A study confirms a link between blood glucose values below the thresholds for the diagnosis of gestational diabetes, and obstetric and neonatal complications in Mediterranean women
A worldwide study conducted in pregnant women and which included only patients from Northern Europe (the HAPO study) revealed that blood glucose levels below the diagnostic thresholds for gestational diabetes are associated with an increased risk of hypertension during pregnancy, preterm birth, non-elective caesarean, macrosomia and other obstetric and neonatal complications. For this reason, the International Association of Diabetes and Pregnancy Study Groups (IADSPSG) decided to review the values used in the blood glucose tests routinely performed in pregnant women and to set new standards, reducing the threshold for the diagnosis of gestational diabetes. However, there is no international consensus on the issue. Many Spanish facilities adhere to earlier criteria such as those established by the National Diabetes Data Group (NDDG), which considers levels between 100 and 105 mg/dL and even above 105 mg/dL normal, while the lower diagnostic threshold set by the IADSPSG for gestational diabetes is 92 mg/dL.
Since the incidence of gestational diabetes is 4-5% higher in Mediterranean countries compared to other parts of Europe, the Spanish Diabetes Society recommended expanding studies to the local population in order to determine the adequacy of the values currently used to diagnose gestational diabetes. This prompted a team of researchers led by Dr. Gemma Sesmilo, head of the Department of Endocrinology, Nutrition and Diabetes at Dexeus University Hospital, and the medical team of Dexeus Women's Health decided to conduct a study in Catalonia in order to check whether the findings of the HAPO study also applied to Mediterranean women.
The study included a total of 5,203 women with a singleton pregnancy and a mean age of 33.8 years who underwent glucose testing in their second trimester of pregnancy at Dexeus University Hospital (between 2008 and 2015). Seven fasting blood glucose categories were established for the purpose of the evaluation: 1: < 75 mg/dL, 2: 75–79 mg/dL, 3: 80–84 mg/dL, 4: 85–89 mg/dL, 5: 90–94 mg/dL, 6: 95–99 mg/dL and 7: 100–124 mg/dL.
As previously shown in the HAPO study, the results confirmed a positive correlation between obstetric and neonatal complications, and blood glucose levels below the diagnostic threshold gestational diabetes according to the criteria of the NDDG. The implication is that at-risk patients may not receive nutritional advice nor any kind of treatment during pregnancy. The authors thus recommend that glucose tests be considered a marker of obstetric risk, and that the values set by the NDDG, which are used by some facilities in Spain be reviewed. There is also a clear need to weigh the best treatment option in each of the blood glucose (and potential risk) categories established.
La recherche a été faite sur un total de 5 203 femmes enceintes d'un seul fœtus, de 33,8 ans en moyenne, auxquelles on a fait passer le test de glycémie au cours du deuxième trimestre de gestation à l'hôpital universitaire Dexeus (entre 2008 et 2015). Pour l'évaluation, sept catégories de glucose à jeun ont été établies : 1 : < 75 mg/dl, 2 : 75-79 mg/dl, 3 : 80-84 mg/dl, 4 : 85-89 mg/dl, 5 : 90-94 mg/dl, 6 : 95-99 mg/dl et 7 : 100-124 mg/dl.
Maternal fasting glycemia and adverse pregnancy outcomes in a Mediterranean population
Sesmilo G, Meler E, Perea V, Rodríguez I, Rodríguez-Melcón A, Guerrero M, Serra B.
Acta Diabetol. 2017 Mar;54(3):293-299. doi: 10.1007/s00592-016-0952-z. Epub 2017 Jan 3.