Dementia: study appears to exonerate Borrelia burgdorferi

  • Ruiz VH & al.
  • JAMA Neurol
  • 27 Sep 2019

  • International Clinical Digest
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Takeaway

  • Older adults seropositive for Borrelia burgdorferi did not have higher risk for dementia, or higher levels of depression or functional decline.

Why this matters

Key results

  • Baseline seroprevalence of B burgdorferi: 6.5%.
  • Relative to seronegative counterparts, seropositive participants:
    • Were older (mean, 77.8 vs 75.7 years; P=.02),
    • Were more often male (86.7% vs 61.0%; P<.010 and>
    • Had lower Center for Epidemiologic Studies Depression scale scores (mean, 2.6 vs 4.6; P<.010>
  • After 6 years, seropositive participants did not have an elevated risk for dementia compared with seronegative peers (adjusted HR, 0.43; P=.25).
  • In addition, no unadjusted or adjusted associations were found between seropositivity and cognitive decline, depressive symptoms, and decline in performance of activities and instrumental activities of daily living.

Study design

  • French prospective cohort study of 689 retired male and female farmers who were aged ≥65 years and agreed to provide a blood sample (Aging Multidisciplinary Investigation study).
  • Main outcomes: cognitive decline, incident dementia, depressive symptoms, and functional decline at 6-year follow-up.
  • Funding: AGRICA; Mutualité Sociale Agricole de Gironde; Caisse Centrale de la MSA.

Limitations

  • Lack of data on B burgdorferi exposure, course.
  • Small number of seropositive participants.
  • Limited duration of follow-up.
  • Unknown generalisability.