Impact of impaired fasting glucose and other metabolic factors on cognitive function in elderly people

Aim: The present study was undertaken to evaluate the impact of impaired fasting glucose (IFG), insulin resistance (IR) and hyperhomocysteinaemia (Hhcy) on cognitive function (CF) in a sample of non-diabetic elderly subjects. Methods and results: One hundred and eighty-two non-diabetic subjects, aged >= 65 years, without signs of previous stroke were included in the study. CF was evaluated by the Mini Mental State Examination (MMSE) score, corrected for age and education. Since diagnostic criteria for IFG have been recently towered from 110 to 100 mg/dL, subjects were categorized according to old (IFG(1997)) and new (IFG(2003)) criteria. IR and Hhcy were defined by the upper quartite of insulin (11.0 UI/L) and Hcy (18.6 mu mol/L) distribution, respectively. The frequency of IFG1997, Hhcy, and IR, but not of IFG2003, showed a linear trend across tertiles of MMSE (p < 0.001). The odds ratio (95% CI) for impaired CF (MMSE < 24.3) was 9.08 (2.97-27.74) for IFG(1997), 3.66 (1.28-10.45) for Hhcy, 2.83 (1.25-6.37) for IR and 1.32 (0.61-2.89) for IFG(2003). Conclusions: Our study shows that IFG(1997), Hhcy and IR are powerful metabolic markers of impaired CF among elderly people. (C) 2005 Elsevier B.V. All rights reserved.