Background: Even though lifestyle modifications and pharmacological interventions have been shown to be effective in patients who have impaired glucose tolerance (IGT) , the patients’ responses to lifestyle changes after receiving the diagnosis of IGT in Thai patients are lacking. Therefore, this study aims to determine the weight changes following the diagnosis of IGT and elucidate the patterns of metformin use among Thai patients with IGT.

Methods: A 5-year retrospective study of newly diagnosed Thai patients with IGT in Theptarin Hospital, Bangkok during 2016-2020 was analyzed. Their weight at the last clinical visit was compared with that at the initial visit. The prevalence and characteristics of metformin prescription were also collected.

Results: Two hundred and sixty-six IGT patients (63.9% female, mean age of 51.8 ± 12.5 years, mean body weight 69.8 ± 15.0 kg, and mean body mass index (BMI) of 26.5 ± 4.7 kg/m2) were diagnosed during 2016-2020. The prevalence of metformin usage among these patients was 21.1%. During the median follow-up of months, the mean weight change was -1.0 ± 3.7 kg. A significant weight reduction was found in metformin group compared with control group, (mean weight change of -2.2 ± 4.7 kg vs. -0.7 ± 3.4 kg; p-value =0.006) . Furthermore, up to 26.8% of patients who was prescribed metformin achieved > 5% weight reduction. Metformin was more frequently prescribed in patients who had age ≥ 60 years, BMI ≥ 35 kg/m2, concomitant statin usage, combined impaired fasting glucose (IFG) and IGT, and patients who had A1C ≥ 6.0%.

Conclusions: Weight reduction is minimal among Thai patients who had IGT. More intensive efforts with structured lifestyle programs should be implemented to prevent diabetes. Metformin should be considered if patients are unable or unwilling to lose weight with lifestyle changes.


W. Chatchomchuan: None. Y. Thewjitcharoen: None. H. Prasartkaew: None. E. Wanothayaroj: None. T. Himathongkam: None.

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