Creatine supplementation is popular among people wanting to increase muscle mass, with Americans spending an estimated $14 million on the supplement annually. (Reference 2) Creatine is safe and beneficial for you to use if you have naturally low creatine levels in your body. One example is if you are a vegetarian. However, creatine supplementation may present a danger to you if you suffer from high blood pressure, also known as hypertension.
Serum Creatinine Link
When creatine is metabolized by your body it produces the waste product creatinine, which your kidneys expel. A 10-year study published in the "American Journal of Hypertension" examined the correlation between serum creatinine levels and predicting the development of hypertension in 229 Japanese adults aged 30 to 69. Though it was one of the few studies ever published examining the link between creatine and high blood pressure, the researchers concluded that elevated creatinine levels have the potential to predict future hypertension. (Reference 4)More research is needed to determine if creatine supplementation directly affects hypertension, however.
The biggest impact creatine supplements can have on your blood pressure is likely through your kidneys. According to the U.S. National Library of Medicine, creatine causes your muscles to retain water, thus increasing the concentration of your urine. Over time, concentrated urine can lead to a reduction in kidney function. (Reference 1) Lowered kidney function in turn leads to excess fluid in your blood vessels and raised blood pressure. (Reference 3)
A 2001 study published in the "Archives of Internal Medicine" examined the prevalence of high serum creatinine levels in direct relation to high blood pressure and kidney disease. The study covered a representational cross-section of the US population and found that African-Americans are 1.7 times as likely to have elevated serum creatinine levels leading to end-stage renal disease as Caucasians. The study also found that elevated serum creatinine levels were more prevalent among older individuals. People in these groups may be at an elevated risk for high blood pressure as a result of creatine use. However, the study result also states that using a single cutoff point to evaluate high serum creatinine levels may skew the results of the study slightly because some groups, such as young men, have higher natural creatinine levels due to more muscle mass. (Reference 5)
Safe Creatine Use
Because there is significant risk potential if you take creatine while having high blood pressure, you should always speak to your physician first. Your body naturally produces creatine in your liver, kidneys and pancreas, and you also obtain a significant amount of creatine from red meat and fish. (Reference 2) Therefore, additional creatine supplementation can drastically elevate your kidney work level and blood pressure, making it inadvisable.