Serum C-reactive protein, uric acid and ferritin levels in gestational diabetes as a screening test

Abstract

To investigate the value of uric acid, ferritin, C-reactive protein (CRP) both alone or in combination as screening tests for gestational diabetes (GDM) confirmed by the gold standard 100-g oral glucose tolerance test (OGTT). STUDY DESIGN: A total of 320 pregnant women at 28-31 weeks gestation during the period of study from January-May 2001 were recruited to the study from Social Security Hospital. A total of 91 subjects with a high risk of GDM from 320 subjects who were referred for an OGTT were available for the study. Fasting serum uric acid, ferritin, CRP levels were measured at the time of glucose challenge test (GCT). The area under curve (AUC), the receiver operating characteristic (ROC) curves for uric acid, ferritin, CRP was also calculated. RESULTS: GDM patients had higher CRP levels compared to patients with GCT?140mg/dl and patients with GCT<140 mg/dl, normal OGTT. There was no significantly difference in ferritin and uric acid levels between these groups. Area under curve was 0.827 for CRP in the prediction of the development of GDM. Two cut-off values were used for CRP, the upper to rule in and the lower to rule out GDM. At a cut-off value of ?2 mg/dl to rule out GDM in 91 patients, 38 (42%) would not need OGTT with 33 (87%) being false positives, 16 (17.5%) would need OGTT with 8 (50%) being false positive and 75 (82%) would not need OGTT with 12 (16%) being false negative. At a cut-off value of ?3mg/dl with the maximum specificity to rule in GDM in 91 patients, 16 (17.5%) would need OGTT with 8 (50%) being false positive and 75 (82%) would not need OGTT with 12 (16%) being false negative. When different levels of CRP were added to GCT, at a CRP cut-off of 2.5 mg/dl, 71 would not need an OGTT with only 9 being false negative to rule out GDM in 91 patients CONCLUSIONS: CRP predicted the presence of GDM. CRP alone or combination with GCT was not a powerful screening test for GDM; even CRP reduced unnecessary OGTT when used together with GCT.