Ramadan fasting and chronic kidney disease: A systematic review.

Ramadan fasting represents one of the five pillars of the Islam creed according to the Sunnah and the second practice of faith for the Shiaa. Even though patients are exempted from observing this religious duty, they may be eager to share this particular moment of the year with their family and peers. However, there are no guidelines or standardized protocols that can help physicians to properly address the issue of patients with chronic kidney disease (CKD) fasting in Ramadan and to correctly advise them. Moreover, in a more interconnected and globalized society, in which more and more Muslim patients live in the Western countries, this topic is of high interest also for the general practitioner. For this purpose, we carried out a systematic review, including also articles written in Arabic, Turkish, and Persian languages. Our main findings are that: recipients of kidney allograft can safely fast during Ramadan;evidences for safety in patients with nephrolithiasis and CKD are instead mixed and controversial. On the other hand,most studies have been carried out during Ramadan falling in cold seasons, and there is scarce information about Ramadan fasting in hot seasons. For these reasons, the findings may be not generalizable and therefore cautions should be taken and applied; the physicians should carefully monitor their patients during the fasting period with an adequate follow-up, in order to avoid any injurious effect.

INTRODUCTION

The holy month of Ramadan (in Arabic and Farsi language, Ramadhaan), the 9th month of the Muslim lunar calendar (Hijra), is of great value and significance among Muslims, representing the month of the descent of the Qu’ran. For the Sunnis, Ramadan fasting (as-sawm) is considered one of the five Islamic pillars of the creed (arkan al-Islam), together with the faith declaration (as-shahada), the ritual prayers (as-salah), the pilgrimage to Mecca (hajj), and charity (zakat). For the Shiites, Ramadan is the second practice of the religious branches (termed also as practices of faith).

Ramadan is not only abstinence from food and drinking, but also from smoking, medication, and sexual intercourses (Surat 2 “Al-Baqarah”, ayyat 183-187).

Ramadan fasting is not, however, a prolonged or continuous fasting, but consists of alternate fasting and feasting (re-feeding) periods.[1] For this reason, it represents a “unique metabolic model.”[18] Predawn meal is termed as suhoor, while after-sunset meal is called iftar. Ramadan duration is variable, since the Islamic calendar is a lunar one and therefore the Islamic year contains 354 days (instead of 365, as in the Gregorian or solar calendar). For this reason, the Ramadan month occurs 11 days earlier every year, and may fall in any period of the year, making a full circle in a span of 33 years. Therefore, mean fasting duration is usually 12-14 h, but depending on the place and the year it can last also up to 18 h[2] or even 22 h, in the extreme latitudes.[1]

Prepuberal and puberal children, menstruating, pregnant and breast-feeding women, sick people, debilitated older subjects, travelers are exempted from this religious duty (Surat 2 “Al-Baqarah”, ayyat 184-185). However, they could be willing to fast and share the spirituality of this month with their family and peers.[3]

The effects of Ramadan fasting on kidney physiology is not a mere academic topic or of limit interest for only the Arabic countries. In a globalized society, the physicians have to face with issues like the management of chronic kidney diseases (CKDs) in Muslim patients that want to fast during Ramadan, since more and more Muslims live in the Western societies.[4] However, information is sparse and no guidelines or standardized protocols exist.[3] For this purpose, we have carried out a systematic review, that could be helpful for general practitioners.

MATERIALS AND METHODS

We systematically searched ISI Web of Science (WoS), Scopus, MEDLINE/PubMed, Google Scholar, Directory of Open Access Journals (DOAJ), EbscoHOST, Scirus, and ProQuest. We used a proper string made up of a combination of key-words such as “fasting,” “CKD” and “chronic renal failure.”

Gray literature was also manually searched. Review articles or research manuscripts not pertinent with the aim of this systematic review were excluded, while all the other research articles (including editorials, letters, case reports) were retained.

No time and language filters were applied.

RESULTS

We identified 25 original articles describing 26 studies [Table 1, with the list of studies divided according to their main topic], and we coded them. Fifteen studies as described in 14 manuscripts focused on kidney transplant, 6 on renal colic, while 5 studies concerned CKDs. Most studies were original researches (20 articles), 3 were conference proceedings, 1 was a letter and 1 was a clinical case report. We summarized in Tables 2 and 3 the demographic characteristics, the clinical suggestions and interventions as well as the main findings, the investigated parameters and the used statistical techniques (when reported by the authors).

Table 1

Studies divided according to their main topic

Table 2

Studies summarized according to the investigated parameters and the used statistical techniques

Table 3

Studies summarized according to the demographic characteristics of the sample and their clinical suggestions, interventions and main findings

Most studies were prospective and observational, with the exceptions of that by Basiri et al., which is a retrospective, database-based study[12] as well as that by Al-Hadramy.[7]

Most studies did not find any differences between fasters and not fasters, or between before and after Ramadan fasting [Table 3].

The study by Bernieh et al. they found improvements during the fasting and after.[13]

Only three studies presented mixed evidences of an increased risk for fasting patients during Ramadan, and three clear negative evidences.

However, most of studies (11/26) were conducted in cold seasons, while only 3 in hot seasons, for the other 12 no information was available [Table 4]. For this reason, the findings may be not generalizable to hot seasons and therefore cautions should be taken and applied when fasting in those periods.

Table 4

Studies divided according to the Ramadan season in which they have been carried out

DISCUSSION

The need for evidence-based protocols

There is a strong need for evidence-based suggestions and guidelines.[3] An alarming letter was published, calling for caution in fasting patients during Ramadan and advising of a “R2 syndrome” (religion and renal failure).[27]

Even though the content of this letter is a bit exaggerated, patients with kidney diseases should be properly advised and counseled before the beginning of Ramadan, as well as during and after the fasting period, about the proper dietary and pharmacological regimen and other behaviors to follow.

This could be done within a multidisciplinary team, made up of a nephrologist, a nutritionist, a psychiatrist or a psychologist. Patients should be carefully checked and assessed, considering both the clinical symptoms and the laboratory exams.

Furthermore, psychological aspects, such as motivation, coping, self-regulation, and patient preferences and adherence/compliance to treatment should be investigated and taken into account.

Ramadan and kidney transplant

Summarizing all the studies dedicated to the relationship between Ramadan fasting and renal allograft, 463 patients who received kidney transplant have been investigated.

The concentration of immunosuppressive drugs tends to remain stable,[4] and biochemical parameters do not change significantly. No organ rejection or deterioration of kidney functions were observed. Only one author reported of adverse effects due to cyclosporine toxicity, acute rejection episodes, and urinary infections.[24] No kidney loss has been documented.

Ramadan and urolithiasis

Summarizing all the collected evidences, 1,262 subjects have been studied using both prospective studies and retrospective database-based surveys.

Ramadan fasting does not seem to deteriorate health condition in subjects with renal colic, does not cause hypercalciuria and does not impair in a statistically significant and clinically relevant way the balance between lithogenic promotors (that is to say, oxalate, calcium, uric acid, phosphates) and inhibitors (citrate, magnesium). Moreover, any renal changes are fully reversible after 10 days from the end of the fasting.[7]

Ramadan and chronic kidney disease

Summarizing all the studies, 140 subjects with CKD have been investigated: 40 on hemodialysis, 18 on peritoneal dialysis (PD), 15 on predialysis, 67 on pharmacological treatment.

If needed, patients can choose between the two clinically available regimens of PD: modified continuous ambulatory PD (three exchanges during the night and icodextrin infusion), modified continuous cycling PD (exchanges over 6-7 h and icodextrin infusion) or continuous cycling peritoneal dialysis (CCPD). Continuous ambulatory peritoneal dialysis is generally preferred by younger patients, whilst CCPD by older subjects.[3]

No severe adverse effects have been recorded, apart from those described by Al-Muhanna.[10] However, the group of patients recruited in this study included also patients suffering from severe renal failure and this could have an impact on the findings of the author.

Recommendations against fasting

Patients suffering from acute tubular necrosis, polyuria (urine volume ≥2.5 L/day), uncontrolled or poorly controlled diabetes mellitus and insipidus or other dysmetabolic disorders, hypertension, angina, postural hypotension, acute infections, active peptic ulcer, significant co-morbidities (such as cardiovascular disorders and chronic liver disease) leading to marked limitations and amendments of daily activities, or with a history of noncompliance and adherence to therapy, dietary and drugs modifications should not fast during the month of Ramadan.

Clinical recommendations for patients willing to fast

Patients should take regularly their treatment twice daily (with suhoor and iftar respectively); if they should need to take drugs more than 2/die, they should consider switching to the former regimen (consulting their physician). If not possible, they should not fast.

They should break the fasting if the plasma creatinine increases by the 30% above the baseline values and/or if you observe clinical symptoms due to changes in serum potassium and sodium.[5]

Patients should be monitored during Ramadan and should be instructed to recognize some alarm symptoms such as an increase in weight (>2 kg from the baseline), lower limb or facial swelling, shortness of breath, dizziness, anorexia or hyporexia, fatigue, weakness or a sense of lethargy.[3] Body weight, blood pressure, biochemical parameters such as fluid and electrolytes should be regularly checked throughout the Ramadan. Patients should attend regular follow-up every 1-2 weeks, before, during and after Ramadan.

When breaking the fasting, they should avoid high-potassium and phosphorous diet (such as dates, apricots, fried food, nuts, cheese, soft juices and drinks, tea, coffee). Moreover, they should drink up to 1-2.5 L of water in order to re-hydrate themselves and compensate a fluid depletion, but avoid exceeding in liquid amount, thus occurring into fluid imbalance and overload.[3]

Water drinking is indeed a good method for preventing and treating both nephrolithias[28] and recurrent renal colic, as proven by a recent systematic review and meta-analysis of randomized clinical trials.[29] Most of the authors of the studies included in this systematic review agree that suggesting and advising patients to take an adequate amount of fluids during the breaks of the fasting is a good clinical practice. This confirms the conclusion of a previous narrative mini-review on the same topic.[30]

If they have a tendency to hyperkalemia, they should take some calcium resonium powder (30 g/die with lactulose once a day).

Anecdotal episodes of hyperkalemia due to free food and drink consumption after the break of fasting or hypokalemia due to PD regimen have been reported in the literature.[31]

Particular attention should be paid to infections, since some fasting patients are on immunosuppressive therapy.[11] According to the therapeutic regimen and combination of drugs, a prophylaxis should be taken into account, considering that the threshold for developing an infection in CKD fasting patients is lower than in healthy subjects.[11] Clinical consultations with pharmacologists and infectious diseases specialists are highly recommended in these cases.

CONCLUSIONS

There are no evidences that Ramadan is injurious for patients with CKD willing to fast,[12345678910111213141516171819202122232425262728293031] even though further high quality research is welcome. Randomized clinical trials are particularly encouraged since there is a lack of evidence-based guidelines and protocols which correctly address the issue of the impact of the fasting on CKD patients and proper counsel and advise them.

In conclusion, if stable and at the least for the categories included in the reviewed studies, patient's eagerness to fast should be taken into account and even encouraged, since spirituality plays a key role in CKDs. The patient feels indeed himself/herself more active being involved in the religious activities, and less depressed and isolated.[3]

AUTHOR CONTRIBUTIONS

Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; Drafting the work or revising it critically for important intellectual content; Final approval of the version to be published; Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.