Kjell Arne Arntzen

Risk Factors for Progression of Carotid Intima-Media Thickness and Total Plaque Area A 13-Year Follow-Up Study: The Tromsø Study

Background and Purpose Data on risk factors for progression of intima-media thickness (IMT) and plaque are scarce. The objective was to determine long-term risk factors for total plaque area (TPA) and IMT as well as risk factors for progression (&Dgr;TPA and &Dgr;IMT). Methods Subjects were 1307 men and 1436 women who participated in a longitudinal population-based study with ultrasound examination of the right carotid artery at baseline and after 13 years of follow-up. Total cholesterol, high-density lipoprotein cholesterol, blood pressure, body mass index, and information about smoking habits, prevalent diabetes, and cardiovascular disease were obtained at baseline. Carotid atherosclerosis was assessed as TPA and mean IMT of plaque-free segments of the common carotid artery. Associations between z-scores of risk factors and carotid atherosclerosis were assessed in multiple linear regression models. Results In multivariable models, total cholesterol, systolic blood pressure, and smoking were stronger predictors of follow-up TPA than of IMT, whereas sex and age were stronger predictors of IMT. Total cholesterol (standardized &bgr;=0.081), systolic blood pressure (standardized &bgr;=0.062), and smoking (standardized &bgr;=0.107) were significant predictors of &Dgr;TPA, whereas only total cholesterol (standardized &bgr;=0.084) was an independent predictor of &Dgr;IMT. The variance explained by traditional cardiovascular risk factors was somewhat greater for TPA than for IMT. Conclusions The cardiovascular risk factors total cholesterol, smoking, and systolic blood pressure were stronger long-term predictors of TPA and TPA progression than for IMT and IMT progression.

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.

Carotid Atherosclerosis Predicts Lower Cognitive Test Results: A 7-Year Follow-Up Study of 4,371 Stroke-Free Subjects – The Tromsø Study

Background: Carotid artery atherosclerosis is a major risk factor for stroke and subsequent cognitive impairment. Prospective population studies have shown associations between carotid intima-media thickness (IMT) and stenosis and cognitive decline and dementia in elderly stroke-free persons, whereas results in the middle-aged are conflicting. Methods: In this prospective population-based study, 4,371 stroke-free middle-aged participants underwent carotid ultrasound examination and assessment of vascular risk factors at baseline and were tested for cognitive function 7 years later. Associations between IMT, number of plaques and total plaque area and cognitive test scores on verbal memory test, digit symbol-coding test and tapping test were assessed in linear regression models. Results: In the multivariable analyses adjusted for sex, age, education, depression and vascular risk factors, the presence of plaques was significantly associated with lower test scores on the verbal memory test (p = 0.01) and on the digit symbol-coding test (p = 0.03). The number of plaques (p = 0.01) and the total plaque area (p = 0.02) were associated with lower scores on the verbal memory test. No significant association was seen between common carotid artery IMT and cognitive test scores. The tapping test was not associated with the carotid ultrasound variables. Conclusions: In this middle-aged general population, subclinical carotid atherosclerosis measured as the presence of plaques, number of plaques and total plaque area were independent long-term predictors of lower cognitive test scores.

The metabolic syndrome and progression of carotid atherosclerosis over 13 years. The Tromsø study

BackgroundThe metabolic syndrome (MetS) is associated with increased risk of cardiovascular disease. In this study, we examine if metabolic syndrome predicts progression of atherosclerosis over 13 years.MethodsParticipants were 1442 men and 1532 women in the population-based Tromsø Study who underwent carotid ultrasound examinations at baseline in the 4th (1994–5) and at follow-up in the 6th survey (2007–8). Of these, 278 men and 273 women fulfilled the criteria for the MetS, defined according to a modified version of the National Cholesterol Education Program Adult Treatment Panel III (NCEP, ATPIII). Carotid atherosclerosis was assessed as total plaque area (TPA) and mean intima-media thickness (IMT) at follow-up and as change in IMT and TPA from baseline to follow-up. Associations between MetS and its components and carotid atherosclerosis were assessed in linear regression models adjusted for age, total cholesterol and daily smoking, stratified by sex.ResultsIMT and TPA levels at follow-up (p < 0.0001) and progression of TPA (p = 0.02) were higher in the MetS group compared to the non-MetS group. In stepwise multivariable models, MetS was associated with TPA (β = 0.372 mm2, p = 0.009) and IMT (β = 0.051 mm, p < 0.0001) in men, and with IMT (β = 0.045 mm, p = 0.001) in women after 13 years of follow-up, but not with progression of IMT or TPA. In analyses stratified by age, MetS predicted progression of IMT (β = 0.043 mm, p = 0.046) and TPA (β = 1.02 mm2, p = 0.002) in men below 50 years of age. Hypertension was predictive of follow-up TPA and IMT in both genders and of progression of TPA in women. Impaired glucose tolerance was associated with follow up levels of IMT and TPA as well as progression in IMT in men. None of the other components of MetS were associated with progression of atherosclerosis.ConclusionsSubjects with MetS had higher levels of IMT and TPA at follow up than those without MetS. Mets predicted progression of IMT and TPA in those below 50 years of age, but not in other age groups, indicating that MetS may be involved in the initiation of the atherosclerotic process.

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

Arntzen KA, Schirmer H, Wilsgaard T, Mathiesen EB. Moderate wine consumption is associated with better cognitive test results: a 7 year follow up of 5033 subjects in the Tromsø Study. Acta Neurol Scand: 2010: 122 (Suppl. 190): 23–29.

Subclinical cardiovascular disease is associated with a high glomerular filtration rate in the nondiabetic general population

A reduced glomerular filtration rate (GFR) in chronic kidney disease is a risk factor for cardiovascular disease. However, evidence indicates that a high GFR may also be a cardiovascular risk factor. This issue remains unresolved due to a lack of longitudinal studies of manifest cardiovascular disease with precise GFR measurements. Here, we performed a cross-sectional study of the relationship between high GFR measured as iohexol clearance and subclinical cardiovascular disease in the Renal Iohexol Clearance Survey in Tromsø 6 (RENIS-T6), a representative sample of the middle-aged general population. A total of 1521 persons without cardiovascular disease, chronic kidney disease, diabetes, or micro- or macroalbuminuria were examined with carotid ultrasonography and electrocardiography. The GFR in the highest quartile was associated with an increased odds ratio of having total carotid plaque area greater than the median of non-zero values (odds ratio 1.56, 95% confidence interval 1.02-2.39) or electrocardiographic signs of left ventricular hypertrophy (odds ratio 1.62, 95% confidence interval 1.10-2.38) compared to the lowest quartile. The analyses were adjusted for cardiovascular risk factors, urinary albumin excretion, and fasting serum glucose. Thus, high GFR is associated with carotid atherosclerosis and left ventricular hypertrophy and should be investigated as a possible risk factor for manifest cardiovascular disease in longitudinal studies.

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

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.

Long-Term Use of Lipid-Lowering Drugs Slows Progression of Carotid Atherosclerosis The Tromsø Study 1994 to 2008

Objective—Data on the effect of lipid-lowering drugs (LLD) on carotid atherosclerosis outside clinical trials are limited. The aim of this study was to determine the effect of LLD on change in carotid intima media thickness and total plaque area in a general population. Approach and Results—Subjects were 1532 women and 1442 men who participated in a longitudinal population-based study with ultrasound examination of intima media thickness and total plaque area in the right carotid artery at baseline and after 13 years follow-up. Long-term use of LLD was defined as use for >5 years, any-time use of LLD was defined as use at baseline or at 6 years or at 13 years of follow-up. In multivariable models adjusted for age, sex, systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, prevalent cardiovascular disease, and daily smoking, long-term use of LLD had a protective effect on progression of both intima media thickness (&bgr;=–0.0387 mm; P=0.002) and total plaque area (&bgr;=–0.400 mm2; P=0.006). There was a weaker protective effect of any-time use of LLD on progression of intima media thickness (&bgr;=–0.024 mm; P=0.046) and total plaque area (&bgr;=–0.318 mm2; P=0.06). Conclusions—LLD protected against progression of carotid atherosclerosis. The protective effect was strongest in long-term users.

Subclinical carotid atherosclerosis and cognitive function

Arntzen KA, Mathiesen EB. Subclinical carotid atherosclerosis and cognitive function.
Acta Neurol Scand: 2011: 124 (Suppl. 191): 18–22.
© 2011 John Wiley & Sons A/S.

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

PurposeTo examine the cross-sectional relationship between drusen, late age-related macular degeneration (AMD), and cognitive function.MethodsWe 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.ResultsLate AMD was associated with decreased performance in the verbal memory test (standardized β=−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 β=−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).ConclusionsThe 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.