Susantitaphong et al. BMC Nephrology (2017) 18:19 DOI 10.1186/s12882-017-0436-6 RESEARCH ARTICLE Open Access A double-blind, randomized, placebo- controlled trial of combined calcitriol and ergocalciferol versus ergocalciferol alone in chronic kidney disease with proteinuria Paweena Susantitaphong*, Siriwan Nakwan, Sadudee Peerapornratana, Khajohn Tiranathanagul, Pisut Katavetin, Nattachai Srisawat, Kearkiat Praditpornsilpa and Somchai Eiam-Ong Abstract Background: KDOQI guideline suggests that nutritional vitamin D should be supplemented in chronic kidney disease (CKD) patients who have vitamin D insufficiency/deficiency. However, there are scarce data regarding the additional benefit of active vitamin D supplement in CKD patients who were receiving nutritional vitamin D supplement. This study was conducted to explore the effect of adding active vitamin D to nutritional vitamin D supplement on proteinuria and kidney function in CKD with vitamin D insufficiency/deficiency. Methods: This double-blind, randomized placebo-controlled trial was performed to answer the above question. Sixty-eight patients with CKD stage 3–4, urine protein to creatinine ratio (UPCR) > 1 g/g, and serum 25OH-D level < 30 ng/mL were enrolled. Patients were randomly assigned to receive 12-week treatment with oral ergocalciferol plus placebo (n = 36) or oral ergocalciferol plus calcitriol (n = 32). Results: ThemeanbaselinevaluesofUPCRofbothgroupswerecomparable(3.6±3.8g/gincombinedgroup and 3.5 ± 3.0 g/g in ergocalciferol group). Following 12-week treatment, there were significant reductions in UPCR from baseline in both groups (2.3 ± 2.1 g/g in combined group and 2.4 ± 2.0 g/g in ergocalciferol group). The percentage reductions in UPCR of both groups were not significantly different. The mean eGFR and blood pressure did not differ between baseline and 12-week follow-up and between both groups. No severe hypercalcemia or serious side effects were noted in both groups. Conclusions: The proteinuria lowering effect of ergocalciferol in CKD patients with vitamin D deficiency was demonstrated. Additional calcitriol supplement did not have more effects on proteinuria. Trial registration: (Thai Clinical Trials Registry (TCTR) 20140929002). Date of registration: September 27, 2014. Keywords: Vitamin D deficiency, CKD, Proteinuria, Ergocalciferol, Calcitriol Background analysis demonstrated that lower estimated glomerular Chronic kidney disease (CKD) is one of the most filtration rate (eGFR) and higher albuminuria were each extremely important non-communicable diseases that independently associated with end-stage renal disease has significant morbidity and mortality consequences (ESRD) and mortality. Both eGFR and albuminuria were [1]. The major complications related to CKD include more strongly associated with ESRD than mortality in cardiovascular disease, infectious complications, and CKD patients [2]. mineral and bone disorder (MBD). A recent meta- Vitamin D deficiency/insufficiency is a common problem in CKD patients due to dysregulation of vitamin D metab- * Correspondence: [email protected] olism from renal insufficiency [3]. Although the definite Division of Nephrology, Department of Medicine, King Chulalongkorn critical serum 25 (OH) D level and benefits of 25 (OH) D Memorial Hospital, Faculty of Medicine, Chulalongkorn University, 1873, Rama 4 Rd., Pathumwan, Bangkok 10330, Thailand supplement in CKD patients remain controversial, In the © The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Susantitaphong et al. BMC Nephrology (2017) 18:19 Page 2 of 8 2003 Kidney Disease Outcomes Quality Initiative (KDOQI) by using Thai-MDRD formula [16]. Exclusion criteria guideline suggested that patients with serum 25(OH) D included active glomerulonephritis, receiving immunosup- levels < 30 ng/mL should receive supplementation with pressive drugs within 3 months before enrollment, adjust- nutritional vitamin D. The dosage regimens were recom- ing RAAS blockade such as angiotensin-converting-enzyme mended to be the same as general population [4]. inhibitors or angiotensin II receptor blockers (ACEIs/ARBs) Besides the classical action of vitamin D as an important within 3 months before enrollment, and serum calcium regulator of mineral bone metabolism, recent evidence level more than 10.2 mg/dL. points to other important functions in different target This study was a double-blind RCT of ergocalciferol, a organs including renal, cardiovascular systems, and im- nutritional vitamin D, with or without calcitriol, an ac- mune response regulation [5]. Vitamin D deficiency was tive vitamin D, in CKD with proteinuria and vitamin D associated with a higher annual incidence of albuminuria, insufficiency/deficiency. We randomly assigned eligible decreased eGFR, and independently predicted 5-year patients in a 1:1 ratio to 40,000 units/week of ergocalcif- incidence of albuminuria [6]. Vitamin D deficiency was erol plus identical placebo or 40,000 units/week of ergo- also a significant risk factor for the development of calciferol plus calcitriol (0.5 μg, two times per week) for CKD stage 3–5 [7, 8]. In addition, vitamin D deficiency 12 weeks. is independently associated with a higher risk of 50% Patients were examined at baseline, 6-week, and 12-week. increase in baseline serum creatinine, ESRD, or death Blood pressures, adverse events, concomitant drug treat- in patients with type II diabetic nephropathy (DN) [9]. ment, and adherence to drug regimens were also recorded. Previous cohort studies showed that daily cholecalciferol, At baseline, 6-week, and 12-week, the blood chemistry pa- a nutritional vitamin D, supplement had a beneficial effect rameters including serum creatinine, cystatin C, calcium, in decreasing albuminuria in CKD and DN [10, 11]. phosphate, albumin, intact parathyroid hormone (iPTH) Active vitamin D has been demonstrated to lessen were measured while urine specimen collection at first void renin-angiotensin aldosterone system (RAAS) and intra- urine including urine protein to creatinine ratio (g/g) were glomerular pressure, and might ameliorate renal injury by determined. The dosages of ACEIs or ARBs were not reducing fibrosis, apoptosis, and inflammation in animal allowed to adjust during the follow-up period. Other anti- models [12]. Several randomized controlled trials in hypertensive treatments were initiated or increased in dose patients with proteinuric kidney disease demonstrated the for controlling blood pressure following the KDIGO guide- benefit of calcitriol or paricalcitol supplement in decreas- line (<130/80 mmHg) [17]. ing proteinuria [13–15]. However, there were no random- ized controlled trials (RCTs) exploring the effect of the additional benefit of active vitamin D supplement in CKD Randomization and masking patients who were receiving nutritional vitamin D supple- Computer-generated concealed randomization schedules, ment. Therefore, this study was conducted to explore the each with permuted block sizes of four, were created. effect of combined nutritional vitamin D and active vita- When an eligible patient had been enrolled, the research min D supplement on proteinuria and kidney function in assistant used sealed opaque envelopes to allocate the pa- CKD with vitamin D insufficiency/deficiency. tient to the next sequential randomization number. This study was double blinded. Patients were not informed Methods which group they were randomly allocated to. The labora- Study design and participants tory personnel processing the samples also had no know- The study was performed during July 2014 and February ledge of each patient’s group assignment. The physicians 2015 in adult Thai CKD patients with proteinuria and who took care of the patients were also masked. vitamin D insufficiency/deficiency at the outpatient clinic at King Chulalongkorn Memorial Hospital (KCMH), Bangkok, Thailand. The study was approved by the Outcomes Institutional Review Board of the Faculty of Medicine, The primary endpoint was the percentage change in Chulalongkorn University (Bangkok, Thailand; IRB.093/57) urine protein to creatinine ratio (UPCR) which was cal- with clinical trial registration (Thai Clinical Trials Registry culated by using the values obtained at baseline and after (TCTR) 20140929002; date of registration: September 27, 12 weeks of follow-up period. Secondary endpoints were 2014). All participants received information of study details the proportion of patients who achieved at least 30% re- before giving written informed consent. The inclusion cri- duction in UPCR, the change of kidney functions, blood teria included eGFR of 15–60 mL/min per 1.73 m2,age pressure level, and blood chemistry. The safety end- 18 years or older, proteinuria greater than 1 g/day, and points and all adverse events were classified and con- serum vitamin D (25-OH) level less than 30 ng/mL. The firmed by personals who were masked to treatment eGFR was calculated with serum creatinine concentrations assignment. Susantitaphong