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Biomedical subjects

S E Vollset

Publications and source records attributed to S E Vollset.

At least 19 recordsLinked to original sources
PubMed2001

Smoking, folate and methylenetetrahydrofolate reductase status as interactive determinants of adenomatous and hyperplastic polyps of colorectum.

Most studies demonstrate increased risk of colorectal cancer (CRC) and adenomas in folate-deficient subjects or that high folate intake may afford some protection. Smoking increases such risk in some but not all studies. We investigated whether smoking, folate status and methylenetetrahydrofolate reductase (MTHFR) genotype predict the risk of adenomatous and hyperplastic polyps of colorectum. By colonoscopy, the type, number, size and extent of dysplasia of colorectal polyps were assessed in 443 subjects aged 63-72 years. We also determined RBC folate and the C667T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene. Smoking, folate status and the C677T MTHFR polymorphism were strong, interactive determinants of high-risk adenomas (HRAs, defined as adenomas > or =10 mm in diameter, adenomas with villous components or with severe dysplasia). The risk was particularly high in smokers with low folate and the CT/TT genotype (risk category T) and in smokers with high folate and the CC genotype (risk category C). With non-smokers with low folate and the CC genotype as reference, the odds ratios (OR, 95% CI) were 8.7 (2.5-29.7) in category T and 9.9 (2.6-38.4) in category C. Notably, this risk pattern was also observed for hyperplastic polyps. In conclusion, in smokers, high folate status may confer increased or decreased risk for HRAs, depending on the MTHFR genotype. These data demonstrate the strong gene-nutrition interaction involving the C677T MTHFR polymorphism.

Adenomatous Polyps↗
PubMed2001

Plasma total cysteine as a risk factor for vascular disease: The European Concerted Action Project.

BACKGROUND: Elevated plasma total homocysteine (tHcy) is a risk factor for cardiovascular disease. Although cysteine is structurally similar and metabolically linked to tHcy, its relation to the risk of cardiovascular disease has received little attention. We studied the relation between plasma total cysteine (tCys) levels and the risk of vascular disease in the coronary, cerebral, and peripheral vessels. METHODS AND RESULTS: This case-control study included 750 patients with vascular disease and 800 age- and sex-matched control subjects recruited from 19 centers in 9 European countries. Conventional risk factors for cardiovascular disease were recorded. In addition, plasma levels of tCys, tHcy, folate, B(6), B(12), and creatinine were measured. Overall, a U-shaped relationship was observed between tCys and risk of vascular disease. With the middle range of 250 to 275 micromol/L tCys used as the reference category, the adjusted risk of vascular disease at low (</=225 micromol/L) tCys levels was 2.1 (95% CI 1.2 to 3.6), and the risk at high (>300 micromol/L) tCys levels was 1.6 (95% CI 1.1 to 2.3). Different shapes of the dose-response relationship were seen for the 3 vascular disease categories. The relation with peripheral vascular and cerebrovascular disease was U-shaped, whereas a weak positive relation was observed with coronary heart disease. CONCLUSIONS: Our data show a significant U-shaped relationship between tCys and cardiovascular disease after adjustment for tHcy, creatinine, and other cardiovascular disease risk factors.

Adult↗
PubMed2001

The Hordaland Homocysteine Studies.

The Hordaland Homocysteine Study is a population-based screening of total plasma homocysteine (tHcy) in approximately 18,000 men and women aged 40-67 yr that took place in 1992-1993 in the county of Hordaland in Western Norway. In this cohort, tHcy was associated with several physiologic and life-style factors, including age and gender, blood pressure, serum cholesterol, smoking, alcohol and coffee consumption, physical activity, diet, and vitamin status. All associations with established cardiovascular risk factors were in the direction expected to confer increased risk. In a subset of 5,883 women aged 40-42 yr, tHcy was associated with previous pregnancy outcomes, including preeclampsia, placental abruption, and neural tube defects. This article reviews the published results from the Hordaland Homocysteine Study in the light of relevant literature. The Hordaland Homocysteine cohort will be used for future investigations of the stability of tHcy and vitamin status over time, and to investigate associations with mortality and morbidity including cancer incidence.

Adult↗
PubMed2001

Biological and clinical implications of the MTHFR C677T polymorphism.

The enzyme methylenetetrahydrofolate reductase (MTHFR) directs folate species either to DNA synthesis or to homocysteine (Hcy) remethylation. The common MTHFR C677T polymorphism affects the activity of the enzyme and hence folate distribution. Under conditions of impaired folate status, the homozygous TT genotype has been regarded as harmful because it is associated with a high concentration of plasma total Hcy, increased risk of neural tube defects and colorectal neoplasias, and can also predispose individuals to adverse effects from drugs with antifolate effects. The MTHFR C677T polymorphism shows no consistent correlation with cardiovascular risk and longevity but, in combination with positive folate balance, the TT genotype is associated with decreased risk of colorectal neoplasias. Because of the high prevalence of this polymorphism in most populations, the TT variant might represent an ancestral genetic adaptation to living constraints (tissue injury or unbalanced vitamin intake) that has become a determinant of disease profiles in modern times.

Cardiovascular Diseases↗
PubMed2001

High intake of energy, sucrose, and polyunsaturated fatty acids is associated with increased risk of preeclampsia.

OBJECTIVE: Preeclampsia is associated with high body mass index, insulin resistance, and hypertriglyceridemia. Our objective was to investigate prospectively whether diet in the first half of pregnancy is associated with the risk for preeclampsia. STUDY DESIGN: This prospective, population-based, cohort study of pregnant women investigated dietary intake early in the second trimester with a quantitative food frequency questionnaire. RESULTS: The questionnaire was completed by 3133 women (83%). Preeclampsia developed in 85 women. Adjusted odds ratio (95% CI) for preeclampsia was 3.7 (1.5-8.9) for energy intake of >3350 kcal/d compared with < or =2000 kcal/d. Adjusted odds ratio (95% CI) for preeclampsia was 3.6 (1.3-9.8) for sucrose intake (percent of total energy) of >25% compared with < or =8.5% and 2.6 (1.3-5.4) for polyunsaturated fatty acids intake (percent of total energy) of >7.5% compared with < or =5.2%. Other energy-providing nutrients were not associated with the risk for preeclampsia. CONCLUSION: The current study suggests that high intakes of energy, sucrose, and polyunsaturated fatty acids independently increase the risk for preeclampsia.

Adult↗
PubMed2001

Plasma total homocysteine and cardiovascular and noncardiovascular mortality: the Hordaland Homocysteine Study.

BACKGROUND: Few population-based studies have assessed relations between plasma or serum total homocysteine (tHcy) and all-cause mortality. OBJECTIVE: Our goal was to study associations between plasma tHcy and all-cause, cardiovascular, and noncardiovascular mortality. DESIGN: This was a prospective cohort study of 2127 men and 2639 women aged 65-67 y in 1992-1993 when they were recruited as part of a population-based national cardiovascular screening program carried out in Hordaland County, Norway. RESULTS: During a median of 4.1 y of follow-up, 162 men and 97 women died. A strong relation was found between plasma tHcy and all-cause mortality. The association was highly significant for noncardiovascular and for cardiovascular causes of death. In a comparison of individuals having tHcy concentrations of 9.0-11.9, 12.0-14.9, 15.0-19.9, or > or = 20 micromol/L with individuals having a tHcy concentration < 9 micromol/L, adjusted mortality ratios were 1.4, 1.9, 2.3, and 3.6 (P for trend = 0.0002) for noncardiovascular and 1.3, 2.1, 2.6, and 3.5 (P for trend = 0.0002) for cardiovascular causes of death. A tHcy increment of 5 micromol/L was associated with a 49% (95% CI: 28%, 72%) increase in all-cause mortality, a 50% (95% CI: 21%, 85%) increase in cardiovascular mortality (121 deaths), a 26% (95% CI: -2%, 63%) increase in cancer mortality (103 deaths), and a 104% (95% CI: 44%, 289%) increase in noncancer, noncardiovascular mortality (33 deaths). CONCLUSION: Plasma tHcy is a strong predictor of both cardiovascular and noncardiovascular mortality in a general population of 65-72-y-olds. These results should encourage studies of tHcy in a wider perspective than one confined to cardiovascular disease.

Adult↗
PubMed2001

Hyperhomocysteinemia and elevated methylmalonic acid indicate a high prevalence of cobalamin deficiency in Asian Indians.

BACKGROUND: In India, most people adhere to a vegetarian diet, which may lead to cobalamin deficiency. OBJECTIVE: The objective was to examine indicators of cobalamin status in Asian Indians. DESIGN: The study population included 204 men and women aged 27-55 y from Pune, Maharashtra, India, categorized into 4 groups: patients with cardiovascular disease (CVD) and diabetes, patients with CVD but no diabetes, patients with diabetes but no CVD, and healthy subjects. Data on medical history, lifestyle, and diet were obtained by interviews and questionnaires. Blood samples were collected for measurement of serum or plasma total cobalamin, holotranscobalamin (holoTC), methylmalonic acid (MMA), and total homocysteine (tHcy) and hemetologic indexes. RESULTS: MMA, tHcy, total cobalamin, and holoTC did not differ significantly among the 4 groups; therefore, the data were pooled. Total cobalamin showed a strong inverse correlation with tHcy (r = -0.59) and MMA (r = -0.54). Forty-seven percent of the subjects had cobalamin deficiency (total cobalamin <150 pmol/L), 73% had low holoTC (<35 pmol/L), 77% had hyperhomocysteinemia (tHcy >15 micromol/L), and 73% had elevated serum MMA (>0.26 micromol/L). These indicators of impaired cobalamin status were observed in both vegetarians and nonvegetarians. Folate deficiency was rare and only 2.5% of the subjects were homozygous for the MTHFR 677C-->T polymorphism. CONCLUSIONS: About 75% of the subjects had metabolic signs of cobalamin deficiency, which was only partly explained by the vegetarian diet. If impaired cobalamin status is confirmed in other parts of India, it may have important health implications.

Adult↗
PubMed2001

Plasma total homocysteine is influenced by prandial status in humans: the Hordaland Hhomocysteine Sstudy.

Plasma total homocysteine (tHcy) is a risk factor for cardiovascular disease, adverse pregnancy outcomes and impaired cognitive function. No population-based studies on the possible influence of prandial status on tHcy have been published. The aim of this study was to investigate the variation in plasma tHcy levels in relation to time since last meal. A cross-sectional, population-based study including 18,044 individuals in Western Norway was conducted. Most subjects were in the age groups 40-42 and 65-67 y. Participants who had not eaten during the past 6 h before the blood sampling had significantly higher mean tHcy levels compared with those who had eaten; 11.7 [95% confidence interval (CI): 11.4-12.1] vs. 11.2 (95% CI: 11.1-11.3) micromol/L among men (P = 0.03) and 10.2 (95% CI: 9.9-10.6) vs. 9.7 (95% CI: 9.6-9.7) micromol/L among women (P = 0.003). In all groups except older women, tHcy concentrations were generally higher with increasing time after a meal (P-trend <0.01 in all 3 groups). These findings suggest that fasting status and time since last meal may influence levels of tHcy and should be considered in studies of tHcy as a risk factor for cardiovascular and other diseases, and when comparing tHcy values among studies.

Adult↗
PubMed2001

Hip disease and the prognosis of total hip replacements. A review of 53,698 primary total hip replacements reported to the Norwegian Arthroplasty Register 1987-99.

We studied the rates of revision for 53,698 primary total hip replacements (THRs) in nine different groups of disease. Factors which have previously been shown to be associated with increased risk of revision, such as male gender, young age, or certain types of uncemented prosthesis, showed important differences between the diagnostic groups. Without adjustment for these factors we observed an increased risk of revision in patients with paediatric hip diseases and in a small heterogeneous 'other' group, compared with patients with primary osteoarthritis. Most differences were reduced or disappeared when an adjustment for the prognostic factors was made. After adjustment, an increased relative risk (RR) of revision compared with primary osteoarthritis was seen in hips with complications after fracture of the femoral neck (RR = 1.3, p = 0.0005), in hips with congenital dislocation (RR = 1.3, p = 0.03), and in the heterogenous 'other' group. The analyses were also undertaken in a more homogenous subgroup of 16,217 patients which had a Charnley prosthesis implanted with high-viscosity cement. The only difference in this group was an increased risk for revision in patients who had undergone THR for complications after fracture of the femoral neck (RR = 1.5, p = 0.0005). THR for diagnoses seen mainly among young patients had a good prognosis, but they had more often received inferior uncemented implants. If a cemented Charnley prosthesis is used, the type of disease leading to THR seems in most cases to have only a minor influence on the survival of the prosthesis.

Adolescent↗
PubMed2001

Determinants of cobalamin status in newborns.

OBJECTIVE: Cobalamin deficiency accompanied by bone marrow dysfunction and impaired central nervous system development has been reported in infants who were born to mothers with low cobalamin intake. We investigated the relation between cobalamin status in newborns and in their healthy mothers who consumed an omnivorous diet. METHODS: Serum cobalamin and the functional markers plasma methylmalonic acid (MMA) and total homocysteine (tHcy) were determined in 173 newborns and their mothers. Forty-five children and mothers were reinvestigated after 6 weeks. RESULTS: At birth, median (interquartile range) serum cobalamin levels were 245 (175-323) pmol/L in the mothers and 314 (238-468) pmol/L in the newborns. In the neonates, serum cobalamin, but not folate, was inversely associated with MMA and tHcy. Among maternal factors, low serum cobalamin was the strongest predictor of impaired cobalamin function (defined as low cobalamin, high tHcy, or high MMA levels) in the newborns. After 6 weeks, the maternal cobalamin levels had increased (to 421 [271-502] pmol/L), whereas the newborn levels had declined (to 230 [158-287] pmol/L). In the same interval, the infants had a marked increase in plasma MMA (from 0.29 [0.24-0.38] to 0.81 [0.37-1.68] micromol/L). At 6 weeks, parity was a strong predictor of cobalamin status in the infant. CONCLUSION: The cobalamin status in the neonatal period is strongly associated with maternal cobalamin status and parity. A reduction in serum cobalamin and an increase in metabolite levels are consistent with impaired cobalamin function in a significant portion of the infants who were born to healthy, nonvegetarian mothers.

Adult↗
PubMed2001

Cod liver oil consumption, smoking, and coronary heart disease mortality: three counties, Norway.

It has been hypothesized that omega-3 fatty acid consumption may lessen the adverse effect of smoking on coronary heart disease (CHD) risk. Thus, we explored whether cod liver oil consumption was protective of coronary heart disease in a cohort of men and women participating in a cardiovascular disease screening in Norway. The study population was aged 35-54 at the time of the baseline screening conducted by the National Health Screening Service of Norway in 1977-1983. Of 56,718 age-eligible men and women, 52,138 participated, of whom 42,612 (82%) completed a dietary questionnaire. Cod liver oil use was reported by 12.5%. At baseline, cod liver oil users had lower triglycerides, adjusting for age, body mass index, time since last meal and income (p < or = .05). As of December 1992, 639 and 118 CHD deaths were observed among the men and women, respectively. Overall, we observed no effect of cod liver oil consumption reported at baseline and CHD mortality in Cox Proportional Hazards analyses [Hazard Ratio (HR) = 1.0 (0.8-1.3)]. In analyses, stratified by smoking status, never smokers and current smokers showed non-significant beneficial associations between cod liver oil use and CHD mortality (HR = 0.7, 95% CI = 0.4-1.5; and HR = 0.8, 95% CI = 0.6-1.2, respectively). However, among former smokers a non-significant excess risk of CHD mortality was associated with cod liver oil use (HR = 1.6, 95% CI = 0.9-2.6). Smokers, regardless of their cod liver oil use were at a substantially higher risk for CHD mortality relative to non-smokers. Omega-3 fatty acid supplementation, as practiced in this cohort, provided no significant benefits to CHD risk among study participants.

Adult↗
PubMed2000

Increasing mortality from amyotrophic lateral sclerosis in Norway?

OBJECTIVE: To investigate a possible increase in incidence of ALS in Norway. METHODS: Death certificate data from all deaths in Norway in the period 1961 to 1994 for ALS, PD, and MG were obtained from Statistics Norway and related to population statistics. Data on ALS was obtained on sex, age, and place of death and compared with mortality data in PD and MG for the same period. Data were standardized using the 1990 population as standard population. Poisson regression was used to test for trends in mortality. The data from the death certificates were related to a clinical study performed on ALS in one of the counties during the same period. RESULTS: The annual mortality of ALS almost doubled during the period studied, rising from 1.38 to 2.54 per 100,000 inhabitants at the end of the study. The increased mortality appeared solely in the population older than 60 years of age, with a peak in mortality in the age group 80 to 84 years. The increase was larger in women than in men, and the ratio between the sexes was 1.32 (men-women, age-adjusted at the end of the study). The mortality in patients with PD showed a similar increase to that seen in ALS, whereas no increase in mortality was observed in patients with a diagnosis of MG. There were considerable differences in ALS mortality in different counties, but no clear regional trends were observed. CONCLUSION: The authors report increasing ALS mortality. Although the increase in mortality is restricted to the population aged 65 years or older, it cannot be explained by increasing age of the general population alone.

Adolescent↗
PubMed2000

Evaluation of diagnostic tests for antinuclear antibodies in rheumatological practice.

To investigate and compare the accuracy and usefulness of diagnostic tests for antinuclear antibodies (ANA) a cross-sectional study of sera derived from patients admitted to the Department of Rheumatology was tested for the presence of ANA using either indirect immunofluorescence on HEp-2 cells, indirect immunoperoxidase techniques on HEp-2 cells and mouse kidney, or two commercial enzyme-linked immunosorbent assays (ELISA). The diagnostic sensitivity and predictive values of the tests were calculated and compared. The accuracy of tests was compared using receiver-operating characteristics (ROC) methodology. All ANA-positive sera were further analysed for the presence of antibodies against extractable nuclear antigens (anti-ENA) and anti-DNA. A moderate to good agreement was found between tests, with kappa ranging from 0.469 to 0.659. Highest sensitivity for systemic lupus erythematosus (SLE; 93.3%) and primary Sjögren's syndrome (SS; 70%) was found using immunofluorescence on HEp-2 cells. Immunofluorescence on HEp-2 cells performed statistically better than the other tests in predicting SLE but not SS. All tests except mouse kidney showed good and comparable performance in detecting sera with anti-ENA and anti-DNA. At the given cut-off values indirect immunofluorescence on HEp-2 cells performed best. All assays except mouse kidney showed performance characteristics sufficient for use in routine analysis of ANA.

Animals↗
PubMed2000

The Norwegian Arthroplasty Register: 11 years and 73,000 arthroplasties.

In 1985, the Norwegian Orthopaedic Association decided to establish a national hip register, and the Norwegian Arthroplasty Register was started in 1987. In January 1994, it was extended to include all artificial joints. The main purpose of the register is to detect inferior results of implants as early as possible. All hospitals participate, and the orthopedic surgeons are supposed to report all primary operations and all revisions. Using the patient's unique national social security number, the revision can be linked to the primary operation, and survival analyses of the implants are done. In general, the survival analyses are performed with the Kaplan-Meier method or using Cox multiple regression analysis with adjustment for possible confounding factors such as age, gender, and diagnosis. Survival probabilities can be calculated for each of the prosthetic components. The end-point in the analyses is revision surgery, and we can assess the rate of revision due to specific causes like aseptic loosening, infection, or dislocation. Not only survival, but also pain, function, and satisfaction have been registered for subgroups of patients. We receive reports about more than 95% of the prosthesis operations. The register has detected inferior implants 3 years after their introduction, and several uncemented prostheses were abandoned during the early 1990s due to our documentation of poor performance. Further, our results also contributed to withdrawal of the Boneloc cement. The register has published papers on economy, prophylactic use of antibiotics, patients' satisfaction and function, mortality, and results for different hospital categories. In the analyses presented here, we have compared the results of primary cemented and uncemented hip prostheses in patients less than 60 years of age, with 0-11 years' follow-up. The uncemented circumferentially porous- or hydroxyapatite (HA)-coated femoral stems had better survival rates than the cemented ones. In young patients, we found that cemented cups had better survival than uncemented porous-coated cups, mainly because of higher rates of revision from wear and osteolysis among the latter. The uncemented HA-coated cups with more than 6 years of follow-up had an increased revision rate, compared to cemented cups due to aseptic loosening as well as wear and osteolysis. We now present new findings about the six commonest cemented acetabular and femoral components. Generally, the results were good, with a prosthesis survival of 95% or better at 10 years, and the differences among the prosthesis brands were small. Since the practice of using undocumented implants has not changed, the register will continue to survey these implants. We plan to assess the mid- and long-term results of implants that have so far had good short-term results.

Activities of Daily Living↗
PubMed2000

Mortality after total hip replacement: 0-10-year follow-up of 39,543 patients in the Norwegian Arthroplasty Register.

We have studied the mortality after total hip replacement (THR) of 39,543 patients, having a mean age of 69 years, who were reported to the Norwegian Arthroplasty Register. The median follow-up time was 5.2 (0-10.4) years. 323 of 6201 deaths occurred during the first 60 postoperative days. The patient mortality was compared with the mortality in the Norwegian population, using standardized mortality ratios (SMR). The SMRs were compared and adjusted for age, gender, and other possible confounders in a Cox regression model incorporating the population mortality. We observed a lower mortality in patients with THR than in the Norwegian population (8-year patient mortality was 25%, versus 30% in the corresponding Norwegian population. SMR = 0.81). There was an increased standardized mortality ratio in patients less than 50 years (SMR = 2.50), patients 50-59 years (SMR = 1.16), patients with THR due to rheumatoid arthritis (SMR = 1.48), and patients with femoral neck fracture (SMR = 1.11). The SMR decreased with increasing age at the time of THR surgery. After revision surgery, the SMR was similar to that after the first primary operation, whereas a second primary operation in the opposite hip was associated with a further reduction in the SMR (SMR = 0.65). During the first 60 postoperative days, all patient categories had a higher mortality than the general population (0.8% mortality, SMR = 1.39).

Aged↗