El Radaman Y Su Dieta

Kidney Diseases

Iranian Journal of Kidney Diseases | Volume 6 | Number 1 | January 2012 33

Original Paper

Effect of Ramadan Fasting on Urinary Risk Factors for

Calculus Formation

Amir Hossein Miladipour,1 Nasser Shakhssalim,2 Mahmoud Parvin,2

Mohaddeseh Azadvari3

Introduction. 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.

Materials and 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. Urinary 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.

IJKD 2012;6:33-8

www.ijkd.org

1Urology and Nephrology

Research Center, Shohada-e-

Tajrish Medical Center, Shahid

Beheshti University of Medical

Sciences, Tehran, Iran

2Urology and Nephrology

Research Center, Shahid

Labbafinejad Medical Center,

Shahid Beheshti University of

Medical Sciences, Tehran, Iran

3Urology and Nephrology

Research Center, Shahid

Beheshti University of Medical

Sciences, Tehran, Iran

Keywords. fasting, urolithiasis,

risk factors

INTRODUCTION

Urinary calculus formation is a common

troublesome and costly urinary system disorder.

Even though dehydration could aggravate the

process of calculus formation throughout the kidney

and urinary outgoing system, the effect of total

abstention from food and water during the month

of Ramadan is unclear. Every year during Ramadan

month, fasting is practiced by Muslims throughout

the world. During Ramadan, the osmolarity of the

urine samples collected, especially in the afternoon

become very high (mean, 849 mOsm/kg to 937

mOsm/kg).1 Not only is the eating pattern greatly

altered during the Ramadan period, but also the

Fasting and Urinary Risk Factors—Miladipour et al

34 Iranian Journal of Kidney Diseases | Volume 6 | Number 1 | January 2012

amount and type of food eaten during the night

may also be significantly different to that usually

consumed during the rest of the year. Moreover,

there is dehydration during the daylight hours of

Ramadan fasting; thus, it seems to be intermittent

dehydration.2

To date, only limited studies have been conducted

about the effect of Ramadan fasting on urinary

calculus formation. This study was designed to

evaluate the effects of fasting during Ramadan

on urinary precipitating and inhibitory factors of

calculus formation.

MATERIALS AND METHODS

We evaluated 57 men aged 30 to 55 years old.

They included 37 recurrent calcium calculus formers

(based on history, radiologic studies, and calculus

analysis) who were recruited from the Stone Clinic

of the Urology and Nephrology Research Center

of Shahid Beheshti University of Medical Sciences

in Tehran. They volunteered for this study and

practiced the Ramadan fasting. Also, 20 randomly

selected men with no history of kidney disease or

calculus formation confirmed by ultrasonography

and laboratory tests were included as controls. All

participants signed an informed consent form for

their participation. None of the participant had

any established metabolic, gastrointestinal, liver,

kidney, cardiovascular, or endocrine disorders

except for urinary calculus formation in the

calculus former group. Individuals with urinary

tract anomalies, urinary tract infection, obesity

(body mass index > 30 kg/m2), and those who

were taking medicines that could affect calcium

metabolism and other urinary factors were excluded

from the study.

Twenty-four-hour urine samples were collected

before the start of Ramadan fasting (U3) and during

Ramadan fasting. Fasting was between 4:00 and

19:00 (15 hours). Collection of the 24-hour urine

during Ramadan fasting was divided in 2 periods

and urine was collected in 2 containers. In the

first one, urine was collected for 20 hours (19:00

to 15:00 of the following day) (U1), and in the

second one urine was collected for 4 hours (15:00

to 19:00) that contained a concentrated urine (U2).

All subjects underwent blood tests including

complete blood count, blood urea nitrogen, serum

creatinine, serum sodium, serum potassium,

fasting blood glucose, serum calcium, serum

phosphate, serum alkaline phosphatase, serum

parathyroid hormone, serum uric acid, and urine

analysis and urine culture. Twenty-four-hour

urine samples were collected in polyethylene

containers with hydrochloric acid 6N or boric

acid as preservative and were stored at -20oC and

analyzed within a month. For metabolic

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