In youth with impaired glucose tolerance (IGT) or recently diagnosed type 2 diabetes (T2D), neither 3 months of glargine followed by 9 months of metformin nor 12 months of metformin alone slowed the progressive deterioration of β-cell function, a recent study found. 91 pubertal, overweight/obese youth aged 10-19 years with IGT (60%) or T2D of <6 months duration (40%) were randomized to either 3 months of insulin glargine with a target glucose of 4.4-5.0 mmol/L followed by 9 months of metformin or to 12 months of metformin alone. Researchers found:

• No significant differences were found between treatment groups as baseline, 12 months, or 15 months in β-cell function, body mass index (BMI) percentile, HbA1c fasting glucose, or oral glucose tolerance test 2-h glucose results.
• In both treatment groups, clamp-measured β-cell function was significantly lower at 12 and 15 months vs baseline.
• HbA1c fell transiently at 6 months within both groups.
• BMI was higher in the glargine followed by metformin vs metformin alone group between 3-9 months.