Is this true : does taking daily creatine increase the creatine lab test and decrease egfr falsely

[Research gathered: 2025-12-20] Daily creatine supplementation commonly raises serum creatinine (making eGFR calculated from creatinine appear lower) without evidence of true renal damage in healthy people; measured GFR or cystatin‑C–based estimates generally do not change meaningfully in trials and meta‑analyses [2][1][3]. Key facts and current information - Creatine intake increases circulating creatinine because creatinine is a nonenzymatic breakdown product of creatine/creatine‑phosphate metabolism, so supplementation elevates serum creatinine even when kidney function is unchanged [1][3]. - Multiple randomized trials and meta‑analyses report a modest, often transient, increase in serum creatinine with typical dosing (loading phases or daily doses of ~3–5 g) but no consistent reduction in true GFR measured or in clinically meaningful renal outcomes in healthy subjects [2][1][5]. - eGFR calculated from serum creatinine will therefore often be lower during creatine use (since eGFR formulas use serum creatinine), which can *falsely suggest* reduced kidney function unless alternative markers or measured GFR are used [3][2]. - More specific kidney biomarkers (e.g., cystatin C, NGAL, KIM‑1, urinary MCP‑1) and direct measures of GFR in studies have generally not shown evidence of kidney injury from standard creatine supplementation in healthy individuals [1][2]. Relevant statistics and data (examples from the literature) - A systematic review and meta‑analysis found a small but statistically significant increase in serum creatinine after creatine supplementation while pooled GFR effects were not statistically different from control groups (meta‑analysis of 5 studies for GFR; intervention n≈69, control n≈74) [2]. - In a 35‑day randomized trial of 3 g and 5 g/day creatine, supplemented groups showed a significant within‑group increase in serum creatinine and decrease in creatinine‑based eGFR, but values remained within normal reference ranges and no other markers indicated renal injury [1]. - A 12‑week study in resistance‑trained healthy individuals consuming a high‑protein diet reported no adverse effect on kidney function from creatine supplementation (no meaningful change in renal measures) [5]. Multiple perspectives and caveats - Clinical‑laboratory interpretation perspective: National kidney organizations note that factors such as creatine supplements, high meat intake, recent intense exercise, and high muscle mass raise serum creatinine and can make creatinine‑based eGFR *appear* lower even when true GFR is unchanged; they recommend using cystatin‑C or combined equations or measured GFR when accuracy is needed [3]. - Safety in healthy populations: The preponderance of clinical trial data indicates creatine (typical doses 3–5 g/day) is safe for kidney function in healthy persons, with elevated serum creatinine reflecting increased creatine turnover rather than renal impairment [2][1]. - Populations not well studied / caution: Long‑term effects in people with preexisting kidney disease, older adults with low muscle mass, or those on nephrotoxic drugs are less well characterized; guidelines and reviews advise caution and medical supervision in those populations because creatinine‑based tests may be misleading and underlying kidney vulnerability is possible [2][3]. - Measurement solution: Using serum cystatin‑C alone or combined creatinine‑cystatin C eGFR equations—or obtaining measured GFR (e.g., iohexol, inulin clearance)—reduces the confounding effect of creatine supplements on kidney assessment [3][2]. Practical implications for clinicians and patients - If a patient is taking creatine and has an isolated rise in serum creatinine or lower creatinine‑based eGFR but no clinical signs of kidney disease, consider supplement use as a likely cause and obtain alternative assessment (cystatin‑C eGFR or measured GFR) before diagnosing renal impairment [3][2]. - For healthy individuals using standard creatine doses (≈3–5 g/day), existing evidence does not support stopping creatine solely because of modest serum creatinine rises in the absence of other abnormal renal markers; nonetheless, monitoring and clinical judgment are advised [1][2]. - For patients with known CKD or risk factors for kidney disease, consult nephrology and consider avoiding or closely monitoring creatine use because the safety evidence in these groups is limited [2][3]. Limitations and uncertainties - Many trials are small, short‑ to medium‑duration, and enroll healthy adults; large long‑term randomized trials in older adults and in people with CKD are limited, so long‑term safety in those groups remains uncertain [2]. - Changes in serum creatinine with creatine use vary between individuals depending on dose, duration, muscle mass, and assay differences; reported magnitudes and durations of increase differ across studies [1][2][3]. Selected source citations (supporting the statements above) - Trials showing increased serum creatinine but no renal injury with 3–5 g/day for 35 days and novel renal biomarkers unchanged [1]. - Systematic review/meta‑analysis reporting modest increases in serum creatinine but no significant pooled GFR decline; subgroup/timeframe analyses described [2]. - National Kidney Foundation guidance summarizing factors that raise serum creatinine (including creatine supplements) and recommending cystatin‑C or combined estimates for more accurate eGFR when confounders exist [3]. - Individual long‑term (12‑week) trial finding no kidney function impairment in resistance‑trained, high‑protein subjects on creatine [5]. If you want, I can: - Extract exact numeric changes (mean Δ creatinine and Δ eGFR) from each cited study and present them in a table with sample sizes and dosing regimens. - Find guideline statements or case reports about creatine in people with CKD.