Biomedical subjects

P Nafstad

Publications and source records attributed to P Nafstad.

At least 19 recordsLinked to original sources

PubMed2006

Metabolic syndrome predicts prostate cancer in a cohort of middle-aged Norwegian men followed for 27 years.

The aim of the study was to establish whether metabolic syndrome predicts the incidence of prostate cancer. The hypothesis was tested using the 27-year follow-up of the prospective cohort of 16,209 men aged 40-49 years who participated in the Oslo Study in 1972-1973. Men with established diabetes and men with cancer diagnosed before screening were excluded, leaving 15,933 for analyses. Metabolic syndrome is here composed of body mass index, nonfasting glucose, triglycerides, and blood pressure or drug-treated hypertension. Two analytical approaches were compared, namely, predefined (adjusted from National Cholesterol Education Program) and quartile values of risk factors. Age, body mass index, and sedentary versus intermediate physical activity at work were significant predictors in univariate proportional hazards regression analyses. Combinations of any two (relative risk = 1.23; p = 0.04) or any three (relative risk = 1.56; p = 0.00) factors of the metabolic syndrome using quartile values of risk factors were predictive of prostate cancer. The number of cases for four factors was too small for analyses. Predefined values of the risk factors were not found to be predictive. In conclusion, metabolic syndrome was found to predict prostate cancer during 27 years of follow-up, indicating an association between insulin resistance and the incidence of prostate cancer.

Adult↗

PubMed2006

Respiratory infections in schoolchildren: co-morbidity and risk factors.

AIMS: To assess co-morbidity and risk factors for otitis media, tonsillopharyngitis, and lower respiratory infections in school children. METHODS: Logistic regression analysis of co-morbidity and risk factors for airway infections in a population based sample of 10 year old children living in Oslo, Norway. MAIN OUTCOME MEASURES: otitis media, tonsillopharyngitis, and lower respiratory infections in past 12 months. RESULTS: Airway infections in 10 year old children were common, and significant co-morbidity was found between the various airway infections. Home dampness was a risk factor for all infections, adjusted odds ratios ranging from 1.2 (95% CI 1.0 to 1.5) to 1.4 (95% CI 1.1 to 1.6) for otitis media and tonsillopharyngitis respectively. Atopic disease was a constitutional risk factor, particularly strong for lower airway infections (adjusted odds ratio 2.4, 95% CI 1.8 to 3.1). African or Asian ethnicities were associated with the airway infections, adjusted odds ratios ranging from 1.2 (95% CI 0.9 to 1.7) to 1.7 (95% CI 1.2 to 2.3). CONCLUSIONS: Respiratory tract infections were common in 10 year old children. There was substantial co-morbidity between upper and lower airway infections. Environmental and constitutional factors were identified and positively associated with the infections. Results support the hypothesis of 1957 that the whole respiratory tract is one unit.

Africa↗

PubMed2006

Particulate matter properties and health effects: consistency of epidemiological and toxicological studies.

Identifying the ambient particulate matter (PM) fractions or constituents, critically involved in eliciting adverse health effects, is crucial to the implementation of more cost-efficient abatement strategies to improve air quality. This review focuses on the importance of different particle properties for PM-induced effects, and whether there is consistency in the results from epidemiological and experimental studies. An evident problem for such comparisons is that epidemiological and experimental data on the effects of specific components of ambient PM are limited. Despite this, some conclusions can be drawn. With respect to the importance of the PM size-fractions, experimental and epidemiological studies are somewhat conflicting, but there seems to be a certain consistency in that the coarse fraction (PM10-2.5) has an effect that should not be neglected. Better exposure characterization may improve the consistency between the results from experimental and epidemiological studies, in particular for ultrafine particles. Experimental data indicate that surface area is an important metric, but composition may play an even greater role in eliciting effects. The consistency between epidemiological and experimental findings for specific PM-components appears most convincing for metals, which seem to be important for the development of both pulmonary and cardiovascular disease. Metals may also be involved in PM-induced allergic sensitization, but the epidemiological evidence for this is scarce. Soluble organic compounds appear to be implicated in PM-induced allergy and cancer, but the data from epidemiological studies are insufficient for any conclusions. The present review suggests that there may be a need for improvements in research designs. In particular, there is a need for better exposure assessments in epidemiological investigations, whereas experimental data would benefit from an improved comparability of studies. Combined experimental and epidemiological investigations may also help answer some of the unresolved issues.

Cardiovascular Diseases↗

PubMed2006

Association between level of physical activity and lung function among Norwegian men and women: the HUNT study.

OBJECTIVE: To estimate the association between level of physical activity in 1984-1986 and 1995-1997 and lung function in 1995-1997 among Norwegian men and women aged 28-80 years. DESIGN: In 1984-1986 and 1995-1997, all residents of Nord-Trøndelag County, Norway, aged > or =20 years were invited to participate in the Nord-Trøndelag Health Studies. These analyses included a sample that took part in both studies and underwent spirometry (n = 8047). We used linear regression models adjusting for potential confounders stratified by sex and age groups (28-49 years, 50-69 years and > or =70 years) to estimate the association between forced expiratory volume in 1 second (FEV1) and physical activity. RESULTS: Men and women who were physically active in 1985 and 1995 had the highest lung function in both sexes and in all age groups. The reduction in FEV1 ranged from 20 ml to 170 ml, similar to 1-7% of predicted values dependent on physical activity level. Lung function was also associated with body mass index (BMI), height, smoking and subjective health. CONCLUSIONS: The findings show that a high level of physical activity corresponds to about 3-5 years of normal decline in FEV1 (30 ml/year), and may therefore overcome the disadvantages of a decline in FEV1 from increasing age.

Adult↗

PubMed2005

Day care center characteristics and children's respiratory health.

UNLABELLED: Day care centers provide an important exposure arena with potential harmful health effects for children. This study has linked health effect data from a survey among 942 3-5-year-old Oslo children with information on day care center characteristics collected during inspection of the 175 day care centers these children attended. The aim of the study was to estimate associations between dampness problems and other building characteristics and several respiratory health outcomes. Dampness problems (sign of molds, water leakage, damage to floor/wall) were observed in 51% of the day care centers. In multiple logistic regression analyses none of the studied symptoms and diseases (nightly cough, blocked or runny nose without common cold, wheeze, heavy breathing or chest tightness, the common cold, tonsillitis/pharyngitis, otitis media, bronchitis, pneumonia, asthma, and allergic rhinitis) were systematically associated with dampness problems or type of ventilation in day care centers. None of the studied indicators of day care center exposures were found to have a clear effect on day care children's respiratory health. Even so this study does not rule out negative health effects of day care center exposures. The study demonstrates that population-based studies of these relations are demanding with regard to assessment of exposure and health outcomes. PRACTICAL IMPLICATIONS: Simple and easy-to-register indicators of exposures like dampness problems and type of ventilation assessed in 175 day care centers were not related to respiratory health among 3-5-year-old Norwegian children attending the day care centers. The study does not rule out negative health effects of day care center exposures, but demonstrates methodological challenges needed to be addressed in studies of health effects of the day care environment.

Air Pollution, Indoor↗

PubMed2005

Allergens and endotoxin in settled dust from day-care centers and schools in Oslo, Norway.

UNLABELLED: Allergy to indoor allergens can cause frequent and severe health problems in children. Because little is known about the content of allergens in the indoor environments in Norway, we wanted to assess the levels of cat, dog and mite allergens in schools and day-care centers in Oslo. Allergen levels in dust samples from 155 classrooms and 81 day-care units were measured using commercially available enzyme-linked immunosorbent assay (ELISA) kits. Additionally, we measured the levels of endotoxin in 31 day-care units, using the limulus amebocyte lysate test. Most of the dust samples contained detectable amounts of cat and dog allergens. In mattress and floor dust (day-care centers), and curtain and floor dust (schools) the median Fel d 1 levels were 0.17, 0.002, 0.02 and 0.079 microg/m2, while the median Can f 1 levels were 1.7, 0.03, 0.1 and 0.69 microg/m2, respectively. Levels of cat and dog allergens in school floor dust were associated with the number of pupils with animals at home. In contrast, <1% of the samples had measurable levels of the mite allergen Der p 1. Moreover, the levels of endotoxin tended to be higher in dust from floors (1.4 ng/m2) compared with that from mattresses (0.9 ng/m2). PRACTICAL IMPLICATIONS: To reduce allergen exposure, allergic individuals should be placed in the classes/rooms with the fewest pet owners. Moreover, mattresses in day-care centers are major reservoirs of cat and dog allergens and should be cleaned frequently.

Air Pollution, Indoor↗

PubMed2003

Baby swimming increases the risk of recurrent respiratory tract infections and otitis media.

AIM: To estimate the association between baby swimming and recurrent respiratory tract infections and otitis media in the first year of life in children of parents without and with atopy. METHODS: Norwegian schoolchildren (n = 2862) was enrolled in a cross-sectional study of asthma and allergy using the questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC). The outcomes were parental retrospective report of recurrent respiratory tract infections and otitis media diagnosed by a physician in the first year of life. The exposure was baby swimming during the same period. Parental atopy reflects a history of maternal or paternal asthma, hayfever or eczema. RESULTS: The prevalence of recurrent respiratory tract infections was higher (12.3%) among children who took part in baby swimming than among those who did not (7.5%). The prevalence of recurrent respiratory tract infections during the first year of life was 5.6% and 10.5%, respectively, in children of parents without and with atopy, whereas the prevalence of baby swimming was 5.6% and 5.1%, respectively, in the two groups. Stratified analysis using parental atopy as strata showed that the increased risk of recurrent respiratory tract infections was only present among children of parents with atopy [adjusted odds ratio (aOR) 2.08, 95% confidence interval (95% CI) 1.08-4.031. A similar trend was present for otitis media (aOR 1.77, 95% CI 0.96-3.25). CONCLUSION: The results of this study suggest that baby swimming and infant respiratory health may be linked. The findings need to be examined in a longitudinal study.

Child↗

PubMed2003

Lung cancer and air pollution: a 27 year follow up of 16 209 Norwegian men.

BACKGROUND: The well documented urban/rural difference in lung cancer incidence and the detection of known carcinogens in the atmosphere have produced the hypothesis that long term air pollution may have an effect on lung cancer. The association between incidence of lung cancer and long term air pollution exposure was investigated in a cohort of Oslo men followed from 1972/73 to 1998. METHODS: Data from a follow up study on cardiovascular risk factors among 16 209 40 to 49 year old Oslo men in 1972/73 were linked to data from the Norwegian cancer register, the Norwegian death register, and estimates of average yearly air pollution levels at the participants' home address in 1974 to 1998. Survival analyses, including Cox proportional hazards regression, were used to estimate associations between exposure and the incidence of lung cancer. RESULTS: During the follow up period, 418 men developed lung cancer. Controlling for age, smoking habits, and length of education, the adjusted risk ratio for developing lung cancer was 1.08 (95% confidence interval, 1.02 to 1.15) for a 10 micro g/m(3) increase in average home address nitrogen oxide (NO(x)) exposure between 1974 and 1978. Corresponding figures for a 10 micro g/m(3) increase in sulphur dioxide (SO(2)) were 1.01 (0.94 to 1.08). CONCLUSIONS: Urban air pollution may increase the risk of developing lung cancer.

Adult↗

PubMed2002

The use of a feather quilt, childhood asthma and allergic rhinitis: a prospective cohort study.

BACKGROUND: Feather bedding has long been considered as a potential source of allergen exposure and thus a potential risk factor for allergic diseases. However, recent cross-sectional studies have reported a higher risk of allergic diseases among users of synthetic bedding compared with feather-bedding users. OBJECTIVE: To explore associations between early life exposure to feather bedding and the risk of developing asthma allergic rhinitis in childhood. METHODS: We assessed the association between early life exposure to feather quilts and the risk of bronchial obstruction during the first 2 years of life and asthma and allergic rhinitis in a prospective 4-year cohort study of 2531 Norwegian children. RESULTS: At the age of 6 months, 24% of the children had a quilt with feathers, decreasing to 20% at the age of 2 years. The adjusted odds ratio for bronchial obstruction 0 to 2 years by exposure to a feather quilt at the age of 6 months was 0.59, 95% confidence interval 0.41 to 0.86, for asthma at the age of 4 years 0.38, 0.23 to 0.64 and for allergic rhinitis at the age of 4 years 0.73, 0.43 to 1.18. CONCLUSION: The use of a feather quilt in early life does not seem to increase the risk of asthma and allergic rhinitis later in childhood.

Allergens↗

PubMed2002

Feasibility of measuring lung function in preschool children.

BACKGROUND: There have been difficulties in applying spirometric tests to children of preschool age. METHODS: The feasibility of measuring lung function was examined in 652 children aged 3-6 years using dynamic spirometry with an animation programme and the guidelines approved by the European Respiratory Society. RESULTS: Data from 603 (92%) children with at least two acceptable forced expiratory manoeuvres were analysed; 408 (68%) achieved at least three acceptable manoeuvres. Children with only two acceptable manoeuvres were younger, shorter, and weighed less (p<0.001). The lower levels of lung function in this group were partly explained by body size. 63% of those with three acceptable manoeuvres had a difference of </=5% between the highest and second highest forced expiratory volume in 1 second (FEV(1)); when a difference of </=10% was applied, 91% of the children were included. A similar trend was seen for forced vital capacity (FVC). The acceptability and reproducibility increased with increasing age, and levels of lung function increased linearly with age. The linear regression model showed that standing height was a satisfactory predictor of lung function; the explained fraction of variance (R(2)) was 59% for FEV(1). Most FVC manoeuvres in children older than 3 years were acceptable and reproducible. CONCLUSIONS: Spirometric testing is feasible in preschool children and may be useful for both clinical practice and research. This study may fill the deficiency in reference values for European preschool children.

Aging↗

PubMed2001

Relation between occurrence of type 1 diabetes and asthma.

A negative association has been observed between type 1 diabetes and atopic diseases in individuals, a finding that supports the Th1/Th2 paradigm. By using published data on disease occurrence in different countries, we show a strong positive association between the occurrence of type 1 diabetes and symptoms of asthma at the population level in Europe and elsewhere. Our finding suggests that there may be common factors influencing susceptibility to the two disorders at the country level. Our observation must be accommodated in explanations of the epidemiology of type 1 diabetes or atopic diseases.

Adolescent↗

PubMed2001

Mortality and temperature in Oslo, Norway, 1990-1995.

The associations between temperature and daily mortality was studied among the citizens of Oslo, Norway, 1990-1995. Data on daily mortality were linked with daily temperatures, relative humidity, wind velocity and air pollution. At temperatures below 10 degrees C, a 1 degrees C fall in the last 7 days average temperature increased the daily mortality from all diseases by 1.4%, respiratory diseases 2.1%, and cardiovascular diseases 1.7%. Above 10 degrees C, there was no statistically significant increase in daily mortality, except for respiratory mortality, which increased by 4.7% per 1 degrees C increase in the last 7 days average temperature. Daily mortality in Oslo increases with temperatures falling below 10 degrees C. The increase starts at lower temperatures than shown in warmer regions of the world, but at higher temperatures than in regions with even colder climates. As well insulated and heated dwellings are standard in Norway today, more adequate clothing during outdoor visits is probably the most important preventive measure for temperature related mortality.

Air Pollutants↗

PubMed2001

Physical activity affects the prevalence of reported wheeze.

The present study examines whether physical activity level (hours per week) among children with and without asthma are associated with the prevalence of reported wheezing and whistling in the chest in the last 12 months. The data are based on a survey of school children, aged 7-16 years (n = 2188), in Oslo in 1994 that employed the ISAAC questionnaire. In children reporting asthma, wheezing and whistling in the chest in the last 12 months was less prevalent among inactive children (66.7%) compared to those who exercised (89.4%) (p = 0.05). The prevalence of wheeze also differed among inactive (4.4%) and active (8.8%) children not reporting asthma (p = 0.02). Positive associations between physical activity and wheezing and whistling in the chest remained present using multiple logistic regression analysis adjusting for sex, age and atopy. Children who are engaged in sports or exercise seem to report asthma symptoms differently than inactive children. These findings raise the question whether level of physical activity could affect some of the variability in reported asthma symptoms when such morbidity is measured as 'wheeze in last 12 months'.

Adolescent↗

PubMed2001

Exposure to pets and atopy-related diseases in the first 4 years of life.

BACKGROUND: It is still unclear how early-life exposure to pets is related to children's risk of developing atopy-related diseases. We estimated associations between early-life exposure to pets and atopy-related diseases at 0-4 years of life in a cohort of Norwegian children. METHODS: A population-based cohort of 2531 children born in Oslo, Norway, was followed from birth to the age of 4 years. Information on early-life exposure to pets, a number of possible confounders, and atopy-related diseases was mainly collected by questionnaire. RESULTS: In logistic regression analysis adjusting for potential confounders, the odds ratio for being exposed to pets in early life (reference category: not exposed) was, for bronchial obstruction at 0-2 years of life, 1.2 (95% confidence interval 0.9, 1.8); for asthma at the age of 4 years, 0.7 (0.5, 1.1); for allergic rhinitis at the age of 4 years, 0.6 (0.4, 1.0); and for atopic eczema at 0-6 months of life, 0.7 (0.5, 0.9). CONCLUSIONS: The results indicate that early-life exposure to pets or lifestyle factors associated with exposure to pets reduce the risk of developing atopy-related diseases in early childhood. However, these findings might also be explained by selection for keeping pets.

Animals↗

PubMed2001

Environmental tobacco smoke, parental atopy, and childhood asthma.

We hypothesized that the joint effect of genetic propensity to asthma and exposure to environmental tobacco smoke on the risk of childhood asthma is greater than expected on the basis of their independent effects. We performed a population-based 4-year cohort study of 2,531 children born in Oslo, Norway. We collected information on the child's health and environmental exposures at birth and when the child was 6, 12, 18, and 24 months and 4 years of age. The outcomes of interest were bronchial obstruction during the first 2 years and asthma at the age of 4 years. Parental atopy was defined as a history of maternal or paternal asthma or hay fever. Exposure to environmental tobacco smoke was defined on the basis of questionnaire information on household smokers at birth. In logistic regression analysis adjusting for confounding, parental atopy alone increased the risk of bronchial obstruction [odds ratio 1.62; 95% confidence interval (CI) 1.10-2.40] and asthma (1.66; 95% CI, 1.08-2.54). In children without parental atopy, there was little effect of exposure to environmental tobacco smoke on bronchial obstruction (1.29; 95% CI, 0.88-1.89) and asthma (0.84; 95% CI, 0.53-1.34). The presence of parental atopy and exposure had a substantial effect both on bronchial obstruction (2.88; 95% CI, 1.91-4.32) and asthma (2.68; 95% CI, 1.70-4.22). The results are consistent with the hypothesized joint effect of parental atopy and exposure to environmental tobacco smoke. This phenomenon--denoted as effect modification of environmental exposure by genetic constitution, or gene by environment interaction--suggests that some genetic markers could indicate susceptibility to environmental factors.

Adult↗

PubMed2000

[Atopic diseases].

Explore the source record for details and available documents.

Environmental Exposure↗

PubMed2000

Upper respiratory morbidity in preschool children: a cross-sectional study.

OBJECTIVES: To estimate the occurrence of and associations between upper respiratory tract infections in preschool children, and to assess constitutional and environmental factors as determinants of these infections. DESIGN: Population-based cross-sectional study. SETTING: Oslo, Norway. PARTICIPANTS: Preschool children, aged 4 to 5 years (3853 completed questionnaires). MAIN OUTCOME MEASURES: Acute and recurrent acute otitis media, tonsillopharyngitis, common cold, and rhinitis. RESULTS: Upper respiratory tract infections were common at age 4 years. During the last month, 7.1% of the children had acute otitis media and 7.5% experienced tonsillopharyngitis. Corresponding figures for common cold and rhinitis were 58.3% and 16. 4%, respectively. During the last 12 months, 9.5% of the children experienced more than 1 bout of acute otitis media, 6.9% had more than 1 tonsillopharyngitis episode, 47.7% contracted more than 2 common colds, and 3.2% had rhinitis weekly or monthly. The lifetime prevalence of recurrent acute otitis media (>/=4 episodes in any 12-month period) was 12.7% (n = 473). Bivariate correlations showed small-to-moderate relationships between the infections. Common cold was only weakly related to otitis media, tonsillopharyngitis, and chronic rhinitis. The probability for developing acute otitis media was almost 4-fold increased in children who had tonsillopharyngitis in the last year (adjusted odds ratio = 4.19; 95% confidence interval, 3.09-5.66). In logistic regression analysis, atopic disease was a strong determinant of all upper respiratory tract infections. Low birth weight increased the risk of acute otitis media. Day care attendance and the presence of siblings, which were considered to be indicators of exposure to respiratory pathogens, increased the risk of upper respiratory tract infections. CONCLUSIONS: In preschool children, acute otitis media, tonsillopharyngitis, and common cold were quite common, while chronic rhinitis was less prevalent and strongly associated with atopic disease. Attendance at day care centers increased the risk of upper respiratory tract infections in this age group, although the effect was weaker than that in younger children.

Acute Disease↗

PubMed2000

Risk of childhood asthma and allergic rhinitis in relation to pregnancy complications.

BACKGROUND: Events occurring during fetal life may affect the development of the immune and respiratory systems and increase the risk of asthma and allergic diseases. OBJECTIVES: We sought to elaborate the relations between the occurrence of pregnancy complications and other pregnancy-related conditions and the risk of bronchial obstruction during the first 2 years of life and the occurrence of asthma and allergic rhinitis by the age of 4 years. Pregnancy complications were considered both as predictors of the health outcomes and as possible effects caused by other prenatal factors. METHODS: A population-based, 4-year, cohort study was carried out involving 2531 children born in Oslo, Norway. We collected information on maternally related (hyperemesis, hypertension, and preeclampsia) and uterus-related complications in pregnancy (antepartum hemorrhage, preterm contractions, insufficient placenta, and restricted growth of the uterus) and the child's health and environmental exposures at birth and at 6, 12, 18, and 24 months and 4 years of age. The outcomes of interest were bronchial obstruction during the first 2 years and asthma and allergic rhinitis at the age of 4 years. RESULTS: In a logistic regression analysis adjusting for potential confounders, uterus-related, but not other pregnancy-related, complications increased the risk of bronchial obstruction (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.3-3.4), asthma (OR, 3.0; 95% CI, 1.8-5.4), and allergic rhinitis (OR, 2.9; 95% CI, 1.6-5.2). These relations were similar in children of atopic and nonatopic parents. CONCLUSIONS: Uterus-related complications in pregnancy increase the risk of having asthma and allergic rhinitis in childhood.

Adult↗