A randomized trial of low-animal-protein or high-fiber diets for secondary prevention of calcium nephrolithiasis.
BACKGROUND
The purpose of this trial was to evaluate the efficacy of a low-animal-protein diet (LAPD) or a high-fiber diet (HFD) for the prevention of calcium nephrolithiasis recurrence.


METHODS
We conducted a 4-year randomized trial comparing the effect of 2 diets in 175 idiopathic calcium stone formers. Fifty-five were assigned to a LAPD (<13% of total energy derived from protein), 60 were assigned to a HFD (>25 g/day fiber) and 60 were placed on a normal diet (control group). The primary outcome measure was the time to the first recurrence of calcium nephrolithiasis. Daily urine compositions were analyzed at baseline, at month 4 (M4), M12, M24, M36 and M48.


RESULTS
Seventy-three patients completed the trial (23 in the LAPD group, 27 in the HFD group and 23 in the control group). Recurrence was 48% (11/23) in the LAPD group, 63% (17/27) in the HFD group and 48% (11/23) in the control group (p = not significant). During follow-up, urinary calcium levels and other urine parameters did not change significantly in the 3 groups, except for a significant decrease in 24-hour urinary sulfate in the LAPD group.


CONCLUSIONS
In idiopathic calcium stone formers, neither a LAPD nor a HFD appeared to provide protection against recurrence.
Dussol
Bertrand
B
Centre de Néphrologie et de Transplantation Rénale, Assistance Publique, Hôpitaux de Marseille, Université Aix-Marseille II, France. bdussol@ap-hm.fr
Iovanna
Cecilia
C
Rotily
Michel
M
Morange
Sophie
S
Leonetti
Françoise
F
Dupuy
Patricia
P
Vazi
Alain
A
Saveanu
Adriana
A
Loundou
Anderson
A
Berland
Yvon
Y
D000328:Adult; D004043:Dietary Fiber / Q000627:therapeutic use*; D004044:Dietary Proteins / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009397:Nephrocalcinosis / Q000175:diagnosis / Q000178:diet therapy* / Q000517:prevention & control*; D053040:Nephrolithiasis / Q000175:diagnosis* / Q000178:diet therapy / Q000517:prevention & control*; D055502:Secondary Prevention; D016896:Treatment Outcome
D004043:Dietary Fiber; D004044:Dietary Proteins