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Objectives The aim of this study was to use the parametric g-formula to estimate the 19-year risk of myocardial infarction (MI) under hypothetical interventions on six cardiovascular risk factors. Design and setting A populations-based cohort study with repeated measurements, the Tromsø Study. Primary outcome measure Myocardial infarction. Participants We estimated the relative and absolute risk reduction under feasible and intensive risk reduction strategies for smoking, physical activity, alcohol drinking, body mass index, total serum cholesterol and systolic blood pressure in 14 965 men and women with 19 years of follow-up (1994–2013). Results The estimated 19-year risk of MI under no intervention was 7.5% in individuals with baseline mean age 49.3 years (range 25–69). This risk was reduced by 30% (95% CI 19% to 39%) under joint feasible interventions on all risk factors, and 70% (60%, 78%) under a set of more intensive interventions. The most effective interventions were lowering of total cholesterol to 5.18 mmol/L and lowering of systolic blood pressure to 120 mm Hg (33% and 37% lower MI risk, respectively). The absolute risk reductions were significantly larger in men, in older participants, in smokers and in those with low education. Conclusion Modification of population levels of cardiovascular risk factors could have prevented close to one-third of the cases of MI in the municipality of Tromsø during 19 years of follow-up. [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]

Objective To compare a comprehensive lifestyle intervention for overweight children performed in groups of families with a conventional single-family treatment. Two-year follow-up data on anthropometric and psychological outcome are presented. Design Overweight and obese children aged 6-12 years with body mass index (BMI) corresponding to ≥27.5 kg/m² in adults were randomised to multiplefamily (n=48) or single-family intervention (n=49) in a parallel design. Multiple-family intervention comprised an inpatient programme with other families and a multidisciplinary team, follow-up visits in their hometown, weekly physical activity and a family camp. Single-family intervention included counselling by paediatric nurse, paediatric consultant and nutritionist at the hospital and follow-up by a community public health nurse. Primary outcome measures were change in BMI kg/m² and BMI SD score after 2 years. Results BMI increased by 1.29 kg/m² in the multiplefamily intervention compared with 2.02 kg/m² in the single-family intervention (p=0.075). BMI SD score decreased by 0.20 units in the multiple-family group and 0.08 units in the single-family intervention group (p=0.046). A between-group difference of 2.4 cm in waist circumference (p=0.038) was detected. Pooled data from both treatment groups showed a significant decrease in BMI SD score of 0.14 units and a significant decrease in parent-reported and self-reported Strength and Difficulty Questionnaire total score of 1.9 units. Conclusions Two-year outcome showed no betweengroup difference in BMI. A small between-group effect in BMI SD score and waist circumference favouring multiple-family intervention was detected. Pooled data showed an overall improvement in psychological outcome measures and BMI SD score. Trial registration number NCT00872807 [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: To compare a new comprehensive lifestyle programme performed in groups of families with overweight (included obese) children with a more conventional single-family programme. The study design and interim anthropometrical results after 12 months are presented. Design: Altogether 97 overweight and obese children aged 6-12 years with body mass index (BMI) corresponding to cut-off point ±27.5 in adults were included. Study participants were randomised to multiple-family intervention (MUFI) or single-family intervention (SIFI) in a parallel design. MUFI comprised a 3-day inpatient programme at the hospital with other families and a multidisciplinary team, follow-up visits in their hometown individually and in groups, organised physical activity twice weekly and a 4-day family camp after 6 months. SIFI comprised individual counselling by paediatric nurse, paediatric consultant and nutritionist at the hospital and follow-up by public health nurse in the community. Solution focused approach was applied in both interventions. Primary outcome measures were change in BMI kg/m² and BMI SD score (BMI SDS). Results: BMI increased by 0.37 units in the MUFI compared to 0.77 units in the SIFI ( p=0.18). BMI SDS decreased by 0.16 units in the MUFI group compared to 0.07 units in the SIFI group ( p=0.07). Secondary endpoint waist circumference decreased 0.94 cm in the multiple-family group and increased 0.95 cm in the single-family group, p=0.04. Conclusions: Interim analysis after 12 months showed no between-group difference in termsof BMI or BMI SDS. The MUFI group had a significant decrease in waist circumference compared to the SIFI group. [ABSTRACT FROM AUTHOR]

Objective Some risk factors for age-related macular degeneration (AMD) have been shown to act differently in women and men. The present study aims to investigate this disparity by examining associations between female hormones, reproductive history and AMD. Methods Women aged 65-87 years were invited to this cross-sectional, population-based study in Norway. Participants underwent physical examination, retinal photography, answered questionnaires and had blood samples taken. Results The sample included 1512 women, of whom 48 (3.2%) had late AMD and 378 (25%) had large drusen >125 μm phenotype. Length of breast feeding per child was significantly associated with late AMD (OR per month 0.80, 95% CI 0.68 to 0.94) in multivariable regression analysis. We observed no associations between late AMD or drusen >125 μm and contraceptives, oral hormonal replacement therapy, parity, age at first childbirth, age of menarche, age of menopause, number of menstruating years or the reason for menopause. Conclusions Longer duration of lactation was associated with lower frequency of maternal late AMD when controlled for confounders. Other reproductive factors and hormone replacement therapy were not significantly associated with AMD. [ABSTRACT FROM AUTHOR]

Background: Seasonal changes in cardiovascular disease (CVD) risk factors may be due to exposure to seasonal environmental variables like temperature and acute infections or seasonal behavioural patterns in physical activity and diet. Investigating the seasonal pattern of risk factors should help determine the causes of the seasonal pattern in CVD. Few studies have investigated the seasonal variation in risk factors using repeated measurements from the same individual, which is important as individual and population seasonal patterns may differ. Methods: The authors investigated the seasonal pattern in systolic and diastolic blood pressure, heart rate, body weight, total cholesterol, triglycerides, high-density lipoprotein cholesterol, C reactive protein and fibrinogen. Measurements came from 38 037 participants in the population-based cohort, the Tromsø Study, examined up to eight times from 1979 to 2008. Individual and population seasonal patterns were estimated using a cosinor in a mixed model. Results: All risk factors had a highly statistically significant seasonal pattern with a peak time in winter, except for triglycerides (peak in autumn), C reactive protein and fibrinogen (peak in spring). The sizes of the seasonal variations were clinically modest. Conclusions: Although the authors found highly statistically significant individual seasonal patterns for all risk factors, the sizes of the changes were modest, probably because this subarctic population is well adapted to a harsh climate. Better protection against seasonal risk factors like cold weather could help reduce the winter excess in CVD observed in milder climates. [ABSTRACT FROM AUTHOR]

Background: Meteorological factors like cold temperatures and heavy snowfalls have been reported to increase myocardial infarction (MI) incidence, but there are inconsistencies in results as well as in methodology in previous studies. The objective of this study was to examine the impact of meteorological factors on incidence of MI in a population-based study in Tromsø,Norway (698399N).Methods: A total of 32 110 participants from the Tromsø Study enrolled between 1974 and 2001 were followed throughout 2004. Each incident case of MI was validated by the review of medical records and death certificates.Meteorological data from the Tromsø Weather Station were collected from the Norwegian MeteorologicalInstitute database. Poisson regression models were applied to analyse the impact of meteorological factors on MI incidence. All analyses were stratified by sex and age.Results: A total of 1882 first-ever MIs were registered. The main finding was an increase in MI incidence among persons older than 65 years with decreasing temperatures (p=0.016) and increasing snowfall (p=0.030). When comparing the lowe and upper limits of the temperature distribution (−10°C with 20°C), the MI risk increased by 47% (RR=1.47, 95% CI 1.09 to 2.13). Comparing limits of the snowfall distribution (10 with 0 mm), the MI risk increased by 44% (rr=1.44, 95% CI 1.07 to 1.94).Conclusions: In this subarctic population, MI incidence was little affected by the weather, probably due to behavioural protection. However, cold weather and heavy snowfall may be associated with increased risk of MI among older people. [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.