Saudi Journal of Kidney Diseases and Transplantation

: 2010  |  Volume : 21  |  Issue : 5  |  Page : 898--902

Fasting Ramadan in chronic kidney disease patients: Clinical and biochemical effects

Bassam Bernieh1, Mohammad Raafat Al Hakim1, Yousef Boobes1, Fikri M Abu Zidan2,  
1 Nephrology Department, Tawam Hospital in Affiliation with Johns Hopkins Medicine, Al Ain, United Arab Emirates
2 Department of Surgery, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates

Correspondence Address:
Bassam Bernieh
Consultant Nephrologist, Tawam Hospital, P.O. Box 15258, Al Ain
United Arab Emirates


Fasting of the month of Ramadan is a pillar of Islam. Muslim patients with chronic kidney disease (CKD) usually fast this month. To determine the effects of fasting on renal function in CKD patients, we prospectively studied 31 (19 males and mean age 54 ±14.2 years) CKD patients during the month of Ramadan 1426 Hijra (4 th October - 4 th November 2005); 14 patients were in stage III CKD, 12 had stage IV and 5 had stage V. The mean estimated glomerular filtration rate (e-GFR) was 29 ± 16.3 mL/min. Diabetes was the main cause of CKD (19 (61%) patients), and hypertension was present in 22 (71%) patients. Clinical assessment and renal function tests were performed one month prior to fasting then during and a month later. Medications were taken in two divided doses at sunset (time of breaking the fast) and pre dawn (before starting the fast). All patients fasted the whole month of Ramadan with a good tolerance, tendency to weight reduction, and lower systolic and diastolic blood pressure. eGFR showed a significant improvement during the fast and the month after. The blood sugar was high during fasting with an increment in the Hb A1c. There was better lipid profile, reduction of the pro­teinuria and urinary sodium. We conclude that this study demonstrates a good tolerance and safety of fasting Ramadan in CKD patients.

How to cite this article:
Bernieh B, Al Hakim MR, Boobes Y, Abu Zidan FM. Fasting Ramadan in chronic kidney disease patients: Clinical and biochemical effects.Saudi J Kidney Dis Transpl 2010;21:898-902

How to cite this URL:
Bernieh B, Al Hakim MR, Boobes Y, Abu Zidan FM. Fasting Ramadan in chronic kidney disease patients: Clinical and biochemical effects. Saudi J Kidney Dis Transpl [serial online] 2010 [cited 2020 Aug 12 ];21:898-902
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Fasting Ramadan is a pillar of Islam. Most healthy adult Muslims should strictly adhere to fasting during the month of Ramadan. How­ever, exemption is given to the sick, [1] travelers, and pregnant and lactating and menstruating women yet they should fast later, when they have no reason for exemption. [1],[2] Islamic lunar calendar of Hijra, moves forward about 11 days every year. Ramadan can, therefore, occur in any of the four seasons and the duration of restricted food and beverage intake can vary from 12 to 18 hours depending upon the exact time of sunrise and sunset in each country or region. Fasting during Ramadan is different from prolonged continuous fasting, in that it is done only between dawn and sunset, and people are allowed to drink and eat freely after sunset till the onset of dawn. [3] Several studies have con­cluded that fasting during Ramadan does not have any adverse effect on healthy adults. [4],[5],[6] Ramadan fasting, in both type I and type II dia­betes mellitus is safe. [7],[8] The safety of fasting has also been demonstrated in renal transplant patients, one year after transplantation. [9],[10],[11],[12] How­ever, the effect of the fasting Ramadan in chro­nic kidney disease (CKD) patients has been only recently reported in a pilot study inclu­ding only 12 patients. [13]

The aim of this study is to evaluate the cli­nical and biochemical safety of fasting Ramadan in patients with chronic kidney disease.

 Patients and Methods

A total number of 45 out patients followed up in the nephrology clinic of our tertiary teac­hing hospital were registered, only the data of 31 (69%) were analyzed, because the remai­ning 14 patients missed one or more of the three visits, and were not eligible for statistical data analysis. There were 19 males, having a mean (SD) age of 54 (4.2) years, and a range of 23 to 81 years. The study was approved by Al Ain medical district ethical committee.

Inclusion criteria

We included patients with CKD (stage II to V) of different etiologies, age more than 18 years, and who were planning to fast, during Ramadan 1426 Hijra, corresponding to October/ November 2005.

Exclusion criteria

We excluded from the study patients with kidney transplant, history of acute tubular nec­rosis due to dehydration, uncontrolled or poorly controlled hypertension or diabetes mellitus, pregnancy, concurrent disorders such as chro­nic liver disease, advanced cardiac disease, active peptic ulcer, history of renal stone; and mandatory medications more than twice a day.

All the study patients were given three ap­pointments: in the month preceding Ramadan, during the last week of Ramadan, and in the month after Ramadan. During these interviews, the patients were assessed clinically along with kidney function tests, blood sugar, HbA1c, to­tal protein, albumin, lipids profile, hemoglo­bin, urine chemistry, proteinuria, and protein to creatinine ratio.

The estimated glomerular filtration rate (e­GFR) was calculated by using the Cockcroft­Gault formula. Mean (SD) eGFR was 29 (16.3) mL/min, with a range of 8 to 58. Accordingly, the staging of CKD included 14 patients with stage III, 12 with stage IV, and 5 with stage V.

Diabetes mellitus (DM) was the leading cause of CKD in this population (61%). Other etio­logies (26%) were chronic glomerulonephritis, systemic lupus nephritis, and unknown in (13%). Hypertension and hyperlipidemia were the main co-morbidities encountered in 71% and 26%, respectively.

Management of DM during Ramadan

Almost all the diabetic patients who were included in the study had type 2 DM; 50% of them were managed with oral hypoglyce­miants agents, 40% with insulin and 10% with both. In the visit prior to Ramadan, the diabe­tic patients were counseled and educated about self-care, including signs and symptoms of hyper- and hypoglycemia, blood glucose mo­nitoring, meal planning, physical activity, me­dication administration, and management of acute complications.

Oral hypoglycemic agents

Metformin was maintained in patient with se­rum creatinine < 132 μmol/L (1.5 mg/dL); two thirds of the total daily dose to be administered immediately before the sunset meal, and the other third with the predawn meal. The main Sulfonylureas used during the study included gliclazide MR and glimepiride; the dose was given before the sunset meal and adjusted ac­cording to the glycemic control and the risk of hypoglycemia. Thiazolidinediones were used at sunset meal without changing the dose.

Insulin therapy

Pre-mixed insulin 70/30 was used in most of the patients on insulin. The usual morning dose was administered at the sunset meal and half of the usual evening dose at the predawn meal.

 Statistical Analysis

Repeated measurement analysis of variance was used to study the within group change over time. [14],[15] Data were analyzed using the Statistical Package for the Social Sciences (SPSS 15 for windows, SPSS Inc, Illinois, USA). A probability of less than 0.05 was accepted as significant.


All the 31 patients included in the study managed to fast the whole month of Ramadan. The fasting time was around 12 hours and the atmosphere temperature was from 18-288 C. None of the patients displayed any new clinical symptoms or signs. The body weight and blood pressure in the three periods of the study are shown in [Table 1]. Renal function and electrolytes and other biochemical measured variables, pre, during and post Ramadan are illustrated in [Table 2]. The changes in the eGFR during the study are shown in [Figure 1]. Urine electrolytes, urine osmolality, proteinuria and protein to creatinine ratio are illustrated in [Table 3].{Table 1}{Table 2}{Table 3}{Figure 1}

There was a reduction in the body weight and in the systolic blood pressure at the end of Ramadan compared to values before it, but it did not reach statistical significance (P= 0.13, P= 0.21 respectively). There was a statistically significant improvement of the eGFR, during Ramadan and one month thereafter (P= 0.017).


The safety of fasting in healthy and diabetics has been demonstrated in numerous studies. [4],[5],[6],[7],[8] All patients in our study tolerated fasting of Ramadan very well. This finding is compa­rable with another recent study. [13] The main positive clinical finding, in our study was the tendency of weight reduction and the decrease in systolic and diastolic blood pressure. The mean weight reduction was 1.4 kg, and 0.7 kg (P= 0.13) in Ramadan and the following month, respectively. This weight reduction has also been documented in several studies; [17],[18],[19] and it is attributed to the reduction of meal frequency during Ramadan, which often results in re­duction of energy intake and loss of body mass and body fat. Other contributing factors are extracellular volume contraction secondary to lower sodium and fluids intake, and the mo­derate degree of dehydration.

Our finding of a better control of blood pre­ssure has also been documented by others. [20] The positive effect of the fasting on blood pre­ssure persisted for a month after Ramadan. The reduction in the blood pressure did not reach statistical significance possibly because of the small number of patients included in this study.

Moreover, there was a significant improve­ment in the estimated GFR, which could be explained by several mechanisms: First, the reduction in the blood pressure during fasting with a positive effect on the kidney function in CKD patients, [21] Second, weight loss indicating reduction in the relative overhydration, with subsequent improvement of cardiac function and better renal perfusion. Third, dietary reduc­tion of protein intake and exogenous creatinine intake. Finally, modest directional changes in serum creatinine and weight result in an incre­ment in eGFR.

We did not notice any serum electrolytes dis­turbances during fasting. Hyperkalemia due the consumption of huge amount of potassium rich food at breaking the fast has been noticed in CKD, kidney transplant, and hemodialysis patients. [13],[16],[22] There was a reduction in the urinary sodium excretion during Ramadan and the following month compared to the month before Ramadan indicating that the kidneys of the studied patients were responding well to the reduced fluid intake during fasting. These results are similar to those of the kidney transplant patients who fasted. [9] The changes in urinary protein excretion, protein to creatinine ratio and urine osmolality were not significant during the three periods of the study.

However, the high blood sugar during the three periods of the study, particularly in Ramadan, is explained by the fact that diabetes is the leading cause of CKD in our study. In­creased blood sugar during fasting was noted specially in diabetics with poor control before Ramadan. [23] In a large epidemiological study conducted in 13 Islamic countries on 12,243 individuals with diabetes, those who fasted during Ramadan had a high rate of acute com­plications, mainly hypo and hyperglycemia. [24] None of our diabetic patients revealed such metabolic complications during fasting. More­over, despite that Hb A1c was within the target level, its changes during the three study pe­riods were significant. Total cholesterol, HDL and LDL were significantly increased in Ra­madan compared to the pre fast period, yet they remained within the normal level. These lipids changes have been documented in other studies. [19],[23]

In conclusion, fasting Ramadan is safe in stable CKD patients. We have observed some im­provement in the eGFR during and post fas­ting. However, fasting should be under close medical supervision with strict attention to fluid intake, daily activity, and adjustment of drug regimens with a special attention for the management of diabetic CKD patients.


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