Population In Northern Sweden Research Articles

A novel stroke locus identified in a northern Sweden pedigree

The population of northern Sweden is characterized by reduced genetic diversity and a high incidence of stroke. We sought to reduce genetic variation further, using genealogic analysis in a set of nuclear families affected by stroke, and we subsequently performed a genome-wide scan to identify novel stroke susceptibility loci. Through genealogy, 7 nuclear families with a common ancestor, connected over 8 generations, were identified. A genome-wide scan using 449 microsatellite markers was performed with subsequent haplotype analyses. A maximum allele-sharing lod score of 4.81 on chromosome 9q31-q33 was detected. Haplotype analysis identified a common 2.2-megabase interval in the chromosomal region in 4 of the nuclear families, where an overrepresentation of intracerebral hemorrhage was observed. We have identified a novel susceptibility locus for stroke. Haplotype analysis suggests that a shared genetic factor is of particular importance for intracerebral hemorrhage.

Genetically controlled differences in behaviour between cycling and non-cycling populations of field vole (Microtus agrestis)

Behavioural tests measuring locomotor activity of single individuals and groups of animals of the same sex have been performed on samples of Microtus agrestis from a cycling population in northern Sweden and a non-cycling population from south Sweden. The activity was higher for animals from the northern population. The differences were more pronounced for males than for females and more for group than for individual activity. The genetic control of this behavioural trait was confirmed by breeding tests. Pure-bred offspring from wild-trapped voles within each area did not deviate from the performance of their parents. The hybrid offspring had intermediate test values. An association between behaviour and population density phase is indicated for the cycling population, but a full cycle has not yet been followed.

Sense of coherence in three cross-sectional studies in Northern Sweden 1994, 1999 and 2004 — patterns among men and women

To explore changes in sense of coherence (SOC) over a 10-year period in the general population in northern Sweden. Three cross-sectional surveys from 1994 (n=1802), 1999 (n=1698) and 2004 (n=1777), conducted within the northern Sweden MONICA Project, were compared. Participants answered questions about gender, age, experience of disease, perceived health, psychosocial factors and Antonovsky's SOC scale with 13 items. A small, but significant, decrease in SOC medians and a shift of cumulative distributions towards slightly lower SOC values were seen both in the total study population and in its male and female subgroups between 1994 and 1999. No changes were seen between 1999 and 2004, with the exception of women between 25 and 44 years of age, who showed a continuous decrease. The present study shows that SOC at a population level in northern Sweden, within a 10-year span, is relatively stable, not withstanding minor changes. These small changes might be attributed to societal changes in Sweden during the 1990s and an increase in "minor'' psychiatric complaints in the Swedish population as a whole during the same period.

Carrier of R14W in Carbonic Anhydrase IV Presents Bothnia Dystrophy Phenotype Caused by Two Allelic Mutations inRLBP1

Bothnia dystrophy (BD) is an autosomal recessive retinitis pigmentosa (arRP) associated with the c.700C>T mutation in the RLBP1 gene. Testing of patients with BD has revealed the c.700C>T mutation on one or both alleles. The purpose of this study was to elucidate the underlying genetic mechanisms along with a clinical evaluation of the heterozygous patients with BD. Patients with BD heterozygous for the RLBP1 c.700C>T were tested for 848 mutations by arrayed primer-extension technology. Further mutation detection was performed by PCR-restriction fragment length polymorphism (RFLP), sequencing, denaturing (d)HLPC and allelic discrimination. The ophthalmic examinations were performed in all c.700C>T heterozygotes. The clinical findings in 10 BD heterozygotes were similar to those in the homozygotes. The presence of a second mutation, c.677T>A, corresponding to p.M226K was detected in all 10 cases. Segregation analysis showed that the mutations were allelic, and the patients were compound heterozygotes [c.677T>A]+[c.700C>T]. One of those patients was also a carrier of the c.40C>T corresponding to the p.R14W change in carbonic anhydrase IV (CAIV) associated with autosomal dominant RP, RP17. His mother, a carrier of the identical change was declared healthy after ophthalmic examination. This sequence variant was found in 6 of 143 tested blood donors. The high frequency of arRP in northern Sweden is due to two mutations in the RLBP1 gene: c.677T>A and c.700C>T. BD is caused by the loss of CRALBP function due to changed physical features and impaired activity of retinoid binding. The CAIV p.R14W sequence variant found in one of the patients with a BD phenotype is a benign polymorphism in a population of northern Sweden.

PRS3 COSTS OF COPD IN SWEDEN ACCORDING TO DISEASE SEVERITY

Objectives: COPD is a common and disabling disease that entails high costs for society. The objectives of this study were to measure the societal costs of COPD in Sweden, and to examine the relationship between severity of illness and costs. Methods: The costs of COPD were examined using a well-defined and representative cohort of subjects with mild, moderate, and severe COPD. Regular telephone interviews regarding resource utilization were made to a cohort of 212 subjects with COPD derived from studies of the general population in Northern Sweden. Results: The annual per capita cost for COPD in Swedish crowns (SEK) was estimated at SEK 13,418 (1,284 US dollars (USD); 1,448 euros (EUR). The direct and indirect costs were SEK 5,592 (42%) and SEK 7,828 (58%), respectively. A highly significant relationship was found between severity of disease and costs. Costs for severe disease were 3 times as high as costs for moderate disease and > 10 times as high as for mild disease. Large individual variations in the level of costs were found. Conclusion: Assuming that the prevalence and treatment patterns are representative of Sweden as a whole, the total costs of COPD to society in 1999 were estimated at SEK 9.1 billion (USD 871 million; EUR 982 million). Subjects with mild disease (83%) accounted for 29%, while subjects with moderate disease (13%) accounted for 41% of the total costs. The subjects with severe disease (4%) accounted for the remainder (30%). Prevention, early diagnosis, and postponement of disease progression should have large monetary and policy implications. (CHEST 2002; 122:1994 –2002)

The genetic population structure of northern Sweden and its implications for mapping genetic diseases

The northern Swedish population has a history of admixture of three ethnic groups and a dramatic population growth from a relatively small founder population. This has resulted in founder effects that together with unique resources for genealogical analyses provide excellent conditions for genetic mapping of monogenic diseases. Several recent examples of successful mapping of genetic factors underlying susceptibility to complex diseases have suggested that the population of northern Sweden may also be an important tool for efficient mapping of more complex phenotypes. A potential factor contributing to these effects may be population sub-isolates within the large river valleys, constituting a central geographic characteristic of this region. We here provide evidence that marriage patterns as well as the distribution of gene frequencies in a set of marker loci are compatible with this notion. The possible implications of this population structure on linkage- and association based strategies for identifying genes contributing risk to complex diseases are discussed.

Temporomandibular disorders, headaches, and cervical pain among females in a Sami population

Objective. The aim of this study was to examine the prevalence and co-morbidity of long-standing, intense, and frequent symptoms of pain and dysfunction in the jaw-face, head, and cervical region among adult females drawn from the Sami population in northern Sweden. Methods. A total of 487 females, taken from the register of the Swedish Sami Parliament or registered as reindeer owners or reindeer herders in the Swedish Board of Agriculture and living in the Arctic region of northern Sweden, participated in a questionnaire study. Results. The prevalence of pain and/or dysfunction in the jaw-face region was 32%, of headaches 61%, and of pain in the cervical region 56%. When the criterion of frequent symptoms (once a week or more often) was used, prevalence dropped to 17%, 19%, and 30%, respectively, and when that of intense symptoms, defined as 5 or more on an 11-point numerical rating scale, was added, prevalence dropped further to 8%, 11%, and 20%, respectively. The majority reported long-standing symptoms (67–98% depending on symptom). A high statistically significant relationship was found between frequent symptoms of pain and/or dysfunction in the jaw-face, frequent headaches, and frequent cervical pain (p<0.0001). Conclusions. Symptoms in the jaw-face, headaches, and cervical pain were frequently reported among a sample of Sami females living in the Swedish Arctic region. The prevalence of symptoms was strongly dependent on criteria of frequency and intensity.

GENETIC DIFFERENCES AMONG NOBLE CRAYFISH (ASTACUS ASTACUS) STOCKS IN FINLAND, SWEDEN AND ESTONIA BASED ON THE ITS1 REGION

Noble crayfish (Astacus astacus) is indigenous to Finland. The distribution of A. astacus has diminished dramatically during the past century, due to environmental changes, crayfish plague (Aphanomyces astaci) outbreaks and stocking of alien signal crayfish (Pacifastacus leniusculus). Due to an active reintroduction policy and partly due to illegal introductions, the origins of noble crayfish populations are somewhat unknown. For conservation purposes it is essential to know if the populations are autochthonous or if they are a mixture of several different populations. Genetic variation of seven Finnish noble crayfish populations was studied comparing the variation in a short tandem repeat in the rDNA internal transcribed spacer 1 region (ITS1 region). Five Swedish and five Estonian populations were used as reference populations. Based on the ITS1 fragment variation, some of the analysed Finnish noble crayfish populations were most likely original populations or originated from one source population. They differed from the other populations according to the Population Divergence Test. However, there were no differences between some of the Finnish populations and this may be a consequence of multiple stockings. Differences among noble crayfish populations from the three countries were also studied. Five of the Finnish populations differed from the Swedish and the Estonian populations. One population, Lake Saimaa, did not differ from one Estonian and two Swedish populations. Furthermore, a population from northern Finland was not different from a population in northern Sweden. The Estonian populations had a larger number of fragments present in their genotypes compared to the Finnish and the Swedish populations. Private fragments, which were typical to only one country, were found in two Finnish, in four Estonian and in three Swedish populations.

Psoriasis care consumption and expectations from a gender perspective in a psoriasis population in northern Sweden

The aim was to analyse use of psoriasis care and expectations from a gender perspective in a psoriasis population. The study is based on questionnaire data from 1,060 subjects. The response rate was 74%. The relation between care consumption and studied variables was measured using regression and chi-square analysis. Care consumption was strongly influenced by age, quality of life, income and joint symptoms. Men visited a dermatologist more often, while women visited a general practitioner and treated themselves topically more frequently. Important expectations among both women and men concerned the receiving of professional care and amelioration, while more women wanted to be treated politely. Expectations were fulfilled, except those regarding amelioration, especially among men. Awareness of gender differences is important among professionals. In order to decrease such differences decision-makers should provide for a maintained specialized care as well as a local health care system of high standard.

Time trends in burdens of cadmium, lead, and mercury in the population of northern Sweden

The time trends of exposure to heavy metals are not adequately known. This is a worldwide problem with regard to the basis for preventive actions and evaluation of their effects. This study addresses time trends for the three toxic elements cadmium (Cd), mercury (Hg), and lead (Pb). Concentrations in erythrocytes (Ery) were determined in a subsample of the population-based MONICA surveys from 1990, 1994, and 1999 in a total of 600 men and women aged 25–74 years. The study took place in the two northernmost counties in Sweden. To assess the effect of changes in the environment, adjustments were made for life-style factors that are determinants of exposure. Annual decreases of 5–6% were seen for Ery-Pb levels (adjusted for age and changes in alcohol intake) and Ery-Hg levels (adjusted for age and changes in fish intake). Ery-Cd levels (adjusted for age) showed a similar significant decrease in smoking men. It is concluded that for Pb and maybe also Hg the actions against pollution during recent decades have caused a rapid decrease of exposure; for Hg the decreased use of dental amalgam may also have had an influence. For Cd, the decline in Ery-Cd was seen only in smokers, indicating that Cd exposure from tobacco has decreased, while other environmental sources of Cd have not changed significantly. To further improve the health status in Sweden, it is important to decrease the pollution of Cd, and actions against smoking in the community are important.

Gyr Falcons, ptarmigan and microtine rodents in northern Sweden

A Gyr Falcon Falco rusticolus population in Northern Sweden (66°N, 17°E) was monitored from 1996 to 2002 in relation to its predator–prey interactions with its main and alternative prey species. Ptarmigan species Lagopus spp., and especially Rock Ptarmigan L. mutus, were the Gyr Falcons’ most important prey and constituted more than 90% of the prey biomass. A 21‐fold difference in ptarmigan abundance was found across Falcon breeding territories. However, this great variation in prey availability corresponded to only about a 10% shift in Gyr Falcon diet across territories, suggesting that the Falcons were reluctant or unable to compensate for declining ptarmigan availability by using alternative prey categories. Gyr Falcons did not respond functionally to microtine rodent abundance. Their diets were unaffected by a peak in the microtine rodent population cycle when Norwegian Lemmings Lemmus lemmus occurred in high numbers in the study area. Gyr Falcons responded numerically to their prey in two ways. First, there was a reproductive response with a significant relationship between the number of chicks fledged and the number of ptarmigan in the breeding territories. Secondly, although the Gyr Falcons did not utilize microtines as prey, there was a relationship between the microtine rodent abundance and the number of pairs that attempted to breed each year. This could be a result of an indirect community interaction, assuming that other predators switched from ptarmigan to microtines as prey, which could have had a positive effect on the breeding performance of the Gyr Falcons. The Gyr Falcons acted as true specialist predators, and their narrow food niche probably reflected a general lack of suitable alternative prey in the study area.

Association of a PDCD1 polymorphism with renal manifestations in systemic lupus erythematosus

To analyze the association of the PD-1.3 polymorphism within the PDCD1 gene in patients with systemic lupus erythematosus (SLE) from the homogeneous population in northern Sweden. The PD-1.3A allele was analyzed in relation to disease manifestations and severity representing various phenotypes of SLE. The study group comprised 260 patients fulfilling at least 4 of the American College of Rheumatology (ACR) criteria for SLE during 1 year. The Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and the Systemic Lupus International Collaborating Clinics/ACR damage index scores were recorded. Population-based, randomly selected individuals (n = 670) from the same geographic area served as controls. DNA was extracted from blood samples from both patients and controls and was genotyped for the PD-1.3 A/G polymorphism, using an ABI Prism 7900HT Sequence Detection System. The frequency distribution of alleles, carriers, or genotypes did not differ between patients and controls. The PD-1.3A allele and carriage of the A allele were highly associated with renal disorder (ACR criterion 7) (P = 0.005, odds ratio [OR] 2.71 [95% confidence interval (95% CI) 1.32-5.55] and P = 0.012, OR 2.62 [95% CI 1.28-5.35], respectively). In regression analysis adjusted for sex and age at disease onset, carriage of the A allele remained significantly associated with renal disorder (P = 0.002, OR 3.54 [95% CI 1.56-8.01]). The presence of proteinuria, as measured by the SLEDAI score, and the presence of renal damage were also significantly associated with carriage of the A allele (P = 0.007, OR 3.88 [95% CI 1.44-10.47] and P = 0.021, OR 2.98 [95% CI 1.18-7.54], respectively). The PD-1.3A allele is associated with renal manifestations in SLE patients from northern Sweden but not with susceptibility to SLE per se.

An epidemiological study on gender differences in self-reported seasonal changes in mood and behaviour in a general population of northern Sweden

Gender differences have been reported regarding symptoms, prevalence and heritability of seasonal affective disorders (SAD). We focus on gender aspects in this study of self-reported seasonal changes in mood and behaviour in a general population. The Seasonal Pattern Assessment Questionnaire (SPAQ) was completed by 2620 adults (55.6% women) aged 35–85 years, enrolled in the Betula prospective random cohort study of Umeå, Sweden. October to February turned out to be suitable winter months. SAD was found in 2.2% and sub-syndromal SAD (S-SAD) in 5.7%. Women had about 1.5 times higher prevalences than men, and seasonality problems decreased with age in both genders. Preference for eating least was distributed with a peak in summer, whereas preference for eating most had a major peak in winter (winter eaters) and a minor peak in summer (summer eaters). Significantly more of winter eaters in women, and significantly more of summer eaters in men, felt worst in winter. Seasonal change in weight was considered significantly as a problem by women but not by men. Winter behaviour of sleeping most was considered significantly as a problem by men but not by women. Women reacted significantly to temperature-related changes (negatively to cold/short days and positively to hot/long days), whereas men reacted significantly to sunshine-related changes (negatively to cloudy days and positively to sunny days). Subtle gender differences may thus underlie the pathophysiology of seasonal problems. Studies of an eventual efficacy of treating SAD women with raised ambient temperature, and gender-specific comparisons with other therapies, would be of interest.

Determinants of quality of life in a psoriasis population in northern Sweden.

The aim of this study was to assess possible determinants of quality of life in psoriasis patients in northern Sweden, and to analyse the association between these determinants and quality of life. A questionnaire was mailed to 1,707 subjects, resulting in a response rate of 74%. The study is therefore based on 1,060 subjects, since 195 denied having psoriasis. Quality of life was measured using a version of the Dermatology Life Quality Index. The extent of the disease was estimated using the patients' sketches. The association between determinants and quality of life was calculated in a risk analysis using logistic regression. Large disease extent and joint symptoms were the strongest indicators for impaired quality of life. Other indicators were withdrawal from medical treatment due to distance to treatment facilities, which strongly influenced the quality of life and choice of treatment.

Diabetes and obesity in Northern Sweden: occurrence and risk factors for stroke and myocardial infarction.

The authors describe the occurrence of diabetes and obesity in the population of Northern Sweden and the role of diabetes in cardiovascular disease. Four surveys of the population aged 25 to 64 years were undertaken during a 14-year time span. Stroke events in subjects 35-74 years during 1985-92 and myocardial infarction in subjects 25-64 years 1989-93 were registered. The prevalence of diagnosed diabetes was 3.1 and 2.0% in men and women, respectively, and 2.6 and 2.7% for previously undiagnosed diabetes. During the 13-year observation period, BMI increased 0.96 kg/m(2) in men and 0.87 in women. The proportion of subjects with obesity (BMI>or=30) increased from 10.3% to 14.6% in men and from 12.5% to 15.7% in women. Hip circumference increased substantially more than waist circumference, leading to a decreasing waits-to-hip ratio (WHR). The relative risk for stroke or myocardial infarction was four to six times higher in a person with diabetes than in those without diabetes. The 28-day case fatality for myocardial infarction, but not for stroke, was significantly higher in both men and women with diabetes. Population-attributable risk for diabetes and stroke was 18% in men and 22% in women and for myocardial infarction it was 11% in men and 17% in women. Obesity is becoming more common, although of a more distal than central distribution. The burden of diabetes in cardiovascular diseases in Northern Sweden is high.

Trends in blood pressure, lipids, lipoproteins and glucose metabolism in the Northern Sweden MONICA project 1986 - 99

The authors present an analysis of time trends in blood pressure, hypertension, and lipids in the adult population of Northern Sweden over the period 1986-99. Four population surveys were undertaken with new and independent cohorts, 25-64 years old. Small changes in blood pressure were observed during the study period with increased systolic blood pressure in men and decreased diastolic blood pressure in women. The proportion with high blood pressure was found to be constant over time and only 50% were prescribed antihypertensive drugs and of these only a minority were normotensive. Total serum cholesterol decreased from 6.4 to 5.7 mmol/l in men and from 6.3 to 5.7 mmol/l in women over the study period, and this was accompanied by an increase in HDL cholesterol by about 10% in both sexes. The proportion with high cholesterol decreased from 41% to 26%. Triglycerides increased between 1986 and 1990 and no further changes were found in the following surveys. In the Northern Sweden MONICA population total cholesterol has declined and HDL cholesterol has increased during the past 13 years and small changes in blood pressure have been observed for both men and women.

Silent myocardial infarction in women with impaired glucose tolerance: The Northern Sweden MONICA study

BackgroundPatients with impaired glucose tolerance (IGT) have an increased risk of cardiovascular disease (CVD) that is independent of traditional risk factors. Hence, slightly elevated glucose levels, even in the non-diabetic range, might be associated with increased macrovascular disease.MethodsWithin the Northern Sweden MONICA project a population survey was performed in 1986. Electrocardiograms (ECG's) were recorded for half of the survey (n = 790) and oral glucose test was carried out in 78 % of those. The association between subjects with ECG's indicating previously unknown myocardial infarction (ukMI), IGT and conventional risk factors were analyzed by logistic regression for men and women separately, adjusting for age, smoking, hypercholesterolemia and hypertension.ResultsImpaired glucose tolerance was significantly more common among women with ukMI, but not in men, compared to the group with normal ECG. In men, no variable was significantly associated with ukMI although the odds ratio (OR) for hypercholesterolemia was of borderline significance, 3.2 (95% confidence interval (CI) 0.9 to 11). The OR of having ukMI was 4.1 (CI 1.1 to 15) in women with IGT compared to women with normal glucose tolerance after multiple adjustment. The OR for hypertension was of borderline significance; 3.3 (CI 0.97 to 11).ConclusionWe found that IGT was associated with ECG findings indicating silent myocardial infarction in women in a middle-aged general population in northern Sweden. The results persisted even after adjusting for known risk factors.

Costs of COPD in Sweden According to Disease Severity

COPD is a common and disabling disease that entails high costs for society. The objectives of this study were to measure the societal costs of COPD in Sweden, and to examine the relationship between severity of illness and costs. The costs of COPD were examined using a well-defined and representative cohort of subjects with mild, moderate, and severe COPD. Regular telephone interviews regarding resource utilization were made to a cohort of 212 subjects with COPD derived from studies of the general population in Northern Sweden. The annual per capita cost for COPD in Swedish crowns (SEK) was estimated at SEK 13,418 (1,284 US dollars (USD); 1,448 euros (EUR). The direct and indirect costs were SEK 5,592 (42%) and SEK 7,828 (58%), respectively. A highly significant relationship was found between severity of disease and costs. Costs for severe disease were 3 times as high as costs for moderate disease and > 10 times as high as for mild disease. Large individual variations in the level of costs were found. Assuming that the prevalence and treatment patterns are representative of Sweden as a whole, the total costs of COPD to society in 1999 were estimated at SEK 9.1 billion (USD 871 million; EUR 982 million). Subjects with mild disease (83%) accounted for 29%, while subjects with moderate disease (13%) accounted for 41% of the total costs. The subjects with severe disease (4%) accounted for the remainder (30%). Prevention, early diagnosis, and postponement of disease progression should have large monetary and policy implications.

No increase in the prevalence of known diabetes between 1986 and 1999 in subjects 25-64 years of age in northern Sweden.

A global increase in diabetes is predicted due to higher body weight and less physical activity. Over the period 1986-1999, the body mass index (BMI) of the adult population of northern Sweden increased from 25.3 to 26.2 and the prevalence of obesity (BMI > or = 30) from 11% to 15%, although this was more distal than central adiposity. Our hypothesis was that this would lead to a higher prevalence of diabetes. Four population surveys with new and independent cohorts of 2000 invited subjects, 25-64 years old, in 1986, 1990, 1994 and 1999. In the first three surveys an oral glucose tolerance test was carried out in 47%. Over the time period 1986-1999 there was no increase in the prevalence of known diabetes. No trends were noted in the finding of previously undiagnosed diabetes or impaired glucose tolerance over the period 1986-1994, although the confidence intervals are wide. Fasting, but not post-load, glucose levels increased with 0.040 mmol/year (95% CI 0.026; 0.055) in men and 0.033 mmol/year (0.023; 0.044) in women. In spite of a marked increase in BMI, we found no increased prevalence of known diabetes over a 13-year observation period, although our data cannot exclude minor increases in undiagnosed diabetes. The development of more distal than abdominal obesity, a diet with less saturated fat and lower glycaemic index and fewer regular smokers in the population may contribute to this. The effects of obesity may thus be attenuated by other secular trends in society and highlight potential ways of curbing the worldwide increase in diabetes.

Pollen limitation of reproduction in a subarctic‐alpine population of Diapensia lapponica (Diapensiaceae)

Determinants of reproductive success (measured as capsule mass) in Diapensia lapponica, an early‐flowering pollen‐risker dependent on insects for pollination, were evaluated in an exposed subarctic‐alpine population in northern Sweden. The species was protogynous and self‐compatible, but self‐deposition of pollen was inefficient. Hand‐pollination increased capsule mass significantly, indicating that reproductive success was severely pollen limited. An experiment designed to test the relative importance of insect pollination in comparison to water availability (precipitation) and shelter (temperature and wind), revealed that exclosure of insects decreased capsule mass significantly, as did watering, whereas shelter tended to increase capsule mass. Pollination was the most important determinant of reproductive success, and the study suggests that pollen limitation may be particularly severe for early‐flowering species, i.e. pollen‐riskers, in exposed locations.