Glycaemic control of Asian patients with type-2 diabetes mellitus on tiered up-titration of metformin monotherapy: A one-year real-world retrospective longitudinal study in primary care

Aims: To determine the glycaemic control and associated factors among patients with type-2 diabetes mellitus on tiered metformin monotherapy over one-year. Methods: Adult Asian patients on metformin monotherapy with tiered dosage up-titration (low < 500 mg/day; medium 500-< 1000 mg/day and high >= 1000 mg/day) are divided into four sub-cohorts based on their baseline HbA1c < 7%(C-< 7); 7%-< 8%(C7-< 8); 8%-< 9%(C8-< 9) and >= 9%(C->= 9). The HbA1c absolute reduction, time to reach glycaemic control (HbA1c < 7%), and time from glycaemic control to failure (HbA1c >= 7%) after the dosage up-titration were the outcomes. Results: Among 5503 eligible patients (mean age = 64.9 years, 45.6% males and 74.6% Chinese), the HbA1c absolute reduction after the up-titration at three months are 0%, 0.4%-0.6%, 0.8%-1.2% and 2.0%-2.1% for C-< 7, C7-< 8, C8-< 9 and C->= 9 respectively. The median time (months) to attain glycaemic control for low, medium and high dosage up-titration were 4, 3, 3(C7-< 8); 12, 7, 4(C8-< 9); NA, 7, 7(C->= 9). Within twelve months after the goal attainment, 36.2%(C-< 7), 48.8%(C7-< 8), 52.7%(C8-< 9) and 45.3%(C->= 9) of patients had treatment failure. Conclusions: The results show that the baseline HbA1c and tiered metformin dosage up-titration are associated with disproportionate HbA1c reduction, time to glycaemic control and time from glycaemic control to failure.