A randomized trial of low-protein diet in type 1 and in type 2 diabetes mellitus patients with incipient and overt nephropathy.

OBJECTIVE: The efficacy of a low-protein diet in the secondary prevention of diabetic nephropathy is not established in patients with type 1 or type 2 diabetes mellitus. To determine whether a low-protein diet slows the decrease in glomerular filtration rate (GFR) and decreases the albumin excretion rate (AER) in diabetic patients with incipient and overt nephropathy, we performed a 2-year prospective, randomized controlled trial comparing the effects of a low-protein diet (0.8 g/kg/day) with a usual-protein diet. SETTING AND PATIENTS: The study was conducted in a University hospital and included 63 type 1 and type 2 diabetic patients with either incipient or overt nephropathy and mild renal failure (prestudy GFR, 80 +/- 20 mL/min). The primary outcome measures were decreased in GFR and 24-hour AER. RESULTS: In the low-protein-diet group, patients were younger (52 +/- 12 versus 63 +/- 9 years old) and more often were type 2 diabetic. During the follow-up period, according to dietary records the low-protein-diet group consumed 16% +/- 3% of total caloric intakes as compared with 19% +/- 4% in the usual-protein-diet group (P < .02), but 24-hour urinary urea excretions did not differ between the two groups. The 2-year GFR decrease was 7 +/- 11 mL/min in the low-protein-diet group and 5 +/- 15 mL/min in the usual-protein-diet group (P = not significant). AER did not increase significantly in the two diet groups during the follow-up period. Blood pressure and glycemic control were similar in the two groups all along the study. The decrease in GFR and AER were also similar in 6 compliant patients according to dietary records and to 24-hour urinary urea excretions from the low-protein-diet group and in 12 patients from the usual-protein-diet group. CONCLUSIONS: A 2-year low-protein diet did not alter the course of GFR or of AER in diabetic patients with incipient or overt nephropathy receiving renin-angiotensin blockers with strict blood pressure control.

A randomized trial of saline hydration to prevent contrast nephropathy in chronic renal failure patients.

BACKGROUND: Contrast nephropathy (CN) is a common cause of renal dysfunction that may be prevented by saline hydration and by drugs such as theophylline or furosemide. Whether oral saline hydration is as efficient as intravenous saline hydration is unknown. The preventive efficacy of theophylline and furosemide for CN remains controversial. The purpose of the current study was to evaluate the efficacy of oral saline hydration and of intravenous saline hydration plus theophylline or furosemide for the prevention of CN. METHODS: We prospectively studied 312 patients with chronic renal failure (serum creatinine 201+/-81 micromol/l, Cockcroft clearance 37+/-12 ml/min/1.73 m(2)), who were undergoing various radiological procedures with a non-ionic, low osmolality contrast agent. Patients were randomly assigned to four arms. In arm A, patients received 1 g/10 kg of body weight/day of sodium chloride per os for 2 days before the procedure. In arm B, patients received 0.9% saline intravenously at a rate of 15 ml/kg for 6 h before the procedure. In arm C, patients received the same saline hydration as in arm B plus 5 mg/kg theophylline per os in one dose 1 h before the procedure. In arm D, patients received the same saline hydration as in arm B plus 3 mg/kg of furosemide intravenously just after the procedure. RESULTS: Patients were well-matched with no significant differences at baseline in any measured parameters. Acute renal failure, defined as an increase in serum creatinine of 44 micromol/l (0.5 mg/dl), occurred in 27 out of 312 patients (8.7%). There was no significant difference between the rate of renal failure in the different arms of the study: five out of 76 (6.6%) in arm A, four out of 77 (5.2%) in arm B, six out of 80 (7.5%) in arm C and 12 out of 79 (15.2%) in arm D. No patient had fluid overload or a significant increase in blood pressure in the 2 days following the radiological procedure. The independent predictors of CN were diabetes mellitus, high baseline serum creatinine and high systolic blood pressure. CONCLUSIONS: Oral saline hydration was as efficient as intravenous saline hydration for the prevention of CN in patients with stage 3 renal diseases. Furosemide and theophylline were not protective.

Prognostic value of inducible myocardial ischemia in predicting cardiovascular events after renal transplantation.

BACKGROUND: The aims of the present study were to determine the prevalence of inducible myocardial ischemia (IMI) in renal transplant recipients (RTR) more than 50 years old, to identify predictors of IMI, and to search for its prognostic value. METHODS: Among the 377 renal transplantations performed between 1989 and 1998 in a single institution, 120 were done in patients > or =50 years old, and 97 were recruited for the study. During the last quarter of 1998, all of them underwent an exercise test (EST), an exercise-thallium 201 single photon emission computed tomography coupled with dipyridamole (SPECT), and 81% of them had a dobutamine stress echocardiography (DSE). Patients with IMI subsequently underwent coronary angiography to detect coronary stenosis. RESULTS: IMI was present in 12 of the 97 patients (10%). The diagnosis was evidenced by EST in four cases, by SPECT in 11 cases, and DSE in three cases. Five of these 12 patients (42%) had significant coronary artery stenosis (> or =50%). Multivariate analysis of several pre- and post-transplant variables evidenced acute rejection and left ventricular hypertrophy as significant correlates of IMI (both P < 0.03). Patients were prospectively followed-up for 48 months for the occurrence of major cardiovascular events. Kaplan-Meier analysis revealed a significant increase in cardiovascular events in the IMI group (P < 0.0001). In addition, the Cox proportional hazards model revealed that IMI and diabetes mellitus had an independent significant effect on the occurrence of major cardiovascular events. CONCLUSION: IMI was present in 10% of RTR aged > or =50 years, and was predicted by acute rejection and left ventricular hypertrophy. IMI had a strong effect on major cardiovascular events in this population.