Gout is a common inflammatory arthropathy associated with hyperuricemia. Substantial evidence links hyperuricemia to the metabolic syndrome and diabetes. Rising serum insulin levels correlate with an increase in serum uric acid (UA). The current study evaluated the effect of pharmacologic insulin on serum UA levels in patients with diabetes.
We conducted a retrospective analysis of previously collected data. The study cohort consisted of patients with both gout and diabetes who had initiated insulin therapy and a matched set of non-insulin users. The change in UA levels was calculated in both groups and compared. Potential confounders were assessed and adjusted for in a matched linear regression model.
In total, 23 patients met criteria for insulin initiators and were matched to 23 non-insulin users. In unadjusted analyses, patients started on insulin had a larger increase in UA (mean change = 1.25mg/dl, interquartile range, IQR: -0.7-2.3) in comparison to those not starting insulin (mean change = 0.06mg/dl, IQR: -1.1-0.9). After controlling for baseline UA and time between UA measurements, regression modeling showed that insulin use was significantly associated with an increase in UA (β = 1.25mg/dl, p = 0.02).
Initiation of insulin among patients with diabetes was associated with a statistically significant increase in serum UA levels. This may affect the risk of gout flares and might suggest the potential for prophylactic therapy.