Reducing salt intake by urine chloride self-measurement in non-compliant patients with chronic kidney disease followed in nephrology clinics: a randomized trial.

BACKGROUND: Adherence to low salt diets and control of hypertension remain unmet clinical needs in chronic kidney disease (CKD) patients. METHODS: We performed a 6-month multicentre randomized trial in non-compliant patients with CKD followed in nephrology clinics testing the effect of self-measurement of urinary chloride (69 patients) as compared with standard care (69 patients) on two primary outcome measures, adherence to a low sodium (Na) diet (<100 mmol/day) as measured by 24-h urine Na (UNa) excretion and 24-h ambulatory blood pressure (ABPM) monitoring. RESULTS: In the whole sample (N = 138), baseline UNa and 24-h ABPM were143 ± 64 mmol/24 h and 131 ± 18/72 ± 10 mmHg, respectively, and did not differ between the two study arms. Patients in the active arm of the trial used >80% of the chloride strips provided to them at the baseline visit and at follow-up visits. At the third month, UNa was 35 mmol/24 h (95% CI 10.8-58.8 mmol/24 h; P = 0.005) lower in the active arm than the control arm, whereas at 6 months the between-arms difference in UNa decreased and was no longer significant [23 mmol/24 h (95% CI -5.6-50.7); P = 0.11]. The 24-h ABPM changes as well as daytime and night-time BP changes at 3 and 6 months were similar in the two study arms (Month 3, P = 0.69-0.99; Month 6, P = 0.73-0.91). Office BP, the use of antihypertensive drugs, estimated Glomerular Filtration Rate (eGFR) and proteinuria remained unchanged across the trial. CONCLUSIONS: The application of self-measurement of urinary chloride to guide adherence to a low salt diet had a modest effect on 24-h UNa and no significant effect on 24-h ABPM.

Urine chloride self-measurement to monitor sodium chloride intake in patients with chronic kidney disease.

Background Excessive sodium intake is a risk factor for hypertension, cardiovascular disease and the risk for kidney failure in chronic kidney disease (CKD) patients. Methods We tested the diagnostic performance and the feasibility of an inexpensive method based on urine chloride strips for self-monitoring sodium intake in a series of 72 CKD patients. Results Twenty-four hour urinary chloride as measured by the reactive strips and 24 h urinary sodium were interrelated (r=0.59, p<0.001). Forty-nine out of 72 patients (78%) had a 24 h urinary sodium >100 mmol/24 h, i.e. the upper limit recommended by current CKD guidelines. The strip method had 75.5% sensitivity and 82.6% specificity to correctly classify patients with urine sodium >100 mmol/24 h. The positive and the negative predictive values were 90.2% and 61.3%, respectively. The overall accuracy (ROC curve analysis) of urine chloride self-measurement for the >100 mmol/24 h sodium threshold was 87% (95% CI: 77%-97%). The large majority of patients (97%) perceived the test as useful to help compliance with the prescribed dietary sodium and considered the test as simple and of immediate application (58%) or feasible but requiring attention (39%). Conclusions A simple and inexpensive test for urine chloride measurement has a fairly good performance for the diagnosis of excessive sodium intake. The test is feasible and it is perceived by CKD patients as helpful for enhancing compliance to the dietary sodium recommendations. The usefulness of this test for improving hypertension control in CKD patients will be tested in a clinical trial (Clinicaltrials.gov RF-2010-2314890).

Socioeconomic Status and Clinical Outcomes in Chronic Kidney Disease: Bootstrap Validation of a Simple Indicator.

Background: Chronic Kidney Disease (CKD) is a complex health condition that interacts significantly with socioeconomic determinants, particularly income status and education. This study developed a simple indicator of socioeconomic status (SES), which is composed of income status and education in CKD patients, and evaluated its impact on health outcomes in this population. Methods: This study was conducted on 561 CKD patients, stages 2-5. The composite SES score was developed by combining the regression coefficients of income and education as predictors of the study endpoint in a multivariable Cox model, normalizing these coefficients to derive weights, and then using these weights to calculate an individual percentage score based on each person's income and education. The composed SES indicator was internally validated through bootstrap analysis. Over a median follow-up time of 36 months, we tracked all-cause death and non-fatal cardiovascular events. Results: Both lack of income (p = 0.020) and low educational level (p = 0.034) were independently related to the combined endpoint. Based on these covariates' regression coefficients, a composite socioeconomic score considering income and educational level was generated. In a Cox regression model, a 10% increase in this composite risk score entailed a 25% increase in the hazard ratio (HR) of the combined endpoint [HR (10% increase): 1.25], and the internally validated 95% CI ranged from 1.14 to 1.41 (p < 0.001). Conclusions: This study underscores the significant impact of a simple, bootstrap-validated composite SES indicator on CKD patients' health outcomes. These findings highlight the importance of considering education and socioeconomic factors in managing and treating CKD patients and inform future research and policy considerations for this population.

Lung ultrasound to detect and monitor pulmonary congestion in patients with acute kidney injury in nephrology wards: a pilot study.

INTRODUCTION: Lung congestion and frank pulmonary edema are established complications of acute kidney injury (AKI) and early detection and monitoring of lung congestion may be useful for the clinical management of AKI patients. METHODS: We compared standardized clinical criteria (including lung crackles and peripheral edema grading) and simultaneous chest ultrasound (US) to detect lung congestion in a series of 39 inpatients with AKI. RESULTS: At baseline, twelve patients (31%) were clinically euvolemic and twelve presented clear-cur cardiovascular congestion (31%) by clinical criteria. Fifteen patients (38%) were hypovolemic. The median number of US-B lines in patients with cardiovascular congestion was much higher (50, inter-quartile range 27-99) than in euvolemic (14, IQR 11-37) and hypovolemic patients (7, IQR 3-16, P < 0.001). Remarkably, a substantial proportion of asymptomatic euvolemic (66%) and hypovolemic (46%) patients had lung congestion of moderate to severe degree (> 15 US-B lines) by lung US. Crackles severity and the number of US-B lines over time were inter-related (Spearman's ρ = 0.38, P < 0.01) but the agreement (Cohen k statistics) between the two metrics was unsatisfactory. Forty-eight percent of patients had lung congestion of moderate to severe degree by lung US and this estimate by far exceeded that by clinical criteria (32%). CONCLUSIONS: This pilot study shows that chest US has potential for the detection of lung congestion at a pre-clinical stage in AKI. The results of this pilot study form the basis for a clinical trial testing the usefulness of this technique for guiding lung congestion treatment in patients with AKI.

Sleep-Disordered Breathing and 24-Hour Ambulatory Blood Pressure Monitoring in Renal Transplant Patients: Longitudinal Study.

Background Sleep-disordered breathing (SDB) is considered a strong risk factor for hypertension in the general population. This disturbance is common in end-stage kidney disease patients on long-term hemodialysis and improves early on after renal transplantation. Whether SDB may be a risk factor for hypertension in renal transplant patients is unclear. Methods and Results We investigated the long-term evolution of simultaneous polysomnographic and 24-hour ambulatory blood pressure (BP) monitoring recordings in a cohort of 221 renal transplant patients. Overall, 404 paired recordings were made over a median follow-up of 35 months. A longitudinal data analysis was performed by the mixed linear model. The apnea-hypopnea index increased from a median baseline value of 1.8 (interquartile range, 0.6-5.0) to a median final value of 3.6 (interquartile range, 1.7-10.4; P=0.009). Repeated categorical measurements of the apnea-hypopnea index were directly associated with simultaneous 24-hour, daytime, and nighttime systolic ambulatory BP monitoring (adjusted analyses; P ranging from 0.002-0.01). In a sensitivity analysis restricted to 139 patients with at least 2 visits, 24-hour, daytime, and nighttime systolic BP significantly increased across visits (P<0.05) in patients with worsening SDB (n=40), whereas the same BP metrics did not change in patients (n=99) with stable apnea-hypopnea index. Conclusions In renal transplant patients, worsening SDB associates with a parallel increase in average 24-hour, daytime, and nighttime systolic BP. These data are compatible with the hypothesis that the link between SDB and hypertension is causal in nature. Clinical trials are, however, needed to definitively test this hypothesis.

Body mass index predicts plasma aldosterone concentrations in overweight-obese primary hypertensive patients.

CONTEXT: Body mass index (BMI) shows a direct correlation with plasma aldosterone concentration (PAC) and urinary aldosterone excretion in normotensive individuals; whether the same applies to hypertensive patients is unknown. OBJECTIVE: Our objective was to determine if BMI predicts PAC and the PAC/plasma renin activity ratio [aldosterone renin ratio (ARR)] in hypertensive patients, and if this affects the identification of primary aldosteronism (PA). DESIGN: This was a prospective evaluation of consecutive hypertensive patients referred nationwide to specialized hypertension centers. MAIN OUTCOME MEASURES: Sitting PAC, plasma renin activity, and the ARR, baseline and after 50 mg captopril orally with concomitant assessment of parameters, including BMI and daily sodium intake, were calculated. RESULTS: Complete biochemical data and a definite diagnosis were obtained in 1125 consecutive patients. Of them 999 had primary (essential) hypertension (PH) and 126 (11.2%) PA caused by an aldosterone-producing adenoma in 54 (4.8%). BMI independently predicted PAC (beta = 0.153; P < 0.0001) in PH, particularly in the overweight-obese, but not in the PA group. Covariance analysis and formal comparison of the raw, and the BMI-, sex-, and sodium intake-adjusted ARR with receiver operator characteristic curves, showed no significant improvement for the discrimination of aldosterone-producing adenoma from PH patients with covariate-adjusted ARR. CONCLUSIONS: BMI correlated with PAC independent of age, sex, and sodium intake in PH, but not in PA patients. This association of BMI is particularly evident in overweight-obese PH patients, and suggests a pathophysiological link between visceral adiposity and aldosterone secretion. However, it does not impact on the diagnostic accuracy of the ARR for discriminating PA from PH patients.

[Pathogenesis of renal failure in hypertension. The role of genetic factors, low weight at birth and endothelial dysfunction]. / Attualità sulla patogenesi dell'insufficienza renale nell'ipertensione. Il ruolo dei fattori genetici, del basso peso alla nascita e della disfunzione endoteliale.

Nephrosclerosis is usually diagnosed in patients with essential hypertension with no or mild proteinuria and no urinary abnormalities. Microalbuminuria is considered to be a marker of high risk for progressive renal disease in patients with diabetes mellitus but there is still no solid evidences that this alteration entails an adverse renal prognosis in essential hypertension. Independently of hypertension, nephrosclerosis is associated with endothelial dysfunction and evidence is accruing that genetic factors and a low number of nephrons at birth are important determinants of this disease.

Hypokalaemia with paralysis: don't forget the thyroid.

The authors report the case of a 33-year-old Italian man who had three episodes of hypokalaemia with paralysis linked to hyperthyroidism. Because of its low prevalence in western populations, the diagnosis of thyrotoxic hypokalaemic periodic paralysis can be easily missed in non-Asian countries.

Visceral leishmaniasis reactivation in transplant patients: a minireview with report of a new case.

An updated review of cases of reactivated visceral leishmaniasis (VL) in transplant patients is presented, with a new report of a kidney transplant patient who had VL caused by reactivation of a dormant infection contracted 21 years previously. Close to the time of disease reactivation, the patient had a primary varicella-zoster infection.

Ultrafiltration intensification in hemodialysis patients improves hypertension but increases AV fistula complications and cardiovascular events.

INTRODUCTION: Hypertension remains a major problem in hemodialysis (HD) patients. METHODS: We performed a pragmatic trial (Pragmatic Clinical Intervention on Blood Pressure Driven by Audit [CLINIDEA]) testing the effectiveness and safety of a 6-month multimodal intervention in hypertensive HD patients regarding the application of higher ultrafiltration (UF) rates or longer or more frequent dialyses in UF-intolerant patients, and an educational intervention to encourage patients to lower their salt and fluid intake. RESULTS: Blood pressure (BP) in hypertensive patients (n=32) fell from 156.8 ± 13.3 / 81.1 ± 8.9 mm Hg to 147.9 ± 18.8 / 77.5 ± 11.1 mm Hg. UF intensification was well tolerated, and the BP goal was achieved without resorting to longer or more frequent dialyses. BP changes were paralleled by a consistent (p<0.01) fall in dry body weight. The trial largely failed at increasing compliance with salt prescription (salt intake: baseline: 156.9 ± 64 mEq/day, 6-month: 150.7 ± 60.3 mEq/day). During the 12 months preceding the trial, the hospitalization rates for arteriovenous (AV) fistula complications and cardiovascular (CV) events were identical in hypertensive and in normotensive patients. However, these complications selectively increased (AV complications: relative risk [RR] = 7.6; CV complication: RR=8.4) in hypertensive patients coinciding with UF intensification during the trial. Increasing the UF rate is an effective BP-lowering intervention in HD patients. However, this intervention is associated with a higher risk for AV complications and CV events. CONCLUSION: Longer and/or more frequent dialyses and better efforts to increase compliance to low salt diets than those put in place in this study are needed to reduce the high prevalence of hypertension in the HD population.

Within-patient reproducibility of the aldosterone: renin ratio in primary aldosteronism.

The plasma aldosterone concentration:renin ratio (ARR) is widely used for the screening of primary aldosteronism, but its reproducibility is unknown. We, therefore, investigated the within-patient reproducibility of the ARR in a prospective multicenter study of consecutive hypertensive patients referred to specialized centers for hypertension in Italy. After the patients were carefully prepared from the pharmacological standpoint, the ARR was determined at baseline in 1136 patients and repeated after, on average, 4 weeks in the patients who had initially an ARR > or =40 and in 1 of every 4 of those with an ARR <40. The reproducibility of the ARR was assessed with Passing and Bablok and Deming regression, coefficient of reproducibility, and Bland-Altman and Mountain plots. Within-patient ARR comparison was available in 268 patients, of whom 49 had an aldosterone-producing adenoma, on the basis of the "4-corner criteria." The ARR showed a highly significant within-patient correlation (r=0.69; P<0.0001) and reproducibility. Bland-Altman plot showed no proportional, magnitude-related, or absolute systematic error between the ARR; moreover, only 7% of the values, for example, slightly more than what could be expected by chance, fell out of the 95% CI for the between-test difference. The accuracy of each ARR for pinpointing aldosterone-producing adenoma patients was approximately 80%. Thus, although it was performed under different conditions in a multicenter study, the ARR showed a good within-patient reproducibility. Hence, contrary to previously claimed poor reproducibility of the ARR, these data support its use for the screening of primary aldosteronism.