Long-term weight loss maintenance with obesity pharmacotherapy: A retrospective cohort study.

Objective: To determine the association of anti-obesity medications (AOMs) with weight loss maintenance over 2 years.

Methods: This is a retrospective observational cohort study of adults treated for obesity between 1 April 2014 and 1 April 2016 at a tertiary academic weight management center and who completed 2 years of follow-up. Main outcome measures were mean percent weight loss, percent of individuals who achieved clinically significant long-term weight loss (≥5% weight loss over 2 years), and long-term weight loss maintenance (achievement of ≥5% weight loss at 1 year and maintenance of the ≥5% reduction for the second year).

Results: Of the 1566 new patients, 421 completed 1- and 2-year follow-up appointments. Patients were mostly female and on average 51 years old; they weighed 100.1 kg and had a BMI of 35.8 kg/m at initial visit. Mean weight losses at 1 and 2 years were 10.1% and 10.2%, respectively. The proportion of patients who experienced ≥5% weight loss was 75.5% at 1 year and 72.9% at 2 years. Long-term weight loss maintenance was achieved by 65.3% of patients. Almost all (96.2%) were on ≥1 AOM at 2 years, with metformin, phentermine, and topiramate among the most prescribed. AOM usage and older age demonstrated trends toward predicting weight loss maintenance over 2 years.

Conclusions: Long-term weight loss maintenance was observed among adults with medically managed obesity who completed 2 years of follow-up.