Summary of mediation analyses related to intervention, change in fitness, and WOMAC summary score. β (s.e.) adjusted for baseline values of outcome variable, age, gender, race/ethnicity, study site, Beck Depression Inventory Score, use of nonsteroidal anti-inflammatory drugs, and baseline metabolic equivalents (METs). βa, effect of intervention condition on mediator; β, effect of intervention condition on outcome without mediator; β′, effect of intervention condition on outcome with mediator; βb, effect of mediator on outcome; DSE, Diabetes Support and Education; ILI, Intensive Lifestyle Intervention; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index.