The function of oral glucose tolerance test protocols in diagnosing and managing gestational diabetes: can insulin requirements be predicted?

Year 2025, Volume: 8 Issue: 2, 325 - 332, 21.03.2025

Gizem Aktemur , Betül Tokgöz Çakır , Gülşan Karabay , Nazan Vanlı Tonyalı , Zeynep Şeyhanlı , Ahmet Arif Filiz , Mevlüt Bucak , Damla Gürkan , Ali Çağlar

Abstract

Aims: This study aims to evaluate the effectiveness of diagnostic tests, clinical, and laboratory markers in predicting insulin requirements in pregnant women diagnosed with gestational diabetes mellitus (GDM). Additionally, we assessed differences in maternal and neonatal outcomes between insulin-managed and diet-managed GDM patients.
Methods: A retrospective analysis was conducted on 406 pregnant women diagnosed with GDM at Ankara Etlik City Hospital between October 2022 and December 2024. Patients were categorized based on the diagnostic method used: the one-step 75 g oral glucose tolerance test (OGTT) or the two-step 100 g OGTT following a 50 g OGTT. Clinical, laboratory, and demographic data were compared between insulin-treated and diet-controlled groups. The predictive capacity of fasting plasma glucose (FPG), glucose levels at 1st, 2nd, and 3rd hours during OGTT, and HbA1c for insulin requirement were assessed using receiver operating characteristic (ROC) analysis.
Results: In the 75 g OGTT group, fasting, 1st-hour, and 2nd-hour glucose levels were significantly higher in the insulin-requiring group (p<0.001). ROC analysis indicated that fasting glucose >92 mg/dl and 2nd hour glucose >160 mg/dl were predictive of insulin requirement. HbA1c >5.25% was also a significant predictor (p=0.009). However, in the 100 g OGTT group, only the 2nd hour glucose level (>169 mg/dl, p=0.032) was predictive of insulin need, while HbA1c was not statistically significant. Birth outcomes showed that insulin-treated patients had an earlier gestational age at delivery (p=0.001), but neonatal outcomes were not significantly different between insulin-treated and diet-managed groups.
Conclusion: The findings suggest that glucose levels and HbA1c in the 75 g OGTT group are more effective in predicting insulin requirements in GDM patients than the 100 g OGTT. The study underscores the importance of identifying predictive markers for early intervention, potentially guiding clinicians in selecting optimal diagnostic methods and improving patient outcomes.

Keywords

Gestational diabetes mellitus, OGTT, insulin therapy, HbA1c, predictive markers, pregnancy outcomes

Oral glukoz tolerans testi protokollerinin gestasyonel diyabetin tanı ve yönetimindeki rolü: insülin gereksinimi öngörülebilir mi?

Abstract

Amaç: Gestasyonel diyabetes mellitus (GDM), maternal ve fetal sonuçları olumsuz etkileyebilen önemli bir gebelik komplikasyonudur. GDM tanısında kullanılan farklı oral glukoz tolerans testi (OGTT) protokollerinin, insülin ihtiyacını öngörmedeki etkinliğinin değerlendirilmesi önemlidir. Bu çalışmada, GDM tanısı alan gebelerde insülin gereksinimini belirlemede kullanılan tanı testleri, klinik ve laboratuvar parametrelerinin rolü incelenmiştir.
Yöntemler: Çalışmaya 406 GDM tanılı gebe dahil edilerek retrospektif analiz gerçekleştirilmiştir. Hastalar, 75 gr OGTT ile tanı konulanlar ve 100 gr OGTT ile tanı konulanlar olarak iki gruba ayrılmıştır. Demografik, klinik ve laboratuvar veriler karşılaştırılarak insülin gereksinimi ile ilişkili parametreler belirlenmiştir. ROC analizi ile insülin ihtiyacını öngörmede en iyi eşik değerler hesaplanmıştır.
Bulgular: 75 gr OGTT ile değerlendirilen hastalarda açlık ve postprandiyal glukoz seviyeleri ile HbA1c düzeyleri, insülin gereksinimini öngörmede anlamlı bulunmuştur (p<0.001). Özellikle 2. saat glukoz seviyesi (>160 mg/dL), insülin ihtiyacını belirlemede yüksek özgüllük ve duyarlılık göstermiştir. 100 gr OGTT ile değerlendirilen hastalarda insülin ihtiyacını öngörmede anlamlı bir fark bulunmamıştır. İnsülin kullanan gebelerde doğum haftasının daha erken olduğu ve erkek bebek doğurma olasılığının daha yüksek olduğu gözlemlenmiştir (p<0.05). Ancak neonatal yoğun bakım ünitesi (NICU) yatış oranları açısından iki grup arasında anlamlı bir fark saptanmamıştır.
Sonuç: 75 gr OGTT ile elde edilen glukoz seviyeleri ve HbA1c düzeyleri, insülin ihtiyacını öngörmede önemli belirteçler olarak öne çıkmaktadır. Tek basamaklı test, klinik karar verme sürecini kolaylaştırabilir ve maliyet etkin bir yaklaşım sağlayabilir.

Keywords

Gestasyonel diyabet, OGTT, insülin ihtiyacı, glukoz tolerans testi, perinatal sonuçlar.

References

• American Diabetes Association Professional Practice Committee. 2. Classification and diagnosis of diabetes: standards of medical care in diabetes-2022. Diabetes Care. 2022;45(Suppl 1):S17-S38. doi:10.2337/dc22-S002
• Cundy T, Ackermann E, Ryan EA. Gestational diabetes: new criteria may triple the prevalence but effect on outcomes is unclear. BMJ. 2014; 348:g1567. doi:10.1136/bmj.g1567
• Frequency of gestational diabetes mellitus at collaborating centers based on iadpsg consensus panel-recommended criteria |diabetes care| American Diabetes Association. Accessed January 27, 2025. https://diabetesjournals.org/care/article/35/3/526/28610/Frequency-of-Gestational-Diabetes-Mellitus-at
• Bellamy L, Casas JP, Hingorani AD, Williams D. Type 2 diabetes mellitus after gestational diabetes: a systematic review and meta-analysis. Lancet. 2009;373(9677):1773-1779. doi:10.1016/S0140-6736(09)60731-5
• Kramer CK, Campbell S, Retnakaran R. Gestational diabetes and the risk of cardiovascular disease in women: a systematic review and meta-analysis. Diabetologia. 2019;62(6):905-914. doi:10.1007/s00125-019-4840-2
• Gestational diabetes mellitus and renal function: a prospective study with 9- to 16-year follow-up after pregnancy |diabetes care| American Diabetes Association. Accessed January 27, 2025. https://diabetesjournals.org/care/article/41/7/1378/36429/Gestational-Diabetes-Mellitus-and-Renal-Function-A
• Metabolic syndrome in childhood: association with birth weight, maternal obesity, and gestational diabetes mellitus |pediatrics| American Academy of Pediatrics. Accessed January 27, 2025. https://publications.aap.org/pediatrics/article-abstract/115/3/e290/67224/Metabolic-Syndrome-in-Childhood-Association-With
• Billionnet C, Mitanchez D, Weill A, et al. Gestational diabetes and adverse perinatal outcomes from 716,152 births in France in 2012. Diabetologia. 2017;60(4):636-644. doi:10.1007/s00125-017-4206-6
• Cheng YKY, Lao TT, Sahota DS, Leung VKT, Leung TY. Use of birth weight threshold for macrosomia to identify fetuses at risk of shoulder dystocia among Chinese populations. Int J Gynecol Obstetr. 2013;120(3): 249-253. doi:10.1016/j.ijgo.2012.10.019
• Neonatal hypoglycemia following diet-controlled and insulin-treated gestational diabetes mellitus |diabetes care| American Diabetes Association. Accessed January 27, 2025. https://diabetesjournals.org/care/article/41/7/1385/36453/Neonatal-Hypoglycemia-Following-Diet-Controlled
• Ford HL, Champion I, Wan A, Reddy M, Mol BW, Rolnik DL. Predictors for insulin use in gestational diabetes mellitus. Eur J Obstetr Gynecol Reproduct Biol. 2022;272:177-181. doi:10.1016/j.ejogrb.2022.03.025
• Insulin therapy and fetoplacental vascular function in gestational diabetes mellitus-Sobrevia-2015-experimental physiology-Wiley Online Library. Accessed January 27, 2025. https://physoc.onlinelibrary.wiley.com/doi/full/10.1113/expphysiol.2014.082743
• Tamagawa M, Kasuga Y, Saisho Y, et al. Predictors of later insulin therapy for gestational diabetes diagnosed in early pregnancy. Endocrine J. 2021;68(11):1321-1328. doi:10.1507/endocrj.EJ21-0118
• Mitra S, Nayak PK, Sahoo J, et al. Predictors for antenatal insulin requirement in gestational diabetes. Gynecol Endocrinol. 2014;30(8):565-568. doi:10.3109/09513590.2014.911274
• Metzger BE, Gabbe SG, Persson B, et al. International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy: response to weinert. Diabetes Care. 2010;33(7):e98. doi:10.2337/dc10-0719
• Huhn EA, Massaro N, Streckeisen S, et al. Fourfold increase in prevalence of gestational diabetes mellitus after adoption of the new International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. J Perinat Med. 2017;45(3):359-366. doi:10.1515/jpm-2016-0099
• Wu ET, Nien FJ, Kuo CH, et al. Diagnosis of more gestational diabetes lead to better pregnancy outcomes: Comparing the International Association of the Diabetes and Pregnancy Study Group criteria, and the Carpenter and Coustan criteria. J Diabet Investigat. 2016;7(1):121-126. doi:10.1111/jdi.12378
• Duran A, Sáenz S, Torrejón MJ, et al. Introduction of IADPSG criteria for the screening and diagnosis of gestational diabetes mellitus results in improved pregnancy outcomes at a lower cost in a large cohort of pregnant women: the St. Carlos gestational diabetes study. Diabetes Care. 2014;37(9):2442-2450. doi:10.2337/dc14-0179
• Feldman RK, Tieu RS, Yasumura L. Gestational diabetes screening: the International Association of the Diabetes and Pregnancy Study Groups compared with Carpenter-Coustan screening. Obstetr Gynecol. 2016; 127(1):10. doi:10.1097/AOG.0000000000001132
• ACOG clinical practice update: screening for gestational and pregestational diabetes in pregnancy and postpartum. Obstetri Gynecol. 2024;144(1): e20. doi:10.1097/AOG.0000000000005612
• American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care. 2013;36(Suppl 1):S67-S74. doi:10.2337/dc13-S067
• Standards of Medical Care in Diabetes-2014 |diabetes care| American Diabetes Association. Accessed January 29, 2025. https://diabetesjournals. org/care/article/37/Supplement_1/S14/37696/Standards-of-Medical-Care-in-Diabetes-2014
• Çelik Ö. Gestasyonel diyabet tanı ve tedavisi. Klin Tıp Bil. 2019;7(3):24-27.
• Milosevic D, Panin VL. Relationship between hematological parameters and glycemic control in type 2 diabetes mellitus patients. J Med Biochem. 2019;38(2):164-171. doi:10.2478/jomb-2018-0021
• Demirtas L, Degirmenci H, Akbas EM, et al. Association of hematological indicies with diabetes, impaired glucose regulation and microvascular complications of diabetes. Int J Clin Exp Med. 2015;8(7):11420-11427.
• Jindal S, Gupta S, Gupta R, et al. Platelet indices in diabetes mellitus: indicators of diabetic microvascular complications. Hematology. 2011; 16(2):86-89. doi:10.1179/102453311X12902908412110
• Mandić-Marković V, Dobrijević Z, Robajac D, et al. Biochemical markers in the prediction of pregnancy outcome in gestational diabetes mellitus. Medicina (Kaunas). 2024;60(8):1250. doi:10.3390/medicina60081250
• Xiang LL, Chen C, Wang QY, Zhu YT, Chen YJ, Zeng Y. Impact of inflammatory factors, hemoglobin A1c, and platelet parameters in gestational diabetes mellitus. Arch Gynecol Obstet. 2023;307(2):439-446. doi:10.1007/s00404-022-06528-x
• Tonguc M, Tayyar AT, Muderris I, Bayram F, Muhtaroglu S, Tayyar M. An evaluation of two different screening criteria in gestational diabetes mellitus. J Matern Fetal Neonatal Med. 2018;31(9):1188-1193. doi:10.1080/ 14767058.2017.1311858
• Olagbuji BN, Atiba AS, Olofinbiyi BA, et al. Prevalence of and risk factors for gestational diabetes using 1999, 2013 WHO and IADPSG criteria upon implementation of a universal one-step screening and diagnostic strategy in a sub-Saharan African population. Eur J Obstet Gynecol Reprod Biol. 2015;189:27-32. doi:10.1016/j.ejogrb.2015.02.030
• Helseth R, Salvesen O, Stafne SN, Mørkved S, Salvesen KA, Carlsen SM. Gestational diabetes mellitus among Nordic Caucasian women: prevalence and risk factors according to WHO and simplified IADPSG criteria. Scand J Clin Lab Invest. 2014;74(7):620-628. doi:10.3109/00365513.2014.928942
• Can Common Clinical Parameters Be Used to identify patients who will need insulin treatment in gestational diabetes mellitus? |Diabetes care| American Diabetes Association. Accessed January 29, 2025. https://diabetesjournals.org/care/article/34/10/2214/27027/Can-Common-Clinical-Parameters-Be-Used-to-Identify
• Yanagisawa K, Muraoka M, Takagi K, et al. Assessment of predictors of insulin therapy in patients with gestational diabetes diagnosed according to the IADPSG criteria. Diabetol Int. 2016;7(4):440-446. doi: 10.1007/s13340-016-0272-0
• Coustan DR, Lowe LP, Metzger BE, Dyer AR, International Association of Diabetes and Pregnancy Study Groups. The hyperglycemia and adverse pregnancy outcome (HAPO) study: paving the way for new diagnostic criteria for gestational diabetes mellitus. Am J Obstet Gynecol. 2010;202(6):654.e1-6. doi:10.1016/j.ajog.2010.04.006
• Li KT, Naik S, Alexander M, Mathad JS. Screening and diagnosis of gestational diabetes in India: a systematic review and meta-analysis. Acta Diabetol. 2018;55(6):613-625. doi:10.1007/s00592-018-1131-1
• Saeedi M, Cao Y, Fadl H, Gustafson H, Simmons D. Increasing prevalence of gestational diabetes mellitus when implementing the IADPSG criteria: a systematic review and meta-analysis. Diabetes Res Clin Pract. 2021;172:108642. doi:10.1016/j.diabres.2020.108642
• Sina M, Cade TJ, Flack J, et al. Antenatal models of care for women with gestational diabetes mellitus: vignettes from an international meeting. Austral New Zealand J Obstetr Gynaecol. 2020;60(5):720-728. doi:10. 1111/ajo.13144