Insulin resistance and metabolic syndrome in primary gout: relation to punched-out erosions

To verify the relation of gout to insulin resistance (IR) and metabolic syndrome (MetS) and find any association of metatarsophalangeal (MTP) joint erosions to the features of MetS and IR.

Forty-six primary gout male patients with a mean age of 41.96 ± 5.77 years were grouped according to the presence of MetS. Twenty-seven age and sex matched healthy volunteers served as controls. Insulin sensitivity was estimated using the homeostatic model assessment index (HOMA-B) for beta cell function and HOMA-IR for peripheral tissue IR.

Gout patients had significantly higher HOMA-IR and HOMA-B compared to controls. Those with MetS (n = 27) had significantly higher serum uric acid (SUA) than those without (n = 19; 11.51 ± 3.72 mg/dL vs. 9.15 ± 2.34 mg/dL; P = 0.012). Gout patients with MTP erosions had notable higher insulin levels and more IR as shown by the higher levels of HOMA-IR and HOMA-B compared to those without. HOMA-IR and HOMA-B significantly correlated with the presence of erosions. Moreover, the presence of erosions significantly correlated with SUA (r = 0.64, P < 0.0001).

The level of SUA is closely related to IR in patients with and without MetS. There is an association of the severity of gout and presence of MTP erosions to IR. Metabolic syndrome forms an important marker for those who develop more punched-out erosions.