A simple screening test for gestational diabetes mellitus (GDM) based on fasting plasma glucose (FPG) at 24 to 28 weeks’ gestation can identify women in resource-constrained areas who might need a 75 gram oral glucose tolerance test (OGTT), according to a study published online ahead of print March 27 in Diabetes Care. Using a FPG value of 4.4 mmol/L as the cutoff point could eliminate the need for approximately one-half of the OGTTs required in China, the authors say. The medical records of 24,854 pregnant women who underwent a 75 gram two-hour OGTT between 24 and 28 weeks of gestation (May 2011 through February 2012) at multiple hospitals throughout China were analyzed. Venous plasma glucose values were measured at zero (fasting), one, and two hours after the 75 gram glucose load. The researchers found that the GDM diagnosis rate increased with rising FPG values. At values greater than 5.1 mmol/L, all 3,149 women with GDM (12.1 percent) were identified. An FPG cutoff value of 4.4 mmol/L ruled out GDM in 15,369 women (38.2 percent) and diagnosed 87.8 percent of women with GDM (specificity of 0.458). Using the cutoffs of 4.4 mmol/L and 5.1 mmol/L to determine who should have the […]
A simple screening test for gestational diabetes mellitus (GDM) based on fasting plasma glucose (FPG) at 24 to 28 weeks’ gestation can identify women in resource-constrained areas who might need a 75 gram oral glucose tolerance test (OGTT), according to a study published online ahead of print March 27 in Diabetes Care. Using a FPG value of 4.4 mmol/L as the cutoff point could eliminate the need for approximately one-half of the OGTTs required in China, the authors say.
The medical records of 24,854 pregnant women who underwent a 75 gram two-hour OGTT between 24 and 28 weeks of gestation (May 2011 through February 2012) at multiple hospitals throughout China were analyzed. Venous plasma glucose values were measured at zero (fasting), one, and two hours after the 75 gram glucose load.
The researchers found that the GDM diagnosis rate increased with rising FPG values. At values greater than 5.1 mmol/L, all 3,149 women with GDM (12.1 percent) were identified. An FPG cutoff value of 4.4 mmol/L ruled out GDM in 15,369 women (38.2 percent) and diagnosed 87.8 percent of women with GDM (specificity of 0.458). Using the cutoffs of 4.4 mmol/L and 5.1 mmol/L to determine who should have the 75 gram OGTT, there is the probability that 12.2 percent of patients with GDM may be missed.
“Women with FPG values between 4.4 and 5.1 mmol/L require a 75-g 2-h OGTT to confirm or rule out GDM,” write the authors, led by Wei-Wei Zhu, M.D., from Peking University First Hospital in China. “This strategy will reduce the number of OGTTs by about half (50.3 percent).”
The authors caution that these conclusions are based on data entirely from the Chinese population but say United Arab Emirates studies also suggest the same cutoff points.
