It ’ s not common that reference ranges are set up to fail . Serum urate is one of those times .
By Dr . Jordan Robertson ND
The upper limit of the urate reference range in both Canada and US is focused on gout , not the overwhelming research that urate is a cardiometabolic risk biomarker .
Testing uric acid , and the associated reference ranges , have historically focused solely on uric acid as a risk factor for gout . The Canadian and American guidelines allow for an upper tolerable limit in men of 8 mg / dl ( 480 umol / L ) and aim for a treatment target of below 6 mg / dl in patients with a previous gout episode who are on urate-lowering therapy such as allopurinol .
This approach is missing a significant opportunity to improve patient outcomes , considering the relationship between hyperuricemia and cardiovascular disease risk . There is likely a window of opportunity to identify and manage patients at risk of CVD at an earlier stage by using serum urate , but the value at which urate begins to mark for cardiovascular risk differs from the target used to assess patients for the risk of gout .
The risk of both cardiovascular disease and kidney stones begins as serum urate levels cross a threshold of 6 mg / dl , well within the acceptable reference range according to Canadian and American standards of care documents . Urate levels have been found to predict MACE ( Major Adverse Cardiovascular Events ) in patients with no other obvious risk factors ( Cui et al ., 2023 ) and have been suggested as a critical step in assessing patients with recurrent kidney stones ( Deng et al ., 2023 ).