The available evidence favors weight loss for overweight/obese patients who have gout, according to researchers who conducted a systematic review.
The quality of evidence for the effects of weight loss on serum uric acid (sUA), achieving sUA target, and gout attacks is low, moderate, and low, respectively, and unfavorable effects may occur at short term, they added.
The researchers at the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, and other centers noted that weight loss is often recommended for gout but that the magnitude of its effect has not been evaluated in a systematic review. To determine the benefits and harms associated with weight loss in overweight and obese patients with gout, they searched 6 data bases for longitudinal studies reporting its effect in these patients.
They assessed risk of bias with the Risk of Bias in Non-Randomised Studies of Interventions and the quality of evidence with the Grading of Recommendations Assessment, Development and Evaluation. Comorbidities selected in the studies in addition to overweight included type 2 diabetes, hypertension, and a high cardiovascular risk profile.
Interventions included diet with and without physical activity, bariatric surgery, diuretics, and metformin (and no intervention). Mean weight losses ranged from 3 kg to 34 kg.
• The effect on sUA ranged from −168 to 30 μmol/L.
• The proportion who achieved sUA target (< 360 μmol/L) ranged from 0% to 60% reduction in patients with raised sUA.
• Beneficial effects on gout attacks were shown in 6 of the 8 studies. One study reported 71% fewer attacks with weight loss.
• Two studies indicated a dose–response relationship for sUA, achieving sUA target, and gout attacks.
• Evidence was not found for the optimal magnitude and intensity of weight loss, but the data suggested that a weight loss of > 7 kg and/or > 2 kg per week from surgery or diet results in a beneficial effect on sUA at medium-term/long-term follow-up and that weight loss of > 3.5 kg showed beneficial effects on gout attacks at medium-term/long-term follow-up.
• At short term, temporary increased sUA and gout attacks tended to occur after bariatric surgery.
The authors suggested that because the current evidence consists of a few studies (mostly observational) of low methodological quality, rigorous prospective studies, preferably randomized controlled trials, are urgently needed.
“Future research should aim at identifying the optimal magnitude and intensity of weight loss, the preferred method of weight loss, including prevention of flare, which cointerventions result in a better effect, and which gout patients will benefit the most, for example, grouped according to type (and possibly severity) of overweight and comorbidities,” they said.
The researchers reported their findings in Annals of the Rheumatic Diseases.
Nielsen SM, Bartels EM, Henriksen M, et al. “Weight loss for overweight and obese individuals with gout: a systematic review of longitudinal studies.” Ann Rheum Dis. 2017 Sep 2. pii: annrheumdis-2017-211472. doi: 10.1136/annrheumdis-2017-211472. [Epub ahead of print]