Anne Elise Eggen

Cohort profile: The Tromsø Study

The Tromso Study was initiated in 1974 in an attempt to help combat the high mortality of cardiovascular diseases in Norway, that was particularly pronounced among middle-aged men. In the mid-1970s, Norwegian men had a 20% risk of dying of myocardial infarction (MI) before the age of 75 years. The situation in Northern Norway was even worse. The primary aim of the Tromso Study was to determine causes of the high cardiovascular mortality, and also to develop ways of preventing heart attacks and strokes. This was reflected through the first name of the study: The Tromso Heart Study. However, during the 37 years since the first examination of the Tromso Study took place, increasing emphasis has been put on other chronic diseases and conditions, in particular atrial fibrillation, venous thromboembolism, diabetes mellitus, osteoporosis and fractures. It has been a deliberate policy to invite a wide range of faculty research groups to join in with subprojects in the surveys, and there are currently some 100 different ongoing research projects based on the data from the consecutive six surveys. The study was initially funded by the University of Tromso, and has been so for the entire period since 1974, but there have also been substantial contributions, directly and indirectly from, for example, the National Screening Services, the Research Council of Norway, Northern Norway Regional Health Authority, Norwegian Council on Cardiovascular Diseases and Norwegian Foundation for Health and Rehabilitation. Teams of investigators approach public research programmes for funding of the different examinations conducted. Tromso is the largest city in Northern Norway. It is situated 400 km north of the Arctic Circle, and has approximately 67 000 inhabitants. The physical living conditions are dominated by dramatic changes in the light with 2 months of midnight sun and 2 months of the polar night. However, due to the Gulf Stream, the climate is relatively mild, the latitude (698N) taken into account.

Perceived barriers to consumption of fish among Norwegian women.

This study aimed to characterize constraints on consumption of fish perceived by consumers in Norway. A random sample of Norwegian women aged 45-69 years answered a self-administered mail questionnaire in 1996 about eating habits, perceived barriers to fish consumption, socioeconomic status, and questions related to health. Altogether, 9407 women answered the questionnaire (response rate: 52.5%). Data were analyzed by means of logistic regression. Limited supply of fish products that satisfy childrens wishes reduce at-home fish consumption. People with health problems and those who wish to lose weight are dissatisfied with the range of products offered in the marketplace. Satisfaction with quality and availability of wild lean codfish, especially in inland regions, is lower than for aqua-cultured fat salmon. Neither income nor education or health factors were significantly associated with consumption levels among those who would like to eat more fish. Higher education and income were associated with increased dissatisfaction about fish consumption, but also with reduced perception of most barriers. It is concluded that improvements in the supply of high-quality fresh and processed fish products that satisfy (a) childrens wishes, (b) health-oriented family members, and (c) convenience-oriented consumers, will significantly increase at-home consumption of fish.

The Acupuncture on Hot Flushes Among Menopausal Women (ACUFLASH) study, a randomized controlled trial

Objective: This study compared the effectiveness of individualized acupuncture plus self-care versus self-care alone on hot flashes and health-related quality of life in postmenopausal women. Methods: This study involved a multicenter, pragmatic, randomized, controlled trial with two parallel arms. Participants were postmenopausal women experiencing, on average, seven or more hot flashes per 24 hours during seven consecutive days. The acupuncture group received 10 acupuncture treatment sessions and advice on self-care, and the control group received advice on self-care only. The frequency and severity (0-10 scale) of hot flashes were registered in a diary. Urine excretion of calcitonin gene-related peptide was assessed at baseline and after 12 weeks. The primary endpoint was change in mean hot flash frequency from baseline to 12 weeks. The secondary endpoint was change in health-related quality of life measured by the Womens Health Questionnaire. Results: Hot flash frequency decreased by 5.8 per 24 hours in the acupuncture group (n = 134) and 3.7 per 24 hours in the control group (n = 133), a difference of 2.1 (P < 0.001). Hot flash intensity decreased by 3.2 units in the acupuncture group and 1.8 units in the control group, a difference of 1.4 (P < 0.001). The acupuncture group experienced statistically significant improvements in the vasomotor, sleep, and somatic symptoms dimensions of the Womens Health Questionnaire compared with the control group. Urine calcitonin gene-related peptide excretion remained unchanged from baseline to week 12. Conclusions: Acupuncture plus self-care can contribute to a clinically relevant reduction in hot flashes and increased health-related quality of life in postmenopausal women.

The Tromsø study: Frequency and predicting factors of analgesic drug use in a free-living population (12–56 years)

In a cross-sectional survey carried out in Tromsø in 1986-7, 19,137 men and women aged 12-56 years from the general population were asked about their use of drugs during the preceding 14 days. Use of analgesics was very common. On average 28% of the women and 13% of the men had used analgesics. Drug use due to menstruation discomfort contributed only partly to the gender difference. Drug use was independent of age from 20 years of age. Factors having an impact on analgesic drug use were analyzed by logistic regression. The most significant predictors of analgesic use were suffering from headache (OR = 14.2(women) OR = 24.4(men)) and infections (OR = 2.0(women) OR = 2.4(men)). Drug users also tended to suffer from symptoms of depression (women) and sleeplessness (men). Lifestyle and sociodemographic factors were also significant predictors, but were of marginal importance (OR < 1.5) compared with occurrence of pain and infections.

Effect of smoking on the serum levels of 25-hydroxyvitamin D depends on the assay employed

OBJECTIVE Because we found higher serum 25-hydroxyvitamin D (25(OH)D) levels among smokers than among non-smokers with analyses using an electrochemiluminescence immunoassay (ECLIA) from Roche, the purpose of the present study was to examine whether this difference between smokers and non-smokers was maintained using other serum 25(OH)D assays. DESIGN A cross-sectional population-based study on 6932 participants from the Tromsø study, 1994-1995, and one validation study comparing six different serum 25(OH)D assays in 53 non-smokers and 54 smokers were performed. METHODS The association between smoking, season and serum 25(OH)D as measured by ECLIA (Roche) was assessed in the population-based study using general linear models with multivariate adjustments. In the validation study, serum levels of 25(OH)D were analysed with liquid chromatography coupled with mass spectrometry assay from two different laboratories, RIA (DiaSorin), HPLC, RIA (IDS) and ECLIA (Roche). T-tests and linear mixed model analyses were performed to compare the serum 25(OH)D levels in smokers and non-smokers within and between the methods. RESULTS In the population-based study, the serum levels of 25(OH)D using the ECLIA method were 51.9, 53.2 and 72.0 nmol/l in never, former and current smokers (P<0.01). In the validation study, the serum concentration of 25(OH)D was 10.3 nmol/l higher in smokers than in non-smokers (P<0.01) using the ECLIA (Roche), while non-significantly lower serum levels of 25(OH)D were found in smokers using the other five methods. CONCLUSIONS These two studies indicate that the ECLIA (Roche) overestimates serum 25(OH)D levels in smokers by unknown mechanisms. If confirmed, this might have clinical consequences, and the issue needs further exploration.

The sixth survey of the Tromsø Study (Tromsø 6) in 2007–08: Collaborative research in the interface between clinical medicine and epidemiology: Study objectives, design, data collection procedures, and attendance in a multipurpose population-based health survey

Aims: To provide a synopsis of the sixth survey of the Tromsø Study, Tromsø 6, objectives and new target areas, study design, follow-up studies, data collection, attendance, and participant characteristics. Methods: The Tromsø Study, initiated in 1974, is an epidemiological, prospective study of health conditions and chronic diseases, and a resource for the surveillance of disease risk factors. The purpose of Tromsø 6 (2007–08) was to collect novel and repeated measurements of exposure data and to assess levels of disease risk factors. Tromsø 6 included a main study that comprised two screening visits and several follow-up studies. Main study data collection: First visit (n=12,984): questionnaires, interviews, measurements of height, weight, hip and waist circumference, heart rate, blood pressure, forearm bone density, grip strength, pain sensitivity measurements, and blood and hair samples and nose and throat swab cultures. Second visit (n=7307): sampling of biological specimens (blood, urine, nose and throat swab cultures) and clinical examinations (12-lead electrocardiography, cognitive tests, visual acuity test, retinal photography, carotid ultrasound, spirometry, dual-energy X-ray absorptiometry, and echocardiography. Results: A total of 12,984 participants aged 30–87 years were examined. The attendance rate was 66%, lower than in previous Tromsø Study surveys. The attendance was lowest in the youngest and oldest, those invited for the first time, and lower in men than women. Conclusions: The completion of the survey with this comprehensive data collection went satisfactorily. The decreasing attendance rate calls for new recruitment strategies and optimisation of the study organisation to facilitate attendance.

Does a variation in self-reported physical activity reflect variation in objectively measured physical activity, resting heart rate, and physical fitness? Results from the Tromsø study

Aims: To study the association between self-reported physical activity (PA) and objectively measured PA, resting heart rate, and physical fitness. Methods: During 2007—08, 5017 men and 5607 women aged 30—69 years attended the sixth survey of the Tromsø study. Self-reported PA during leisure-time and work were assessed and resting heart rate was measured. In a sub-study, the activity study, PA (Actigraph LLC) and physical fitness (VO2max) were objectively measured among 313 healthy men and women aged 40—44 years. Results: Self-reported leisure PA was significantly correlated with VO2max (ml/kg/min) (women 0.40, p < 0.001, men 0.44 p < 0.001) and moderate-to-vigorous PA (>2000 counts/min) (women 0.28, p < 0.01, men 0.25, p < 0.01). The intra-class correlation coefficient between self-reported leisure PA and overall PA (counts/min) measured by accelerometer was 0.62 (95% CI 0.51, 0.71) for women and 0.59 (95% CI 0.47, 0.69) for men, and for VO2max the intra-class correlation coefficient was 0.86 (95% CI 0.81, 0.90) for both sexes. Among all participants, an inverse dose—response relationship was observed between self-reported leisure PA and resting heart rate for both men and women (p < 0.0001). More women than men met the international recommendations of 10,000 step counts/day (27% vs. 22%) and the recommendation of at least 30 minutes/day of moderate-to-vigorous intensities (30% vs. 22 %). Conclusions: The Tromsø physical activity questionnaire has acceptable validity and provides valid estimates of high-intensity leisure activity. However, these results underscore the need for collecting objectively PA measurements in large epidemiological studies.

Consumption of seafood: the influence of overweight and health beliefs

Abstract This study investigated the relationship between self reported body weight and health perceptions and choice of seafood in a region with a traditionally high-level of fish consumption. A random sample of women aged 45–69 years who live in northern Norway answered a self-administrated questionnaire about eating habits, socioeconomic factors and questions related to health sent to them by mail; 7556 women answered the questionnaire (56.1% response rate) which was analyzed by logistic regression methods in which odds ratios (OR) were calculated. The mean frequency of consumption of seafood was 15 times a month. Some 46% of the respondents were overweight, 77% agreed that food is important for health and 55% had a desire to reduce weight. Overweight women consumed less lean fish than normal weight women (OR=0.8). Fish consumption was not associated with the desire to reduce weight. Fat and lean fish, but not processed fish, consumption are associated with the perception that food is important for health. A generally healthy food consumption pattern was strongly associated with weekly fish consumption, with normal weight and with the desire to reduce weight. Very high family income was associated with higher fat fish consumption (OR=1.9) normal body weight and for the desire to reduce weight (OR=2.1). High fish consumption in childhood and the belief that food is important for health were strongly associated with high fish consumption (OR=2.1 and 1.4 respectively for lean fish). Kids 60 years compared with 45–49 years). It is concluded that the desire to reduce weight does not influence fish consumption, but overweight women consume less lean fish than women of normal weight. Normal body weight and the desire to reduce overweight are associated with a broader healthy lifestyle pattern, in which seafood has a role in the diet. Higher fish consumption is associated with increasing consumers’ belief and behavior according to foods importance to health, high fish consumption in childhood and a higher level of education and income.

Hormone replacement therapy in Norwegian women 1996-1997.

OBJECTIVES To assess the prevalence of hormone replacement therapy (HRT) among Norwegian women and examine factors related to use. MATERIALS AND METHODS A random sample of 18,199 Norwegian women aged 45-64 years responded to a postal questionnaire in 1996-1997. The questionnaire included questions about menstruation status and fertility, oral contraceptives (OC) and HRT use, lifestyle, health and socio-economic status. The response rate was 60%. RESULTS Overall prevalence of ever using systemic or local HRT was 43.9%. Current use was reported by 31.9% of the women. The highest prevalence was in the age group of 55-59 years where 57.4% reported ever use, and 43.1% current use. Mean duration of use among current users was 4.6 years. More than 60% of the women were classified as postmenopausal, two-thirds of them naturally postmenopausal. The prevalence of ever using HRT was 51.8%. Prevalence of use was higher among earlier OC users, smokers, lean women and in households with high income. Among older women, users had a higher educational level than non-users, while this difference disappeared among the youngest of the women. Fixed combinations of estradiol and noretisteroneacetate either cyclic or continuous, are used by six out of ten users. CONCLUSIONS Our results confirm the increasing trend in sales of estrogens in Norway and suggest that user patterns are changing. More than four out of ten women aged 45-64 years reported ever use of HRT, and one out of three reported current use. Socio-economic differences between users and non-users seem to disappear among women under 55 years of age, but persist in the older age groups. Short time use still dominates.

Patterns of medicine use in a general population (0-80 years). The Influence of age, gender, diseases and place of residence on drug use in Norway.

Data from the Norwegian Health Survey, a national cross‐sectional study, were collected through interviews with a randomly drawn sample of members of private households, including 5454 women and 5122 men (0–80+ years) in 1985. The response rate was 78.7%. They were interviewed at home and asked questions regarding health conditions and drug use in the preceding 14 days due to diseases, illnesses or injuries. Drug use decreased with age in childhood, but the overall age trend showed an increase with age. The gender differences were observed through the childbearing years (15–49 years) and above 70 years of age. Higher medicine use in women compared with men was due to a higher frequency of diagnoses of diseases/illnesses/injuries and a higher medicine use among those women with a diagnosis. Higher medicine use among women due to womens reproductory role can only be a part of the explanation. The gender difference in medicine use was also distinct after the menopause. Use of both prescribed and non‐prescribed medicines was sporadic, and self‐medication decreased in both sexes when obtaining medicines from the doctor. The regional variations in self‐reported medicine use were mainly due to variation in the frequency of self‐reported diseases/illnesses/injuries.