Question special

I'm interested in understanding is there a dose-dependent effect with GLP-1 agonists and glycemic control? This question relates to the one posed by Su-Ann earlier regarding weight loss. Liraglutide is approved up to a dose of 1.8mg for diabetes. Was this dose threshold set at 1.8mg due to side effects? Could we potentially see a further dose-dependent effect on HbA1c if it were titrated up to 3.0mg as was done in this trial? If there's no dose-dependent effect, why is that?