Search

Background: Management of incidental unruptured intracranial aneurysms (UIAs) remains challenging and depends on their risk of rupture, estimated from the assumed prevalence of aneurysms and the incidence of aneurysmal subarachnoid haemorrhage. Reported prevalence varies, and consistent criteria for definition of UIAs are lacking. We aimed to study the prevalence of UIAs in a general population according to different definitions of aneurysm.Methods: Cross-sectional population-based study using 3-dimensional time-of-flight 3 Tesla MR angiography to identify size, type and location of UIAs in 1862 adults aged 40-84 years. Size was measured as the maximal distance between any two points in the aneurysm sac. Prevalence was estimated for different diameter cutoffs (≥1, 2 and 3 mm) with and without inclusion of extradural aneurysms.Results: The overall prevalence of intradural saccular aneurysms ≥2 mm was 6.6% (95% CI 5.4% to 7.6%), 7.5% (95% CI 5.9% to 9.2%) in women and 5.5% (95% CI 4.1% to 7.2%) in men. Depending on the definition of an aneurysm, the overall prevalence ranged from 3.8% (95% CI 3.0% to 4.8%) for intradural aneurysms ≥3 mm to 8.3% (95% CI 7.1% to 9.7%) when both intradural and extradural aneurysms ≥1 mm were included.Conclusion: Prevalence in this study was higher than previously observed in other Western populations and was substantially influenced by definitions according to size and extradural or intradural location. The high prevalence of UIAs sized <5 mm may suggest lower rupture risk than previously estimated. Consensus on more robust and consistent radiological definitions of UIAs is warranted. [ABSTRACT FROM AUTHOR]

Objectives Large differences exist in the burden of cardiovascular disease (CVD) between Russia and Western European countries including Norway. Obesity prevalence may contribute to the differences. We investigated whether difference in the level of adiposity, assessed using body mass index and waist-to-hip ratio(WHR), could explain intercountry differences in the burden of carotid plaque, a measure of atherosclerosis, in the populations. Design Cross-sectional analysis. Logistic and linear regression models were used. Setting We used population-based cross-sectional Know Your Heart (KYH) study in Russia and the Tromsø 7 study (Tromsø 7) in Norway. Participants 3262 and 1800 men and women aged 40–69 years in KYH and Tromsø 7, respectively. Primary and secondary outcome The presence of carotid plaques and plaque score assessed using ultrasound. Results The presence of carotid plaques and plaque score were higher in KYH than Tromsø 7 regardless of age group and sex. A positive association between carotid plaque burden and adiposity was found (OR of having at least one plaque per SD in WHR 1.18 (95% CI 1.06 to 1.31) for men; 1.15 (1.06 to 1.25) for women)) adjusted for age, smoking and education in a pooled analysis of the two studies. There was little evidence of the interaction between study and adiposity. These effects did not differ between the two studies. However, neither adiposity nor CVD risk factors (smoking, systolic blood pressure, cholesterol, glycosylated haemoglobin) explained the higher carotid plaque burden in KYH compared with Tromsø 7. Conclusion Adiposity, especially abdominal adiposity, is a risk factor for carotid plaque in Russia and Norway, although neither adiposity nor established CVD risk factors explained the higher plaque burden in Russia. To reduce the CVD burden in Russia, beyond prevention and treatment of adiposity, further research is required to understand why Russia has a high burden of atherosclerosis. [ABSTRACT FROM AUTHOR]

Objectives There is a shift in the smoking population from daily smokers to light or occasional smokers. The knowledge about possible adverse health effects of this new smoking pattern is limited. We investigated smoking habits with focus on occasional smoking in relation to total mortality in a follow-up study of a Norwegian general population. Setting A population study in Tromsø, Norway. Methods We collected smoking habits and relevant risk factors in 4020 women and 3033 men aged 30–89 years in the Tromsø Study in 2001. The subjects were followed up regarding total mortality through June 2015. Results Among the participants, there were 7% occasional smokers. Occasional smokers were younger, more educated and used alcohol more frequently than other participants. A total of 766 women and 882 men died during the follow-up. After the adjustment for confounders, we found that occasional smoking significantly increased mortality by 38% (95% CI 8% to 76%) compared with never smokers. We report a dose–response relationship in the hazards of smoking (daily, occasional, former and never smoking).Conclusions Occasional smoking is not a safe smoking alternative. There is a need for information to the general public and health workers about the health hazards of occasional smoking. More work should be done to motivate this often well-educated group to quit smoking completely. [ABSTRACT FROM AUTHOR]

Objectives Elevated blood cholesterol is a modifiable risk factor for cardiovascular disease. Cholesterol level surveillance is necessary to study population disease burden, consider priorities for prevention and intervention and understand the effect of diet, lifestyle and treatment. Previous studies show a cholesterol decline in recent decades but lack data to follow individuals born in different decades throughout life. Methods We investigated changes in age-specific and birth cohort-specific total cholesterol (TC) levels in 43 710 women and men born in 1905-1977 (aged 20-95 years at screening) in the population-based Tromsø Study. Fifty-nine per cent of the participants had more than one and up to six repeated TC measurements during 1979-2016. Linear mixed models were used to test for time trends. Results Mean TC decreased during 1979-2016 in both women and men and in all age groups. The decrease in TC in age group 40-49 years was 1.2 mmol/L in women and 1.0 mmol/L in men. Both the 80th and the 20th percentile of the population TC distribution decreased in both sexes and all age groups. Longitudinal analysis showed that TC increased with age to a peak around middle age followed by a decrease. At any given age, TC significantly decreased with increase in year born. Lipid-lowering drug use was rare in 1994, increased thereafter, but was low (<3% in women and <5% in men) among those younger than 50 years in all surveys. Between 1994 and 2016, lipid-lowering drug treatment in individuals 50 years and older explained 21% and 28% of the decrease in TC levels in women and men, respectively. Conclusions We found a substantial decrease in mean TC levels in the general population between 1979 and 2016 in all age groups. In birth cohorts, TC increased with age to a peak around middle age followed by a decrease. [ABSTRACT FROM AUTHOR]

Objective To investigate the association between echocardiographic measurements with emphasis on diastolic dysfunction and risk of atrial fibrillation (AF) in a population-based cohort study. Methods We followed 2406 participants from the Tromsø Study from 1994 to 2010. Left atrial (LA) size and mitral Doppler indices as measured by echocardiography were used for evaluating diastolic dysfunction. Information concerning age, systolic blood pressure, height, heart rate, body mass index, total and high-density lipoprotein cholesterol, self-reported use of alcohol, smoking, coffee, physical activity, antihypertensive treatment, prevalent coronary heart disease, valvular heart disease, heart failure, hypertrophy, diabetes and palpitations were obtained at baseline. The outcome measure was clinical AF, documented by an ECG. Results AF was detected in 462 subjects (193 women). Mean age at baseline was 62.6 years. Incidence rate of clinical AF was 12.6 per 1000 personyears. In multivariable Cox proportional hazards regression analysis, moderately enlarged LA was associated with 60% (95% CI 1.2 to 2.0) increased risk of AF. Severely enlarged LA had HR for AF of 4.2 (95% CI 2.7 to 6.5) with p value for linear trend <0.001, and the association was similar in both sexes. Abnormal mitral Doppler flow adjusted for predictor variables did not show a statistically significant association with AF risk. However, when LA size was also adjusted for, the risk of AF increased by 30% (95% CI 1.0 to 1.6). Conclusions Our findings suggest that enlarged LA as a measure for diastolic dysfunction is a significant risk factor for AF in both sexes, and adding measures of abnormal diastolic flow increased the predictive ability significantly. [ABSTRACT FROM AUTHOR]

Background To describe trends in cardiovascular risk factors and change over time across education levels, and study the influence from medicine use and gender. Methods Data from participants (30–74 years) of the Tromsø Study in 1994–1995 (n=22 108) and in 2007– 2008 (n=11 565). Blood samples, measurements and self-reported educational level and medicine use were collected. Results Differences in risk factor levels across education groups were persistent for all risk factors over time, with a more unfavourable pattern in the lowest education group. The exception was cholesterol, with the reduction being largest in the lowest educated, resulting in weakened educational trends over time. While a significant educational trend in cholesterol persisted among the non-users of lipid-lowering drugs (LLD), no educational trend in cholesterol was found among the LLD users in 2007–2008. The strongest educational trends were found for daily smoking and Body Mass Index (BMI). In 2007–2008 the odds for being a smoker were five times higher among the lowest educated compared to the highest educated. In men, the odds for being in the highest quintile of the BMI distribution were, in 2007–2008, almost doubled in the lowest compared to the highest educated. The lowest educated women had 6.2 mm Hg higher mean systolic blood pressure than the highly educated, mean BMI of 26.4 kg/m2 and smoking prevalence of 37.7%. Conclusions The difference across education groups for cholesterol levels decreased, while the educational gap persisted over time for the other risk factors. Use of LLD seemed to contribute to the reduction of social differences in cholesterol levels. [ABSTRACT FROM AUTHOR]

Background The Rose Angina Questionnaire (RAQ) was constructed in the 1960s for assessing the population burden of angina. Studies have found that screening positivity by RAQ conferred an elevated risk of coronary heart disease (CHD). It is, however, not clear to what extent Rose angina represents early CHD in relatively young adults who are free of known CHD. If representing CHD, Rose angina is expected to carry prognostic information in addition to the risk conferred by other risk factors. Methods The Tromsø Study is a population-based cohort study in Northern Norway. All men aged 20–54 years (n=8238) and women aged 20–49 years (n=8001), free of known cardiovascular disease (CVD), who participated in a survey 1979–1980, were followed throughout 2010 for incident myocardial infarction (MI), and for incident MI or stroke used as proxy for incident CVD. HRs were estimated using a Cox proportional hazard regression model. Results In age-adjusted analyses, Rose angina predicted MI and CVD in both sexes. The excess risk was substantially accounted for by CVD risk factors, leaving no significantly elevated MI risk above the risk explained by these factors (adjusted HR 1.31; 95% CI 0.95 to 1.80 in men, HR 1.20; 95% CI 0.69 to 2.10 in women). A similar pattern was seen for CVD (adjusted HR 1.16; 95% CI 0.87 to 1.55 in men and 1.30; 95% CI 0.82 to 2.06 in women). Conclusions Rose angina predicted MI and CVD in a 29-years’ follow-up of a relatively young population. Established CVD risk factors were important mediators. [ABSTRACT FROM AUTHOR]

Objective: CHA2DS2-VASc score, left atrial (LA) size and atrial fibrillation (AF) have individually been associated with stroke risk. Our aim was to investigate the predictive ability of combinations of these factors for the odds of incident stroke in a population-based cohort study., Methods: We followed 2844 participants from the Tromsø Study from 1994 to 2012. Information on LA size and CHA2DS2-VASc score (age, sex, congestive heart failure, hypertension, vascular disease, stroke and diabetes) were obtained at baseline. AF status was recorded from medical records. The outcome measure was all strokes. The association between covariates and stroke was investigated by means of multivariate logistic regression analysis., Results: A total of 325 participants (45% women, mean age at baseline 59.3 years) had a stroke. Incidence rates for stroke were 6.4 in women and 8.4 in men per 1000 person-years. Participants with CHA2DS2-VASc ≥1 and LA size <2.8 had ∼4 times (95% CI 2.6 to 5.3) increased odds of stroke, whereas participants with CHA2DS2-VASc ≥1 and LA size ≥2.8 had ∼9 times (95% CI 5.3 to 16.4) increased odds of stroke, compared with participants with CHA2DS2-VASc score 0, irrespective of AF status. Adjustment for significant covariates had minimal impact on the OR estimates., Conclusions: Combining CHA2DS2-VASc score ≥1 and enlarged LA size identified participants with high odds of stroke regardless of AF status.