Nutritional recommendations for gout: An update from clinical epidemiology.

Objective: To present the evidence for nutritional lifestyle changes recommended for gout patients; an explicit focus will be on the evidence for weight loss in overweight gout patients based on a recent systematic review and to describe methodological details for an upcoming weight loss trial.

Methods: We did a pragmatic but systematic search in MEDLINE for current guidelines that had made an attempt to make nutritional recommendations for gout. The quality of the evidence for the nutritional recommendations was evaluated based on the guidelines' own ratings and converted into a common simple version based on the GRADE system. The recently published systematic review on weight loss for gout, was based on six databases from which longitudinal studies that had quantified the effects following weight loss were included. The internal validity was assessed with the ROBINS-I tool and the quality of the evidence was assessed with the GRADE approach. Based on the results of the systematic review, a trial was designed, adhering to the principles of evidence based research.

Results: We included 17 guidelines. Most guidelines recommend avoiding or limiting alcohol intake (15; i.e. 88%), lose weight if relevant (12; 71%), and reduce fructose intake (11; 65%). The majority of the evidence for the nutritional recommendations was rated Moderate/Low or Very Low quality. Our recent systematic review on weight loss included 10 studies and found that the available evidence indicates beneficial effects of weight loss for overweight and obese gout patients, but the evidence is of low to moderate quality. As a consequence, researchers from the Parker Institute are launching a randomized trial to explore the short-term effects related to a diet-induced weight loss in obese gout patients.

Conclusions: The nutritional recommendations for gout are generally based on low quality evidence. In terms of weight loss as a management strategy, the available evidence is in favor of weight loss for overweight/obese gout patients. However, since the current evidence consists of only a few studies (mostly observational) of low methodological quality, the Parker Institute are now initiating a rigorous exploratory randomized trial. Similar efforts are needed for other nutritional management strategies for gout.