C-reactive protein elevation linked to gestational diabetes: early pregnancy

OB/GYN News, Dec 1, 2003 by Nancy Walsh

ATLANTA -- Elevations in maternal C-reactive protein during early pregnancy are associated with an increased risk for gestational diabetes, Dr. Chun-Fang Qiu said at the annual meeting of the Society for Pediatric and Perinatal Epidemiologic Research.

In a prospective cohort study that enrolled 851 women, those whose C-reactive protein (CRP) concentrations were in the highest tertile by 16 weeks' gestation had a 5.2-fold increased risk of developing gestational diabetes, compared with those in the lowest tertile. (See chart.)

Elevations in acute phase proteins indicating subacute inflammation have previously been reported in association with type 2 diabetes. There is a relatively large body of literature documenting positive associations of CRP with insulin resistance, hyperglycemia, and glucose intolerance, said Dr. Qiu of Swedish Medical Center, Seattle. Little attention has been paid to the potential role of inflammation in the etiology of gestational diabetes, however, with only one published study suggesting such a link (Diabetes Care 26[3]:819-24, 2003).

Among the potential factors linking inflammation with gestational diabetes are the following, he said in a poster session:

* Proinflammatory cytokines, including tumor necrosis factor (TNF)-[alpha] and interleukin-6, regulate the hepatic synthesis of CRP, Dr. Qiu said at the meeting, cosponsored by the University of Utah.

* TNF-[alpha] has been shown to inhibit insulin receptor signaling by cutting tyrosine kinase activity and by inducing serine phosphorylation of the insulin receptor substrate.

* Pharmacologic blockage of TNF-[alpha] results in increased signaling capacity of the insulin receptor.

* TNF-[alpha] also has been implicated as a mediator of insulin resistance via its ability to induce endothelial dysfunction.