Patients with low urate levels may face higher risk of early death

Adults with low blood levels of urate may be at higher risk of having low skeletal muscle mass and strength and may face a higher risk of early death according to a new research published in Arthritis & Rheumatology. 

It remains controversial whether low serum urate (SU) levels contribute to adverse outcomes. The researchers evaluated the relation of low SU to sarcopenia, and assessed whether sarcopenia confounds associations between low SU and mortality.

The study used 1999–2006 data from the National Health and Nutrition Examination Survey. Among 13,979 participants aged 20 years and older, low blood urate concentrations were associated with low lean mass, underweight body mass index, and higher rates of weight loss.

Low blood urate was associated with a 61% higher risk of death (through 2015) before adjusting for body composition, but risk was non-significant after adjusting for body composition and weight loss.

"These observations support what many have intuited, namely that people with low serum urate levels have higher mortality and worse outcomes not because low urate is bad for health, but rather that low urate levels tend to occur among sicker people, who have lost weight and have adverse body composition," said lead author Joshua F. Baker, MD, MSCE, of the University of Pennsylvania.

"While this observational study doesn't disprove a causal association, it does suggest that great care is needed in interpreting epidemiologic associations between urate levels and health outcomes."

The researchers concluded that Sarcopenia and weight loss are more common among those with low serum urate concentrations. The differences in body composition may help to explain associations between low serum urate and associated higher mortality.

Reference:

Baker, J.F., Weber, D.R., Neogi, T., George, M.D., Long, J., Helget, L.N., England, B.R. and Mikuls, T.R. (2022), Associations between low serum urate, body composition, and mortality. Arthritis Rheumatol. Accepted Author Manuscript.https://doi.org/10.1002/art.42301