trial evidence for BP lowering in CKD patients is compounded by the fact that the association between BP levels and clinical outcomes in patients with CKD suggests the presence of a J-curve, which makes extrapolations from general population studies especially difficult. The recent completion of the Systolic Blood Pressure Intervention Trial (SPRINT), which enrolled a large number of patients with mild to moderate CKD, has raised hope for much-needed clarity about the ideal systolic BP target in this patient population. This review discusses the epidemiology of hypertension in CKD and the pathophysiologic underpinnings of the distinct associations between BP levels and clinical outcomes in patients with CKD, and it examines the applicability of the SPRINT results to the general CKD population.

Blood Pressure Parameters and their Associations with Death in Patients with Chronic Kidney Disease

PURPOSE OF REVIEW

Optimal blood pressure (BP) parameters among patients with chronic kidney disease (CKD) have been a matter of debate. This review critically evaluates recent literature to better define the associations of BP parameters and death among individuals with non-dialysis-dependent CKD.

RECENT FINDINGS

Observational studies report a "U- or J-shaped" association between BP and all-cause mortality in CKD and caution-intensive BP lowering in the elderly. Causes of death have been evaluated in a recent report noting higher cardiovascular and non-cardiovascular/non-malignant-related mortality among CKD population with SBP < 110 and > 150 mmHg. Very few randomized control trials evaluated the impact of different BP targets on patient-centered outcomes in those with CKD. Recently published SPRINT trial results suggest that intensive SBP control (<120 mm Hg) reduces cardiovascular events and all-cause death among non-diabetic patients with and without CKD. Clinical trial evidence supports lower BP target in those with mild to moderate non-diabetic CKD. However, clinical trials are warranted to further determine the beneficial effects of intensive blood pressure control in diabetic CKD population. In elderly population with CKD, BP targets might need to be individualized based on their comorbidities, life expectancy, and other factors.

Blood Pressure Targets in CKD: Lessons Learned from SPRINT and Previous Observational Studies

Hypertension management is one of the most common clinical tasks in the care of patients with chronic kidney disease (CKD). Elevated blood pressure (BP) is associated with greater risk of all-cause mortality, cardiovascular (CV) disease, and CKD progression in this population. However, it is still debated, to what target(s) BP should be lowered in patients with signs of kidney damage. The Systolic Blood Pressure Intervention Trial (SPRINT) provided new and important information about the effects of lowering systolic BP to a target of <120 mmHg, which is lower than the levels currently recommended by the most guidelines (<140/90 mmHg). The SPRINT results were not only exciting but also surprising for many clinicians because evidence from well-conducted observational studies in CKD patient showed increased mortality in patients with CKD whose office systolic BP levels were <120 mmHg, as compared with systolic BP in 120-139 mmHg range. In the present review, we will discuss whether a systolic BP goal of <120 mmHg that was found to be beneficial for CV and all-cause mortality outcomes in the SPRINT can be generalized to the entire CKD population.