The coming fiscal crisis: nephrology in the line of fire.

Nephrologists in the United States face a very uncertain economic future. The astronomical federal debt and unfunded liability burden of Medicare combined with the aging population will place unprecedented strain on the health care sector. To address these fundamental problems, it is conceivable that the federal government will ultimately institute rationing and other budget-cutting measures to rein in costs of ESRD care, which is generously funded relative to other chronic illnesses. Therefore, nephrologists should expect implementation of cost-cutting measures, such age-based rationing, mandated delayed dialysis and home therapies, compensated organ donation, and a shift in research priorities from the dialysis to the predialysis patient population. Nephrologists also need to recognize that these changes, which are geared toward the population level, may make it more difficult to advocate effectively for the needs of individual patients.

Location not quantity of blood pressure measurements predicts mortality in hemodialysis patients.

BACKGROUND: Blood pressure (BP) measurements obtained outside the dialysis unit are prognostically superior. Whether it is the greater number of measurements made outside the dialysis unit that correlates with prognosis or whether BPs outside dialysis units are ecologically more valid is unknown. METHODS AND RESULTS: A prospective cohort study was conducted in 133 patients on chronic hemodialysis. BP was measured by the patients at home for 1 week, over an interdialytic interval by ambulatory recording, and by 'routine' and standardized methods in the dialysis unit for 2 weeks. Up to 6 BPs were randomly selected from a 44-hour recording of ambulatory or 1-week recording of home BPs, such that the dialysis unit BPs were exactly matched to the number of ambulatory or home BPs. The relationship with left ventricular hypertrophy and all-cause mortality was analyzed using receiver-operating characteristic curves and Cox proportional hazards analysis, respectively. Over a median follow-up of 24 months, 46 patients (31%) died. A BP change of 10/5 mm Hg increased the risk of all-cause mortality by 1.22 (95% CI 1.07-1.38)/1.18 (95% CI 1.05-1.31) with the average of the 44-hour recording and 1.20 (95% CI 1.07-1.34)/1.15 (95% CI 1.03-1.27) when up to 6 random BPs from the same ambulatory recording were drawn and averaged. With home BPs the hazard ratios were 1.17/1.15 per 10/5 mm Hg increase in BP with the average of 1-week recording and 1.18/1.13 when up to 6 random BPs were drawn and averaged. Limited duration ambulatory BP monitoring of any 6-hour interval during the first 24 h or 4-day home BP recorded after the midweek dialysis was similarly predictive of all-cause mortality. CONCLUSIONS: In patients on hemodialysis, the location, not the quantity, of the BP recordings obtained outside the dialysis unit is associated with target organ damage and mortality.

On the importance of pedal edema in hemodialysis patients.

BACKGROUND AND OBJECTIVES: Volume control is a key component of treatment of hemodialysis patients. The role of pedal edema as a marker of volume is unknown. The objective of this study was to determine factors that are associated with edema. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A cross-sectional study of asymptomatic hemodialysis patients (n = 146) in four university-affiliated hemodialysis units was conducted. Echocardiographic variables, blood volume monitoring, plasma volume markers (plasma renin and aldosterone and N-terminal pro B-type natriuretic peptide), and inflammation markers (C-reactive protein and IL-6) were measured as exposures, and edema was measured as outcome. RESULTS: In a multivariate logistic regression analysis, age, body mass index, and left ventricular hypertrophy were independent determinants of edema. Compared with patients with normal or low weight, overweight patients had odds ratio for edema of 5.7 (95% confidence interval [CI] 1.0 to 31.8), and obese patients of 44.8 (95% CI 9.0 to 223). Patients in the top quartile of left ventricular mass index and normal to low weight had odds ratio of edema of 7.7 (95% CI 2.3 -25.9), those who were overweight of 43.5 (95% CI 3.9 to 479.8), and those who were obese of 344.8 (95% CI 33.8 to 3515). Inferior vena cava diameter, blood volume monitoring, plasma volume markers, and inflammation markers were not determinants of edema. CONCLUSIONS: Pedal edema correlates with cardiovascular risk factors such as age, body mass index, and left ventricular mass but does not reflect volume in hemodialysis patients.

Blood pressure recordings within and outside the clinic and cardiovascular events in chronic kidney disease.

BACKGROUND: Blood pressure (BP) measured outside the clinic correlates better with cardiovascular outcomes in patients with essential hypertension. To assess the role of out-of-clinic BP recordings in predicting cardiovascular events in patients with chronic kidney disease (CKD), a prospective cohort study was conducted in 217 veterans with CKD. METHODS: BP was measured outside the clinic at home and by 24-hour ambulatory recordings, and in the clinic by 'routine' and standardized methods. Patients were followed over a median of 3.4 years to assess the combined end-point of total mortality, myocardial infarction or stroke. RESULTS: Average (+/-SD) home BP was 147.0 +/- 21.4/78.3 +/- 11.6 mm Hg, 24-hour ambulatory BP 133.5 +/- 16.6/73.1 +/- 11.1 mm Hg and in-clinic BPs were 155.2 +/- 25.6/84.7 +/- 14.2 mm Hg by the standardized method, and 144.5 +/- 24.2/75.4 +/- 14.7 mm Hg by the 'routine' method. A 1 SD increase in systolic BP increased the hazard ratio (HR) of the composite end-point by 1.16 (95% CI 0.89-1.50) for routine BP, 1.57 (95% CI 1.19-2.09) for standardized BP, 1.66 (95% CI 1.27-2.17) for home BP, and 1.42 (95% CI 1.10-1.84) for 24-hour ambulatory BP recording. The HR of the composite end-point was only significant for hypertension defined by 24-hour ambulatory BP monitoring (HR 2.22 (95% CI 1.23-4.01)). Adjusted for the propensity scores, BP measured by the ambulatory technique was not an independent predictor of cardiovascular events. Non-dipping was associated with increased cardiovascular risk, but not when adjusted for other risk factors. CONCLUSION: Risk factors that differentiate hypertension or non-dipping appear to confer a cardiovascular risk in CKD.

Out-of-hemodialysis-unit blood pressure is a superior determinant of left ventricular hypertrophy.

Blood pressures (BPs) obtained in the dialysis unit correlate poorly with ambulatory BP and left-ventricular hypertrophy (LVH). We compared the performance of BP obtained within and outside the dialysis unit as a correlate of LVH. BP was obtained in the dialysis unit using routine and standardized methods and outside the dialysis unit using home and ambulatory BP monitoring in 140 patients (mean age, 56 years; 89 men; 129 blacks; and 59 with diabetes mellitus) on chronic hemodialysis for > or =3 months. Dialysis unit BP recordings were averaged over 2 weeks, and home BP averaged over 1 week. Ambulatory BP monitoring was performed during an interdialytic interval. Echocardiography was performed immediately after dialysis for the assessment of left-ventricular mass. Left ventricular mass/height(2.7) of >51 g/m2 was taken as evidence of LVH. Test performance of various BPs was compared using receiver operating characteristic curves. Average ambulatory BP was 129.7+/-21.2/73.6+/-13.1 mm Hg, home BP was 139.4+/-21.2/79.0+/-12.5 mm Hg, standardized predialysis BP was 142.1+/-21.7/74.9+/-13.3 mm Hg, postdialysis was 120.9+/-20.8/69.6+/-12.5 mm Hg, routine predialysis was 145.6+/-20.7/79.4+/-13.1 mm Hg, and postdialysis was 132.0+/-19.3/72.6+/-11.1 mm Hg. Left ventricular mass/height(2.7) was 59.1+/-16.5, and 68% had LV hypertrophy. Diastolic BP measured by any technique was not associated with LVH. Routine and standardized measurements of BP were similarly weak correlates of LVH. Systolic BP outside the dialysis unit was a stronger correlate of LVH compared with dialysis unit BP.

Correlates of systolic hypertension in patients with chronic kidney disease.

Hypertension in patients with chronic kidney disease (CKD) is predominantly systolic. The contribution of risk factors for hypertension to the overall systolic blood pressure (BP) is unknown. To study the relationship between risk factors for hypertension and systolic BP in patients with CKD, 232 veterans (mean age 67 years; 96% men; 20% black; 39% with diabetes mellitus; estimated glomerular filtration rate [GFR] 48 mL/min per 1.73 m2) had clinic (routine and standardized measurements) and out-of-clinic (home and 24-hour ambulatory) BPs recorded. In multivariate analysis, using 17 risk factors, the log of the urine protein/creatinine ratio was the strongest predictor of systolic BP regardless of the BP measurement technique. The strength of the relationship between proteinuria and systolic BP was in the order ambulatory > home > standardized clinic > routine clinic BP measurement. Other independent predictors were age, race, and number of antihypertensive drugs used, and the model fit was better for out-of-clinic than clinic BP recordings. Estimated GFR was not an independent predictor of systolic BP by any technique. Nocturnal dipping was associated with higher estimated GFR, higher serum albumin, younger age, and less proteinuria. Proteinuria is the most important correlate of systolic BP in older men, the strongest relationship of which was with ambulatory and home systolic BP. Out-of-clinic BP recordings correlate better with target organ damage, as measured by proteinuria, and may be of greater clinical value than clinic BP recordings in predicting hypertension-related outcomes such as end-stage renal disease and death.

Home blood pressure monitoring in CKD.

BACKGROUND: Blood pressure (BP) control is the mainstay of stalling the progression of cardiorenal disease, yet the performance characteristics of BPs obtained in the clinic (CBPs) by routine or standardized methods or at home (HBP) in diagnosing hypertension or assessing its control are unknown. METHODS: Two hundred thirty-two patients (20% black; 4% women; mean age, 67 years; 35% with diabetes) with chronic kidney disease (CKD) underwent a single 24-hour ambulatory BP (ABP) monitoring (ABPM) and concomitant recording of CBP and HBP for 1 week. Hypertension is defined as systolic BP of 130 mm Hg or greater or diastolic BP of 80 mm Hg or greater on average awake 24-hour ABPM. RESULTS: Average ABP was 135.2 +/- 15.9/75.6 +/- 11.0 mm Hg. Thirty-five percent of patients had isolated systolic hypertension; 3%, isolated diastolic hypertension; 27%, combined systolic and diastolic hypertension; and 35%, normotension or well-controlled BP. The prevalence of "white-coat effect" was estimated as 28% to 30% by means of CBPs and 24% by means of HBPs. Well-controlled BP in the clinic, but poorly controlled BP by means of ABPM, masked hypertension, was seen in 26% to 29% by means of CBPs, but only 13% with HBP monitoring. CONCLUSION: In patients with CKD, HBP is superior in reducing the misclassification of hypertension caused by the white-coat effect and masked hypertension commonly seen with CBPs. An average HBP of approximately 140/80 mm Hg appears to be the best correlate of hypertension defined by means of ABPM.

Etiology and management of hypertension in chronic kidney disease.

The kidneys are vital in the pathogenesis of hypertension and are also pathologically affected by the presence of hypertension. The prevalence of hypertension in chronic kidney disease (CKD) depends on age, the severity of renal failure, and proteinuria. The intricate and inextricable relationship between CKD and hypertension seems to cause cardiovascular disease that has assumed epidemic proportions. This article discusses the etiology and treatment of hypertension in CKD so that it can be better controlled.