Body Mass Index and Waist Circumference as Predictors of Disability in Nonagenarians: The Vitality 90+ Study.
BACKGROUND
Only scarce data exist on the association between obesity and disability in the oldest old. The purpose of this prospective study is to examine if body mass index and waist circumference (WC) are associated with incident mobility and activities of daily living (ADL) disability in nonagenarians.


METHODS
We used longitudinal data from the Vitality 90+ Study, which is a population-based study conducted at the area of Tampere, Finland. Altogether 291 women and 134 men, aged 90-91 years, had measured data on body mass index and/or WC and did not have self-reported mobility or ADL disability at baseline. Incident mobility and ADL disability was followed-up on median 3.6 years (range 0.6-7.8 years). Mortality was also followed-up. Multinomial logistic regression models were used for the analyses, as death was treated as an alternative outcome. The follow-up time was taken into account in the analyses.


RESULTS
Neither low or high body mass index, nor low or high WC, were associated with incident mobility disability. In women, the lowest WC tertile (<82 cm) was associated with an increased probability of incident ADL disability when compared to the middle WC tertile (odds ratio 3.98, 95% CI 1.35-11.77).


CONCLUSIONS
Obesity is not associated with incident mobility or ADL disability in nonagenarians. Instead, low WC is associated with an increased risk of developing ADL disability in nonagenarian women.
Faculty of Social Sciences, University of Tampere, Finland.|Gerontology Research Center, University of Tampere and University of Jyväskylä, Finland.|Faculty of Sport and Health Sciences, University of Jyväskylä, Finland.
Inna
I
Lisko
Faculty of Social Sciences, University of Tampere, Finland.|Gerontology Research Center, University of Tampere and University of Jyväskylä, Finland.
Kristina
K
Tiainen
Faculty of Social Sciences, University of Tampere, Finland.|Gerontology Research Center, University of Tampere and University of Jyväskylä, Finland.|The UKK Institute for Health Promotion Research, Tampere, Finland.
Jani
J
Raitanen
Gerontology Research Center, University of Tampere and University of Jyväskylä, Finland.|Faculty of Medicine and Life Sciences, University of Tampere, Finland.|Center of Laboratory Medicine, Tampere University Hospital, Finland.
Juulia
J
Jylhävä
Gerontology Research Center, University of Tampere and University of Jyväskylä, Finland.|Faculty of Medicine and Life Sciences, University of Tampere, Finland.|Center of Laboratory Medicine, Tampere University Hospital, Finland.
Mikko
M
Hurme
Faculty of Social Sciences, University of Tampere, Finland.|Gerontology Research Center, University of Tampere and University of Jyväskylä, Finland.
Antti
A
Hervonen
Faculty of Social Sciences, University of Tampere, Finland.|Gerontology Research Center, University of Tampere and University of Jyväskylä, Finland.
Marja
M
Jylhä
Faculty of Social Sciences, University of Tampere, Finland.|Gerontology Research Center, University of Tampere and University of Jyväskylä, Finland.|Department of Public Health, University of Turku and Turku University Hospital, Finland.
Sari
S
Stenholm
D000203:Activities of Daily Living; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015992:Body Mass Index; D004185:Disability Evaluation; D006233:Persons with Disabilities; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D009765:Obesity / Q000175:diagnosis* / Q000453:epidemiology / Q000534:rehabilitation; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D055105:Waist Circumference
Disability; Mobility; Obesity; Obesity paradox; Oldest old; Physical function