Biomedical subjects

R J Hamburger

Publications and source records attributed to R J Hamburger.

At least 19 recordsLinked to original sources

PubMed2001

Normouricemia in the syndrome of inappropriate antidiuretic hormone secretion.

Hyponatremia is seen in 40% to 60% of hospitalized acquired immune deficiency syndrome (AIDS) patients. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) and volume contraction are the most common causes. The serum uric acid level can be used to distinguish between these two causes of hyponatremia. Hypouricemia is the rule in SIADH, whereas hyperuricemia commonly accompanies volume contraction. This report presents an AIDS patient with SIADH and normouricemia secondary to pyrazinamide and ethambutol.

Acquired Immunodeficiency Syndrome↗

PubMed2000

The natural history of incidental renal artery stenosis in patients with aortoiliac vascular disease.

PURPOSE: To examine the association between incidentally discovered renal artery stenosis and deterioration of renal function as determined by the change in serum creatinine concentration over time. SUBJECTS AND METHODS: We performed a retrospective review of consecutive patients who underwent aortography for aortoiliac vascular disease. Angiograms were reviewed for renal artery stenosis, defined as a narrowing of at least 20% compared with adjacent normal renal artery. For patients with at least 180 days of subsequent follow-up, the change in serum creatinine concentration per year was compared in patients who had or did not have renal artery stenosis. RESULTS: Of the 201 patients, 96 (48%) had some degree of renal artery stenosis in one or both renal arteries, including 53 (26%) who had at least one stenosis > or= 50% and 40 (20%) who had bilateral stenoses. The only clinical predictor of renal artery stenosis was a history of coronary artery disease (odds ratio = 2.0, 95% confidence interval: 1.2 to 3.8, P = 0.001). Among the 174 patients with > or =180 days of follow-up, there was no statistically significant difference (P = 0.88) in the mean change in serum creatinine concentration per year in the 78 patients with renal artery stenosis (0.06+/-0.33 mg/dL per year) as compared with the 96 patients without renal artery stenosis (0.06+/-0.22 mg/dL per year). Grouping the patients by the maximal percentage of stenosis did not reveal any difference in the mean changes in serum creatinine concentration per year. CONCLUSIONS: Although renal artery stenosis is a common incidental finding in patients with atherosclerotic vascular disease, it is an uncommon cause of progressive renal disease.

Aged↗

PubMed2000

A trial of two iron-dextran infusion regimens in chronic hemodialysis patients.

AIM: To test the ability to elicit a hemoglobin (Hb) response in patients on chronic hemodialysis, we prospectively compared two regimens of iron dextran administration, 100 mg once weekly (QW) or 100 mg once every dialysis (QD), both given for 10 doses. PATIENTS AND METHODS: Twenty-three consecutive patients on chronic hemodialysis received iron dextran intravenously if they had absolute or functional iron deficiency. There was no difference in the Hb response between regimens. RESULTS: Both groups had a significant increase in Hb from 10.5+/-1.5 g/dl at baseline, to 11.1+/-1.7 g/dl at 1 month, 1.4+/-2.1 g/dl at 2 months and 11.6+/-1.9 g/dl at 3 months. The increment in Hb at 1 month was similar (QD 0.62+/-1.245 g/dl vs. QW 0.64+/-1.464 g/dl) between the two groups despite a large difference in the amount of iron received. Serum ferritin, transferrin saturations or epoetin dose did not change significantly. At the end of 3 months 12 patients did not need further iron therapy as judged by the serological markers of iron stores. Of these 12 patients, 3 had serum ferritins of > 1,000 ng/ml. Weekly dosing of iron was associated with more medication errors than dosing every dialysis. Baseline iron stores could not predict the responsiveness to intravenous iron therapy as judged by an increase in Hb concentration at 1 month or at 3 months. CONCLUSION: This study confirms the efficacy of 1,000 mg of intravenous iron administered over a 3-month period in patients with functional iron deficiency. It underscores the importance of careful monitoring of iron stores and highlights the need for developing better parameters of functional iron stores in hemodialysis patients.

Anemia, Iron-Deficiency↗

PubMed1999

Effect of membrane composition and structure on solute removal and biocompatibility in hemodialysis.

Effect of membrane composition and structure on solute removal and biocompatibility in hemodialysis. Significant changes in extracorporeal membranes have occurred over the past five decades in which hemodialysis (HD) has been available as a therapy for both acute renal failure (ARF) and end-stage renal disease (ESRD). For cellulosic membranes, these changes have included a reduction in thickness, hydroxyl group substitution, and an increase in pore size. These modifications have resulted in enhanced efficiency of small solute removal, a broader spectrum of overall solute removal, and an attenuation of complement activation in comparison to the thick, unsubstituted cellulosic membranes of low permeability used in the early days of HD therapy. Synthetic membranes, originally developed specifically for use in high-flux HD and hemofiltration, have also evolved during this same time period. In fact, the initially clear distinction between low-flux regenerated cellulosic and high-flux synthetic membranes has become blurred, as membrane formulators have developed products designed to appeal to enthusiasts for both membrane formats. The purpose of this review is to characterize both the solute removal and biocompatibility characteristics of dialysis membranes according to their composition (that is, polymeric makeup) and structure. In this regard, the manner in which membrane biocompatibility interacts with flux is highlighted.

Biocompatible Materials↗

PubMed1998

Age-race subgroup compared with renin profile as predictors of blood pressure response to antihypertensive therapy. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents.

CONTEXT: Renin profiling and age-race subgroup may help select single-drug therapy for stage 1 and stage 2 hypertension. OBJECTIVE: To compare the plasma renin profiling and age-race subgroup methods as predictors of response to single-drug therapy in men with stage 1 and 2 hypertension as defined by the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. DESIGN: The Veterans Affairs Cooperative Study on Single-Drug Therapy of Hypertension, a randomized controlled trial. SETTING: Fifteen Veterans Affairs hypertension centers. PATIENTS: A total of 1105 ambulatory men with entry diastolic blood pressure (DBP) of 95 to 109 mm Hg, of whom 1031 had valid plasma and urine samples for renin profiling. INTERVENTIONS: Randomization to 1 of 6 antihypertensive drugs: hydrochlorothiazide, atenolol, captopril, clonidine, diltiazem (sustained release), or prazosin. MAIN OUTCOME MEASURE: Treatment response as assessed by percentage achieving goal DBP (<90 mm Hg) in response to a single drug that corresponded to patients' renin profile vs a single drug that corresponded to patients' age-race subgroup. RESULTS: Clonidine and diltiazem had consistent response rates regardless of renin profile (76%, 67%, and 80% for low, medium, and high renin, respectively, for clonidine and 83%, 82%, and 83%, respectively, for diltiazem for patients with baseline DBP of 95-99 mm Hg). Hydrochlorothiazide and prazosin were best in low- and medium-renin profiles; captopril was best in medium- and high-renin profiles (low-, medium-, and high-renin response rates were 82%, 78%, and 14%, respectively, for hydrochlorothiazide; 88%, 67%, and 40%, respectively, for prazosin; and 51%, 83%, and 100%, respectively, for captopril for patients with baseline DBP of 95-99 mm Hg). Response rates for patients with baseline DBP of 95 to 99 mm Hg by age-race subgroup ranged from 70% for clonidine to 90% for prazosin for younger black men, from 50% for captopril to 97% for diltiazem for older black men, from 70% for hydrochlorothiazide to 92% for atenolol for younger white men, and from 84% for hydrochlorothiazide to 95% for diltiazem for older white men. Patients with a correct treatment for their renin profile but incorrect for age-race subgroup had a response rate of 58.7%; patients with an incorrect treatment for their renin profile but correct for age-race subgroup had a response rate of 63.1% (P = .30). After controlling for DBP and interactions with treatment group, age-race subgroup (P<.001) significantly predicted response to single-drug therapy, whereas renin profile was of borderline significance (P= .05). CONCLUSIONS: In these men with stage 1 and stage 2 hypertension, therapeutic responses were consistent with baseline renin profile, but age-race subgroup was a better predictor of response.

Adult↗

PubMed1998

Prevention and Treatment of Hypertension Study (PATHS): effects of an alcohol treatment program on blood pressure.

OBJECTIVE: To determine whether blood pressure is reduced for at least 6 months with an intervention to lower alcohol intake in moderate to heavy drinkers with above optimal to slightly elevated diastolic blood pressure, and whether reduction of alcohol intake can be maintained for 2 years. DESIGN: A randomized controlled trial. METHODS: Six hundred forty-one outpatient veterans with an average intake of 3 or more alcoholic drinks per day in the 6 months before entry into the study and with diastolic blood pressure 80 to 99 mm Hg were randomly assigned to a cognitive-behavioral alcohol reduction intervention program or a control observation group for 15 to 24 months. The goal of the intervention was the lower of 2 or fewer drinks daily or a 50% reduction in intake. A subgroup with hypertension was defined as having a diastolic blood pressure of 90 to 99 mm Hg, or 80 to 99 mm Hg if recently taking medication for hypertension. RESULTS: Reduction in average weekly self-reported alcohol intake was significantly greater (P<.001) at every assessment from 3 to 24 months in the intervention group vs the control group: levels declined from 432 g/wk at baseline by 202 g/wk in the intervention group and from 445 g/wk by 78 g/wk in the control group in the first 6 months, with similar reductions after 24 months. The intervention group had a 1.2/0.7-mm Hg greater reduction in blood pressure than the control group (for each, P = .17 and P = .18) for the 6-month primary end point; for the hypertensive stratum the difference was 0.9/0.7 mm Hg (for each, P = .58 and P = .44). CONCLUSIONS: The 1.3 drinks per day average difference between changes in self-reported alcohol intake observed in this trial produced only small nonsignificant effects on blood pressure. The results from the Prevention and Treatment of Hypertension Study (PATHS) do not provide strong support for reducing alcohol consumption in nondependent moderate drinkers as a sole method for the prevention or treatment of hypertension.

Adult↗

PubMed1997

Proteinuria in mild to moderate hypertension: results of the VA cooperative study of six antihypertensive agents and placebo. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents.

The prevalence and natural history of severe proteinuria in mild to moderate hypertension are not completely defined. We screened 1635 men with a history of hypertension and randomized 1292 with untreated diastolic blood pressure (DBP) 95-109 mmHg to single-drug treatment with either hydrochlorothiazide, atenolol, captopril, clonidine, diltiazem-SR, prazosin, or placebo in a double-blind prospective trial. Twenty-seven of 1635 patients (1.7%) satisfying clinical criteria for primary hypertension were found to have developed proteinuria > 1000 mg/24 hours and were removed from the study. Follow-up data were obtained on 19 of these 27 patients. One patient was found to have focal segmental sclerosis and progressed to end-stage renal disease. Three other patients developed severe (serum creatinine > 3.5 mg/dl) chronic renal failure (one with diabetic nephropathy), one progressed from serum creatinine 1.4 to 2.2 mg/dl, but 14 of the 19 remained with stable serum creatinine < 2.0 mg/dl on follow-up for 6-9 years. Data were available for 1076 of 1155 (93%) treated study patients at end titration, 522/600 (87%) at one year and 322/444 (73%) at two years. There were significant associations for proteinuria with obesity and higher systolic blood pressure. There was a trend toward significant difference in mean 24-hour protein excretion rates at baseline between black (127 mg) and white (139 mg) patients (p = 0.07). There were no statistically significant changes in urinary protein excretion/24 hours between or within the different treatment groups (including placebo). Eighteen patients were removed from the study during the active treatment phase for proteinuria > 1000 mg/24 hours: hydrochlorothiazide 4, placebo 3, diltiazem 3, prazosin 3, atenolol 2, clonidine 2, and captopril 1. We conclude: (1) the prevalence of severe (> 1 g/24 hours) proteinuria in the hypertensive population is significant but does not necessarily imply a poor prognosis; (2) mean 24-hour urinary protein excretion rates did not vary in response to the different classes of antihypertensive drugs; and (3) there was no drug-specific increase in proteinuria detected in this study.

Adult↗

PubMed1997

Sleep apnea in renal failure.

Sleep apnea is a surprisingly common disorder in end-stage renal disease (ESRD) and chronic renal failure. The symptoms of sleep apnea frequently go unreported or may be misdiagnosed as uremia, depression, chronic illness, or insomnia. A review of the literature was performed to define the prevalence, morbidity, and treatment of sleep apnea syndrome in the ESRD patient. Sleep apnea occurs in at least 60% of ESRD patients. The known complications of sleep apnea include arrhythmias, pulmonary hypertension, and systemic hypertension. In addition, sleep apnea has been implicated in coronary artery disease and strokes. The contribution of sleep apnea to the high mortality from cardiac disease and stroke in peritoneal dialysis and hemodialysis patients is unknown. The causes of the increased prevalence of sleep apnea in ESRD patients are unknown and likely differ from the general population, but the treatment is similar. The literature suggests that modality of renal replacement therapy does not matter; however, large nocturnal volume peritoneal dialysis may worsen sleep apnea. Renal transplantation may be curative. In conclusion, sleep apnea may be an under-diagnosed disease in patients on dialysis. There are significant reasons to suspect that sleep apnea may worsen the morbidity and mortality of ESRD, and there are potential successful therapies.

Humans↗

PubMed1996

Comparison of plasma lipid and lipoprotein profiles in hypertensive black versus white men. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents.

An abnormal plasma lipid and lipoprotein profile is an independent and strong predictor of mortality and morbidity from coronary artery disease (CAD). We report on plasma lipid and lipoprotein profiles with respect to race, age, obesity, blood pressure (BP), smoking, and drinking history in 1,292 male veterans with a diastolic BP of 95 to 109 mm Hg while off antihypertensive medications. Blacks had 24% (p <0.001) lower triglycerides than whites. In contrast, the following parameters were higher in blacks than in whites by the indicated percentages: high-density lipoprotein (HDL) cholesterol, 16% (p <0.001); HDL2 cholesterol, 36% (p <0.001); apolipoprotein (Apo) A1, 8% (p <0.001); HDL/low-density lipoprotein (LDL), 18% (p = 0.018); HDL2/LDL, 36% (p = 0.031); HDL2/HDL3, 21% (p <0.001); and Apo A1/Apo B, 15% (p <0.001). Triglycerides were unchanged up to age 60, but were lower by 24% (p <0.001) in those aged > or = 70. Apo A1 levels were higher (p <0.001), whereas LDL cholesterol was lower (p <0.008) in moderate alcohol consumers versus abstainers. Triglycerides were higher (p <0.001), whereas HDL, HDL2 cholesterol, and Apo A1 were lower (p <0.001) with increasing obesity. Moderate alcohol consumption had a strong favorable effect on HDL, HDL2, and HDL3 cholesterol among subjects of normal weight, but this effect was diminished in obese subjects. Total and LDL cholesterol were higher by 6.4% (p = 0.001) and 9.4% (p <0.003), respectively, whereas HDL cholesterol remained unchanged in those with diastolic BP of 105 to 109 mm Hg versus those with diastolic BP of 95 to 99 mm Hg. We conclude that hypertensive black men have lipid and lipoprotein profiles indicative of less CAD risk than white men. Chronic moderate alcohol consumption correlates with a favorable plasma lipid and lipoprotein profile in normal, but not obese, men. Obesity is associated with an adverse plasma lipid and lipoprotein profile. Thus, race, alcohol intake, and obesity may be important modifiers of CAD in untreated hypertensive men.

Apolipoprotein A-I↗

PubMed1996

Emphysematous cystitis and pyelitis in a diabetic renal transplant recipient.

Emphysematous cystitis is a rare complication of urinary tract infection. Patients with diabetes mellitus, neurogenic bladder, bladder outlet obstruction, and recurrent urinary tract infection are at increased risk for the disease. We present a case of emphysematous cystitis and pyelitis in a diabetic renal transplant recipient. He was treated with antibiotics alone with complete clinical and radiologic resolution. The clinical course was benign, as described in most patients. The prognosis of emphysematous cystitis is good after early diagnosis and prompt treatment with appropriate antibiotics, blood glucose control, and adequate urinary drainage.

Cystitis↗

PubMed1996

Risk factors for peritonitis in long-term peritoneal dialysis: the Network 9 peritonitis and catheter survival studies. Academic Subcommittee of the Steering Committee of the Network 9 Peritonitis and Catheter Survival Studies.

To determine factors involved in peritoneal dialysis-associated peritonitis and catheter loss, all point prevalent peritoneal dialysis patients in Health Care Finance Administration (HCFA) end-stage renal disease (ESRD) Network 9 were followed throughout 1991 for peritonitis events and throughout 1991 to 1992 for catheter survival. Data were collected by questionnaires compiled by the dialysis facility and validated by network staff. Peritonitis was reported 1,168 times in 729 of the 1,930 patients. By gamma-Poisson regression, a significantly increased risk for peritonitis was observed for patients with previous peritonitis, black race, and those dialyzing with standard connectors or cyclers compared with disconnect systems. Decreased risks were observed for patients with longer ESRD experience and when prophylactic antibiotics were administered before catheter insertion. Postinsertion leakage, diabetes, visual problems, previous or current immunosuppression, and physical activity were not risk factors. Infection of any kind caused the removal of 68% of the 414 catheters lost. Patients with downward-directed tunnels were less likely to experience concomitant exit site/tunnel infections associated with peritonitis. Peritonitis episodes with Staphylococcus epidermidis-like organisms were more likely to resolve with a single course of antibiotics. Perhaps because of their higher infection rate, blacks were more likely than whites to use a disconnect system. In general, the outcome of peritonitis in blacks was similar to that in whites, except that blacks were less likely to be hospitalized and were less likely to die.

Catheters, Indwelling↗

PubMed1996

Potassium transport in the connecting tubule.

The connecting tubule (CNT) of the rabbit is a distinct anatomic and functional segment, but little is known about its role in potassium secretion. We have examined potassium secretion in the CNT using the technique of in vitro microperfusion. Chemical flux was determined using an ion-sensitive microelectrode and rubidium flux was used to estimate the unidirectional lumen-to-bath potassium flux. In control tubules, the transepithelial potential difference was -4.1 +/- 1.1 mV and there was a net potassium flux (JK) of -17.94 +/- 4. 53 pmol mm-1 min-1 that was stable for up to 3 h. The lumen-to-bath 86Rb flux was 2.78 +/- 0.38 pmol mm-1 min-1. This value represents 12% of the calculated bath-to-lumen flux of 22.32 +/- 2.51 pmol mm-1 min-1. In comparing potassium transport in the CNT to that of the cortical collecting tubule, the net flux and unidirectional fluxes were significantly greater in the CNT. In the CNT ouabain 0.01 mM decreased JK from -25.25 +/- 2.81 to -2.07 +/- 1.94 pmol mm-1 min-1, a value not significantly different from zero. Potassium flux in the CNT was flow-dependent. As the perfusion rate was increased from 5.0 +/- 0.5 to 13.9 +/- 1.1 nl/min, net JK increased from -20.65 +/- 5.47 to -44.29 +/- 13.32 pmol mm-1 min-1. When the perfusion rate was further increased to 26.1 +/- 1.9 nl/min, the net JK increased to -57.28 +/- 12.38 pmol mm-1 min-1, a value significantly greater than that obtained at a nominal perfusion rate of 5 nl/min. Both the lumen-to-bath and bath-to-lumen potassium fluxes increased as the perfusion rate increased. These studies are consistent with an important role of the CNT in renal potassium excretion.

Animals↗

PubMed1996

Is peritoneal dialysis the preferred modality in the diabetic patient?

There has been much debate recently whether peritoneal dialysis is an acceptable modality of renal replacement therapy in the diabetic patient. The authors review the recent continuous ambulatory peritoneal dialysis (CAPD) mortality literature and suggest that mortality can be improved by increasing the quantity of peritoneal dialysis delivered. The major disadvantages and advantages of CAPD are reviewed and presented. Peritoneal dialysis remains a viable modality of renal replacement therapy in the appropriate diabetic patient provided an adequate dose of dialysis is maintained.

Adult↗

PubMed1995

Response to a second single antihypertensive agent used as monotherapy for hypertension after failure of the initial drug. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents.

BACKGROUND: An important issue in clinical practice is how to treat patients whose blood pressure does not respond to the first antihypertensive drug selected. OBJECTIVE: To analyze the antihypertensive response of patients who had failed to achieve their diastolic blood pressure goal (< 90 mm Hg at the end of 8 to 12 weeks of titration) with one of six randomly allocated drugs or placebo to the random allocation of an alternate drug. METHODS: We initially randomized 1292 men with diastolic blood pressure of 95 to 109 mm Hg to treatment with hydrochlorothiazide, atenolol, captopril, clonidine hydrochloride, diltiazem hydrochloride (sustained release), prazosin hydrochloride, or placebo. Of 410 men in whom initial treatment failed, 352 qualified for randomization to the alternate drug. RESULTS: Of the 352 patients, 173 (49.1%) achieved their goal diastolic blood pressure, in 133 (37.8%) the alternate drug failed, and 46 (13.1%) left the study for various reasons. Overall response rates were as follows: diltiazem, 63%; clonidine, 59%; prazosin, 47%; hydrochlorothiazide, 46%; atenolol, 41%; and captopril, 37%. The best response rate for patients in whom hydrochlorothiazide failed was achieved with diltiazem (70%); after atenolol failure, clonidine (86%); after captopril failure, prazosin (54%); after clonidine failure, diltiazem (100%); after diltiazem failure, captopril (67%); and after prazosin failure, clonidine (53%). The combined response rate for patients initially randomized to an active treatment was 76.0%, which is similar to that achieved by the combination of two drugs in previous studies. CONCLUSIONS: We conclude that sequential single-drug therapy is a rational approach for treatment of hypertension in patients in whom initial drug therapy has failed.

Adult↗

PubMed1994

Importance of obesity, race and age to the cardiac structural and functional effects of hypertension. The Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents.

OBJECTIVES: The purpose of this study was to determine the effects of obesity and its interaction with age, race and the magnitude of blood pressure elevation in a large cohort of patients with mild to moderate hypertension and a high prevalence of left ventricular hypertrophy. BACKGROUND: Obesity, race and age each have important effects on the incidence and severity of hypertension and may contribute to the effects of blood pressure elevation on the cardiac manifestations of hypertension. METHODS: Left ventricular structure and function were assessed with two-dimensional targeted M-mode echocardiography in 692 men with mild to moderate hypertension (average blood pressure 153/100 mm Hg), and the data were compared in relation to obesity (determined from body mass index), age, race, blood pressure, physical activity, plasma renin activity, urinary sodium excretion, hematocrit, heart rate and serum lipids. RESULTS: Left ventricular hypertrophy was common (63% with increased left ventricular mass, 22% with left ventricular hypertrophy on the electrocardiogram [ECG]). On multivariable regression analysis, body mass index was the strongest predictor of left ventricular mass and magnified the slope relation of blood pressure to left ventricular mass. Despite a greater prevalence of ECG left ventricular hypertrophy in blacks (31%) than in whites (10%), left ventricular mass and echocardiographic prevalence of left ventricular hypertrophy did not differ by race. However, septal, posterior left ventricular and relative wall thickness were greater in black than in white men. CONCLUSIONS: Obesity is the strongest clinical predictor of left ventricular mass and left ventricular hypertrophy in men, even in those with mild to moderate hypertension of sufficient severity to be associated with a high prevalence of left ventricular hypertrophy. Moreover, independent effects of systolic blood pressure on left ventricular mass are amplified by obesity. Although race does not affect left ventricular mass or the prevalence of left ventricular hypertrophy, black race is associated with greater relative wall thickness, itself a predictor of unfavorable cardiovascular outcome.

Age Factors↗

PubMed1994

Continuous ambulatory peritoneal dialysis and hemodialysis: comparison of patient mortality with adjustment for comorbid conditions.

A historical prospective national sample of 1,725 diabetic and 2,411 non-diabetic Medicare end-stage renal disease (ESRD) patients incident from 1986 to 1987 was analyzed for the mortality of patients selected to receive continuous ambulatory peritoneal dialysis (CAPD) or hemodialysis (HD) with adjustment for patient characteristics, including the presence of comorbid conditions at onset of ESRD. Cox proportional hazards analyses were used to compare the mortality of CAPD and HD patients. Patients were followed from 30 days following onset of ESRD until two to four years post-onset. No statistically significant difference in relative mortality risk (RR) was found among non-diabetic patients selected for CAPD compared to HD (RR = 0.84 for CAPD versus HD, P = 0.25), while evidence of higher adjusted mortality for CAPD compared to HD was found among diabetic patients (RR = 1.26, P = 0.03). Mortality analyses adjusted for pre-treatment risk factors suggest that CAPD and HD provide incident non-diabetic ESRD patients with similar expected survival outcomes. Evidence that increased mortality was associated with CAPD among diabetic patients, particularly among elderly patients, suggests the need for further controlled studies of mortality among CAPD patients with diabetes.

Aged↗

PubMed1993

Single-drug therapy for hypertension in men. A comparison of six antihypertensive agents with placebo. The Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents.

BACKGROUND: Characteristics such as age and race are often cited as determinants of the response of blood pressure to specific antihypertensive agents, but this clinically important issue has not been examined in sufficiently large trials, involving all standard treatments, to determine the effect of such factors. METHODS: In a randomized, double-blind study at 15 clinics, we assigned 1292 men with diastolic blood pressures of 95 to 109 mm Hg, after a placebo washout period, to receive placebo or one of six drugs: hydrochlorothiazide (12.5 to 50 mg per day), atenolol (25 to 100 mg per day), captopril (25 to 100 mg per day), clonidine (0.2 to 0.6 mg per day), a sustained-release preparation of diltiazem (120 to 360 mg per day), or prazosin (4 to 20 mg per day). The drug doses were titrated to a goal of less than 90 mm Hg for maximal diastolic pressure, and the patients continued to receive therapy for at least one year. RESULTS: The mean (+/- SD) age of the randomized patients was 59 +/- 10 years, and 48 percent were black. The average blood pressure at base line was 152 +/- 14/99 +/- 3 mm Hg. Diltiazem therapy had the highest rate of success: 59 percent of the treated patients had reached the blood-pressure goal at the end of the titration phase and had a diastolic blood pressure of less than 95 mm Hg at one year. Atenolol was successful by this definition in 51 percent of the patients, clonidine in 50 percent, hydrochlorothiazide in 46 percent, captopril in 42 percent, and prazosin in 42 percent; all these agents were superior to placebo (success rate, 25 percent). Diltiazem ranked first for younger blacks (< 60 years) and older blacks (> or = 60 years), among whom the success rate was 64 percent, captopril for younger whites (success rate, 55 percent), and atenolol for older whites (68 percent). Drug intolerance was more frequent with clonidine (14 percent) and prazosin (12 percent) than with the other drugs. CONCLUSIONS: Among men, race and age have an important effect on the response to single-drug therapy for hypertension. In addition to cost and quality of life, these factors should be considered in the initial choice of a drug.

Age Factors↗

PubMed1992

Acute effects of indomethacin on the disposition of a potassium load.

We examined the effects of acute indomethacin administration on the disposition of a potassium load in anesthetized rats. In response to the potassium load, indomethacin-treated animals had greater plasma potassium concentrations and smaller increases in fractional excretion of potassium than did vehicle-treated rats, but there was no change in urine flow rate. Findings were consistent with indomethacin-induced impairment of renal potassium excretion. The effects of indomethacin in adrenalectomized animals were comparable to those that were observed in intact rats, which indicates that inhibition of aldosterone release was not responsible for the acute effects of indomethacin. No differences in plasma potassium were noted after indomethacin or vehicle infusion in the animals that underwent bilateral ureteral ligation, which suggests that indomethacin did not impair extrarenal potassium disposition. These results indicate that acute administration of indomethacin impairs the response to a potassium load, not as a result of inhibition of aldosterone secretion or extrarenal potassium distribution but by means of inhibition of renal potassium excretion.

Adrenalectomy↗