Creatinine

Why is Creatinine important for your Healthspan?

‍Creatinine levels are a primary indicator of kidney function. Healthy kidneys are essential for filtering waste products from the blood, maintaining fluid and electrolyte balance, and regulating blood pressure. Elevated creatinine levels can signal that the kidneys are not functioning optimally, potentially leading to a buildup of toxins and increased risk for chronic kidney disease and related health complications that can impact overall vitality and longevity. Monitoring creatinine helps assess kidney performance and guides actions to preserve this vital organ system.

‍What is Creatinine?

Creatinine is a chemical waste product that is generated from muscle metabolism. Specifically, it's a byproduct of the normal breakdown of creatine phosphate, a molecule that stores energy in muscles for quick use. The amount of creatinine produced daily is relatively constant and depends largely on an individual's muscle mass. Once produced, creatinine is released into the bloodstream, where it is then filtered out by the kidneys and excreted from the body in the urine. Because it is almost entirely removed from the blood by the kidneys, creatinine levels in the blood serve as a common and practical marker for how well the kidneys are filtering waste, often used in calculating the estimated Glomerular Filtration Rate (eGFR).

‍How do we take action?

If creatinine levels are found to be elevated, one should consult with a healthcare provider to investigate the underlying cause of reduced kidney function. Strategies often involve managing chronic conditions that impact kidney health, such as high blood pressure and diabetes, through diet, exercise, and appropriate medications. Maintaining good hydration, avoiding excessive intake of protein, and being mindful of certain medications or supplements that can affect kidney function are also important. Regular monitoring of creatinine and eGFR helps track kidney health and allows for timely interventions to protect kidney function.

(Be mindful that creatine supplementation can augment creatinine levels. This is not harmful in healthy populations, but is important context to provide if discussing this metric with a primary care provider).

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‍Additional Sources

1. Hosten AO. BUN and Creatinine. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 193. Available from: https://www.ncbi.nlm.nih.gov/books/NBK305/

2. Clark J. F. (1997). Creatine and phosphocreatine: a review of their use in exercise and sport. Journal of athletic training, 32(1), 45–51.

3. Perrone, R. D., Madias, N. E., & Levey, A. S. (1992). Serum creatinine as an index of renal function: new insights into old concepts. Clinical chemistry, 38(10), 1933–1953.

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