Functionality and Mortality in Obese Nursing Home Residents: An Example of ‘Risk Factor Paradox’? Rebecca Kaiser, Katrin Winning, MD, Wolfgang Uter, MD, Dorothee Volkert, PhD, Stephanie Lesser, PhD, Peter Stehle, PhD, Matthias J. Kaiser, MD, Cornel C. Sieber, MD, and Juergen M. Bauer, MD Background: Although the percentage of obese nurs- ing home residents is increasing, few longitudinal studies have reported on functionality and mortality in this subpopulation. The aim of the present study was to explore functionality and mortality in obese nursing home residents during a 1-year follow-up and to compare these results with those of residents within the normal and low BMI range. Methods: Two hundred residents (147 female, 53 male, mean age 85.6  7.8 years) from 2 Nuremberg nursing homes were included. Body weight and height were measured in all participants. BMI was cal- culated and categorized as low ( \ 20 kg/m 2 ), normal (20–30 kg/m 2 ), and high (.30 kg/m 2 ). Handgrip strength, timed ‘‘up and go’’ test, and Barthel’s Activ- ities of Daily Living were applied as functional param- eters. All measurements were done at baseline and after a 1-year follow-up. Results: At baseline, the prevalence of obesity was 23.5%, whereas low BMI values were present in 8.5% of the residents. After 1 year, there was no significant decline of functionality in the obese group, whereas functional parameters deteriorated significantly in study participants with normal BMI. One-year mortal- ity was lowest in the obese (12.8%), with no deaths in residents with BMI of 35 kg/m 2 or higher. Mortality was highest in residents with low BMI (58.8%). Conclusion: In nursing home residents, obesity is asso- ciated with increased survival and stable functional- ity. These observations may therefore be regarded as an expression of ‘‘risk factor paradox’’ in this spe- cific population of older individuals. (J Am Med Dir Assoc 2010; 11: 428–435) Keywords: Obesity; elderly; nursing home; functional- ity; mortality In most Western societies, the prevalence of obesity in older persons has been increasing constantly in past decades. A recent study on newly admitted nursing home residents re- ported that the prevalence of obesity rose from 15% to more than 25% between 1992 and 2002. 1 Bradway et al 2 observed a predominance of studies focusing on community-dwelling obese elderly and a lack of surveys regarding obese nursing home residents. A negative association between body weight and functionality in community-dwelling older persons or newly admitted nursing home residents was found in several studies. 3–11 To our knowledge, corresponding data on nutritional status and functional parameters for nursing home residents have not yet been published and data on mortality in obese nursing home residents are still scarce. The association between high body mass index (BMI) and mortality in older persons in general has been analyzed in nu- merous studies. Although some found an increased risk of mortality among community-living obese elderly compared with those with normal weight, 12,13 other authors observed a decreased mortality risk in those with high BMI 14–16 or at least no increased risk. 17 Data on the relationship between high BMI and mortality in nursing home residents have also been inconsistent. 18,19 As information on functionality and mortality in nursing home residents is highly relevant for the judgment of the level of care that society will have to face in future decades, it is im- portant to provide additional data in this field. The aim of the present study was to explore the association of obesity with functionality and mortality in nursing home residents during a 1-year follow-up. METHODS All residents of 2 communal nursing homes in Nuremberg, Germany, were approached to participate in the present study from June 2007 until December 2008. Residents younger than Department of Geriatric Medicine, University of Erlangen-Nuremberg, Germany (R.K., K.W., D.V., M.J.K., C.C.S., J.M.B.); Department of Medical Informatics, Biometry and Epidemiology, University of Erlangen-Nuremberg, Germany (W.U.); Department of Nutrition and Food Sciences (IEL) - Nutritional Physiology, University of Bonn, Germany (S.L., P.S.). This study was supported by a grant of the Else Kroener-Fresenius-Foundation (Bad Homburg, Germany). Juergen M Bauer was supported by the Robert- Bosch-Foundation fellowship program (Stuttgart, Germany). The authors have no conflicts of interest. Address correspondence to Rebecca Kaiser, Institute for Biomedicine of Aging, University of Erlangen-Nuremberg, Heimerichstr. 58, D-90419 Nurem- berg, Germany. E-mail: Rebecca.Kaiser@aging.med.uni-erlangen.de Copyright Ó2010 American Medical Directors Association DOI:10.1016/j.jamda.2009.10.004 428 Kaiser et al JAMDA – July 2010