No change in 24-h sodium intake estimated from spot urine in Norwegian adults from 2006 to 2019: the population-based Trøndelag Health Study (HUNT)

OBJECTIVE

Monitoring time trends in salt consumption is important for evaluating the impact of salt reduction initiatives on public health outcomes. There has so far not been available data to indicate if salt consumption in Norway has changed during the previous decade. We aimed to assess whether average 24-h salt intake estimated from spot urine samples in the adult population of mid-Norway changed from 2006-2008 to 2017-2019 and to describe variations by sex, age and educational level.

DESIGN

Repeated cross-sectional studies.

SETTING

The population-based Trøndelag Health Study (HUNT).

PARTICIPANTS

In each of two consecutive waves (HUNT3: 2006-2008 and HUNT4: 2017-2019), spot urine samples were collected from 500 men and women aged 25-64 years, in addition to 250 men and women aged 70-79 years in HUNT4. Based on spot urine concentrations of Na, K and creatinine and age, sex and BMI, we estimated 24-h Na intake using the International Cooperative Study on Salt and Blood Pressure (INTERSALT) equation for the Northern European region.

RESULTS

Mean (95 % CI) estimated 24-h salt intakes in men were 11·1 (95 % CI 10·8, 11·3) g in HUNT3 and 10·9 (95 % CI 10·6, 11·1) g in HUNT4, P = 0·25. Corresponding values in women were 7·7 (95 % CI 7·5, 7·9) g and 7·7 (95 % CI 7·5, 7·9) g, P = 0·88. Mean estimated salt intake in HUNT4 decreased with increasing age in women, but not in men, and it did not differ significantly across educational level in either sex.

CONCLUSIONS

Estimated 24-h salt intake in adult men and women in mid-Norway did not change from 2006-2008 to 2017-2019.

Program for data extraction in primary health records: a valid tool for knowledge production in general practice?

Objectives

Research in general practice demands it-tools which give the practitioner trusty results. Medrave 4 is a program designed for extraction of data from all areas of the health record. We wanted to do research on the database in a health center, but found no proof of the quality of the data extracted by Medrave 4. Today the database contains about 40,000 records. In this study we wanted to examine if the program could extract correct data.

Results

From the database 20 records were randomly selected from five different time periods, making a total of 100 records. 14 records did not meet the inclusion criteria, resulting in 86 records included in the study. In phase one these variables were registered manually from the records: Age, gender, systolic and diastolic blood pressure (from free text) and six different laboratory tests. In phase two, Medrave 4 extracted the same variables from the same records. Medrave 4 found correct systolic and diastolic blood pressure values in 79 records (92%). The laboratory results were extracted correct in all 86 records (100%). We conclude that Medrave 4 can be a useful tool in quantifying the work of general practitioners.

May telephone surveys provide reliable public health surveillance data for municipalities? Mode effects differ between categories of questions. The HUNT Study, Norway

Background: Availability of data on health and its determinants at the local area level is a prerequisite for developing interventions and public health campaigns locally. Collecting self-reported data by means of telephone interviews may rapidly provide relevant data. The reliability of such data may be questioned. In this study, we sought to compare exact similar questions addressed by a recent telephone survey with a previous large scale and very comprehensive population health survey (The Nord-Trøndelag Health Study 2006-08 – HUNT3), conducted a few years earlier in the same geographical region. This was done in order to examine the reliability of telephone interviews as a method to provide data on health and determinants to enable municipal authorities to get a sufficient overview.Methods: One rural and one urban municipality covered by HUNT3 using paper questionnaires were resurveyed through computer assisted telephone interviews. The weighted results for 34 dichotomized variables were compared using chi square tests.Results: The comparison of results between the rural and the urban samples and HUNT3 involved 68 chi square tests, 25 of which (38%) displayed significant differences. The ability of the telephone survey to replicate the results from HUNT3 was only moderate, but with differences between survey themes. Comparability was poor for adverse life events and mental health factors, fair for behavioural and risk factors, and skewed for general health and life satisfaction. The replication was good for reports on the less sensitive and subjective theme of cultural participation.Conclusion: The comparability of the data differed between themes. The differences may be ascribed to mode effects and to some extent the time lag between the surveys. Because replicability on issues that may be more embarrassing or stressful to recall appears to be poorer, and the more subjective self-assessments of health and well-being appear skewed, it is reasonable to conclude that there is an interviewer effect in the telephone survey. The use of a questionnaire through mail or web to monitor public health in municipalities should be considered as an alternative.

Validity of the FINDRISC as a prediction tool for diabetes in a contemporary Norwegian population: a 10-year follow-up of the HUNT study

OBJECTIVE

The Finnish Diabetes Risk Score (FINDRISC) is a recommended tool for type 2 diabetes prediction. There is a lack of studies examining the performance of the current 0-26 point FINDRISC scale. We examined the validity of FINDRISC in a contemporary Norwegian risk environment.

RESEARCH DESIGN AND METHODS

We followed 47 804 participants without known diabetes and aged ≥20 years in the HUNT3 survey (2006-2008) by linkage to information on glucose-lowering drug dispensing in the Norwegian Prescription Database (2004-2016). We estimated the C-statistic, sensitivity and specificity of FINDRISC as predictor of incident diabetes, as indicated by incident use of glucose-lowering drugs. We estimated the 10-year cumulative diabetes incidence by categories of FINDRISC.

RESULTS

The C-statistic (95% CI) of FINDRISC in predicting future diabetes was 0.77 (0.76 to 0.78). FINDRISC ≥15 (the conventional cut-off value) had a sensitivity of 38% and a specificity of 90%. The 10-year cumulative diabetes incidence (95% CI) was 4.0% (3.8% to 4.2%) in the entire study population, 13.5% (12.5% to 14.5%) for people with FINDRISC ≥15 and 2.8% (2.6% to 3.0%) for people with FINDRISC <15. Thus, FINDRISC ≥15 had a positive predictive value of 13.5% and a negative predictive value of 97.2% for diabetes within the next 10 years. To approach a similar sensitivity as in the study in which FINDRISC was developed, we would have to lower the cut-off value for elevated FINDRISC to ≥11. This would yield a sensitivity of 73%, specificity of 67%, positive predictive value of 7.7% and negative predictive value of 98.5%.

CONCLUSIONS

The validity of FINDRISC and the risk of diabetes among people with FINDRISC ≥15 is substantially lower in the contemporary Norwegian population than assumed in official guidelines. To identify ~3/4 of those developing diabetes within the next 10 years, we would have to lower the threshold for elevated FINDRISC to ≥11, which would label ~1/3 of the entire adult population as having an elevated FINDRISC necessitating a glycemia assessment.

The association of high sensitivity C-reactive protein and incident Alzheimer disease in patients 60 years and older: The HUNT study, Norway

Background

With ageing, long-standing inflammation can be destructive, contributing to development of several disorders, among these Alzheimer’s disease (AD). C-reactive protein (CRP) is a relatively stable peripheral inflammatory marker, but in previous studies the association between highly sensitive CRP (hsCRP) and AD have shown inconsistent results. This study examines the association between AD and hsCRP in blood samples taken up to 15 years prior to the diagnoses of 52 persons with AD amongst a total of 2150 persons ≥60 years of age.

Results

Data from Norway’s Nord-Trøndelag Health Study (HUNT 2) and the Health and Memory Study (HMS) were linked. The participants had an average age of 73 years, and diagnosed with AD up to 15 years [mean 8.0 (±3.9)] following hsCRP measurement. Logistic regression models showed an adverse association between hsCRP and AD in participants aged 60-70.5 (odds ratio: 2.37, 95% CI: 1.01-5.58). Conversely, in participants aged 70.6-94, there was an inverse association between hsCRP and AD (odds ratio: 0.39, 95% CI: 0.19-0.84). When applying multivariate models the findings were significant in individuals diagnosed 0.4-7 years after the hsCRP was measured; and attenuated when AD was diagnosed more than seven years following hsCRP measurement.

Conclusions

Our study is in line with previous studies indicating a shift in the association between hsCRP and AD by age: in adults (60-70.5 years) there is an adverse association, while in seniors (>70.6 years) there is an inverse association. If our findings can be replicated, a focus on why a more active peripheral immune response may have a protective role in individuals ≥70 years should be further examined.

Basic lifestyle advice to individuals at high risk of type 2 diabetes: a 2-year population-based diabetes prevention study. The DE-PLAN intervention in the HUNT Study, Norway

OBJECTIVE

Among individuals at high risk for diabetes identified through a population survey, we performed an intervention study with basic lifestyle advice aiming to prevent diabetes.

RESEARCH DESIGN AND METHODS

Among 50 806 participants in the HUNT3 Survey (2006-2008), 5297 individuals with Finnish Diabetes Risc Score (FINDRISC ≥15 were invited to an oral glucose tolerance test (OGTT) and an education session with lifestyle advice, and 2634 (49.7%) attended. Among them, 2380 people without diabetes were included in the prevention study with repeated examinations and education sessions after 6, 12, and 24 months. We examined participation, diabetes incidence, glycemia, and adiposity during follow-up.

RESULTS

Of 2380 participants, 1212 (50.9%) participated in ≥3 of the four examinations. Diabetes was detected in 3.5%, 3.1%, and 4.0% of individuals at the 6-month, 12-month, and 24-month examinations, respectively, indicating a 10.3% 2-year diabetes incidence. Mean (95% CI) increases from baseline to 2-year follow-up were 0.30 (0.29 to 0.32) percentage points (3.3 (3.2 to 3.5) mmol/mol) for Hemoglobin A_1c, 0.13 (0.10 to 0.16) mmol/L for fasting serum-glucose, 0.46 (0.36 to 0.56) mmol/L for 2-hour OGTT s-glucose, 0.30 (0.19 to 0.40) kg/m² forbody mass index (BMI) (all p<0.001) and -0.5 (-0.9 to -0.2) cm for waist circumference (p=0.004), with broadly similar estimates by baseline age, sex, education, depressive symptoms, BMI, physical activity, and family history of diabetes. Only 206 (8.7%) participants had evidence of >5% weight loss during follow-up; their fasting and 2-hour s-glucose did not increase, and HbA_1c increased less than in other participants.

CONCLUSION

Basic lifestyle advice given to high-risk individuals during three group sessions with 6-month intervals was not effective in reducing 2-year diabetes risk.

Are elderly HUNT participants healthier than before?

BACKGROUND

Since the number of elderly people will rise in the years to come, knowledge about their health trends is important for social planning. The objective of this study was to investigate trends in health development among elderly people over 70 years in Nord-Trøndelag county.

MATERIAL AD METHOD

In the Nord-Trøndelag Health Study (HUNT) we have collected health data over three rounds: HUNT1 (1984 – 86), HUNT2 (1995 – 97) and HUNT3 (2006 – 08). Using cross-sectional analyses, we have studied changes in self-reported health, level of functioning and the use of health services. The material includes 12 391 persons (85 % participation) in HUNT1, 11 069 (69.3 % participation) in HUNT2 and 8 194 in HUNT3 (54.7 % participation).

RESULTS

Subjective health and activities of daily living (ADL functions) were assessed as better in HUNT3 than in HUNT2. Self-reported physical activity increased from HUNT1 to HUNT3. The use of home-help services decreased from HUNT2 to HUNT3, while the use of nursing homes and home nursing services remained unchanged. The use of general practitioner services increased in all periods, while the use of outpatient services increased strongly from HUNT1 to HUNT2.

INTERPRETATION

It appears that the elderly inhabitants of Nord-Trøndelag county feel that their health has improved and that they have become more self-reliant and more physically active in the period from 1984 to 2008, but the findings need to be interpreted with some caution due to the decline in the participation rate from HUNT1 to HUNT3.

Association between blood pressure and Alzheimer disease measured up to 27 years prior to diagnosis: the HUNT Study

Background

A lot of attention has been paid to the relationship of blood pressure and dementia because epidemiological research has reported conflicting evidence. Observational data has shown that midlife hypertension is a risk factor for cognitive decline and dementia later in life, whereas there is evidence that low blood pressure is predictive in later life. The aim of the present study was to examine the association between dementia and blood pressure measured up to 27 years (mean 17.6 years) prior to ascertainment.

Methods

In Nord-Trøndelag County, Norway, incident dementia data were collected during 1995–2011, and the diagnoses were validated by a panel of experts in the field. By using the subjects’ personal identification numbers, the dementia data were linked to data from the Nord-Trøndelag Health Study (the HUNT Study), a large, population-based health study performed in 1984–1986 (HUNT 1) and 1995–1997 (HUNT 2). A total of 24,638 participants of the HUNT Study were included in the present study, 579 of whom were diagnosed with Alzheimer disease, mixed Alzheimer/vascular dementia, or vascular dementia. Multiple logistic regression analyses were conducted to analyze the association between dementia and blood pressure data from HUNT 1 and HUNT 2.

Results

Over the age of 60 years, consistent inverse associations were observed between systolic blood pressure and all-cause dementia, mixed Alzheimer/vascular dementia, and Alzheimer disease, but not with vascular dementia, when adjusting for age, sex, education, and other relevant covariates. This was observed for systolic blood pressure in both HUNT 1 and HUNT 2, regardless of antihypertensive medication use. There was an adverse association between systolic blood pressure, pulse pressure, and Alzheimer disease in individuals treated with antihypertensive medication under the age of 60 years.

Conclusions

Our data are in line with those in previous studies demonstrating an inverse association between dementia and systolic blood pressure in individuals over the age of 60 years. We cannot exclude a survival effect, however. Among middle-aged subjects (<60 years), elevated systolic blood pressure and pulse pressure were associated with eventual Alzheimer disease in individuals who reported using antihypertensive medication.

Electronic supplementary material

The online version of this article (doi:10.1186/s13195-017-0262-x) contains supplementary material, which is available to authorized users.

The impact of iron status and smoking on blood divalent metal concentrations in Norwegian women in the HUNT2 Study

Low iron (Fe) stores may result in increased absorption of divalent metals, in particular cadmium (Cd). We have previously shown that in non-smoking women participating in the Norwegian HUNT2 cohort study this also included other divalent metals, e.g. manganese (Mn) and cobalt (Co). The diet is the main source of metals in non-smoking individuals, whereas in smoking individuals tobacco smoke contributes significant amounts of Cd and lead (Pb). The aim of the present study was to investigate the impact of smoking on the relationship between low iron status and divalent metals. Blood concentrations of the divalent metals Cd, Mn, Co, Pb, copper (Cu) and zinc (Zn), determined using an Element 2 sector field mass spectrometer (ICP-MS), were investigated in smoking women of fertile age (range 21-55 years) (n=267) from the HUNT2 cohort. Among these, 82 were iron-deplete (serum ferritin<12μg/L) and 28 had iron deficiency anaemia (serum ferritin<12μg/L & Hb<120g/L). 150 (56%) women smoked 10 or more cigarettes daily, 101 (38%) had smoked for more than 20 years, and 107 (40%) had smoked for 11-20 years. Results from the smoking population were compared with results from our previous study in non-smoking women (n=448) of which 132 were previous smokers, all from the same cohort. Increasing concentrations of Cd in blood were observed for previous smokers, low-to-moderate smokers and high intensity smokers in all subgroups compared to never smokers, and according to age groups, education level, BMI and serum ferritin. Smokers had higher Pb concentrations than non-smokers in all subgroups, but less pronounced than for Cd. Smoking was not associated with Mn and Co concentrations in blood. In multiple regression models, low ferritin was associated with increased blood concentrations of Cd, Pb, Mn and Co. Ferritin was strongly associated with Cd at low smoking intensity, but was not a significant factor in heavy smokers, where intensity and duration of smoking emerged as main determinants. Ferritin associations with Co and Pb varied with tertiles of blood Cd. Ferritin emerged as the main determinant of blood Co and Mn, while for blood Pb, age and smoking intensity had higher impact. Cu and Zn remained within reference values and no significant associations with ferritin were found. Strong positive associations between blood concentrations of Pb, Mn, Cd and Co were observed, also when controlled for their common association with ferritin. Apart from these associations, the models showed no significant interactions between the divalent metals studied. Mild anaemia (110<Hb<120g/L) did not seem to have any effect independent of low ferritin. The results indicate that low serum ferritin facilitates absorption of certain divalent metal ions in female smokers as well as the previously shown effect in non-smokers. Even if smoking provides Pb and Cd, the mutual associations between Cd and other divalent metals in blood persisted in medium and heavy smokers. This indicates that the interrelationship between Cd and divalent metals not only reflect effects on the absorption, but possibly also on kinetic processes such as transportation in blood and other compartments, including excretion.

The genetics of blood pressure regulation and its target organs from association studies in 342,415 individuals

To dissect the genetic architecture of blood pressure and assess effects on target organ damage, we analyzed 128,272 SNPs from targeted and genome-wide arrays in 201,529 individuals of European ancestry, and genotypes from an additional 140,886 individuals were used for validation. We identified 66 blood pressure-associated loci, of which 17 were new; 15 harbored multiple distinct association signals. The 66 index SNPs were enriched for cis-regulatory elements, particularly in vascular endothelial cells, consistent with a primary role in blood pressure control through modulation of vascular tone across multiple tissues. The 66 index SNPs combined in a risk score showed comparable effects in 64,421 individuals of non-European descent. The 66-SNP blood pressure risk score was significantly associated with target organ damage in multiple tissues but with minor effects in the kidney. Our findings expand current knowledge of blood pressure-related pathways and highlight tissues beyond the classical renal system in blood pressure regulation.

Kultur og helse i HUNT – En metodeevaluering

Flere studier har indikert at det er sammenheng mellom kulturdeltagelse og helse, men mange av studienehar vesentlige svakheter. Befolkningsstudier med et stort antall deltagere har flere fordeler, bl.a. er det muligå kontrollere for konfunderende faktorer. Men i slike undersøkelser må antall spørsmål ofte begrenses,og det kan derfor stilles spørsmål ved hvor presis og relevant informasjonen blir. Ved HUNT3 (2006-08)ble to spørsmål om kulturdeltagelse inkludert: «Hvor mange ganger har du i løpet av de siste 6 månedervært på/i: Museum, kunstutstilling/konsert, teater, kino/kirke, bedehus/idrettsarrangement", og «Hvormange ganger har du løpet av de siste 6 måneder selv drevet med: Foreningsvirksomhet/musikk, sang,teater/menighetsarbeid/friluftsliv/dans/trening, idrett». Målet med denne studien var å undersøke hvordanspørsmålene ble oppfattet og tolket. Var informasjonen relevant til bruk i en epidemiologisk studie somHUNT? Det ble gjennomført tre fokusgruppeintervjuer med til sammen 17 deltakere i alderen 20 til 80 år.Flertallet hadde høyere utdanning. Tema som gikk igjen ble gruppert i kategorier, som bestod av beskrivelserover informantenes synspunkter og meninger. Hovedinntrykket fra fokusgruppeintervjuene var atinformantene mente at spørsmålene i HUNT3 ga et grovt estimat på kulturaktivitetene i befolkningen. Vårkonklusjon er at spørsmålene var tilstrekkelig presise til å bruke i analyser på gruppenivå.

Blood pressure changes during 22-year of follow-up in large general population - the HUNT Study, Norway

Background

While hypertension still is a major health problem worldwide, some studies have indicated that the blood pressure level has decreased in some populations. This population based cohort study aims at analysing blood pressure changes in a large Norwegian population over a 22 year period.

Methods

Data is acquired from three comprehensive health surveys of the HUNT Study conducted from 1984–86 to 2006–08. All citizens of Nord-Trøndelag County, Norway, >20 years were invited: 74,549 individuals participated in 1984–86; 64,523 in 1995–97; and 43,905 in 2006–08.

Results

Both systolic and diastolic blood pressure levels decreased substantially from mid 1980s to mid 2000s, with the most pronounced decrease from 1995–97 to 2006–08 (from 136.0/78.9 to 128.3/70.9 mmHg in women and from 140.1/82.1 to 133.7/76.5 mmHg in men). Although the use of blood pressure lowering medication increased, there was a considerable decrease even in those who reported never use of medication (mean decrease 6.8/7.2 mmHg in women and 6.3/5.3 mmHg in men), and the decrease was most pronounced in the elderly (mean decrease 16.1/12.4 mmHg in women and 14.7/10.4 mmHg in men aged 80+). Mean heart rate, total cholesterol and daily smoking decreased, self-reported hard physical activity increased, while body weight and the prevalence of diabetes increased during the same period.

Conclusions

The BP decrease might seem paradoxically, as body weight and prevalence of diabetes increased during the same period. Salt consumption might have decreased, but no salt data is available. The parallel decrease in mean heart rate might indicate reduction in the white-coat phenomenon, or increased use of beta blockers or calcium channel blockers for other diagnosis than hypertension. Additionally, the data could support the “healthy obese” hypothesis, i.e., that subgroups in the population can sustain obesity without serious health consequences.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0257-8) contains supplementary material, which is available to authorized users.

Impact of sex and age on the performance of FINDRISC: the HUNT Study in Norway

OBJECTIVE

The Finnish Diabetes Risk Score (FINDRISC) is recommended as a screening tool for diabetes risk. However, there is a lack of well-powered studies examining the performance of FINDRISC by sex and age. We aim to estimate, by sex and age, the prevalence of elevated FINDRISC and positive predictive value (PPV) of FINDRISC for identifying impaired glucose metabolism (IGM) in a general Norwegian population.

RESEARCH DESIGN AND METHODS

We estimated the prevalence of elevated FINDRISC (≥15) among 47 694 adults in the third survey of the Nord-Trøndelag Health Study (HUNT3, 2006-08). Among 2559 participants who participated in oral glucose tolerance testing, we estimated the PPV of elevated FINDRISC for identifying unknown prevalent diabetes and other forms of IGM.

RESULTS

The prevalence of elevated FINDRISC was 12.1% in women, 9.6% in men, and increased from 1.5% at age 20-39 to 25.1% at age 70-79 years. The PPVs of elevated FINDRISC were 9.8% for diabetes, 16.9% for impaired glucose tolerance, 8.2% for impaired fasting glucose, and 34.9% for any form of IGM. The PPV for IGM was lower in women (31.2%) than in men (40.4%), and increased from 19.1% at age 20-39 to 55.5% at age ≥80 years.

CONCLUSIONS

FINDRISC identified more women than men as high-risk individuals for diabetes. FINDRISC had a high PPV for detecting prevalent IGM, and the PPV was higher in men than in women and in the older individuals. Our data indicate that the impact of sex and age on diabetes risk is not fully captured by FINDRISC, and that refinements to it might improve diabetes prediction.

Genetic Effects on Longitudinal Changes from Healthy to Adverse Weight and Metabolic Status – The HUNT Study

Introduction

The complexity of obesity and onset and susceptibility of cardio-metabolic disorders are still poorly understood and is addressed here through studies of genetic influence on weight gain and increased metabolic risk longitudinally.

Subjects/Methods

Twenty seven previously identified obesity, eating disorder or metabolic risk susceptibility SNPs were tested for association with weight or metabolically related traits longitudinally in 3999 adults participating both in the HUNT2 (1995–97) and HUNT3 (2006–08) surveys. Regression analyses were performed with changes from normal weight to overweight/obesity or from metabolically healthy to adverse developments with regards to blood pressure, glucose, HDL cholesterol, triglycerides or metabolic syndrome as outcomes. Additionally, a sub-sample of 1380 adolescents was included for testing association of nine SNPs with longitudinal weight gain into young adulthood.

Results

The most substantial effect on BMI-based weight gain from normal to overweight/obesity in adults was observed for the DRD2 variant (rs6277)(OR: 0.79, 95% CI: 0.69–0.90, P = 3.9x10^-4, adj. P = 0.015). DRD2 was not associated with BMI on a cross-sectional level. In the adolescent sample, FTO (rs1121980) was associated with change to overweight at adulthood in the combined male-female sample (OR: 1.27, 95% CI: 1.09–1.49, P = 3.0x10^-3, adj. P = 0.019) and in females (OR: 1.53, 95% CI: 1.23–1.91, P = 1.8x10^-4, adj. P = 0.003). When testing for association to longitudinal adverse developments with regard to blood pressure, blood lipids and glucose, only rs964184 (ZNF259/APOA5) was significantly associated to unfavourable triglyceride changes (OR: 1.66, 95% CI: 1.36–2.03, P = 5.7x10^-7, adj. P = 0.001). Pleiotropic effects on metabolic traits, however, were observed for several genetic loci cross-sectionally, ZNF259/APOA5, LPL and GRB14 being the most important.

Conclusions

DRD2 exhibits effects on weight gain from normal weight to overweight/obesity in adults, while, FTO is associated to weight gain from adolescence to young adulthood. Unhealthy longitudinal triglyceride development is strongly affected by ZNF259/APOA. Our main finding, linking the DRD2 variant directly to the longitudinal weight gain observed, has not previously been identified. It suggests a genetic pre-disposition involving the dopaminergic signalling pathways known to play a role in food reward and satiety linked mechanisms.

Modern biobanks in Norway

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Alcohol consumption and risk of dementia up to 27 years later in a large, population-based sample: the HUNT study, Norway

The relationship between alcohol consumption and dementia risk is unclear. This investigation estimates the association between alcohol consumption reported in a population-based study in the mid-1980s and the risk for dementia up to 27 years later. The entire adult population in one Norwegian county was invited to the Nord-Trøndelag Health Study during 1984–1986 (HUNT1): 88 % participated. The sample used in this study includes HUNT1 participants born between 1905 and 1946 who completed the questionnaire assessing alcohol consumption. A total of 40,435 individuals, of whom 1084 have developed dementia, are included in the analysis adjusted for age, sex, years of education, hypertension, obesity, smoking, and symptoms of depression. When adjusting for age and sex, and compared to reporting consumption of alcohol 1–4 times during the last 14 days (drinking infrequently), both abstaining from alcohol and reporting consumption of alcohol five or more times (drinking frequently) were statistically significantly associated with increased dementia risk with hazard ratios of 1.30 (95 % CI 1.05–1.61) and 1.45 (1.11–1.90), respectively. In the fully adjusted analysis, drinking alcohol frequently was still significantly associated with increased dementia risk with a hazard ratio of 1.40 (1.07–1.84). However, the association between dementia and abstaining from alcohol was no longer significant (1.15, 0.92–1.43). Equivalent results for Alzheimer’s disease and vascular dementia indicated the same patterns of associations. When adjusting for other factors associated with dementia, frequent alcohol drinking, but not abstaining from alcohol, is associated with increased dementia risk compared to drinking alcohol infrequently.

Somatic health of patients at an outpatient clinic for substance abuse

BACKGROUND

Previous studies have detected a considerable degree of somatic illness among substance abusers. At our outpatient clinic for substance abuse we frequently find that referral documents provide scant information on somatic illnesses, and that patients complain of poor contact with their GP. We wished to investigate these issues.

MATERIAL AND METHOD

From September 2009 to November 2012 a total of 155 of 365 patients (42%) at an outpatient clinic for substance abuse at Levanger Hospital were included in the study. Information was gathered on somatic illnesses according to ICPC using patient-reported medical history, clinical examination, laboratory tests, review of somatic hospital records and/or information from GPs. Somatic health information in referral documents, supplementary information from GPs and patient-GP relationships were examined.

RESULTS

Altogether 119 men and 36 women with an average age of 41.7 years were included. Alcohol was the preferred intoxicant for 110 patients. We found an average of 4.2 disease diagnoses and 0.8 symptom diagnoses per patient. Dental disease was present in 69 patients, hypertension in 56, allergies in 45 and morbid obesity in 37. More serious diseases such as cancer and hepatic failure were detected. ECG showed pathology in 32 of 107 patients examined. A total of 101 referrals lacked information on somatic health. Sixty doctors replied to letters containing questions regarding somatic supplementary information. A total of 92 patients reported good or acceptable contact with their GP, 19 reported poor contact and 19 declined to answer the question, while 15 patients reported no contact and 10 reported that they had just changed their GP.

INTERPRETATION

The substance abusers in this study had several somatic diagnoses, and many reported poor contact with their GPs. There are grounds for questioning whether the requirements set by the specialist health service for adequate health provisions for patients at the outpatient clinic for substance abuse are being met.

Mental health and wellbeing in spouses of persons with dementia: the Nord-Trøndelag Health Study

Background

Caring for a spouse diagnosed with dementia can be a stressful situation and can put the caregiving partner at risk of loss of mental health and wellbeing. The main aim of this study was to investigate the relationship between dementia and spousal mental health in a population-based sample of married couples older than 55 years of age. The association was investigated for individuals living together with their demented partner, as well as for individuals whose demented partner was living in an institution.

Methods

Data on dementia were collected from hospitals and nursing homes in the county of Nord-Trøndelag, Norway. These data were combined with data on spousal mental health, which were collected in a population-based health screening: the Nord-Trøndelag Health Study (HUNT). Of 6,951 participating couples (>55 years), 131 included one partner that had been diagnosed with dementia.

Results

Our results indicate that after adjustment for covariates, having a partner with dementia is associated with lower levels of life satisfaction and more symptoms of anxiety and depression than reported by spouses of elderly individuals without dementia. Spouses living together with a partner diagnosed with dementia experienced moderately lower levels of life satisfaction (0.35 standard deviation [SD]) and more symptoms of depression (0.38 SD) and anxiety (0.23 SD) than did their non-caregiving counterparts. Having a partner with dementia that resided in a nursing home was associated with clearly lower life satisfaction. Compared with non-caregivers, these spouses reported lower levels of life satisfaction (1.16 SD), and also more symptoms of depression (0.38 SD), and more symptoms of anxiety (0.42 SD).

Conclusions

Having a partner with dementia is associated with loss of mental health and reduced life satisfaction. The risk of adverse mental health outcomes is greatest after the partner’s nursing home admission.

Cohort profile: the Health and Memory Study (HMS): a dementia cohort linked to the HUNT study in Norway

The aim of the Health and Memory Study (HMS) of Nord-Trøndelag, Norway, was primarily to establish a database suitable as basis for a large number of studies on dementia. Data from the HMS study were collected via questionnaires and examinations during the period from 1995 to 2011. The dementia panel consists of 620 participants residing in nursing homes and 920 participants referred to memory clinics of Nord-Trøndelag. Data from this dementia panel may be linked to the Nord-Trøndelag Health Study (the HUNT study), three large population based health surveys that took place in 1984-86 (HUNT1), 1995-97 (HUNT2) and 2006-08 (HUNT3). Data collection is complete and the participation rate in the HUNT1 for patients diagnosed with dementia was 86%. The sub-studies in the HMS are focused on examining risk factors, caregiver burden, healthcare consumption and economic consequences of treating and having dementia. Researchers interested in the HMS study are invited to contact HUNT at hunt@medisin.ntnu.no.

The prevalence of metabolic syndrome and metabolically healthy obesity in Europe: a collaborative analysis of ten large cohort studies

BACKGROUND

Not all obese subjects have an adverse metabolic profile predisposing them to developing type 2 diabetes or cardiovascular disease. The BioSHaRE-EU Healthy Obese Project aims to gain insights into the consequences of (healthy) obesity using data on risk factors and phenotypes across several large-scale cohort studies. Aim of this study was to describe the prevalence of obesity, metabolic syndrome (MetS) and metabolically healthy obesity (MHO) in ten participating studies.

METHODS

Ten different cohorts in seven countries were combined, using data transformed into a harmonized format. All participants were of European origin, with age 18-80 years. They had participated in a clinical examination for anthropometric and blood pressure measurements. Blood samples had been drawn for analysis of lipids and glucose. Presence of MetS was assessed in those with obesity (BMI ≥ 30 kg/m2) based on the 2001 NCEP ATP III criteria, as well as an adapted set of less strict criteria. MHO was defined as obesity, having none of the MetS components, and no previous diagnosis of cardiovascular disease.

RESULTS

Data for 163,517 individuals were available; 17% were obese (11,465 men and 16,612 women). The prevalence of obesity varied from 11.6% in the Italian CHRIS cohort to 26.3% in the German KORA cohort. The age-standardized percentage of obese subjects with MetS ranged in women from 24% in CHRIS to 65% in the Finnish Health2000 cohort, and in men from 43% in CHRIS to 78% in the Finnish DILGOM cohort, with elevated blood pressure the most frequently occurring factor contributing to the prevalence of the metabolic syndrome. The age-standardized prevalence of MHO varied in women from 7% in Health2000 to 28% in NCDS, and in men from 2% in DILGOM to 19% in CHRIS. MHO was more prevalent in women than in men, and decreased with age in both sexes.

CONCLUSIONS

Through a rigorous harmonization process, the BioSHaRE-EU consortium was able to compare key characteristics defining the metabolically healthy obese phenotype across ten cohort studies. There is considerable variability in the prevalence of healthy obesity across the different European populations studied, even when unified criteria were used to classify this phenotype.

Hypertension in patients with cranial nerve vascular compression syndromes and comparison with a population-based cohort

OBJECT

Although essential arterial hypertension (AH) represents a major health issue, its underlying causes remain unknown. An intriguing hypothesis is that AH in some cases may be caused by vascular compression of the rostral ventrolateral medulla (RVLM). Because hemifacial spasms (HFSs) are caused by vascular compression of the seventh cranial nerve in close proximity to the RVLM, one would, if this hypothesis is correct, expect to find a positive association between the occurrence of AH and chronic HFSs. Such a positive association would not be expected in patients with trigeminal neuralgia (TN), since TN is caused by vascular compression of the fifth cranial nerve, which is not close to the RVLM.

METHODS

In view of this background, the authors conducted a retrospective population-based study to investigate how the occurrence of AH in patients with either HFSs or TN compares with the prevalence of AH in the general population, when adjusted for sex and age. The general population was represented by participants of the Nord-Trøndelag Health Study 3 (HUNT3).

RESULTS

The prevalence of AH in the authors' patients with HFSs was significantly higher than in a sex- and age-adjusted sample from the general population; this was not true for the patients with TN.

CONCLUSIONS

The authors suggest that the data provide supporting evidence to the theory that compression of the RVLM may be one cause of AH.

Urinary albumin excretion as a marker of endothelial dysfunction in migraine sufferers: the HUNT study, Norway

OBJECTIVE

To investigate urine albumin leakage as a marker of endothelial dysfunction in migraine patients.

DESIGN

A population-based health study.

PARTICIPANTS

303 patients with migraine, 1009 patients with non-migraine headache and 5287 headache-free controls.

OUTCOMES

The association between urine albumin- to-creatine ratio (ACR) and headache status was investigated in the Nord-Trøndelag Health Study (HUNT-2). Patients were selected in two strata, based on either (1) self-reported hypertension/diabetes (morbid sample) or (2) a random sample. Analyses were performed using analysis of covariance.

RESULTS

There was no association between headache status and ACR in the study population (p=0.23, mean ACR for migraine 1.66, 95% CI 1.31 to 2.01, for non-migraine headache 1.90, 95% CI 1.71 to 2.09 and for no headache 1.73, 95% CI 1.64 to 1.81) after relevant adjustments. Similarly, no association between headache status and ACR was seen when the analysis was stratified for morbid and random samples, or for migraine with and without aura.

CONCLUSIONS

We found no evidence of increased urine albumin leakage in migraine sufferers when compared with headache-free controls. This could indicate that systemic endothelial dysfunction is not a prominent feature of migraine.

Low 25-hydroxyvitamin D level is independently associated with non-alcoholic fatty liver disease

BACKGROUND AND AIMS

We sought to explore associations between serum 25-hydroxyvitamin D [25(OH)D] levels and non-alcoholic fatty liver disease [NAFLD] in an integrated healthcare delivery system in the U.S.

METHODS AND RESULTS

Six hundred and seven NAFLD cases were randomly matched 1:1 with controls for age, sex, race and season of measurement. Conditional logistic regression was used to evaluate if serum 25(OH)D levels were associated with increased odds of NAFLD (diagnosed by ultrasound) after adjusting for body mass index and history of diabetes, renal, peripheral vascular and liver diseases (model 1) and also for hypertension (model 2). Mean (SD) serum 25(OH)D level was significantly lower in the group with NAFLD as compared with that in the matched control group (75 ± 17 vs. 85 ± 20 nmol/L [30 ± 7 vs. 34 ± 8 ng/mL], P<0.001). Inadequate 25(OH)D status progressively increased the odds of NAFLD when classified categorically as sufficient (25(OH)D 75 nmol/L [>30 ng/mL], reference group), insufficient (37-75 nmol/L [15-30 ng/mL]; adjusted odds ratio [OR]: 2.40, 95% confidence interval [CI]: 0.90-6.34) or deficient (<37 nmol/L [<15 ng/mL]; adjusted OR: 2.56, 95% CI: 1.27-5.19). When modeled as a continuous variable, increased log10 25(OH)D was inversely associated with the risk of prevalent NAFLD (adjusted OR: 0.25, 95% CI: 0.064-0.96, P=0.02).

CONCLUSION

Compared with matched controls, patients with NAFLD have significantly decreased serum 25(OH)D levels, suggesting that low 25(OH)D status might play a role in the development and progression of NAFLD.

Sedentary behaviour and risk of mortality from all-causes and cardiometabolic diseases in adults: evidence from the HUNT3 population cohort

BACKGROUND

Sedentary behaviour is a potential risk factor for chronic-ill health and mortality, that is, independent of health-enhancing physical activity. Few studies have investigated the risk of mortality associated with multiple contexts of sedentary behaviour.

OBJECTIVE

To examine the prospective associations of total sitting time, TV-viewing time and occupational sitting with mortality from all causes and cardiometabolic diseases.

METHODS

Data from 50,817 adults aged ≥20 years from the Nord-Trøndelag Health Study 3 (HUNT3) in 2006-2008 were linked to the Norwegian Cause of Death Registry up to 31 December 2010. Cox proportional hazards models examined all-cause and cardiometabolic disease-related mortality associated with total sitting time, TV-viewing and occupational sitting, adjusting for multiple potential confounders including physical activity.

RESULTS

After mean follow-up of 3.3 years (137,315.8 person-years), 1068 deaths were recorded of which 388 were related to cardiometabolic diseases. HRs for all-cause mortality associated with total sitting time were 1.12 (95% CI 0.89 to 1.42), 1.18 (95% CI 0.90 to 1.57) and 1.65 (95% CI 1.24 to 2.21) for total sitting time 4-<7, 7-<10 and ≥10 h/day, respectively, relative to <4 h/day after adjusting for confounders (p-trend=0.001). A similar pattern of associations was observed between total sitting time and mortality from cardiometabolic diseases, but TV-viewing time and occupational sitting showed no or borderline significant associations with all-cause or cardiometabolic disease-related mortality over the same follow-up period.

CONCLUSIONS

Total sitting time is associated with all-cause and cardiometabolic disease-related mortality in the short term. However, prolonged sitting in specific contexts (ie, watching TV, at work) do not adversely impact health in the same timeframe. These findings suggest that adults should be encouraged to sit less throughout the day to reduce their daily total sitting time.

Cohort profile of the Young-HUNT Study, Norway: a population-based study of adolescents

The Young-HUNT Study is the adolescent part (13-19 years) of HUNT, the Nord-Trøndelag Health Study, Norway. Three cross-sectional surveys have been conducted: Young-HUNT1 (1995-97), Young-HUNT2 (2000-01) and Young-HUNT3 (2006-08). Major public health issues, including somatic and mental health, quality of life and health behaviours are covered. Young-HUNT was performed in schools visited by trained nurses. Data collection included self-reported questionnaires, structured interviews, clinical measurements and, in Young-HUNT3, buccal smears. The total response rates varied from 90% to 83% and the Young-HUNT database includes 17 820 teenagers. Some Young-HUNT1 participants constitute the baseline for two follow-up studies: a 4-year follow-up through adolescence to Young-HUNT2 and an 11-year follow-up into young adulthood to the adult HUNT3. Longitudinal data are also obtained by linkage of data from Young-HUNT to different national health registers. Linkage to family registers allows the possibility of studying genetic and environmental interactions through generations. Presently 20 PhD students are working with the data, 11 Young-HUNT based PhD theses have been completed and more than 50 scientific papers published.

Trends in overweight and obesity over 22 years in a large adult population: the HUNT Study, Norway

Some reports indicate that the obesity epidemic may be slowing down or halting. We followed body mass index (BMI) and waist circumference (WC) in a large adult population in Norway (n = 90 000) from 1984-1986 (HUNT1) through 1995-1997 (HUNT2) to 2006-2008 (HUNT3) to study whether this is occurring in Norway. Height and weight were measured with standardized and identical methods in all three surveys; WC was also measured in HUNT2 and HUNT3. In the three surveys, mean BMI increased from 25.3 to 26.5 and 27.5 kg m^-2 in men and from 25.1 to 26.2 and 26.9 kg m^-2 in women. Increase in prevalence of obesity (BMI ≥ 30 kg m^-2) was greater in men (from 7.7 to 14.4 and 22.1%) compared with women (from 13.3 to 18.3 and 23.1%). In contrast, women had a greater increase in abdominal obesity (WC ≥ 102 cm for men and WC ≥ 88 cm for women). There was a continuous shift in the distribution curve of BMI and WC to the right, demonstrating that the increase in body weight was occurring in all weight groups, but the increase of obesity was greatest in the youngest age groups. Our data showed no signs of a halt in the increase of obesity in this representative Norwegian population.

The association between vascular factors and subjective memory impairment in older people: The HUNT Study, Norway

<p><em><strong>Objectives:</strong></em> Subjective memory impairment (SMI) is often considered an early sign of dementia. This study investigates the relationship between SMI and dementia-related vascular factors in older people.</p><p><em><strong>Method:</strong></em> This study was based on data from 12,255 individuals, 65 years and older, participating in the Nord-Trøndelag health study, third survey 2006-08 (HUNT3). SMI, vascular diseases, exercise, smoking, and alcohol consumption were self-reported. Blood pressure, cholesterol and body mass index (BMI) were clinically measured. SMI were predicted using linear regression analysis.</p><p><em><strong>Results:</strong></em> Stroke and heart disease were associated with SMI. High exercise intensity was associated with less SMI. Respondents with high systolic blood pressure (SBP) reported less SMI than those with moderate SBP. In men, low SBP was associated with significantly more SMI compared to those with moderate SBP. In women, moderate alcohol consumption compared to low alcohol consumption was associated with significantly more SMI.</p><p><em><strong>Conclusion:</strong></em> SMI was positively associated with stroke and heart disease in this study. For the other investigated vascular factors, we did not find strong relationships with SMI. However, for preventive and treatment purposes, it is noteworthy that high exercise intensity and high systolic blood pressure was associated with less SMI in both genders.</p>

Leisure time activities in adolescence in the presence of susceptibility genes for obesity: risk or resilience against overweight in adulthood? The HUNT study

BACKGROUND

Environment, health behavior, and genetic background are important in the development of obesity. Adolescents spend substantial part of daily leisure time on cultural and social activities, but knowledge about the effects of participation in such activities on weight is limited.

METHODS

A number of 1450 adolescents from the Norwegian HUNT study (1995-97) were followed-up in 2006-08 as young adults. Phenotypic data on lifestyle and anthropometric measures were assessed using questionnaires and standardized clinical examinations. Genotypic information on 12 established obesity-susceptibility loci were available for analyses. Generalized estimating equations were used to examine the associations between cultural and social activities in adolescence and adiposity measures in young adulthood. In addition, interaction effects of a genetic predisposition score by leisure time activities were tested.

RESULTS

In girls, participation in cultural activities was negatively associated with waist circumference (WC) (B = -0.04, 95%CI: -0.08 to -0.00) and with waist-hip ratio (WHR) (B = -0.058, 95%CI: -0.11 to -0.01). However, participation in social activities was positively associated with WC (B = 0.040, CI: 0.00 to 0.08) in girls and with BMI (B = 0.027, CI: 0.00 to 0.05) in boys. The effect of the obesity-susceptibility genetic variants on anthropometric measures was lower in adolescents with high participation in cultural activities compared to adolescents with low participation.

CONCLUSION

This study suggests that the effects of cultural activities on body fat are different from the effects of participation in social activities. The protective influence of cultural activities in female adolescents against overweight in adulthood and their moderating effect on obesity-susceptibility genes suggest that even cultural activities may be useful in public health strategies against obesity.

The HUNT study: participation is associated with survival and depends on socioeconomic status, diseases and symptoms

Background

Population based studies are important for prevalence, incidence and association studies, but their external validity might be threatened by decreasing participation rates. The 50 807 participants in the third survey of the HUNT Study (HUNT3, 2006-08), represented 54% of the invited, necessitating a nonparticipation study.

Methods

Questionnaire data from HUNT3 were compared with data collected from several sources: a short questionnaire to nonparticipants, anonymous data on specific diagnoses and prescribed medication extracted from randomly selected general practices, registry data from Statistics Norway on socioeconomic factors and mortality, and from the Norwegian Prescription Database on drug consumption.

Results

Participation rates for HUNT3 depended on age, sex and type of symptoms and diseases, but only small changes were found in the overall prevalence estimates when including data from 6922 nonparticipants. Among nonparticipants, the prevalences of cardiovascular diseases, diabetes mellitus and psychiatric disorders were higher both in nonparticipant data and data extracted from general practice, compared to that reported by participants, whilst the opposite pattern was found, at least among persons younger than 80 years, for urine incontinence, musculoskeletal pain and headache. Registry data showed that the nonparticipants had lower socioeconomic status and a higher mortality than participants.

Conclusion

Nonparticipants had lower socioeconomic status, higher mortality and showed higher prevalences of several chronic diseases, whilst opposite patterns were found for common problems like musculoskeletal pain, urine incontinence and headache. The impact on associations should be analyzed for each diagnosis, and data making such analyses possible are provided in the present paper.

Cohort Profile: the HUNT Study, Norway

The HUNT Study includes large total population-based cohorts from the 1980ies, covering 125 000 Norwegian participants; HUNT1 (1984-86), HUNT2 (1995-97) and HUNT3 (2006-08). The study was primarily set up to address arterial hypertension, diabetes, screening of tuberculosis, and quality of life. However, the scope has expanded over time. In the latest survey a state of the art biobank was established, with availability of biomaterial for decades ahead. The three population based surveys now contribute to important knowledge regarding health related lifestyle, prevalence and incidence of somatic and mental illness and disease, health determinants, and associations between disease phenotypes and genotypes. Every citizen of Nord-Trøndelag County in Norway being 20 years or older, have been invited to all the surveys for adults. Participants may be linked in families and followed up longitudinally between the surveys and in several national health- and other registers covering the total population. The HUNT Study includes data from questionnaires, interviews, clinical measurements and biological samples (blood and urine). The questionnaires included questions on socioeconomic conditions, health related behaviours, symptoms, illnesses and diseases. Data from the HUNT Study are available for researchers who satisfy some basic requirements (www.ntnu.edu/hunt), whether affiliated in Norway or abroad.

The relationship between religious attendance and blood pressure: the HUNT Study, Norway

OBJECTIVE

Research from the United States shows a possible relationship between religious attendance (RA) and blood pressure (BP). The religious context in the United States differs widely from Scandinavia. The aim was, therefore, to test whether the relationship between RA and BP is specific to the religious culture in the United States or whether a similar relationship exists between RA and BP in a Norwegian context.

DESIGN AND METHOD

Data from the Nord-Trøndelag Health Study's third wave, HUNT 3 (2006-08), was used. The associations between RA and diastolic (DBP) and systolic (SBP) blood pressure in women (n = 20,066) and men (n = 15,898) were investigated in a cross-sectional study using multiple regression analyses.

RESULTS

Mean DBP for women/men was 71.0 mmHg/76.7 mmHg. Mean SBP was 128.5 mmHg/134.0 mmHg; 39.1%/42.8% of women/men never attended religious services, 3.8%/3.4% attended more than 3x/month. The bivariate associations were statistically significant between RA and SBP in both genders and women's DBP but not men's DBP. After adjustment, inverse associations between RA and DBP/SBP for both genders were found. The RA-DBP relationship (p < 0.001) demonstrated a gradient in effect for both genders, with increasing RA associated with decreasing DBP, with 1.50/1.67 mmHg lower in women/men respectively in those attending more than 3x/month, 0.87/1.16 mmHg lower in those attending 1-3x/month, and 0.49/0.10 mmHg less in those attending 1-6x/6 months. Differences in RA-SBP (p < 0.05) were 2.12/1.71 mmHg, 0.30/0.11 mmHg, and 0.58/0.63 mmHg, respectively.

CONCLUSION

In a large population-based survey in Norway, RA was associated with lower DBP and SBP after adjusting for relevant variables.

Genome-wide association study to identify common variants associated with brachial circumference: a meta-analysis of 14 cohorts

Brachial circumference (BC), also known as upper arm or mid arm circumference, can be used as an indicator of muscle mass and fat tissue, which are distributed differently in men and women. Analysis of anthropometric measures of peripheral fat distribution such as BC could help in understanding the complex pathophysiology behind overweight and obesity. The purpose of this study is to identify genetic variants associated with BC through a large-scale genome-wide association scan (GWAS) meta-analysis. We used fixed-effects meta-analysis to synthesise summary results across 14 GWAS discovery and 4 replication cohorts comprising overall 22,376 individuals (12,031 women and 10,345 men) of European ancestry. Individual analyses were carried out for men, women, and combined across sexes using linear regression and an additive genetic model: adjusted for age and adjusted for age and BMI. We prioritised signals for follow-up in two-stages. We did not detect any signals reaching genome-wide significance. The FTO rs9939609 SNP showed nominal evidence for association (p<0.05) in the age-adjusted strata for men and across both sexes. In this first GWAS meta-analysis for BC to date, we have not identified any genome-wide significant signals and do not observe robust association of previously established obesity loci with BC. Large-scale collaborations will be necessary to achieve higher power to detect loci underlying BC.

Being Normal Weight but Feeling Overweight in Adolescence May Affect Weight Development into Young Adulthood-An 11-Year Followup: The HUNT Study, Norway

Objectives. To explore if self-perceived overweight in normal weight adolescents influence their weight development into young adulthood and if so, whether physical activity moderates this association. Methods. A longitudinal study of 1196 normal weight adolescents (13-19 yrs) who were followed up as young adults (24-30 yrs) in the HUNT study. Lifestyle and health issues were assessed employing questionnaires, and standardized anthropometric measurements were taken. Chi square calculations and regression analyses were performed to investigate the associations between self-perceived overweight and change in BMI or waist circumference (WC) adjusted for age, age squared, sex, and other relevant cofactors. Results. Adolescents, defined as being normal weight, but who perceived themselves as overweight had a larger weight gain into young adulthood than adolescents who perceived themselves as normal weight (difference in BMI: 0.66 units [CI95%: 0.1, 1.2] and in WC: 3.46 cm [CI95%: 1.8, 5.1]). Level of physical activity was not found to moderate this association. Conclusions. This study reveals that self-perceived overweight during adolescence may affect development of weight from adolescence into young adulthood. This highlights the importance of also focusing on body image in public health interventions against obesity, favouring a "healthy" body weight taking into account natural differences in body shapes.

Anxiety and depression lowers blood pressure: 22-year follow-up of the population based HUNT study, Norway

Background

For decades, symptoms of anxiety and depression have been included among psychological factors associated with development of hypertension. Although this has been questioned in recent studies, most findings have been based on a single assessment of mental distress at baseline. We examined these associations using repeated assessments of anxiety, depression and blood pressure.

Methods

Data on 17,410 men and women aged 20 to 67 participating in the Nord-Trøndelag Health Study (HUNT) in Norway in 1984-86 were re-examined 11 and 22 years later. The main outcome was change in mean blood pressure (mm Hg) during follow-up.

Results

We found that a high symptom level score (≥80^th percentile) of combined anxiety and depression at baseline, as compared to a lower symptom level, was associated with lower mean systolic (-0.67 mm Hg, p = 0.044) and diastolic (-0.25 mm Hg, p = 0.201) blood pressure at year 22. A high symptom level present at all three examinations was associated with a stronger decrease in mean systolic (-1.59 mm Hg, p = 0.004) and diastolic (-0.78 mm Hg, p = 0.019) blood pressure and with a 20% (p = 0.001) lower risk of developing hypertension (BP ≥140/90 mm Hg) at year 22. The associations were only slightly attenuated in multivariate analyses, with no evidence of a mediating effect of alteration in heart rate.

Conclusions

This study do not support previous hypothesis that emotional stress may be a cause of hypertension. Our findings indicate that symptoms of anxiety and depression are associated with decrease in blood pressure, particularly when a high symptom level can be detected over decades.

Kan apolipoprotein-nivåer målt fra opptinte blodprøver etter 12-14 års nedfrysing brukes for epidemiologiske formål? En pilotanalyse av HUNT 2-data

I Norge er det lagret store mengder nedfrosne blodprøver fra helseundersøkelser av ulike slag. Stabilitet av målinger av apolipoproteiner fra langtids nedfrosne blodprøver er lite dokumentert. Ny forståelse av lipoproteinenes fysiologi og betydning for utvikling av ateromatose reiser spørsmålet om andre lipoproteinkomponenter enn total (TC), LDL (LDL-C) og HDL-kolesterol (HDL-C) bør vurderes som risikomarkører. Ikke minst gjelder dette apolipoproteinene og balansen mellom apolipoprotein B (apoB) og apolipoprotein A-1 (apoA-1). Nedfrosne blodprøver kunne kanskje anvendes til å analysere sammenheng mellom nivåer på apolipoproteiner og utvikling av kardiovaskulære hendelser, hvis det ikke har skjedd vesentlige konsentrasjonsforandringer under lagring. For å undersøke dette ble det foretatt en pilotstudie av blodprøver fra 300 personer i HUNT 2. For disse hadde en ferske blodprøver, og i 2009 opptinte blodprøvemålinger av lipoproteiner samt apoB og apo A-1. Disse har bare vært lagret ved –40 ºC. Resultatene viste at TC var øket med 0,3 mmol/L fra fersk til smeltet tilstand til tross for at HDL-C var blitt redusert med 0,25 mmol/L. Korrelasjonene mellom ferske og opptinte prøver var høye (0,93-0,99). Variasjonskoeffisientene var derimot høye (5,8-13,7%) og endringene var nivåavhengige. Nivåene på apolipoproteinene var klart høyere, mens apoB/apoA-1 ratio samsvarte mer med andre studierapporter. Korrelasjonene mellom apo-og lipoproteiner var på et nivå man gjenfinner i andre studier. Resultatene må tolkes som bare indikative på at apolipoproteiner, og da spesielt ratio apoB/apoA-1, kan brukes i HUNT 2 til prognostiske studier av kardiovaskulære hendelser og død. Hoveddelen av HUNT 2 biobank har imidlertid ligget i ro i –80 ºC og lipoproteiner endres neppe ved denne temperatur. Prognostiske studier med apolipoproteiner som prediktorer burde derfor med rimelig sikkerhet kunne utføres i HUNT 2. Endelig bevis for dette kan imidlertid først oppnås når slike opptinte prøver blir analysert.Can frozen and thawed blood samples stored for 12-14 years be used to measure levels of apolipoproteins? Analysis from HUNT 2 data.            English Summary: In Norway, large numbers of frozen blood samples from health surveys are stored in freezers at –70 to –80 ºC. An assumption has been that levels of lipoproteins (total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG)) have been kept at constant levels during long-term storage. The stability of long-term storage of apolipoproteins is weakly documented. The Health Survey of Nord-Trøndelag in 1995-97 (HUNT 2) provides the possibility to analyse relationships between levels of lipoproteins and incident cardiovascular disease. A project group consisting of the present authors questioned whether use of apolipoproteins as risk markers may give at least as good predictive value as the traditional lipoproteins and whether the frozen samples in HUNT 2 can be used for this purpose. To investigate this issue a pilot study based on 300 thawed blood samples from HUNT 2 was performed. For these subjects lipoprotein levels measured at screening in 1995-97 were available as well as the same levels from the thawed samples including also apolipoprotein B (apoB) and apolipoprotein A-1 (apoA-1). For special reasons these samples had only been frozen down to –40 ºC.

A common haplotype in NAPEPLD is associated with severe obesity in a Norwegian population-based cohort (the HUNT study)

Obesity has a strong genetic etiology involving numerous identified metabolic pathways and others not yet examined. We investigated the association between severe obesity and genetic variation in selected candidate genes, including three drug-related genes: cannabinoid receptor 1 (CNR1), N-acyl phosphatidylethanolamine phospholipase D (NAPEPLD), and gastric lipase (LIPF); and three genes related to inflammation: nicotinamide phosphoribosyltransferase, six-transmembrane epithelial antigen of the prostate 4 (STEAP4) and interleukin 18 (IL-18). Subjects were 1,632 individuals with severe obesity (BMI ≥ 35 kg/m²) and 3,379 controls (BMI 20-24.9 kg/m²) that took part in a Norwegian population based cohort study. Tagging single-nucleotide polymorphisms (SNPs) of the coding region of these genes were analyzed. SNP-haplotypes for each gene were constructed in order to analyze allelic, genotypic, and haplotypic association to obesity. A single SNPs rs17605251 in NAPEPLD was nominally associated with BMI ≥ 35 kg/m² (P = 0.035). A common haplotype in NAPEPLD was associated with BMI ≥ 35 kg/m² after correction for multiple testing. The allele frequency was 56.8% in cases and 60.3% in controls, giving an odds ratio (OR) of 0.87 (95% confidence interval (CI) 0.79, 0.95; P = 0.0016). Homozygosity for this haplotype was protective against obesity (OR 0.79 (CI 0.70-0.91); P = 0.00059). The SNP rs7913071 in LIPF was associated with obesity, but the association lost statistical significance after correction for multiple testing. The CNR1, IL-18, STEAP4, and nicotinamide phosphoribosyltransferase genes were not associated with obesity. In conclusion a common haplotype in NAPEPLD, an enzyme involved in endocannabinoid synthesis, was protective against obesity.

Body mass index and mortality in elderly men and women: the Tromso and HUNT studies

BACKGROUND

The impact of body mass index (BMI; kg/m(2)) and waist circumference (WC) on mortality in elderly individuals is controversial and previous research has largely focused on obesity.

METHODS

With special attention to the lower BMI categories, associations between BMI and both total and cause-specific mortality were explored in 7604 men and 9107 women aged ≥ 65 years who participated in the Tromsø Study (1994-1995) or the North-Trøndelag Health Study (1995-1997). A Cox proportional hazards model adjusted for age, marital status, education and smoking was used to estimate HRs for mortality in different BMI categories using the BMI range of 25-27.5 as a reference. The impact of each 2.5 kg/m(2) difference in BMI on mortality in individuals with BMI < 25.0 and BMI ≥ 25.0 was also explored. Furthermore, the relations between WC and mortality were assessed.

RESULTS

We identified 7474 deaths during a mean follow-up of 9.3 years. The lowest mortality was found in the BMI range 25-29.9 and 25-32.4 in men and women, respectively. Mortality was increased in all BMI categories below 25 and was moderately increased in obese individuals. U-shaped relationships were also found between WC and total mortality. About 40% of the excess mortality in the lower BMI range in men was explained by mortality from respiratory diseases.

CONCLUSIONS

BMI below 25 in elderly men and women was associated with increased mortality. A modest increase in mortality was found with increasing BMI among obese men and women. Overweight individuals (BMI 25-29.9) had the lowest mortality.

A 7-year prospective study of sense of humor and mortality in an adult county population: the HUNT-2 study

OBJECTIVE

To prospectively explore the significance of sense of humor for survival over 7 years in an adult county population.

METHODS

Residents in the county of Nord-Trøndelag, Norway, aged 20 and older, were invited to take part in a public health survey during 1995-97 (HUNT-2), and 66,140 (71.2 %) participated. Sense of humor was estimated by responses to a cognitive (N = 53,546), social (N = 52,198), and affective (N = 53,132) item, respectively, taken from the Sense of Humor Questionnaire (SHQ). Sum scores were tested by Cox survival regression analyses applied to gender, age, and subjective health.

RESULTS

Hazard ratios were reduced with sense of humor (continuous scale: HR = 0.73; high versus low by median split: HR = 0.50) as contrasted with increase of HR with a number of classical risk factors (e.g., cardiovascular disease: HR = 6.28; diabetes: HR = 4.86; cancer: HR = 4.18; poor subjective health: HR = 2.89). Gender proved to be of trivial importance to the effect of sense of humor in survival. Subjective health correlated positively with sense of humor and therefore might have presented a spurious relation of survival with humor, but sense of humor proved to reduce HR both in individuals with poor and good subjective health. However, above age 65 the effect of sense of humor on survival became less evident.

CONCLUSION

Sense of humor appeared to increase the probability of survival into retirement, and this effect appeared independent of subjective health. Age under 65 mediated this effect, whereas it disappeared beyond this age.

FTO genotype and weight gain in obese and normal weight adults from a Norwegian population based cohort (the HUNT study)

The fat mass and obesity associated gene ( FTO) is associated with bodyweight and obesity. The aim of this study was to investigate if FTO genotype affects weight gain in adulthood. We investigated the weight development over a period of 11 years in a case-control study, consisting of 1,632 cases (BMI≥35 kg/m (2)) and 3,379 normal weight controls (BMI 20-24.9 kg/m (2)) from a Norwegian population based cohort, the HUNT study. Subjects were aged 20-80 at baseline, 25% men and 75% women. FTO genotype was assessed by genotyping of the SNP rs1421085. A strong association between FTO and obesity was found, consistent with an additive gene effect. Cases had an average weight gain of 11.1 kg, whereas controls had an average weight gain of 1.4 kg. Genotype was neither associated with weight gain in obese, nor controls. Cases had an average weight gain of 10.7 kg for individuals with zero risk alleles, 11.3 for one risk allele and 11.1 kg for two risk alleles. Controls had an average weight gain of 1.4 kg, 1.4 and 1.3 for the respective genotypes. In conclusion, FTO was associated with obesity, but not with weight gain in adults during 11 years of follow-up.

Sex differences in time trends for overweight and obesity in adolescents: the Young-HUNT study

AIMS

To investigate sex differences in the prevalence and extent of overweight and obesity in adolescents aged 14-18 years.

METHODS

Standardized measurements of height and weight were collected from surveys of adolescents in the same geographical area in 1966-69 (n = 8378) and in 1995-97 (n = 6673). The prevalence rates of overweight and obesity were calculated using criteria approved by the International Obesity Task Force. The extents of overweight and obesity were assessed by computing age- and sex-specific body mass index (BMI) percentiles.

RESULTS

In 1995-97, 17.2% met the criteria for either overweight or obesity, as compared with 10.7% in 1966-69. The prevalence of overweight and obesity combined was higher in girls (13.0%) than in boys (8.5%) in 1966-69 (difference 4.5%, 95% confidence interval (CI) 3.1-5.9), while no sex difference was found in 1995-97 (girls 16.9%, boys 17.5%, difference -0.6, 95% CI -2.3-1.1). The increase in overweight was greater in boys (6.2PP, 95% CI 4.7-7.6) than in girls (1.9PP, 95% CI 0.4-3.5), while the sex difference in increased obesity was smaller (boys 2.8PP, 95% CI 2.1-3.4, girls 2.0PP, 95% CI 1.3-2.6). The increase in extent of overweight and obesity was highest in boys. The values of the 85th percentile and the 95th percentile in boys increased by 1.3 and 3.0 BMI units, respectively. The corresponding increases in girls were 0.7 and 1.7 BMI units.

CONCLUSIONS

A marked sex difference in time trends for both the prevalence and extent of overweight and obesity, with a more pronounced increase in boys than in girls, was demonstrated. This might have implications for preventive strategies.