Effect of creatine supplementation on kidney stones recurrence inathlete: a case report

Abstract

Introduction. Several studies examined the effects of creatine monohydrate

supplementation on renal function, but no previous study has investigated its effects

on kidney stones in humans.

Observation. A renal ultrasound in a healthy young athlete (without a known

renal morphological anomaly, normal kidney function, normal phospholipid and uric

acid data) revealed a kidney stone of 11 mm in the lower right calyx. Extracorporeal shock wave lithotripsy was applied in order to break the down stone. Twenty-one days later, a follow-up renal ultrasound showed the absence of stones in the kidney. One week later, the athlete started creatine monohydrate supplementation for two months. Fourteen months after stopping creatine monohydrate supplementation, a third renal ultrasound confirmed the absence of stones in the kidney.

Conclusion. Two months of creatine monohydrate supplementation in an athlete with a history of kidney stones could not be associated with kidney stone recurrence in the long run.

INTRODUCTION

Creatine monohydrate supplementation (CMS) is an effective way to increase sports performance, especially in short duration and high intensity exercises, and it is one of the most commonly used dietary supplements worldwide 1, 2. Decades of research have consistently shown that short- and long-term CMS is safe in healthy individuals and in a number of patient populations 3.

Several studies examined the effects of CMS on renal function 4, 5, 6, but to the best of the authors’ knowledge, no previous study has investigated the effects of CMS on kidney stones in humans.

In the present study, we investigated the case of an athlete with kidney stones where CMS in recommended doses did not cause new kidney stones.

CASE REPORT

The present case was reported according to the “CAse REports” (CARE)

guidelines 7. A healthy muscular resistance-trained 28-year-old man without renal

morphological anomaly (weight = 110 kg; height = 184 cm; body mass index = 29.5 kg/m2; experience in bodybuilding ≈ 12 years; training frequency ≈ 6 days/week; training intensity = high; with a well-balanced diet and no supplement consumption for 5 years; and no history of illegal drug use), with a history of a kidney stone excretion (18 years, right kidney, diameter of 0.6 mm), consulted because of severe pain in the

right flank and lower right abdomen. The kidney function, the phospholipid and the uric

acid data were normal. Painkillers were prescribed, and based on the patient's history, a kidney stone was suspected. A urine test revealed a high number of erythrocytes of

878.00 elements/high power field (normal range: 0-5 elements/high power field). A renal ultrasound revealed a kidney stone (diameter: 11 mm) in the lower right calyx (Figure 1 A ). In order to break the stone down, and because it was too big to cross the

Figure 1. Renal ultrasound examination of right (A1, B1, andC1) and left (A2, B2, and C2) kidneys.

(A) First renal ultrasound: 11 mm kidney stone in the lower right calyx (A1) of the athlete. (B) Second ultrasound (21 days after extracorporeal shock wave lithotripsy): no kidney stone. C) Third renal ultrasound (14 months after the last day of creatine monohydrate supplementation): no kidney stone.

ureter, an extracorporeal shock wave lithotripsy (ESWL) was applied. Twenty-one days after the ESWL, the athlete's kidneys were examined with a second renal ultrasound confirming the absence of the kidney stone (Figure 1 B ).

One week after the last renal ultrasound examination, the athlete decided to start taking CMS. For this purpose, the patient reportedly purchased the CMS approved by the Iranian ministry of health (300 grams CMS produced by Z-KONZEPT company, Germany). The patient reported the consumption of five grams/day of the supplement (just before training) for two months. During this period, the athlete reported to drink enough water (by his own account the color of his urine was bright) and performed high-intensity bodybuilding training (six days/week, one-day rest), without any modifications to his diet.

Fourteen months after ending his CMS cycle, the third renal ultrasound showed no new kidney stone formations (Figure 1 C ). In addition, the ultrasound showed no increase in prostate size as compared with pre-CMS examination (Figure 2 ). In addition, the size of the liver, gall bladder, spleen, bladder, and kidneys did not change after CMS.

Figure 2. Renal ultrasound examination of prostate.

(A) Pre creatine monohydrate supplementation (21 days after extracorporeal shock wave lithotripsy). (B) Fourteen months after stopping creatine monohydrate supplementation. Note: prostate size was normal in the 2 conditions.

DISCUSSION

The use of CMS is increasing among athletes. As the kidneys have a significant role in removing creatine consumed from plasma and excrete it in the urine 8, there has been anecdotal concern about the detrimental effects of CMS on the kidneys. In addition, possible increases in creatinine level associated with CMS and the elevated serum of creatinine in stone formers led to speculation that creatine could cause kidney stone formation.

Several studies showed that CMS is safe and does not induce renal damage 1, 9, 10. However, the efficacy of CMS on kidney function is controversial and it is still

unknown how safe CMS is for people with or at risk of kidney disease 5. Several studies have shown that CMS in healthy individuals 10, athletes 11, bodybuilders 12, and people with type 2 diabetes13 did not change creatinine levels in urine. Also, a recent systematic review and meta-analysis showed that increases in serum creatinine due to CMS did not indicate kidney damage 1.

On the other hand, some case reports suggested that CMS could affect kidney function in some situations. Nonetheless, these studies have severe limitations that makes it difficult to draw valid conclusions, such as short-term creatine supplementation 5, no evaluation of the patient’s condition prior to the supplementation 14, use of other types of supplements 15, and having a history of renal damage 16.

In the present case report, though the athlete has a history of kidney stones, CMS was not associated with the formation of new kidney stones. To the best of the authors’ knowledge, no previous study had examined the effects of CMS on kidney stones in humans. However, there is a concern regarding the potential effects of CMS on the kidney function. It has been shown that three months of creatine supplementation can impair renal function in a 19-year old Division I football player 17. Also, two months of CMS deteriorated renal function in a 25-year-old man with a previous history of renal dysfunction 18. On the other hand, five grams of CMS for 12 weeks seems to not affect kidney function in a young man with a single kidney, mildly decreased glomerular filtration rate, and ingesting and a high-protein diet 5.

We also showed that creatine consumption did not cause prostate enlargement (Figure 2 ). CMS has been anecdotally associated with prostate enlargement by increasing dihydrotestosterone levels 19, 20. Since only one study has suggested that CMS may increase dihydrotestosterone levels, and the lack of evidence for the

association between this biochemical finding and prostatic hypertrophy, there is no

basis to believe that CMS can cause this condition. One limitation of the present case

report is the unknown type of the calculation (radiopaque or radiolucent).

In conclusion, 5 g/day of CMS for two months was not associated with the recurrence of kidney stones in an athlete with a history of this condition. This finding should be confirmed by prospective studies involving a larger number of participants in a well-controlled setting. While creatine users with a history of kidney stones are advised to monitor their condition with the guidance of a professional specialist, there has been no evidence to date to believe that creatine can cause kidney stones.