The Review: “Effects of Creatine Supplementation on Renal Function: A Systematic Review and Meta-Analysis”

Introduction

A 2019 systematic review and meta-analysis examined whether creatine supplementation affects kidney function, a common concern for those considering its benefits for strength and energy. With 15 studies involving a total of 497 participants, this study provides valuable insights, especially for postmenopausal women who are concerned about creatine’s safety. Creatine is widely recognized for its role in improving exercise performance, but its impact on kidney health has prompted questions due to the kidney’s role in processing waste byproducts like creatinine and urea, which can be influenced by supplementation.

Study Design and Methodology

This review is notable for its robust design, drawing from comprehensive searches across databases like PubMed, Cochrane, and Web of Science. The researchers carefully selected studies that used standardized markers of kidney health, such as creatinine levels, creatinine clearance, and plasma urea concentration. They included studies of both short and long durations, allowing them to evaluate creatine’s effects over various periods and at different dosages (5-20g per day). These markers provide a clear picture of kidney function, as creatinine clearance, for example, reflects the kidney’s ability to filter blood and remove waste products.

The study’s methodology included standardized quality assessment tools to ensure reliability. Researchers excluded studies involving pre-existing kidney conditions, animal studies, and non-research articles, thus focusing solely on randomized controlled trials and case studies relevant to kidney health. Each study’s quality was further evaluated with tools like the Physiotherapy Evidence Database (PEDro) scale for randomized trials, which yielded high average scores, further underscoring the study’s credibility.

Key Findings

The meta-analysis found that creatine supplementation did not significantly impact the key kidney health markers:

• Creatinine Levels: Creatine use did not significantly change serum creatinine levels (Standardized Mean Difference [SMD] = 0.48, 95% CI 0.24-0.73), indicating no harm to kidney function in healthy participants. This remained consistent across studies of various durations, from short-term to long-term (up to 132 weeks) .
• Creatinine Clearance: Similarly, studies showed no significant changes in creatinine clearance rates. This suggests that the kidneys’ filtering ability was unaffected by creatine, even at higher dosages or with extended use. For example, Kreider et al., a long-term study lasting up to 21 months, found no negative effects on kidney filtration in athletes, aligning with the broader meta-analysis findings .
• Plasma Urea Levels: Plasma urea, another indicator of kidney function, remained stable across studies (SMD = 1.10, 95% CI 0.34-1.85), showing that protein metabolism and urea excretion were not disrupted by creatine use.

Specific Findings for Postmenopausal Women

The study included specific research on postmenopausal women, providing direct insights into this group’s response to creatine supplementation. Notably, research by Neves et al., as referenced in the study, focused on postmenopausal women and found no adverse effects on kidney function. This aligns with similar findings in individuals with type 2 diabetes, as seen in the study by Gualano et al., reinforcing the potential safety of creatine for older adults with unique physiological needs . This offers evidence-based reassurance for older women, suggesting that creatine may be safely incorporated under medical guidance.

For older women concerned about the safety of creatine supplementation, this study offers solid reassurance. The researchers conclude that “most of the studies did not demonstrate renal damage with creatine supplementation,” and their data supports the use of creatine at standard dosages for healthy individuals without renal concerns. This comprehensive review suggests that creatine, when taken as directed, is safe and does not negatively impact kidney health. For those considering creatine, this study provides a strong evidence base to support its safe use under appropriate guidance.

About The Review

As part of The Next Chapter, our dedicated women’s health blog, we strive to empower our readers by bridging the gap between complex scientific research and practical understanding. The Review is our mini-series of literature reviews, where we dive into the science behind creatine supplementation and other relevant postmenopausal health subjects. By breaking down the latest findings from the scientific community, we aim to help our customers make informed decisions about how cheap and effective supplementation can support their health and well-being.