Diagnostic accuracy of oral glucose tolerance tests, fasting plasma glucose and haemoglobin A1c for type 2 diabetes in women with polycystic ovary syndrome: A systematic review and meta-analysis.

Aims: To inform international guidelines, a systematic review and meta-analysis was conducted to assess the performance of diagnostic methods for type 2 diabetes in women with polycystic ovary syndrome (PCOS).
Methods: An updated systematic search was conducted on five databases from 2017 until October 2023 and combined with prior searches (from inception). Meta-analyses of diagnostic accuracy tests were conducted.
Results: Nine studies comprising 2628 women with PCOS were included. Against the oral glucose tolerance test, a haemoglobin A1C (HbA1c) ≥ 6.5% had a pooled sensitivity of 50.00% (95% confidence interval (CI): 35.53-64.47), specificity of 99.86% (95%CI: 99.49-99.98), and positive and negative predictive values of 92.59% (95%CI: 75.27-98.09) and 98.27% (95%CI: 97.73-98.68), respectively, with an accuracy of 98.17% (95%CI: 97.34-98.79). Fasting plasma glucose values ≥ 7.0 mmol/L had a pooled sensitivity of 58.14% (95%CI: 42.13-72.99), specificity of 92.59% (95%CI: 75.35-98.08), positive and negative predictive values of 92.59% (95%CI: 75.35-98.08) and 99.09% (95%CI: 98.71-99.36), respectively, and an accuracy of 99.00% (95%CI: 98.46-99.39) against the oral glucose tolerance test.
Conclusions: To our knowledge, this is the first systematic review assessing the performance of diagnostic methods for type 2 diabetes in women with PCOS. We demonstrate that using a cut-off for HbA1c of ≥6.5% in this population may result in misdiagnosis of half of the women with type 2 diabetes. Our results directly informed the recommendations of the 2023 International PCOS Guideline, suggesting that the oral glucose tolerance test is the optimal method for screening and diagnosing type 2 diabetes in women with PCOS and is superior to fasting plasma glucose and HbA1c.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Aya Mousa and Helena Teede are financially supported by fellowships from the Australian National Health and Medical Research Council (NHMRC). Joop Laven received grants from Ferring, Merck, Roche Diagnostics and AnshLabs and received consultancy honoraria from Ferring, Gedeon Richter and Roche Diagnostics. All other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024. Published by Elsevier Ltd.)