This is a 52 week, single center, open-labeled, randomized controlled trial.
A total of 150 subjects with obesity, who are free of types 1 and 2 diabetes, as well as
contraindications to weight loss, will be randomly assigned to one of three treatment groups:
1) lifestyle counseling, as currently recommended by the Centers for Medicare and Medicaid
Services (CMS) (i.e., CMS-Alone); 2) CMS lifestyle counseling plus liraglutide (i.e.,
CMS-Liraglutide); or 3) CMS-Liraglutide plus a portion-controlled diet (i.e., Multi-Component
Intervention).
Subjects in all three groups will have 14 brief (15 minute) lifestyle counseling visits the
first 24 weeks, followed by monthly visits in weeks 25-52. This is the schedule and duration
of counseling visits recommended by CMS. Counseling sessions will be delivered by a
physician, nurse practitioner or registered dietitian (RD) working in consultation with the
former providers.
Subjects in all three groups also will have brief physician visits at weeks 1, 4, 8, 16, 24,
36, and 52 (total of 7 visits). These visits are needed for subjects in both liraglutide
groups to monitor their response to the medication. These visits are included for subjects in
CMS-Alone to match the intensity of medical care provided the two other groups.
The primary outcome is % reduction in initial body weight, as measured from randomization to
week 52. Secondary outcomes include the proportion of participants who at week 52 lose >5%,
>10%, and >15% of initial weight, as well as % reduction in weight at week 24 and the
proportion of participants who meet the three categorical weight losses at this time. The
secondary efficacy measures include changes (from randomization to week 52) in cardiovascular
disease (CVD) risk factors, glycemic control, mood, quality of life, eating behavior,
appetite, sleep, and satisfaction with weight loss.
Safety endpoints will include physical examination, adverse events (AEs), standard laboratory
tests, and mental health assessed by the Columbia Suicidality Severity Rating Scale (C-SSRS)
and Patient Health Questionnaire (PHQ-9).
Statistical Analysis. Using a sample size equation for longitudinal clustered samples, a
randomization sample of 50 subjects in CMS-Alone, 50 in CMS-Liraglutide, and 50 in the
Multi-Component Intervention provides >80% power to detect the two primary contrasts to be
statistically significant. This estimate allows for 20% attrition during the 52-week trial,
resulting in approximately 40 treatment completers per group. The ITT longitudinal
statistical design will further improve power by allowing the inclusion of available data for
non-completers and the adjustment of possible variance reducing baseline covariates.