1157 INFLAMMATION IS ASSOCIATED WITH EXCESSIVE DAYTIME SLEEPINESS AND IMPAIRED COGNITIVE PERFORMANCE IN PATIENTS WITH MILD COGNITIVE IMPAIRMENT (MCI)

Abstract

Introduction: It has been shown that inflammatory markers are elevated in patients with cognitive impairment and are associated with excessive daytime sleepiness (EDS). Furthermore, we have previously shown that extended sleep/sleepiness in patients with Mild Cognitive Impairment (MCI) is associated with impaired cognitive performance. The aim of this study was to assess the associations between inflammation, objective sleep, and cognition among patients with MCI. Methods: A sub-sample of 119 patients with MCI were recruited from a large, population-based cohort in the island of Crete, Greece of 3140 older adults (>60yrs). The goal of this study was to assess the prevalence and risk factors associated with cognitive impairment. All participants underwent medical history/physical examination, extensive neuropsychiatric and neuropsychological evaluation, 3-day 24-h actigraphy and a single morning IL-6 and TNFa plasma level. Associations between (a) inflammatory markers and sleep variables and (b) inflammatory markers and cognition, were assessed using Linear Regression Analysis controlling for gender, age, BMI and depression for the former, and age, gender, and education, for the later. Results: Peripheral levels of IL-6 were 1.2 ± 0.83 pgr/ml(mean ±SD), and TNFa were 1.18 ± 0.57pgr/ml. Regression analysis found a borderline significant association between IL-6 and daytime Total Sleep Time (r=0.186, p=0.07). Furthermore, regression analyses revealed significant associations between IL-6 and a number of episodic memory indices including immediate (β = -0.279, p = 0.003) and delayed word list recall (β = -0.25, p = .013), delayed complex figure reproduction (β = -0.26, p =0 .010), and autobiographic memory (β = -0.25, p =0 .009), and between TNFa and delayed word list recall (β= -0.217, p = -0.028). Conclusion: These data indicate that in patients with MCI, EDS and cognitive impairment are associated with inflammation. It appears that improvement of inflammation through pharmacologic and/or behavioral i.e. exercise, interventions may improve the prognosis in patients with MCI.