Colchicine inhibits the formation of the Nod-like Receptor Family Pyrin Domain Containing 3 (NLRP3) inflammasome, a key component in the obesity-associated inflammatory cascade. In a retrospective study, long-term colchicine treatment had glycemic benefit in patients with gout. Other research has suggested that suppressing NLRP3 could improve peripheral insulin resistance as well as β-cell insulin production. However, no randomized controlled trial had yet investigated colchicine’s long-term effects on glucose metabolism in adults with obesity and metabolic syndrome (MetS).
The NIH researchers enrolled 40 adults to receive either colchicine or placebo; 37 completed the 3-month study. Adherence was high in both groups.
Colchicine significantly reduced multiple markers of obesity-associated inflammation, including high sensitivity C-reactive protein and erythrocyte sedimentation rate. The colchicine group also had moderate but statistically significant reductions in white blood cell count, monocytes, neutrophils, and platelets, without significant effects on lymphocyte count.
Although colchicine’s effects on the primary outcome of insulin sensitivity were not significant, some of the secondary outcomes related to glucose homeostasis—eg, insulin resistance and fasting insulin—suggest colchicine treatment may improve hepatic insulin sensitivity. Moreover, the researchers say, a trend toward improvement in disposition index suggests that the drug might potentially delay the onset of diabetes in people at risk.
While some small, short-term studies had suggested that colchicine might worsen metabolic variables by inhibiting insulin secretion, other recent retrospective studies found long-term colchicine use did not negatively affect insulin secretion or glycemic control. In this study, similarly, the researchers say, chronic colchicine use did not impair first-phase insulin response or insulin sensitivity, and other markers of metabolic health, such as hemoglobin A 1c and cholesterol, were not significantly changed. However, the researchers acknowledge that their study may have been too small to confirm those differences, and say larger studies are warranted.