GLP1R and type 2 diabetes mellitus: in patients with T2DM (38) found that continuous GLP-1 administration via a subcutaneous pump to raise serum GLP-1 levels from a mean of 9.7 pM at baseline to 282 pM over 6 weeks significantly reduced plasma glucose concentrations, improved glycated hemoglobin, and enhanced insulin sensitivity and β-cell function compared to placebo, with no significant limiting side effects reported.