Elevated Blood Sugar May Raise Risk of Cognitive Decline

Previously, studies suggest a causal link between diabetes and dementia.  Paul K. Crane, from the University of Washington (Washington, USA), and colleagues analyzed data collected on 2,581 men and women, ages 65 and older between 1994 and 1996, enrolled in the Group Health Cooperative, who did not have dementia at the study’s start; an additional 811 subjects enrolled between 2000 and 2002.  Participants were asked to return at 2-year intervals for dementia evaluation, and 2,067 of the participants, each of whom were members for at least 5 years prior to the study’s start and had at least five measurements of blood glucose or glycated hemoglobin (HbA1c) over 2 or more years prior to the study, had at least one follow-up visit.  The final analysis encompassed 35,264 glucose measurements and 10,208 measurements of HbA1c obtained from 839 men and 1,228 women who had a baseline mean age of 76. The participants included 232 patients with diabetes.  During a median follow-up of 6.8 years, 524 participants developed dementia, consisting of 74 with diabetes and 450 without. Patients without diabetes and who developed dementia had significantly higher average glucose levels in the 5 years before diagnosis of dementia), equating to a hazard ratio of 1.18.  Among the patients with diabetes, glucose levels averaged 190 mg/dL in those who developed dementia versus 160 mg/dL in those who did not, equating tot a hazard ratio of 1.40.  The study authors conclude that: “ Our results suggest that higher glucose levels may be a risk factor for dementia, even among persons without diabetes.”