1. Prevention Research Center, School of Public Health, University of South Carolina, Columbia, SC 29208
2. Department of Health Studies and Gerontology, the University of Waterloo, Waterloo, Ontario, Canada; Centre for Activity and Ageing, the University of Western Ontario, London, Ontario, Canada; St. Joseph's Health Centre, London, Ontario, Canada
3. Lawson Diabetes Centre, the University of Western Ontario, London, Ontario, Canada; St. Joseph's Health Centre, London, Ontario, Canada