A1c

The SURMOUNT-1 trial initially found that patients with obesity taking tirzepatide for 72 weeks lost 15% to 22.5% of their initial weight, on average, depending on the dose, and also saw a significant average reduction in their levels of glycated hemoglobin, known as A1c levels, a standard measure of blood sugar control.

The new study focused on 1,032 of these patients who initially had obesity and prediabetes -- a diabetes precursor condition in which A1c levels are above normal but below the threshold for diabetes.

More than 90% of the patients on tirzepatide had normal A1c levels at 176 weeks, versus 59% of placebo-treated patients.

A follow-up analysis, 17 weeks after stopping treatment, found modest gains in weight and A1c levels, bringing some patients back into the prediabetes and diabetes ranges, and underscoring the likely need for chronic treatment.

A hemoglobin A1c test measures the percentage of HbA1c present relative to the total amount of hemoglobin.