|Year : 2015 | Volume
| Issue : 2 | Page : 320-324
|Effects of fasting during Ramadan on renal function of patients with chronic kidney disease
Houda Mbarki1, Nada Tazi1, Adil Najdi2, Nabil Tachfouti3, Mohamed Arrayhani4, Tarik Sqalli4
1 Department of Nephrology, Hassan II University Hospital, Fez, Morocco
2 Laboratory of Epidemiology and Public Health, Faculty of Medicine, Fez, Morocco
3 Laboratory of Epidemiology and Public Health; Medicine Department, Faculty of Medicine, Fez, Morocco
4 Department of Nephrology, Hassan II University Hospital; Medicine Department, Faculty of Medicine, Fez, Morocco
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|Date of Web Publication||3-Mar-2015|
| Abstract|| |
Fasting during Ramadan is prohibited when an individual's health is endangered. Little work has been published in this direction in patients with chronic kidney disease (CKD). We aimed to evaluate the impact of fasting during Ramadan on the renal function of patients with CKD, adjusting for the initial degree of renal impairment. We prospectively studied 60 patients with CKD (35 females; mean age 45.6 ± 15.8 years). All study patients were older than 15 years, being followed-up at the nephrology clinic for more than six months, having a stable CKD during the preceding six months and who had fasted during Ramadan the previous year. Patients who had a medical contra-indication for fasting were excluded from the study [severe or resistant arterial hypertension, insulin-requiring diabetes, acute renal failure (ARF), active renal disease, repetitive urolithiasis or terminal chronic renal failure]. Statistical analysis was performed in collaboration with the epidemiology lab at the Fez Medical School using the SPSS software version 17. Three of the study patients developed ARF in the first week and four of them at the end of the month of the study period. The risk of developing ARF was significantly higher for patients with baseline creatinine clearance of <60 mL/min/1.73 m 2 . However, the small sample size does not allow us to draw any firm conclusions on fasting during Ramadan in stable CKD patients. Studies on larger numbers of patients are recommended.
|How to cite this article:|
Mbarki H, Tazi N, Najdi A, Tachfouti N, Arrayhani M, Sqalli T. Effects of fasting during Ramadan on renal function of patients with chronic kidney disease. Saudi J Kidney Dis Transpl 2015;26:320-4
|How to cite this URL:|
Mbarki H, Tazi N, Najdi A, Tachfouti N, Arrayhani M, Sqalli T. Effects of fasting during Ramadan on renal function of patients with chronic kidney disease. Saudi J Kidney Dis Transpl [serial online] 2015 [cited 2018 May 26];26:320-4. Available from: http://www.sjkdt.org/text.asp?2015/26/2/320/152494
| Introduction|| |
Fasting during the sacred month of Ramadan is one of the five pillars of Islam. It consists of stopping eating and drinking from sunrise to sunset. Duration of the fasting ranges from 10 to 18 h per day, and varies according to the geographic location and the season. During this holy month, lifestyle and eating habits change and cause biological variations.  Several studies have concluded that fasting during Ramadan does not have any adverse effect on healthy adults. ,,
Fasting during Ramadan is prescribed in the Quran for every pubescent Muslim, mentally capable and without any of the religious exemptions. ,, Also, fasting is prohibited if the health of the individual is compromised. Based on the Quran and the Sharia, the Jurisprudence created rules that prevent Muslims with chronic diseases from injury and pain. ,
Professor Gharbi, endocrinologist and member of the Rabat Regional Oulama Council, explains that there is no consensus on this issue. However, it seems that everybody agrees that "an individual that fears his illness will worsen if he fasts has the permission not to fast during Ramadan"; the level of sickness allowing the renunciation to fasting is left to the appreciation of the faithful. It varies among different religious authorities. 
The opinion of nephrologists is often solicited on the practice of fasting among patients with chronic kidney diseases (CKD). Very few studies have been performed on the benefits and risk of fasting in patients with CKD. For this reason, prohibiting or discouraging a patient with CKD from fasting during Ramadan is always controversial.
| Aim of the Study|| |
This study was conducted to evaluate the impact of fasting during Ramadan on the renal function of patients with CKD, adjusted for the initial degree of renal impairment.
| Subjects and Methods|| |
Type of study
We conducted a prospective study and included patients being followed-up in the nephrology clinic at the Hassan II University Hospital in Fez, Morocco.
They were selected from the nephrology clinic during the three months preceding Ramadan of the year 2010. We included patients older than 15 years, followed-up at the nephrology clinic for more than six months, having stable CKD during the preceding six months, and who have fasted during Ramadan of the preceding year.
We defined CKD by the presence of mild to moderate chronic renal failure (CRF) (creatinine clearance >15 mL/min/1.73 m 2 ) or by the existence of signs of kidney damage (proteinuria >0.3 g/24 h and/or hematuria). Patients who had a medical contra-indication for fasting were excluded from the study. They included patients with severe or resistant arterial hypertension (HTA), insulin-requiring diabetes, acute renal failure (ARF), active renal disease, repetitive urolithiasis or terminal CRF.
All the patients were seen thrice during the study: Before Ramadan, a week after commencing the fast and at the end of the month of Ramadan. The records of the patients were scrutinized for age, gender, morbidity, initial nephropathy and its duration, smoking and number of drugs prescribed. The following parameters were collected at each consultation: Arterial pressure, daily urine volume, weight and the creatinine clearance using the Cockcroft and Gault formula.
The occurrence of an episode of ARF after the first week of fasting or at the end of Ramadan was the principal judgment criterion in our study. We defined it according to the recommendations of the Moroccan Society of Nephrology based on the presence of one of the following elements: 
- Increase of serum creatinine ≥5 mg/L relative to the initial value.
- Increase of serum creatinine ≥50% relative to the initial value.
- Reduction of the glomerular filtration rate (GFR) ≥25% relative to the initial value.
We defined ARF superimposed on a pre-existing CRF as an acute reduction of the GFR ≥50%. 
| Statistical Analysis|| |
Statistical analysis was made in collaboration with the epidemiology lab at the Fez Medical School using the SPSS software version 17.
We studied the evolution of renal function before, during and after the fasting month among the three patient groups, created based on the level of initial renal function: Creatinine clearance >60 mL/min (Group 1), 30-59 mL/ min (Group 2) and 15-29 mL/min (Group 3).
Depending on the occurrence or not of ARF, we divided our patients into two groups. For univariate analysis, we compared their clinical and biological parameters in order to determine the factors associated with the occurrence of ARF subsequent to fasting.
Student's t test allowed us to compare the quantitative variables. We chose the Chi-square test and Fisher's exact test. A P-value <0.05 was considered statistically significant.
| Results|| |
Our sample consisted of 175 patients with CKD who were seen at the nephrology clinic during the three months preceding Ramadan. Among them, 108 patients had one or more medical contraindications for fasting: Insulin-requiring diabetes (33.7%), terminal CRF (32.6%), active renal disease (23.5%), repetitive nephrolithiasis (5.1%), severe HTA (1%) and others (2%).
Demographic parameters of patients
Fasting was authorized for 67 patients. During the follow-up period, seven of them missed one or more consultations and were therefore excluded from the study. Of the remaining 60 patients, there were 35 females and 25 males. The average age was 45.6 ± 15.8 years, with a range of 16-87 years.
The cause of CKD included the following: Glomerulonephritis (50%), nephroangiosclerosis and polycystic nephropathy (13.3% each), diabetic nephropathy (8.3%) and other nephropathies (3.3%). The nephropathy was undetermined in 11.7% of the patients.
The average creatinine clearance was 72.85 ± 40 mL/min/1.73 m 2 , with extremes ranging between 19.6 and 166 mL/min/1.73 m 2 . HTA was the principal co-morbidity found in our patients. There were 29 patients in Group 1, 26 in Group 2, and five in Group 3. Patients in Group 1 were younger, and HTA was more frequently encountered in Group 3. The three groups were similar for the other parameters [Table 1].
|Table 1: Characteristics of the study patients according to the degree of chronic kidney disease.|
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Evolution of creatinine clearance
Three patients developed ARF during the first week of fasting (two from Group 2 and one from Group 3). The remaining patients could successfully fast the entire month. The laboratory tests performed at the end of the month for the remaining 57 patients revealed that four of them had developed ARF (three from Group 2 and one from Group 1). Overall, seven patients (11.7%) developed superimposed ARF while fasting during Ramadan [Figure 1]. Of these seven patients, there was complete recovery of renal function to baseline in five patients, while two patients showed partial recovery.
|Figure 1: Changes in creatinine clearance before, during and after fasting during Ramadan.|
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Factors associated with the occurrence of ARF [Table 2]
On univariate analysis, no significant association was found between the occurrence of ARF and any of the following characteristics: Age, gender, education, smoking and initial nephropathy. ARF was more frequently associated with diabetes, HTA and cardiac disease, although the association was not statistically significant.
|Table 2: Comparisons of clinical data between the two groups (with and without ARF, univariate analysis).|
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We also did not find any significant association between the degree of CKD according to the initial grouping and the risk of developing ARF during fasting. Nonetheless, this risk was significantly higher for patients with a creatinine clearance <60 mL/min/1.73 m 2 compared with those with a clearance that was >60 mL/min/1.73 m 2 .
Hypotension (decrease ≥20 mm Hg) was noted in four of the seven patients (57%) with ARF, against seven (13%) without ARF (P = 0.04). Reduced urine volume and weight loss (>1 kg) were comparable in the two groups.
| Discussion|| |
In our study, superimposed ARF occurred in 11.7% of the patients who fasted during Ramadan. Our results showed that the risk of occurrence of ARF is significantly associated with the presence of moderate to severe CRF (creatinine clearance <60 mL/min/1.73 m 2 ).
On review of the literature, we found few studies on the safety of fasting during Ramadan in patients with CKD. Bernieh et al  concluded that fasting is well tolerated by the 31 patients who had renal failure (clearance <60 mL/min/ 1.73m 2 ). In an Egyptian study by El-Wakil et al  that compared 15 patients who had renal failure (clearance <60 mL/min/1.73 m 2 ) with six healthy adults, the variation of GFR before and after Ramadan were similar in the two groups. All the studies had small patient samples and none looked at the risk of fasting according to the degree of CKD.
The analysis of medical records of the seven patients who developed ARF during the fast did not reveal any factor accountable for worsening of renal function. Hypotension was more frequently seen in this group, and this could be attributed to dehydration related to low intake of liquids. A drop in the arterial pressures was also found in a study from the United Arab Emirates.  In the El-Wakil study, renal tubular lesions, evaluated by the increase in the levels of urinary N-acetyl-B-D-glucosaminidase, were more frequent among patients with renal failure. This could be explained by the vulnerability of the tubules to renal hypo-perfusion, particularly in patients with CKD. The recovery of renal function after the end of fasting, seen in five of our seven patients who had ARF, is another argument to support the role of hypovolemia.
| Conclusion|| |
The small sample of our study does not allow us to conclude with certainty that fasting during Ramadan is safe and not associated with renal injury among stable CKD patients and those who have a creatinine clearance >60 mL/min/1.73 m 2 . However, caution should be exercised in patients with CKD, and they may need more intense monitoring during fasting.
Conflict of interest: None declared.
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Dr. Houda Mbarki
Department of Nephrology, Hassan II University Hospital, Fez
[Table 1], [Table 2]
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