BackgroundThe aim of the present study was to investigate whether the therapeutic efficacy of acarbose and metformin is correlated with baseline HbA1c levels in Chinese patients with newly diagnosed type 2 diabetes mellitus (T2DM). MethodsData for 711 subjects were retrieved from the MARCH (Metformin and AcaRbose in Chinese as initial Hypoglycemic treatment) trial database and reviewed retrospectively. Patients were grouped according to baseline HbA1c levels (<7%, 7%-8%, and >8%) and the results for these three groups were compared between acarbose and metformin treatments. ResultsAcarbose and metformin treatment significantly improved T2DM-associated parameters (weight, fasting plasma glucose [FPG], postprandial glucose [PPG], glucagon-like peptide-1 [GLP-1], HOMA-IR, and total cholesterol) across all HbA1c levels. Acarbose decreased PPG and HOMA- significantly more than metformin, but only in subjects with lower baseline HbA1c (PPG in the <7% and 7%-8%, HOMA- in the <7% groups; all P < 0.05). Acarbose decreased triglyceride (TG) levels, and the areas under the curve (AUC) for insulin and glucagon more than metformin at all HbA1c levels (P < 0.05). After 24 weeks treatment, metformin decreased FPG levels significantly more than acarbose for all baseline HbA1c groups (all P < 0.001). With the exception of FPG, PPG, and TG levels, differences between the two treatment groups observed at 24 weeks were not detected at 48 weeks. ConclusionsAcarbose decreased PPG and TG and spared the AUC for insulin more effectively in patients with low-to-moderate baseline HbA1c levels, whereas metformin induced greater reductions in FPG. These results may help guide selection of initial therapy based on baseline HbA1c.