Biomedical subjects

Tom Wilsgaard

Publications and source records attributed to Tom Wilsgaard.

14 recordsLinked to original sources

PubMed2006

Body mass index and coronary heart disease risk score: the Tromsø study, 1979 to 2001.

PURPOSE: The purpose of the study is to examine the association between longitudinal change in body mass index (BMI) and change in coronary heart disease (CHD) risk score by using the Framingham risk score equation. METHODS: A general adult population in the municipality of Tromsø, Norway, was invited to four consecutive examinations in 1979 to 1980, 1986 to 1987, 1994 to 1995, and 2001. A total of 10,214 men and women aged 20 to 61 years at baseline attended at least three times. Associations were examined by using fixed-effects regression methods for longitudinal data. RESULTS: We observed a significant association between BMI change and risk score change in all baseline age groups. The association was significantly strengthened by age in women, but not men. A BMI increase of 3 kg/m(2) in subjects aged 40 to 49 years was associated with risk score increases of 0.45 points (95% confidence interval [CI], 0.29-0.62) in men and 0.66 points (95% CI, 0.52-0.80) in women. CONCLUSIONS: The well-known increase in body weight is associated with adverse CHD risk in both men and women.

Adult↗

PubMed2006

Changes in haemoglobin levels according to changes in body mass index and smoking habits, a 20-year follow-up of a male cohort: the Tromsø Study 1974-1995.

Haemoglobin level declines with increasing age in cross sectional studies. Little is known about the longitudinal changes of haemoglobin. Because both high or low haemoglobin levels increase mortality and morbidity we examined how changes in lifestyle factors like body mass index (BMI) and smoking habits influence cohort changes in haemoglobin level. In all, 4159 men aged 20-49 years at baseline were examined in 1974 and 1994-1995 in a longitudinal, population-based study from the municipality of Tromsø, Northern Norway. Mean haemoglobin was 148 g/l. There was no difference in mean haemoglobin after 20 years in any strata of age. Mean BMI increased 2.1 kg/m(2). The prevalence of smokers decreased 20.1 percentage points. In a multiple regression analysis increase in BMI was associated with increased haemoglobin change. Smoking cessation lowered mean haemoglobin 1.6 g/l compared to never smokers. Haemoglobin increased 0.8 g/l in smoking quitters whose BMI increased >2.5 kg/m(2) compared to a decrease of 6.7 g/l in weight reducers. There was a positive dose-response relationship between changes in cigarettes smoked per day and change in haemoglobin among consistent smokers. In conclusion, in contrast to cross sectional studies, mean haemoglobin did not change during 20 years ageing of relatively young men. This could be explained by higher BMI and less smoking. The increase in BMI affected haemoglobin change to such an extent that the reduction in haemoglobin due to smoking cessation was counteracted. Prospective studies are needed to address the health implications.

Adult↗

PubMed2006

Longitudinal reference ranges for estimated fetal weight.

OBJECTIVE: The aims of the present study were to establish reference ranges for the growth of estimated fetal weight (EFW) between gestational weeks 20 and 42 and to determine the effect of fetal and maternal factors. METHODS: This prospective longitudinal study was based on 634 low-risk pregnancies and a total of 1799 examinations. Gestational age was computed from last menstrual period. Head circumference, abdominal circumference, and femur length were measured using ultrasound, and EFW was calculated using the formula of Combs et al. The statistical analysis was based on regression analysis and multilevel modeling. RESULTS: Intrauterine growth expressed by EFW showed a continuous pattern until term. Males were calculated to be 5% heavier than female fetuses at 20 gestational weeks and 3% at 40 weeks. Otherwise, the fetal and maternal effects on intrauterine growth correspond to a weight shift of 1.3% for breech/nonbreech, 2.5% for each increase in maternal height tertile, and -4% for smoking/nonsmoking. Maternal age higher than 34 years had a significant increased EFW of 4.5% compared with maternal age less than 24 years. Cephalic index in the third tertile had a 1.1% lower EFW compared with the first tertile. Maternal weight, body mass index, and parity did not influence the EFW. Terms for customization to individualize the growth patterns are presented. CONCLUSIONS: The present growth chart is recommended as robust reference ranges for assessing EFW and growth. Fetal and maternal variables can be added into the models to individualize the prediction of EFW.

Adult↗

PubMed2005

Longitudinal reference charts for growth of the fetal head, abdomen and femur.

OBJECTIVES: The aims of the present study were to establish improved reference charts for growth of the fetal head, abdomen and femur, and to determine the effect of fetal and maternal factors. STUDY DESIGN: This prospective longitudinal study included 650 low-risk pregnancies. Outer-outer biparietal diameter (BPD), head circumference (HC), mean abdominal diameter (MAD), abdominal circumference (AC) and femur length (FL) were measured by ultrasound, and the statistical analysis was based on regression analysis and multilevel modeling. RESULTS: Reference percentiles for the growth of MAD, AC and FL showed continuous growth in gestational week 10-40, while BPD and HC showed a slightly blunted growth toward the end of pregnancy. FL was the only variable that was not influenced by gender. There was a significant negative association between breech presentation and all five biometrical variables, while maternal weight was positively associated with all five variables. Cephalic index significantly influenced BPD and HC. Maternal height had a positive effect on BPD, HC, AC and FL, and parity had a positive effect on MAD and AC, while smoking influenced negatively HC, MAD, and FL. Terms for calculating conditional reference values and customisation for individualised growth assessment are presented. CONCLUSIONS: New reference charts for the growth of fetal head, abdomen and femur are suggested for assessing fetal size and growth, and can be adjusted for maternal and fetal factors to suite individual pregnancies.

Abdomen↗

PubMed2005

Determining lifestyle correlates of body mass index using multilevel analyses: the Tromsø Study, 1979-2001.

Increases in overweight and obesity have been observed globally in both developed and developing countries. The authors assessed the relation between lifestyle factors and body mass index (BMI) (weight (kg)/height (m)2) in a population-based longitudinal study, using BMI and its subsequent change as responses in a multilevel model. The authors included 11,115 men and women aged 20-61 years at baseline who were living in the municipality of Tromsø, Norway, and who participated in three or four consecutive health surveys between 1979-1980 and 2001. Baseline age, physical activity at work, coffee consumption, and desired BMI (i.e., the BMI that the subjects reported they would like to have) were positively associated with baseline BMI, whereas height, alcohol consumption, leisure-time physical activity, and level of education were inversely associated. Most relations were found to be stronger in women than in men. Clinically relevant effect sizes were observed for most of the significant associations, especially in women. For instance, on an ordinal scale, a one-category increase in educational level would decrease the mean baseline BMI among women by 0.30 kg/m2. Significant associations between several lifestyle factors and subsequent BMI change revealed that observed baseline associations were strengthened over time, especially in women.

Adult↗

PubMed2005

Reference ranges for umbilical vein blood flow in the second half of pregnancy based on longitudinal data.

OBJECTIVES: To construct new reference ranges for serial measurements of umbilical vein (UV) blood flow. METHODS: Prospective longitudinal study of blood flow velocities and diameter of the UV measured at four-weekly intervals during 19 to 42 weeks' gestation in 130 low-risk singleton pregnancies. Regression models and multilevel modeling were used to construct the reference ranges. RESULTS: On the basis of 511 sets of longitudinal observations, we established new reference percentiles of UV diameter, blood flow velocities, volume flow, and blood flow normalized for fetal weight and abdominal circumference. They reflected some of the developmental patterns of previous cross-sectional studies, but with important differences, particularly near term. The UV blood flow showed a continuous increase until term, whereas the flow normalized per unit fetal weight, a corresponding reduction. Calculating the blood flow on the basis of intensity-weighted mean velocity or 0.5 of the maximum velocity gave almost interchangeable results for most fetuses. CONCLUSION: New reference ranges for UV blood flow based on longitudinal observations appear slightly different from cross-sectional studies, and should be more appropriate for serial evaluation of fetal circulation.

Adolescent↗

PubMed2005

Reference ranges for serial measurements of umbilical artery Doppler indices in the second half of pregnancy.

OBJECTIVE: The purpose of this study was to construct new reference ranges for serial measurements of commonly used umbilical artery Doppler indices (pulsatility index, resistance index, and systolic:diastolic ratio). STUDY DESIGN: This was a prospective longitudinal study of the umbilical artery Doppler indices that were obtained serially at the free-loop of umbilical cord at 4-week intervals at 19 to 42 weeks of gestation in 130 low-risk singleton pregnancies. A total of 513 observations were used to construct the reference ranges with the use of multilevel modeling. RESULTS: Longitudinally established percentiles of Doppler indices from the present study show a continuous reduction throughout the second half of pregnancy without any plateau or increase near term, as reported previously. There was a significant negative association between Doppler indices and placental weight and neonatal birth weight, but not with gender. The intraobserver coefficients of variation for the umbilical artery pulsatility index, resistance index, and systolic:diastolic ratio were 10.5%, 6.8 %, and 13.0 %, respectively. CONCLUSION: New reference ranges for umbilical artery Doppler indices that are based on longitudinal observations appear to be slightly different from cross-sectional studies and are more appropriate for serial evaluation of fetal hemodynamics.

Adolescent↗

PubMed2004

Serum high-density lipoprotein cholesterol, metabolic profile, and breast cancer risk.

BACKGROUND: The prevalence of metabolic syndrome (obesity, glucose intolerance, low serum high-density lipoprotein cholesterol [HDL-C], high serum triglycerides, hypertension) is high and increasing in parallel with an increasing breast cancer incidence worldwide. HDL-C represents an important aspect of the syndrome, yet its role in breast cancer is still undefined. METHODS: In two population-based screening surveys during 1977-1983 and 1985-1987, serum HDL-C was assayed enzymatically among 38,823 Norwegian women aged 17-54 years at entry. Height, weight, blood pressure, serum lipids, fat and energy intake, physical activity, parity, oral contraceptive use, hormone therapy use, alcohol intake, and tobacco use were also assessed. We used Cox proportional hazards modeling to estimate the relative risk (RR) of breast cancer associated with serum HDL-C levels and to adjust for potential confounding variables. We performed stratified analyses to evaluate effect modification by body mass index (BMI) and menopausal status. All statistical tests were two-sided. RESULTS: During a median follow-up of 17.2 years, we identified 708 cases of invasive breast cancer. In multivariable analysis, the risk of postmenopausal breast cancer was inversely related to quartile of HDL-C (P(trend) =.02). Among women with HDL-C above 1.64 mmol/L (highest quartile) versus below 1.20 mmol/L (lowest quartile), the relative risk was 0.75 (95% confidence interval [CI] = 0.58 to 0.97). The HDL-C association was confined to women in the heavier subgroup (BMI > or =25 kg/m2), for whom the relative risk of postmenopausal breast cancer in those with HDL-C above 1.64 mmol/L versus below 1.20 mmol/L was 0.43 (95% CI = 0.28 to 0.67; P(trend)<.001; P(interaction) =.001). CONCLUSION: Low HDL-C, as part of the metabolic syndrome, is associated with increased postmenopausal breast cancer risk.

Adolescent↗

PubMed2004

[Patient satisfaction with primary health care before and after the introduction of a list patient system].

BACKGROUND: The main objective was to compare patient satisfaction in general practice before and after the introduction of a list patient system for general practitioners (GPs) in Norway in 2001. MATERIAL AND METHODS: Postal survey sent to a random sample of inhabitants in Northern and Eastern Norway. A total of 1133 questionnaires from 2000 and 1141 from 2003 were included in the analysis (58% of the sample). RESULTS: From 2000 to 2003 there was a significant increase in the amount of respondents who answered that they were confident to get help if needed, and fewer reported unsuccessful attempts to contact a GP on the phone. Respondents were increasingly very satisfied with most aspects of the doctor-patient relationship and overall satisfaction also improved. We found a reduced proportion of very satisfied respondents in relation to some accessibility aspects. INTERPRETATION: The changes may be interpreted as changes in the quality and accessibility of services and as an expression of changes in expectations to and confidence in the system as a whole. If the changes are related to the new list patient system, it seems to be more successful with regard to quality than to accessibility.

Family Practice↗

PubMed2004

Change in serum lipids and body mass index by age, sex, and smoking status: the Tromsø study 1986-1995.

PURPOSE: The steady increase in body weight is becoming a major health problem in western societies. How body weight increase influences established disease risk factors is the focus of our study. METHODS: We assessed the association between 8-year change in body weight and serum lipids in a population-based study comprising 15,624 men and women aged 20 to 61 years at baseline in 1986. Comparisons between different strata of age, sex, initial weight, and categories of smoking status change were also addressed. RESULTS: Significant associations between body mass index (BMI) change and change in high density lipoprotein (HDL) cholesterol, total cholesterol, and triglycerides were observed in all 10-year age groups both in men and women. The weakest associations were observed in persons older than 50 years of age and the associations were also weaker in women than in men. In quartile groups of baseline BMI, a significant linear trend was observed for HDL cholesterol in men and for total cholesterol in both men and women. The associations were less adverse for persons in a higher quartile group of baseline BMI. The association between BMI change and serum lipid change was strongest for persons who were consistent smokers or non-smokers at each survey. CONCLUSIONS: We conclude that an increase in BMI has been shown to be associated with adverse changes in serum lipids. The associations were weaker in women than in men.

Adult↗

PubMed2003

Causes of death in polymyalgia rheumatica. A prospective longitudinal study of 315 cases and matched population controls.

OBJECTIVE: To determine causes of death in patients with pure polymyalgia rheumatica (PMR) compared to matched population controls. METHODS: In a population based study from 1987-1997, 315 patients were diagnosed with PMR. The patients were each randomly assigned four population controls, totally 1,260 controls. The date and causes of death were identified from the data files at Statistics Norway up to the end of 1997. RESULTS: A total of 65 cases (20.6%) with PMR died compared to 338 (26.8%) among the controls (mortality rate ratio (MRR) = 0.73, 95% CI 0.56-0.97, p = 0.03). No statistically significant difference was found between patients and controls with regard to mortality from coronary heart disease or stroke (MRR=0.78, 95% CI 0.52-1.18), cancer (MRR = 0.59, 95% CI 0.30-1.17), and other causes (MRR=0.75, 95% CI 0.48-1.17). CONCLUSION: The increased survival found in patients with PMR could not be explained by reduction in any particular cause of death.

Aged↗

PubMed2003

Change in plasma levels of vitamin D after consumption of cod-liver and fresh cod-liver oil as part of the traditional north Norwegian fish dish "Mølje".

OBJECTIVE: To assess changes in plasma 25-hydroxy vitamin D (25(OH)D) concentrations after ingestion of < >, a traditional north Norwegian fish dish rich in vitamin D. METHODS: Thirty-three volunteers all living in the city of Tromsø, located in northern Norway (latitude 690), were served a "Mølje" meal consisting of cod, hard roe, cod liver, and fresh cod-liver oil. The amounts of liver, and cod-liver oil consumed were weighed and recorded. Blood samples were collected before the meal, and at 4 hours, 12 hours and 5 days after it. The cod liver and cod-liver oil were analysed for vitamin D content and the plasma samples for the metabolite 25(OH)D. Trends in plasma 25(OH)D levels during the five-day observation period were analysed. The study was conducted at the beginning of April of 2000. RESULTS: Among the 33 participating subjects, 69.7% had baseline plasma 25(OH)D concentrations below 50 nmol/l and for one-quarter of the subjects, they were < 37.5 nmol/l The participants who acknowledged taking cod-liver oil supplements had significantly higher baseline 25(OH)D plasma levels at the outset of the study compared to those reporting not doing so (p = 0.02). Changes in plasma 25(OH)D levels relative to baseline concentrations were significantly associated with the body mass index (p < 0.01). CONCLUSION: Vitamin D status in populations living in circumpolar areas needs more research to investigate to what degree people living in the Arctic areas are at increased risk for vitamin D insufficiency and to determine the role of the traditional diet in preventing such deficiency.

Adult↗

PubMed2002

[Incisional hernia after surgery for abdominal aortic aneurysm].

BACKGROUND: Incisional hernia in patients electively operated on the abdominal aorta is common. METHODS: Patients with abdominal aortic aneurysm and with aorto-iliac occlusive disease (n = 231) operated at Tromsø University Hospital between 1992 and 1998 were identified. Data were obtained from patient files and from a postal questionnaire sent to 172 patients and returned by 140 (85%). RESULTS: Mean follow-up time was 3.5 years; 49 out of 140 patients (35%) had incisional hernia, 42 of these had been operated for aneurysm and seven for occlusive disease. Patients operated for aneurysm had an increased risk of developing incisional hernia (OR 3.1, p = 0.03). Obesity and smoking were associated risk factors. The hernias appeared earlier in patients with aorta aneurysm than in patients with occlusive disease (p < 0.01). A large proportion of the patients reported discomfort due to their hernias. INTERPRETATION: Abdominal aorta aneurysm seems to be associated with alterations in the connective tissue. Incisional hernia is a significant source of morbidity in patients operated for abdominal aortic aneurysm.

Aged↗

PubMed2002

No increased frequency of malignant neoplasms in polymyalgia rheumatica and temporal arteritis. A prospective longitudinal study of 398 cases and matched population controls.

OBJECTIVE: To determine the prevalence and incidence of cancer in patients with polymyalgia rheumatica (PMR) and temporal arteritis (TA) compared to matched population controls. METHODS: In a population based study 1987-97, 398 patients were diagnosed with PMR or TA. Each patient was randomly assigned 4 age and sex matched controls from the same county, totaling 1592 controls. All patients and controls were cross-checked with data files at the Cancer Registry of Norway, for cancers registered up to the end of 1998. RESULTS: Prior to inclusion, cancer was diagnosed in 32 patients with PMR or TA (8.0%) and 153 controls (9.6%) (OR 0.82, 95% CI 0.55-1.22, p = 0.3). After inclusion, malignant neoplasms were discovered in 34 patients with PMR or TA (9.3%) compared to 143 controls (10.8%) (relative risk 0.86, 95% CI 0.59-1.26, p = 0.4). Thus there was no difference between patients with PMR or TA and their controls regarding prevalence or incidence of cancer. The interval between inclusion and the time of diagnosis of malignant neoplasm did not differ between patients and controls. No significant difference in types or localization of malignant neoplasms was found in patients compared to controls. CONCLUSION: No differences were found in frequencies or types of malignant neoplasms between patients with PMR or TA and population controls. Neither PMR nor TA as defined by present diagnostic criteria appears associated with cancer.

Giant Cell Arteritis↗