Urinary Sodium and Potassium Excretion and CKD Progression.

CKD is a major risk factor for ESRD, cardiovascular disease, and premature death. Whether dietary sodium and potassium intake affect CKD progression remains unclear. We prospectively studied the association of urinary sodium and potassium excretion with CKD progression and all-cause mortality among 3939 patients with CKD in the Chronic Renal Insufficiency Cohort Study. Urinary sodium and potassium excretion were measured using three 24-hour urine specimens, and CKD progression was defined as incident ESRD or halving of eGFR. During follow-up, 939 CKD progression events and 540 deaths occurred. Compared with the lowest quartile of urinary sodium excretion (<116.8 mmol/24 h), hazard ratios (95% confidence intervals) for the highest quartile of urinary sodium excretion (≥194.6 mmol/24 h) were 1.54 (1.23 to 1.92) for CKD progression, 1.45 (1.08 to 1.95) for all-cause mortality, and 1.43 (1.18 to 1.73) for the composite outcome of CKD progression and all-cause mortality after adjusting for multiple covariates, including baseline eGFR. Additionally, compared with the lowest quartile of urinary potassium excretion (<39.4 mmol/24 h), hazard ratios for the highest quartile of urinary potassium excretion (≥67.1 mmol/24 h) were 1.59 (1.25 to 2.03) for CKD progression, 0.98 (0.71 to 1.35) for all-cause mortality, and 1.42 (1.15 to 1.74) for the composite outcome. These data indicate that high urinary sodium and potassium excretion are associated with increased risk of CKD progression. Clinical trials are warranted to test the effect of sodium and potassium reduction on CKD progression.

Anemia and risk for cognitive decline in chronic kidney disease.

BACKGROUND: Anemia is common among patients with chronic kidney disease (CKD) but its health consequences are poorly defined. The aim of this study was to determine the relationship between anemia and cognitive decline in older adults with CKD. METHODS: We studied a subgroup of 762 adults age ≥55 years with CKD participating in the Chronic Renal Insufficiency Cohort (CRIC) study. Anemia was defined according to the World Health Organization criteria (hemoglobin <13 g/dL for men and <12 g/dL for women). Cognitive function was assessed annually with a battery of six tests. We used logistic regression to determine the association between anemia and baseline cognitive impairment on each test, defined as a cognitive score more than one standard deviation from the mean, and mixed effects models to determine the relation between anemia and change in cognitive function during follow-up after adjustment for demographic and clinical characteristics. RESULTS: Of 762 participants with mean estimated glomerular filtration rate of 42.7 ± 16.4 ml/min/1.73 m(2), 349 (46 %) had anemia. Anemia was not independently associated with baseline cognitive impairment on any test after adjustment for demographic and clinical characteristics. Over a median 2.9 (IQR 2.6-3.0) years of follow-up, there was no independent association between anemia and change in cognitive function on any of the six cognitive tests. CONCLUSIONS: Among older adults with CKD, anemia was not independently associated with baseline cognitive function or decline.

Predictors of high sensitivity cardiac troponin T in chronic kidney disease patients: a cross-sectional study in the chronic renal insufficiency cohort (CRIC).

BACKGROUND: Cardiac troponin T is independently associated with cardiovascular events and mortality in patients with chronic kidney disease (CKD). Serum levels of high sensitivity cardiac troponin T (hs-TnT) reflect subclinical myocardial injury in ambulatory patients. We sought to determine the distribution and predictors of hs-TnT in CKD patients without overt cardiovascular disease (CVD). METHODS: We studied 2464 participants within the multi-ethnic Chronic Renal Insufficiency Cohort (CRIC) who did not have self-reported CVD. We considered renal and non-renal factors as potential determinants of hs-TnT, including demographics, comorbidities, left ventricular (LV) mass, serologic factors, estimated glomerular filtration rate (eGFR) and albumin to creatinine ratio. RESULTS: Hs-TnT was detectable in 81% of subjects, and the median (IQR) hs-TnT was 9.4 pg/ml (4.3-18.3). Analysis was performed using Tobit regression, adjusting for renal and non-renal factors. After adjustment, lower eGFR was associated with higher expected hs-TnT; participants with eGFR < 30 ml/min/1.73 m(2) had 3-fold higher expected hs-TnT compared to subjects with eGFR > 60. Older age, male gender, black race, LV mass, diabetes and higher blood pressure all had strong, independent associations with higher expected hs-TnT. CONCLUSIONS: Knowledge of the determinants of hs-TnT in this cohort may guide further research on the pathology of heart disease in patients with CKD and help to stratify sub-groups of CKD patients at higher cardiovascular risk.

Hypertension awareness, treatment, and control in adults with CKD: results from the Chronic Renal Insufficiency Cohort (CRIC) Study.

BACKGROUND: A low rate of blood pressure control has been reported in patients with chronic kidney disease (CKD). These data were derived from population-based samples with a low rate of CKD awareness. STUDY DESIGN: Cross-sectional. SETTING & PARTICIPANTS: Data from the baseline visit of the Chronic Renal Insufficiency Cohort (CRIC) Study (n = 3,612) were analyzed. Participants with an estimated glomerular filtration rate of 20-70 mL/min/1.73 m(2) were identified from physician offices and review of laboratory databases. OUTCOMES: Prevalence and awareness of hypertension, treatment patterns, control rates, and factors associated with hypertension control. MEASUREMENTS: Following a standardized protocol, blood pressure was measured 3 times by trained staff, and hypertension was defined as systolic blood pressure > or =140 mm Hg and/or diastolic blood pressure > or =90 mm Hg and/or self-reported antihypertensive medication use. Patients' awareness and treatment of hypertension were defined using self-report, and 2 levels of hypertension control were evaluated: systolic/diastolic blood pressure <140/90 and <130/80 mm Hg. RESULTS: The prevalence of hypertension was 85.7%, and 98.9% of CRIC participants were aware of this diagnosis and 98.3% were treated with medications, whereas 67.1% and 46.1% had hypertension controlled to <140/90 and <130/80 mm Hg, respectively. Of CRIC participants with hypertension, 15%, 25%, 26%, and 32% were using 1, 2, 3, and > or =4 antihypertensive medications, respectively. After multivariable adjustment, older patients, blacks, and those with higher urinary albumin excretion were less likely, whereas participants using angiotensin-converting enzyme inhibitors and angiotensin receptor blockers were more likely to have controlled their hypertension to <140/90 and <130/80 mm Hg. LIMITATIONS: Data were derived from a single study visit. CONCLUSIONS: Despite almost universal hypertension awareness and treatment in this cohort of patients with CKD, rates of hypertension control were suboptimal.

Self-Reported Tobacco, Alcohol, and Illicit Drug Use and Progression of Chronic Kidney Disease.

BACKGROUND AND OBJECTIVES: Previous studies suggest that tobacco, alcohol, and illicit drug use is associated with CKD. We examined the associations of substance use with CKD progression and all-cause mortality among patients with CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The Chronic Renal Insufficiency Cohort Study is a prospective, longitudinal cohort study among 3939 participants with CKD in the United States. Self-reported tobacco smoking, alcohol drinking, marijuana use, and hard illicit drug (cocaine, heroin, or methamphetamine) use were obtained at baseline and annual follow-up visits. CKD progression was defined as incident ESKD or halving of eGFR. Substance use was modeled as the cumulative average exposure to capture both recent and long-term use in multivariable time-dependent Cox regression. RESULTS: Over a median 5.5-year follow-up, 1287 participants developed CKD progression, and 1001 died. Baseline proportions of tobacco smoking, alcohol drinking, marijuana use, and hard illicit drug use were 13%, 20%, 33%, and 12%, respectively. Compared with nonsmoking throughout follow-up, multivariable-adjusted hazard ratios for persistent tobacco smoking were 1.02 (95% confidence interval, 0.86 to 1.21) for CKD progression and 1.86 (95% confidence interval, 1.54 to 2.24) for all-cause mortality. Compared with nondrinking throughout follow-up, multivariable-adjusted hazard ratios for persistent alcohol drinking were 1.06 (95% confidence interval, 0.88 to 1.29) for CKD progression and 0.73 (95% confidence interval, 0.58 to 0.91) for all-cause mortality. Compared with nonuse throughout follow-up, multivariable-adjusted hazard ratios for persistent marijuana use were 0.94 (95% confidence interval, 0.82 to 1.07) for CKD progression and 1.11 (95% confidence interval, 0.96 to 1.30) for all-cause mortality. Compared with nonuse throughout follow-up, multivariable-adjusted hazard ratios for persistent hard illicit drug use were 1.25 (95% confidence interval, 1.00 to 1.55) for CKD progression and 1.41 (95% confidence interval, 1.10 to 1.81) for all-cause mortality. CONCLUSIONS: Hard illicit drug use is associated with higher risk of CKD progression and all-cause mortality, tobacco smoking is associated with higher risk of all-cause mortality, and alcohol drinking is associated with lower risk of all-cause mortality among patients with CKD.

Inflammatory Markers and Risk for Cognitive Decline in Chronic Kidney Disease: The CRIC Study.

INTRODUCTION: Chronic kidney disease (CKD) is associated with an increased risk of cognitive decline, but the mechanisms remain poorly defined. We sought to determine the relation between serum inflammatory markers and risk of cognitive decline among adults with CKD. METHODS: We studied 757 adults aged ≥55 years with CKD participating in the Chronic Renal Insufficiency Cohort Cognitive study. We measured interleukin (IL)-1ß, IL-1 receptor antagonist, IL-6, tumor necrosis factor (TNF)-α, high-sensitivity C-reactive protein (hs-CRP), and fibrinogen in baseline plasma samples. We assessed cognitive function at regular intervals in 4 domains and defined incident impairment as a follow-up score more than 1 SD poorer than the group mean. RESULTS: The mean age of the sample was 64.3 ± 5.6 years, and the mean follow-up was 6.2 ± 2.5 years. At baseline, higher levels of each inflammatory marker were associated with poorer age-adjusted performance. In analyses adjusted for baseline cognition, demographics, comorbid conditions, and kidney function, participants in the highest tertile of hs-CRP, the highest tertile of fibrinogen, and the highest tertile of IL-1ß had an increased risk of impairment in attention compared to participants in the lowest tertile of each marker. Participants in the highest versus lowest tertile of TNF-α had a lower adjusted risk of impairment in executive function. There was no association between other inflammatory markers and change in cognitive function. DISCUSSION: Among adults with CKD, higher levels of hs-CRP, fibrinogen, and IL-1ß were associated with a higher risk of impairment in attention. Higher levels of TNF-α were associated with a lower risk of impaired executive function.

Association of QT-Prolonging Medication Use in CKD with Electrocardiographic Manifestations.

BACKGROUND AND OBJECTIVES: Several drugs used in CKD can prolong electrocardiographic conduction. We examined the use of electrocardiogram QT-prolonging medications in predialysis CKD and their association with QT duration. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In total, 3252 Chronic Renal Insufficiency Cohort participants with at least one study electrocardiogram between 2003 and 2011 were included. QT-prolonging medications used in 100 or more visits (n=16,451 visits) along with diuretics and proton pump inhibitors, given their potential for electrolyte disturbances, were examined for QT interval prolongation. RESULTS: Mean QT interval corrected for heart rate was at 414±21 (±SD) milliseconds and prolonged (≥450 milliseconds) in 4.6% of electrocardiograms. QT interval corrected for heart rate was inversely related to serum potassium and calcium. Medications classified as QT prolonging were taken at 76% of visits, with two or more of these taken at 33% of visits. Of 30 medications examined, eight were associated with statistically significant QT interval corrected for heart rate prolongation after adjustment for comorbidities, potassium, and calcium, including amiodarone (+10±2 milliseconds), metolazone (+7±2 milliseconds), fluoxetine (+4±1 milliseconds), citalopram (+4±1 milliseconds), hydroxyzine (+4±1 milliseconds), escitalopram (+3±2 milliseconds), venlafaxine (+3±1 milliseconds), and furosemide (+3±0 milliseconds). Potassium-depleting diuretics were associated with minimal decrements in potassium (between 0.1 and 0.3 mEq/L) and smaller changes in calcium. Diuretics associated with a change in QT interval corrected for heart rate before adjustment for potassium and calcium were metolazone (+8±3 milliseconds), furosemide (+4±1 milliseconds), and spironolactone (-3±3 milliseconds). Most of the QT prolongation associated with metolazone and furosemide, but not spironolactone, remained after adjustment for potassium and calcium. Proton pump inhibitors were not associated with QT prolongation. CONCLUSIONS: Use of medications associated with QT prolongation is common in CKD; the safety implications of these findings should be considered in these high-risk patients. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2017_08_09_CJASNPodcast_17_09_b.mp3.

Masked Hypertension and Elevated Nighttime Blood Pressure in CKD: Prevalence and Association with Target Organ Damage.

BACKGROUND AND OBJECTIVES: Masked hypertension and elevated nighttime BP are associated with increased risk of hypertensive target organ damage and adverse cardiovascular and renal outcomes in patients with normal kidney function. The significance of masked hypertension for these risks in patients with CKD is less well defined. The objective of this study was to evaluate the association between masked hypertension and kidney function and markers of cardiovascular target organ damage, and to determine whether this relationship was consistent among those with and without elevated nighttime BP. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This was a cross-sectional study. We performed 24-hour ambulatory BP in 1492 men and women with CKD enrolled in the Chronic Renal Insufficiency Cohort Study. We categorized participants into controlled BP, white-coat, masked, and sustained hypertension on the basis of clinic and 24-hour ambulatory BP. We obtained echocardiograms and measured pulse wave velocity in 1278 and 1394 participants, respectively. RESULTS: The percentages of participants with controlled BP, white-coat, masked, and sustained hypertension were 49.3%, 4.1%, 27.8%, and 18.8%, respectively. Compared with controlled BP, masked hypertension independently associated with low eGFR (-3.2 ml/min per 1.73 m(2); 95% confidence interval, -5.5 to -0.9), higher proteinuria (+0.9 unit higher in log2 urine protein; 95% confidence interval, 0.7 to 1.1), and higher left ventricular mass index (+2.52 g/m(2.7); 95% confidence interval, 0.9 to 4.1), and pulse wave velocity (+0.92 m/s; 95% confidence interval, 0.5 to 1.3). Participants with masked hypertension had lower eGFR only in the presence of elevated nighttime BP (-3.6 ml/min per 1.73 m(2); 95% confidence interval, -6.1 to -1.1; versus -1.4 ml/min per 1.73 m(2); 95% confidence interval, -6.9 to 4.0, among those with nighttime BP <120/70 mmHg; P value for interaction with nighttime systolic BP 0.002). CONCLUSIONS: Masked hypertension is common in patients with CKD and associated with lower eGFR, proteinuria, and cardiovascular target organ damage. In patients with CKD, ambulatory BP characterizes the relationship between BP and target organ damage better than BP measured in the clinic alone.

Comparison of quality-of-hypertension-care indicators for groups treated by physician versus groups treated by physician-nurse team.

PURPOSE: To determine whether the type of health care provider (i.e., physician versus physician-nurse team) affected the quality of hypertension care given to two groups of randomly selected adult women. DATA SOURCES: Three indicators measured the quality of hypertension care: blood pressure control level, knowledge of hypertension, and discussion about blood pressure medications with the health care provider(s). Blood pressure readings were taken with a 24-hr ambulatory blood pressure monitor, and demographic data from survey results taken at orientation and researcher-collected data on posttreatment knowledge of hypertension and cognitive representations of hypertension were gathered. Chi-square and t tests were used to analyze the data. CONCLUSIONS: The group whose care was managed by a physician-nurse team demonstrated lower means for 24-hr systolic blood pressure and diastolic blood pressure (systolic: M = 132, SD = 14.9; diastolic: M = 75, SD = 11.3) than the group whose care was managed only by one or more physicians (systolic: M = 136, SD = 13.4; diastolic: M = 79, SD = 11.24). Also, the group whose care was managed by a physician-nurse team revealed significantly higher scores for discussion of blood pressure medication than the group whose care was managed only by one or more physicians. There were no group differences for knowledge of hypertension. IMPLICATIONS FOR PRACTICE: Nurses qualified to assist with meeting the needs of hypertension clients in primary care settings can positively affect clients' knowledge about blood pressure medication and--perhaps as a result of this knowledge--how well the clients control their blood pressure.

Chronic kidney disease and cognitive function in older adults: findings from the chronic renal insufficiency cohort cognitive study.

OBJECTIVES: To investigate cognitive impairment in older, ethnically diverse individuals with a broad range of kidney function, to evaluate a spectrum of cognitive domains, and to determine whether the relationship between chronic kidney disease (CKD) and cognitive function is independent of demographic and clinical factors. DESIGN: Cross-sectional. SETTING: Chronic Renal Insufficiency Cohort Study. PARTICIPANTS: Eight hundred twenty-five adults aged 55 and older with CKD. MEASUREMENTS: Estimated glomerular filtration rate (eGFR, mL/min per 1.73 m(2)) was estimated using the four-variable Modification of Diet in Renal Disease equation. Cognitive scores on six cognitive tests were compared across eGFR strata using linear regression; multivariable logistic regression was used to examine level of CKD and clinically significant cognitive impairment (score < or =1 standard deviations from the mean). RESULTS: Mean age of the participants was 64.9, 50.4% were male, and 44.5% were black. After multivariable adjustment, participants with lower eGFR had lower cognitive scores on most cognitive domains (P<.05). In addition, participants with advanced CKD (eGFR<30) were more likely to have clinically significant cognitive impairment on global cognition (adjusted odds ratio (AOR) 2.0, 95% CI=1.1-3.9), naming (AOR=1.9, 95% CI=1.0-3.3), attention (AOR=2.4, 95% CI=1.3-4.5), executive function (AOR=2.5, 95% CI=1.9-4.4), and delayed memory (AOR=1.5, 95% CI=0.9-2.6) but not on category fluency (AOR=1.1, 95% CI=0.6-2.0) than those with mild to moderate CKD (eGFR 45-59). CONCLUSION: In older adults with CKD, lower level of kidney function was associated with lower cognitive function on most domains. These results suggest that older patients with advanced CKD should be screened for cognitive impairment.