Independent Weight Loss Maintenance for Communities With Arthritis in North Carolina: the I-CAN Clinical Trial

Results from the Intensive Diet and Exercise for Arthritis (IDEA) trial showed that 10%
diet-induced weight loss combined with exercise (D+E) was twice as effective at relieving
knee pain and improving function and mobility as previous long-term weight loss and exercise
programs in similar cohorts. The treatment effects of D+E on these clinical outcomes were
mediated by changes in self-efficacy over the course of the trial. However, most people tend
to regain most or all of the lost weight in three to five years. The challenge is maintaining
the weight loss and sustaining the efficacy of the intervention.

Our current trial (WE-CAN) is designed to adapt the successful IDEA intervention to
real-world clinical and community settings. As WE-CAN participants in the D+E group complete
their intervention, the investigators will leverage our organizational infrastructure to
maintain weight-loss without supervised intervention by increasing participant confidence to
establish and adhere to a routine of good exercise and diet behaviors independently.

Participants will include 212 older adults aged ≥ 51 yrs. with knee osteoarthritis (OA) who
achieved a weight loss ≥ 5% in the D+E intervention arm of the WE-CAN trial. All WE-CAN
participants meet the ACR clinical criteria for knee OA, which includes knee pain on most
days of the week plus at least three of the following six: age ≥ 50 years, stiffness < 30
min/day, crepitus, bony tenderness, bony enlargement, and/or no palpable warmth. Eligible
WE-CAN D+E participants will be randomized to either 6-month facilitated weight-loss
maintenance or health education control interventions. The primary aim is to compare the
effects of a 6-month weight-loss maintenance intervention grounded in social cognitive theory
to a health education intervention on maintaining weight loss subsequent to a 12-month
unsupervised follow-up period. Secondary aims will compare the two interventions on WOMAC
knee pain and function, health-related quality of life (SF-36), 6-minute walk distance, and
weight-loss maintenance self-efficacy following the 12-month unsupervised period. The study
team will also establish the cost-effectiveness of a 6-month facilitated weight-loss
maintenance intervention for older adults with knee OA by conducting cost-effectiveness and
budgetary impact analyses using data from the current trial in a validated computer-simulated
model of knee OA.

There have been numerous attempts to prevent weight regain in adults. This study is
significant in that it is designed to encourage older adults with knee OA that have
experienced significant weight loss to develop strategies that will build self-efficacy for
maintaining weight loss on their own long after the active intervention ends.

Inclusion Criteria:

- age ≥ 51

- achieved a weight loss ≥ 5% in the D+E intervention arm of the WE-CAN trial

Exclusion Criteria:

- Weight loss < 5% of baseline body weight

- Significant co-morbid disease that would threaten safety or impair ability to
participate in interventions or testing (Blindness; Type 1 diabetes; Severe coronary
artery disease)

- Inability to finish 18-month study or unlikely to be compliant (Planning to leave area
> 2 month during the next 18 months)