Biomedical subjects

Nikulás Sigfússon

Publications and source records attributed to Nikulás Sigfússon.

6 recordsLinked to original sources

PubMed2006

[The health risk associated with smoking has been seriously underestimated. The Reykjavik Study].

OBJECTIVE: To assess the risk for coronary heart disease, myocardial infarction, cancer deaths, and all deaths associated with different smoking categories as determined by smoking status at a baseline examination only and at a baseline with reexamination 15-19 years later (persistent smokers). MATERIAL AND METHODS: The participants were a random sample of 2930 men and 3084 women aged 34-61 years (when selected in 1967) invited for various standardized examinations under two periods, 1967-1972 and 1979-1991 and followed-up until the end of year 2001. The main outcome measures were clinical coronary heart disease, myocardial infarction, cancer deaths, and all deaths. Risk was calculated for each smoking category as determined by two assessments of smoking habits and also compared with the risk as determined by one baseline examination only. RESULTS: Mean follow-up for men was 26 years (SD 9 years). For women the mean follow-up was 28 years (SD 7 years). There were substantial differences in hazard ratios (HR) and median lifetime in smoking groups as determined by one or two examinations. In men the greatest difference in hazard ratios was for cancer deaths (one examination: 2.80, two: 3.83) in women for total deaths (3.02 vs. 3.7). Loss of median lifetime was greatest in "heavy" cigarette smoking men (one examination: eight years; two examinations: 13 years), in women the corresponding figures were nine and 10 years, in "light" cigarette smokers, the figures for men were four and nine years, and for women four and six years. CONCLUSIONS: Middle-aged men smoking one or more packets of cigarettes per day shorten their life expectancy by 13 years and middle-aged women by 10 years. Only one baseline determination of smoking status with subsequent follow-up underestimates the health risk associated with smoking by 15-40% at least in populations where smoking prevalence is declining.

Adult↗

PubMed2005

[Coronary risk factors among men and women in Iceland. Results from the Reykjavik Study 1967-1985. 1992].

The Reykjavík Study 1967-1985: Risk factors for coronary heart disease mortality have been investigated in a prospective study of 8001 randomly selected Icelandic men and 8468 women. The men were aged 34-64 and the women 34-76 at the time of their first examination. After followup from 2-17 years 1140 (14.2%) of the men and 537 (6.3%) of the women had died. Coronary heart disease accounted for 43% of the mortality among the men, cancer 27% and cerebrovascular disease 7%. This distribution is in contrast to what was found among the women. Coronary heart disease accounted for 19.4% of the mortality, cancer 42.3% while the relative contribution of cerebrovascular mortality was similar. The effects of various factors were assessed simultaneously with multivariate survival analysis using the Cox's proportional hazard model. Age, serum total cholesterol, triglycerides, smoking and systolic blood pressure were all significant independent risk factors for coronary heart disease mortality in both sexes. Fasting blood sugar was of borderline significance, reaching significance among men, but not among women. However, since the women have much lower risk of dying from coronary heart disease than the men the absolute risk associated with each of the risk factors is much lower in the women.

Coronary Disease↗

PubMed2003

[Changes in smoking habits in the last thirty years in middle-aged Icelanders and their causes - Results from population surveys of the Icelandic Heart Association.].

OBJECTIVE: During the last thirty years the Research Clinic of the Icelandic Heart Association has been engaged in several extensive cardiovascular population surveys. Smoking habits have been assessed by a questionnaire and the purpose of the present study is to describe the changes in smoking habits during the period 1967-2001, their causes and the reliability of the information gathered. MATERIAL AND METHODS: The subjects were participants in four population surveys: The Reykjavik Study 1967-1996, Survey of "Young People" 1973-1974 and 1983-1985, MONICA Risk Factor Surveys 1983, 1988-1989 and 1993-1994 and the "Reykjavik Offspring Study" 1997-2001. The age of participants was 30-88 years and 26,311 examinations of males and 26,222 of females were performed, a number of individuals attending more often than once. A standardized smoking questionnaire was used and the reliability was assessed. RESULTS: Smoking prevalence decreased substantially in both sexes during the study period. In the youngest male group the prevalence decreased from 65% to 42%, but in the oldest from 45% to 19%, while in the youngest female group the decrease was from 50% to 35% but in the oldest age group from 30% to 20%. The decrease in smoking was almost exclusively in the category of "light smokers" (i.e. 1-14 cigarettes a day or pipe/cigar smoker). The main reasons for quitting smoking were concerns about health and symptoms associated with smoking and the cost. The cost had greater weight at the beginning of the period than during the latter part but health concerns seem to be increasingly important. Compared to other countries smoking prevalence in Icelandic males is low but high in females. CONCLUSION: During the last three decades smoking prevalence in Icelanders 30 years and older has decreased substantially. The main reasons for quitting smoking are health concerns and cost. Continued information about the deleterious effects of smoking as well as increase in the price of tobacco is likely to reduce further the smoking prevalence.

English Abstract↗

PubMed2002

Increased total mortality and cancer mortality in men with Dupuytren's disease: a 15-year follow-up study.

The aim of the present study was to evaluate the mortality rate and causes of death of individuals with Dupuytren's disease. In 1981/82, as part of The Reykjavík Study, a general health survey, 1297 males were examined for clinical signs of Dupuytren's disease. Based on the clinical evaluation the participants were classified into three groups: (1) those with no signs of Dupuytren's disease were referred to as the reference cohort; (2) those with palpable nodules in the palmar fascia were classified as having stage 1; and (3) those who had contracted fingers or had been operated on due to contractures were classified as having stage 2 of Dupuytren's disease. In 1997, after a 15- year follow-up period, the mortality rate and causes of death were investigated in relation to the clinical findings from 1981/82. Information about causes of death were obtained from the National Icelandic Death Registry and the Icelandic Cancer Registry. During the follow-up period, 21.5% (225/1048) of the reference cohort were deceased compared to 29.9% (55/184) of those with stage 1 and 47.7% (31/65) of those with stage 2 of Dupuytren's disease. When adjusted for age, smoking habits and other possible confounders, individuals with stage 2 of the disease showed increased total mortality [hazard ratio (HR) = 1.6; 95% CI 1.1-2.4]. Cancer deaths were increased (HR = 1.9; CI 1.0-3.6). In contrast, participants with stage 1 of Dupuytren's disease did not show increased mortality. A moderate but non-significant increase in cancer incidence was observed among individuals with stage 2 of Dupuytren's disease (HR = 1.5; 95% CI 0.9-2.4, P = 0.15). The study showed increased total mortality of individuals with Dupuytren's disease stage 2, where 42% of the excess in mortality could be attributed to cancer deaths.

Aged↗

PubMed2002

Do lipids, blood pressure, diabetes, and smoking confer equal risk of myocardial infarction in women as in men? The Reykjavik Study.

BACKGROUND: Studies on coronary risk factors in men and women are mainly based on mortality data and few compare results of both sexes with consistent study design and diagnostic criteria. This study assesses the major risk factors for coronary events in men and women from the Reykjavik Study. DESIGN: Within a prospective, population-based cohort study individuals without history of myocardial infarction were identified and the relative risk of baseline variables was assessed in relation to verified myocardial infarction or coronary death during follow-up. METHODS: Of the 9681 women and 8888 men who attended risk assessment from 1967-1991, with follow-up period of up to 28 years, 706 women and 1700 men suffered a non-fatal myocardial infarction or coronary death. RESULTS: Serum cholesterol was a significant risk factor for both sexes, with hazard ratios (HR) decreasing with age. Systolic blood pressure was a stronger risk factor for women as was ECG-confirmed left ventricular hypertrophy (women HR 2.89, 95% confidence interval [CI] 1.67-5.01; men HR 1.11 [CI 0.86-1.43]). Fasting blood glucose > or =6.7 mmol/L identified significantly higher risk for women (HR 2.65) than men (HR 2.08) as did self-reported diabetes. Triglyceride risk was significantly higher for women and decreased significantly with age. Smoking increased risk two- to five-fold, increasing with dose, for women, which was significantly higher than the doubling in risk for men. CONCLUSIONS: This large study of the major risk factors compared between the sexes demonstrates similar relative risk of myocardial infarction associated with cholesterol for both sexes, however, the relative risk is higher in women for many other risk factors such as smoking, diabetes, elevated triglycerides and left ventricular hypertrophy.

Adult↗

PubMed2002

[The relationship between educational level, physical activity and mortality.].

OBJECTIVES: The relationship between educational level and mortality is well known. This has been shown in the Reykjavik Study and was only partly accounted for by unequal distribution of known risk factors. The objective of the present study was to explore the relationship between educational level and physical activity and whether that relationship could partly explain differences in mortality. MATERIAL AND METHODS: This is a part of the Reykjavik Study. Presented is data from 18,912 participants, divided into four groups by educational level. Physical activity was assessed by questionnaire. The relationship between physical activity and educational level was assessed by logistic regression and between mortality and educational level by Cox regression analysis. Adjustments were made for age, year of examination, known risk factors (serum lipids, blood pressure, height, weight, smoking, use of anti-hyertensive drugs and 90 min glucose tolerance) and physical activity. RESULTS: There was a positive relationship between physical activity and educational level (p<0.001). By adding adjustments for physical activity to a multiple regression analysis containing other known risk factors the relationship between total mortality and educational level was reduced. For highest versus lowest educational group hazard ratio was elevated from 0.77 to 0.80 for men and from 0.91 to 0.93 for women. Same trend existed for cardiovascular mortality and to a less extent for cancer mortality. CONCLUSION: The association between educational level and mortality can be partly explained by differences in leisure-time physical activity. In spite of adjustments for known risk factors and physical activity there remains a statistically significant relationship between educational level and mortality.

English Abstract↗