Atrial fibrillation is associated with cognitive decline in stroke-free subjects: the Tromsø Study.

BACKGROUND AND PURPOSE: Previous studies have shown associations between atrial fibrillation (AF) and cognitive decline. We investigated this association in a prospective population study, focusing on whether stroke risk factors modulated this association in stroke-free women and men. METHODS: We included 4983 participants (57% women) from the fifth survey of the Tromsø Study (Tromsø 5, 2001), of whom 2491 also participated in the sixth survey (Tromsø 6, 2007-2008). Information about age, education, blood pressure, body mass index, lipids, smoking, coffee consumption, physical activity, depression, coronary and valvular heart disease, heart failure and diabetes was obtained at baseline. AF status was based on hospital records. The outcome was change in cognitive score from Tromsø 5 to Tromsø 6, measured by the verbal memory test, the digit-symbol coding test and the tapping test. RESULTS: Mean age at baseline was 65.4 years. The mean reduction in the tapping test scores was significantly larger in participants with AF (5.3 taps/10 s; 95% CI: 3.9, 6.7) compared with those without AF (3.8 taps/10 s; 95% CI: 3.5, 4.1). These estimates were unchanged when adjusted for other risk factors and were similar for both sexes. AF was not associated with change in the digit-symbol coding or the verbal memory tests. CONCLUSION: Atrial fibrillation in stroke-free participants was independently associated with cognitive decline as measured with the tapping test.

Cognitive function, drusen, and age-related macular degeneration: a cross-sectional study.

PURPOSE: To examine the cross-sectional relationship between drusen, late age-related macular degeneration (AMD), and cognitive function. METHODS; We included 2149 stroke-free participants from the population-based Tromsø Study in Norway. Retinal photographs were graded for presence of drusen and AMD. Cognitive function was assessed using the verbal memory test (short verbal memory), digit-symbol coding test (processing speed), and the tapping test (psychomotor tempo). We assessed the relationship between drusen, late AMD, and cognitive test scores, adjusted for potential confounders. RESULTS: Late AMD was associated with decreased performance in the verbal memory test (standardized ß=-0.23, 95% confidence interval (CI): -0.51 to -0.01). Intermediate and large drusen were associated with decreased performance in the digit-symbol coding test (standardized ß=-0.14 and -0.19, 95% CIs: -0.23 to -0.05 and -0.29 to -0.09, respectively). Participants with large drusen were more likely to have test scores in the lowest quartile of the digit-symbol coding test (odds ratio (OR)=1.9, 95% CI: 1.1-3.5) and the tapping test (OR=1.6, 95% CI: 1.0-2.6), but not in the verbal memory test (OR=1.0, 95% CI: 0.6-1.6). CONCLUSIONS: The findings suggest a relationship between drusen deposition and reduced cognitive function. Although the relationships between drusen, late AMD, and the cognitive test results varied in strength and significance across the types of cognitive test, and may partly have been caused by residual confounding, it is not unlikely that a genuine but weaker relationship exists between drusen deposition and cognitive decline.

Carotid artery plaque progression and cognitive decline: the Tromsø Study 1994-2008.

BACKGROUND: Carotid atherosclerosis is a risk factor for stroke and cognitive decline, but knowledge on how progression of carotid atherosclerosis affects cognitive function in stroke-free individuals is scarce. METHODS: In the population-based Tromsø study, we calculated the change in ultrasound-assessed carotid plaque number and total plaque area from baseline (survey 4) to follow-up 7 years later (survey 5) in 4274 middle-aged stroke-free subjects. Cognitive function was assessed at follow-up by the verbal memory test, the digit-symbol coding test, and the tapping test and repeated after an additional 6 years in a subgroup of 2042 subjects (survey 6). Associations between the average of survey 4 and survey 5 plaque scores and the progression of plaque scores and cognitive test scores were assessed in regression analyses adjusted for baseline age, sex, education, depression, and cardiovascular risk factors. RESULTS: Progression of total plaque area was associated with lower scores in the digit-symbol coding test (multivariable adjusted standardized ß, -0.03; 95% CI, -0.05 to -0.00; P = 0.04) and the tapping test (ß, -0.03; 95% CI, -0.06 to -0.00; P = 0.03). Similar results were seen for progression of plaque number. The average plaque scores were associated with lower scores in all cognitive tests (P-values ≤ 0.01). No association was found between plaque scores and cognitive decline. CONCLUSIONS: The average plaque scores were associated with lower scores in all cognitive tests. Progression of plaque scores was associated with lower scores in the digit-symbol coding test and the tapping test, but not with the verbal memory test or with cognitive decline.

Subclinical carotid atherosclerosis and cognitive function.

Carotid artery atherosclerosis is a major risk factor for stroke and subsequent cognitive impairment. Recent studies indicate that carotid atherosclerosis without clinical stroke may also be an independent risk factor for cognitive decline and dementia. Ultrasonography is an easily assessable and non-invasive method to measure different stages of the carotid artery atherosclerotic process and is widely used in clinical assessment as well as in epidemiological and clinical research. We give a brief review of studies that have investigated degrees of the subclinical atherosclerosis in the carotid arteries in relation to cognitive function and dementia, and we discuss several possible mechanisms that could explain the association between atherosclerosis and cognitive impairment.

Impact of cardiovascular risk factors on cognitive function: the Tromsø study.

BACKGROUND AND PURPOSE: The role of cardiovascular risk factors in the pathogenesis of cognitive impairment and dementia remains still unclear. We examined the impact of cardiovascular risk factors on cognitive function in a large longitudinal population study. METHODS: Subjects were 5033 stroke-free men and women who participated in a longitudinal population-based study. Cardiovascular risk factors were measured at baseline, and cognitive function was assessed after 7 years of follow-up with verbal memory test, digit-symbol coding test, and tapping test. RESULTS: Diabetes, systolic blood pressure, and current smoking were independently associated with lower cognitive test results in men and women. Low physical activity was independently associated with lower scores in women. We found no consistent association between total-cholesterol, HDL-cholesterol, coronary heart disease or BMI, and cognitive test results. CONCLUSIONS: Diabetes, smoking, hypertension, and low physical activity were associated with lower cognitive test results. The study suggests that these modifiable risk factors should be emphasized in the prevention of cognitive decline.

Moderate wine consumption is associated with better cognitive test results: a 7 year follow up of 5033 subjects in the Tromsø Study.

BACKGROUND: The impact of moderate alcohol consumption on cognitive function and dementia is unclear. We examined the relationship between consumption of different alcoholic beverages and cognitive function in a large population-based study. METHODS: Subjects were 5033 stroke-free men and women who participated in a longitudinal population-based study in Tromsø, Norway. Alcohol consumption and other cardiovascular risk factors were measured at baseline and cognitive function was assessed after 7 years follow up with verbal memory test, digit-symbol coding test and tapping test. RESULTS: Moderate wine consumption was independently associated with better performance on all cognitive tests in both men and women. There was no consistent association between consumption of beer and spirits and cognitive test results. Alcohol abstention was associated with lower cognitive performance in women. CONCLUSIONS: Light-to-moderate wine consumption was associated with better performance on cognitive tests after 7 years follow up.