Dietary Sodium Modifies Serum Uric Acid Concentrations in Humans.
BACKGROUND
Subjects with hypertension are frequently obese or insulin resistant, both conditions in which hyperuricemia is common. Obese and insulin-resistant subjects are also known to have blood pressure that is more sensitive to changes in dietary sodium intake. Whether hyperuricemia is a resulting consequence, moderating or contributing factor to the development of hypertension has not been fully evaluated and very few studies have reported interactions between sodium intake and serum uric acid.


METHODS
We performed further analysis of our randomized controlled clinical trials (Australian New Zealand Clinical Trials Registry #12609000161224 and #12609000292279) designed to assess the effects of modifying sodium intake on concentrations of serum markers, including uric acid. Uric acid and other variables (including blood pressure, renin, and aldosterone) were measured at baseline and 4 weeks following the commencement of low (60 mmol/day), moderate (150 mmol/day), and high (200-250 mmol/day) dietary sodium intake.


RESULTS
The median aldosterone-to-renin ratio was 1.90 [pg/ml]/[pg/ml] (range 0.10-11.04). Serum uric acid fell significantly in both the moderate and high interventions compared to the low sodium intervention. This pattern of response occurred when all subjects were analyzed, and when normotensive or hypertensive subjects were analyzed alone.


CONCLUSIONS
Although previously reported in hypertensive subjects, these data provide evidence in normotensive subjects of an interaction between dietary sodium intake and serum uric acid. As this interaction is present in the absence of hypertension, it is possible it could play a role in hypertension development, and will need to be considered in future trials of dietary sodium intake.


CLINICAL TRIALS REGISTRATION
The trials were registered with the Australian and New Zealand Clinical Trials Registry as ACTRN12609000161224 and ACTRN1260.
['Todd|Alwyn S|AS|', 'Walker|Robert J|RJ|', 'MacGinley|Robert J|RJ|', 'Kelly|Jaimon|J|', 'Merriman|Tony R|TR|', 'Major|Tanya J|TJ|', 'Johnson|Richard J|RJ|']
D000328:Adult D000368:Aged D000450:Aldosterone D001794:Blood Pressure D004032:Diet D004039:Diet, Sodium-Restricted D005260:Female D006801:Humans D006973:Hypertension D008297:Male D008875:Middle Aged D012083:Renin D012084:Renin-Angiotensin System D012982:Sodium, Dietary D014527:Uric Acid
sodium uric acid hypertension blood pressure urate