Body Mass Index and Nine-Year Mortality in Disabled and Nondisabled Older U.S. Individuals

Authors

  • Alexander M. Kulminski PhD,

    1. From the *Department of Sociology, Center for Population Health and Aging, Population Research Institute, Duke University, Durham, North CarolinaInstitute of Genetics and Cytology, Belarus Academy of Sciences, Minsk, Belarus.
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  • Konstantin G. Arbeev PhD,

    1. From the *Department of Sociology, Center for Population Health and Aging, Population Research Institute, Duke University, Durham, North CarolinaInstitute of Genetics and Cytology, Belarus Academy of Sciences, Minsk, Belarus.
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  • Irina V. Kulminskaya PhD,

    1. From the *Department of Sociology, Center for Population Health and Aging, Population Research Institute, Duke University, Durham, North CarolinaInstitute of Genetics and Cytology, Belarus Academy of Sciences, Minsk, Belarus.
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  • Svetlana V. Ukraintseva PhD,

    1. From the *Department of Sociology, Center for Population Health and Aging, Population Research Institute, Duke University, Durham, North CarolinaInstitute of Genetics and Cytology, Belarus Academy of Sciences, Minsk, Belarus.
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  • Kenneth Land PhD,

    1. From the *Department of Sociology, Center for Population Health and Aging, Population Research Institute, Duke University, Durham, North CarolinaInstitute of Genetics and Cytology, Belarus Academy of Sciences, Minsk, Belarus.
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  • Igor Akushevich PhD,

    1. From the *Department of Sociology, Center for Population Health and Aging, Population Research Institute, Duke University, Durham, North CarolinaInstitute of Genetics and Cytology, Belarus Academy of Sciences, Minsk, Belarus.
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  • Anatoli I. Yashin PhD

    1. From the *Department of Sociology, Center for Population Health and Aging, Population Research Institute, Duke University, Durham, North CarolinaInstitute of Genetics and Cytology, Belarus Academy of Sciences, Minsk, Belarus.
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Address correspondence to Alexander Kulminski, Center for Population Health and Aging, Duke University, Trent Hall, Room 002, Trent Dr., Box 90408, Durham, NC 27708. E-mail: Alexander.Kulminski@duke.edu

Abstract

OBJECTIVES: To investigate the relationship between body mass index (BMI) and 9-year mortality in older (≥65) Americans with and without disability.

DESIGN: Cohort study.

SETTING: The unique disability-focused National Long Term Care Survey (NLTCS) data that assessed the health and well-being of older individuals in 1994 were analyzed.

PARTICIPANTS: Four thousand seven hundred ninety-one individuals in the 1994 survey.

MEASUREMENTS: BMI (kg/m2) was calculated from self- or proxy reports of height and weight. The analysis was adjusted for 1-year change in BMI and demographic and health-related factors, as well as reports by proxies, and death occurring during the first 2 years after the interview.

RESULTS: The relative risk of death as a function of BMI formed a nonsymmetric U-shaped pattern, with larger risks associated with lower BMI (<22.0) and minimal risks for BMI of 25.0 to 34.9. (BMI 22.0–24.9 was the reference.) Adjustments for demographic and health-related factors had little effect on this pattern. Nondisabled individuals exhibited a similar U-shaped pattern but with lower risks associated with lower BMI. For disabled individuals, the mortality–risk pattern was higher for lower BMI (<22.0) and flat for higher BMI, thus exhibiting an inverse J shape. BMI patterns were age sensitive, with disability status affecting sensitivity.

CONCLUSION: Overweight or mild (grade 1) obesity was not a risk factor for 9-year mortality in older Americans participating in the 1994 NLTCS. A flatter BMI pattern of the relative risk of death for disabled than for nondisabled individuals suggests that optimal body weight can be sensitive to age and health and well-being.

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