Type 2 Diabetes Mellitus and Cognitive Decline in Two Large Cohorts of Community-Dwelling Older Adults

Authors

  • Olivia I. Okereke MD, SM,

    1. From the *Division of AgingChanning LaboratoryDivision of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts§Department of Epidemiology, Harvard Medical School, Boston, MassachusettsVeterans Affairs Boston Healthcare System, Jamaica Plain, Massachusetts.
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  • Jae H. Kang ScD,

    1. From the *Division of AgingChanning LaboratoryDivision of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts§Department of Epidemiology, Harvard Medical School, Boston, MassachusettsVeterans Affairs Boston Healthcare System, Jamaica Plain, Massachusetts.
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  • Nancy R. Cook ScD,

    1. From the *Division of AgingChanning LaboratoryDivision of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts§Department of Epidemiology, Harvard Medical School, Boston, MassachusettsVeterans Affairs Boston Healthcare System, Jamaica Plain, Massachusetts.
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  • J. Michael Gaziano MD,

    1. From the *Division of AgingChanning LaboratoryDivision of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts§Department of Epidemiology, Harvard Medical School, Boston, MassachusettsVeterans Affairs Boston Healthcare System, Jamaica Plain, Massachusetts.
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  • JoAnn E. Manson MD, DrPH,

    1. From the *Division of AgingChanning LaboratoryDivision of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts§Department of Epidemiology, Harvard Medical School, Boston, MassachusettsVeterans Affairs Boston Healthcare System, Jamaica Plain, Massachusetts.
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  • Julie E. Buring ScD,

    1. From the *Division of AgingChanning LaboratoryDivision of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts§Department of Epidemiology, Harvard Medical School, Boston, MassachusettsVeterans Affairs Boston Healthcare System, Jamaica Plain, Massachusetts.
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  • Francine Grodstein ScD

    1. From the *Division of AgingChanning LaboratoryDivision of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts§Department of Epidemiology, Harvard Medical School, Boston, MassachusettsVeterans Affairs Boston Healthcare System, Jamaica Plain, Massachusetts.
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  • Presented at the poster session of the Alzheimer's Association International Conference on Prevention of Dementia, Washington, DC, June 2007.

Address correspondence to Dr. Olivia Okereke, Channing Laboratory 3rd floor, 181 Longwood Avenue, Boston, MA 02115. E-mail: ookereke@partners.org

Abstract

OBJECTIVES: To relate diabetes mellitus (DM) status and duration to late-life cognitive impairment and decline in men and women.

DESIGN: Prospective cohort.

SETTING: Community.

PARTICIPANTS: Five thousand nine hundred seven men in the Physicians' Health Study II and 6,326 women in the Women's Health Study (mean age 74.1 and 71.9, respectively, at baseline cognitive assessment); 553 men and 405 women had DM.

MEASUREMENTS: Primary outcomes were general cognition (the Telephone Interview for Cognitive Status (TICS) and a global score averaging five tests) and verbal memory. All participants had second assessments approximately 2 years later; women had third assessments an average of 4 years later.

RESULTS: In adjusted linear regression models, participants with DM had significantly lower baseline scores for all outcomes, and longer duration of DM was associated with lower scores (P-trends <.001). Men with DM had significantly greater 2-year cognitive decline than men without DM, and longer duration of DM was associated with worse decline (P-trends ≤.01). In repeated-measures analyses of response profiles, women with DM had significantly greater 4-year cognitive decline in all outcomes than women without DM. In women, as in men, there was generally greater cognitive decline with longer duration of DM (e.g., the adjusted mean difference in decline on the TICS associated with duration of ≥5 years was −0.74 (95% confidence interval=−1.05 to −0.43) points (P-trend <.001). There were no significant sex–DM interactions.

CONCLUSION: Type 2 DM and longer duration of DM are similarly related to cognitive impairment and decline in men and women.

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