Body mass index modulates the relationship of sugar-sweetened beverage intake with serum urate concentrations and gout.

Introduction: Both sugar-sweetened beverage (SSB) intake and body mass index (BMI) are associated with elevated serum urate concentrations and gout risk. The aim of this study was to determine whether the associations of SSB intake with serum urate and gout are moderated by BMI.

Method: The effects of chronic SSB intake on serum urate and gout status were analysed in a large cross-sectional population study. The effects of an acute fructose load on serum urate and fractional excretion of uric acid (FEUA) were examined over 180 minutes in a short-term intervention study. In all analyses, the responses were compared in those with BMI <25 mg/kg(2) (low BMI) and ≥25 mg/kg(2) (high BMI).

Results: In the serum urate analysis (n = 12,870), chronic SSB intake was associated with increased serum urate in the high BMI group, but not in the low BMI group (P difference = 3.6 × 10(-3)). In the gout analysis (n = 2578), chronic high SSB intake was associated with gout in the high BMI group, but not in the low BMI group (P difference = 0.012). In the acute fructose loading study (n = 76), serum urate was increased in the high BMI group at baseline and throughout the observation period (PBMI group <0.0001), but there were similar acute serum urate increases in both BMI groups in response to the fructose load (P interaction = 0.99). The baseline FEUA was similar between the two BMI groups. However, following the fructose load, FEUA responses in the BMI groups differed (P interaction <0.0001), with increased FEUA at 120 minutes and 180 minutes in the low BMI group and reduced FEUA at 60 minutes in the high BMI group.

Conclusions: These data suggest that BMI influences serum urate and gout risk in response to chronic SSB intake, and renal tubular uric acid handling in response to an acute fructose load. In addition to many other health benefits, avoidance of SSBs may be particularly important in those with overweight/obesity to prevent hyperuricaemia and reduce gout risk.

Trials Registration: Australian Clinical Trials Registry ACTRN12610001036000 . Registered 24 November 2010.