Effect of Ramadan fasting on urinary risk factors for calculus formation.
BACKGROUND
Even though dehydration could aggravate formation of urinary calculi, the effects of fluid and food restriction on calculus formation is not thoroughly defined. The purpose of this study is to evaluate the effects of fluid and food restriction in Ramadan fasting on urinary factors in kidney and urinary calculus formation.


METHODS
Fifty-seven men aged 30 to 55 years old, including 37 recurrent calcium calculus formers and 20 with no history of kidney calculi were evaluated for blood tests, ultrasonography investigations, urinalysis, urine culture, and also 24-hour urine collection test. Metabolites including calcium, oxalate, citrate, uric acid, magnesium, phosphate, potassium, sodium, and creatinine were measured before and during Ramadan fasting. The values of calculus-precipitating solutes as well as inhibitory factors were documented thoroughly.


RESULTS
Total excretion of calcium, phosphate, and magnesium in 24-hour urine and also urine volume during fasting were significantly lower than those in the nonfasting period. Urine concentration of calcium during fasting was significantly lower than nonfasting (P < .001). Urine concentrations of uric acid, citrate, phosphate, sodium, and potassium during fasting were significantly higher than nonfasting. Uric acid supersaturation was accentuated, and calcium phosphate supersaturation was decreased significantly during fasting. There was no significant increase in calcium oxalate supersaturation during the fasting period.


CONCLUSIONS
Fasting during Ramadan has different effects on total excretion and concentrations of urinary precipitate and inhibitory factors contributing to calculus formation. We did not find enough evidence in favor of increased risks of calculus formation during Ramadan fasting.
Urology and Nephrology Research Center, Shohada-e-Tajrish Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. amiladi@hotmail.com
Amir Hossein
AH
Miladipour
Nasser
N
Shakhssalim
Mahmoud
M
Parvin
Mohaddeseh
M
Azadvari
D000328:Adult; D002118:Calcium / Q000652:urine; D002129:Calcium Oxalate / Q000652:urine; D002130:Calcium Phosphates / Q000652:urine; D002951:Citrates / Q000652:urine; D005215:Fasting / Q000009:adverse effects / Q000652:urine*; D006801:Humans; D007492:Iran; D007514:Islam; D007669:Kidney Calculi / Q000209:etiology*; D008274:Magnesium / Q000652:urine; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000652:urine; D012307:Risk Factors; D012964:Sodium / Q000652:urine; D014527:Uric Acid / Q000652:urine
D002130:Calcium Phosphates; D002951:Citrates; D002129:Calcium Oxalate; D014527:Uric Acid; C020243:calcium phosphate; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium