Electrocardiographic and other clinical correlates of walking ability in older women Sara Mutikainen a, *, Taina Rantanen a,b , Markku Ale ´n a,c,d , Markku Kauppinen b , Jouko Karjalainen e , Alfredo Ortega-Alonso a,b , Jaakko Kaprio f,g,h , Urho M. Kujala a a Department of Health Sciences, University of Jyva ¨skyla ¨, PO Box 35 (Viveca), FIN-40014 University of Jyva ¨skyla ¨, Finland b Finnish Center for Interdisciplinary Gerontology, University of Jyva ¨skyla ¨, PO Box 35 (Viveca), FIN-40014 University of Jyva ¨skyla ¨, Finland c Department of Medical Rehabilitation, Oulu University Hospital, PO Box 25, FIN-90029 Oulu University Hospital, Finland d Institute of Health Sciences, University of Oulu, PO Box 25, FIN-90029 Oulu University Hospital, Finland e Unit for Sports and Exercise Medicine, University of Helsinki, Paasikivenkatu 4, FIN-00250 Helsinki, Finland f Department of Public Health, University of Helsinki, PO Box 41, FIN-00014 Helsinki, Finland g National Institute for Health and Welfare, PO Box 30, FIN-00271 Helsinki, Finland h Institute for Molecular Medicine Finland FIMM, PO Box 20, FIN-00014 University of Helsinki, Finland 1. Introduction Ability to walk several hundreds of meters in a reasonable time is a significant factor for maintaining independence in old age. The inability to walk 400 m is associated with increased risk for persistent mobility limitation and/or mobility disability, thereby increasing the risk of losing independence. Decreased walking ability is also associated with increased risk for mortality (Newman et al., 2006). The six-minute walking test is a reliable and valid method to estimate functional exercise capacity and walking ability in older persons (Solway et al., 2001). Many factors are known to be associated with the results of this test. In our population of older women genetic factors explained about 20% of the variability in six-minute walking distance (Ortega-Alonso et al., 2006). According to population-based studies, reduced six-minute walk- ing distance is associated with increasing age (Lord and Menz, 2002; Enright et al., 2003) and BMI (Hulens et al., 2003), female gender (Camarri et al., 2006), shorter height (Camarri et al., 2006) and presence of several chronic diseases, such as heart failure (Bittner et al., 1993) and stroke (Eng et al., 2002). Six-minute walking distance can be improved by increasing physical activity (Hulens et al., 2003) and lower limb muscle strength (Lord and Menz, 2002; Hulens et al., 2003). Until now, the association between electrocardiographic (ECG) variables and walking ability in a non-clinical, older population has been unknown. Although a person does not have an overt, diagnosed cardiac disease, ECG can reveal negative asymptomatic changes in cardiac function, which may be associated with decreased exercise capacity and walking ability. In addition, aging can cause changes in ECG variables (e.g., T wave changes, left axis deviation) (Yasumura and Shibata, 1989), which are partly similar as those caused by cardiac diseases and thus the ECG variables in older people may be associated with decreased exercise capacity Archives of Gerontology and Geriatrics 51 (2010) 216–221 ARTICLE INFO Article history: Received 11 May 2009 Received in revised form 20 October 2009 Accepted 26 October 2009 Available online 24 November 2009 Keywords: Walking ability Electrocardiography in aging subjects Clinical examination ABSTRACT The purpose of this study was to examine how resting electrocardiographic (ECG) and other clinical variables, which can be included in a routine clinical examination, predict walking ability in older women. Three hundred and twenty women (63–75 years) without overt cardiac diseases and apparent mobility limitations were studied. Measurements performed were clinical examination (standard 12- lead resting ECG, assessment of physical activity level, presence of chronic diseases, use of beta-blockers, body mass index (BMI), ability to squat, resting blood pressure) and six-minute walking test. Participants walked 533  75 m in the six-minute walking test. The best electrocardiographic predictors of long walking distance were high TV 5 and TII, but their explanation rates were small (4.5% and 3.8%, respectively). In hypertensive participants (systolic blood pressure = SBP  160 mmHg), the respective values were 9.3% and 5.8%. The best predictors of long walking distance were ability to squat without limitations and low BMI (15.5% and 13.6%, respectively). Altogether the studied variables explained 36% of the variation in walking distance. The data gathered in clinical examination give useful information for the assessment of walking ability in relatively healthy older women. Resting ECG does not give clinically significant additional information for the assessment in subjects without overt cardiac disease. ß 2009 Elsevier Ireland Ltd. All rights reserved. * Corresponding author. Tel.: +358 14 260 4594; fax: +358 14 260 4600. E-mail address: sara.mutikainen@gmail.com (S. Mutikainen). Contents lists available at ScienceDirect Archives of Gerontology and Geriatrics journal homepage: www.elsevier.com/locate/archger 0167-4943/$ – see front matter ß 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.archger.2009.10.011