Insights from basic adjunctive examinations of GCK-MODY, HNF1A-MODY, and type 2 diabetes: A systemic review and meta-analysis

Background: Glucokinase maturity-onset diabetes of the young (GCK-MODY) is difficult to distinguish from other diabetic forms. This article aims to characterize the differences in results from routine examinations between GCK-MODY and hepatocyte nuclear factor 1-α (HNF1A)-MODY or type 2 diabetes (T2D) patients in different periods of diabetes.

Methods: Ovid Medline, Embase, and the Cochrane Library were searched up until October 9, 2022 for articles containing baseline characteristics of GCK-MODY, HNF1A-MOFY, and T2D, excluding pregnant women. The pooled standardized mean differences were derived using a random-effects model.

Results: Compared to HNF1A-MODY, GCK-MODY patients had lower indicators of glucose metabolism. Total triglycerides (TG) (-0.93 [-1.66, -0.21] mmol/l) were consistently lower in GCK-MODY patients in the all-family-members subgroup analysis. Compared to T2D, GCK-MODY patients were younger at diagnosis and had lower body mass index (BMI), lower high-sensitivity C-reactive protein (hsCRP) (-0.60 [-0.75, -0.44] mg/l), lower fasting C-peptide (FCP), and lower 2-hour postprandial glucose (2-h PG). Indicators of glycated hemoglobin (HbA1c) and fasting blood glucose (FPG) were consistently lower in subgroup studies with all family members of GCK-MODY patients as well.

Conclusions: Lower HbA1c, FPG, 2-h PG, and change in 2-h PG may help to diagnose GCK-MODY differentially from HNF1A-MODY at an early stage, and lower TG may strengthen such a diagnosis in the follow-up stages. Younger age combined with lower BMI, FCP, hsCRP, and 2-h PG may be useful to distinguish GCK-MODY from MODY-like T2D, whereas results of glucose metabolism indicators such as HbA1c and FPG may not help physicians until after a long follow-up period.