Effect of Dietary Protein Restriction on Prognosis in Patients With Diabetic Nephropathy (LPD)
|Type 1 Diabetes Mellitus With Diabetic Nephropathy||Dietary Supplement: low protein diet Dietary Supplement: normal protein diet|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Effect of Dietary Protein Restriction on Prognosis in Patients With Diabetic Nephropathy|
- Cumulative incidence of ESRD requiring dialysis or transplantation, and death [ Time Frame: 4 years ]
Cause of death was obtained from death certificate by an independent observer. Before the development of uremic symptoms, patients were referred to the department of nephrology at the University Hospital of Herlev or Rigshospitalet, when GFR deteriorated below 10 to 20 ML/min/1.73m2, where accepted criteria for initiation of dialysis and transplantation were applied on patients from both diet groups. Patients continued their scheduled visits and treatment in the study until the end of the four-year follow up.
This was assesed every 3 months until the end of the 4 year follow up period.
- Rate of decline of GFR [ Time Frame: 4 years ]rate of decline was measured if the patient had a minimum of one year of follow up and a minimum of 3 GFR measures during the study. All measures of GFR during the study period (including baseline) were used to calculate the rate of decline(the slopes) of GFR. GFR was measured every 6 months during the 4 years of follow up.
|Study Start Date:||April 1995|
|Study Completion Date:||June 2000|
|Primary Completion Date:||June 2000 (Final data collection date for primary outcome measure)|
|Experimental: Low protein diet||
Dietary Supplement: low protein diet
An iso-caloric low protein diet of 0.6 g/kg/day was prescribed during the whole study duration.
The same dietician gave nutritional advices at least every three months during the whole study period. Patients were also seen by the same doctor during each visit for the whole study period.
Supplementation of Calcium of 500mg/day.
Urine albumin losses >= 2 g/day wre replaced by increasing dietary protein on a gram-for-gram basis, only if the patient was compliant with the prescribed low-protein diet.
|Active Comparator: Normal protein diet||
Dietary Supplement: normal protein diet
The patients pre-study diet during the whole study period
Patients were also seen by the same doctor during each visit for the whole study period.
The study was a prospective, randomized, unmasked, controlled trial carried out at the Steno Diabetes Center. With concealed randomization the patients were (in blocks of two according to the level of GFR) assigned to receive either a usual-protein diet or a low-protein diet.
After randomization an iso-caloric low-protein diet of 0.6 g/kg/day was prescribed to patients in the low-protein diet group. The usual-pro tein diet consisted of the patients' pre-study diet.
The planned duration of follow-up was four years, scheduled visits every three-months. All patients gave complete history of medication, underwent examination of weight, urinary albumin-, sodium- and urea excretion, serum albumin, serum urea, hemoglobin, hemoglobin A1c, blood pressure, serum total-cholesterol, high-density lipoprotein (HDL) cholesterol.
GFR, serum triglycerides,calcium and phosphorous, anthropometric measurements, nutritional status and smoking habits were evaluated every six months.
Dietary protein intake was estimated on the basis of three consecutive 24-hour urine samples completed before each visit, using urinary excretion of urea nitrogen.
GFR was measured by plasma clearance of 51Cr-EDTA over a 4 hour period and standardized for 1.73m2 body surface area using the same surface for each patient during the study.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01521910
|Steno Diabetes Center|
|Gentofte, Denmark, 2820|
|Principal Investigator:||Henrik P Hansen, MD||Steno Diabetes Center|