Familial predisposition and susceptibility to the effect of other risk factors for myocardial infarction.
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STUDY OBJECTIVES: To assess if familial predisposition to myocardial infarction (MI) is an indicator of increased susceptibility to the effect of other established risk factors. The study assessed whether a family history of MI modifies the effect of arterial blood pressure, plasma cholesterol, high and low density lipoprotein cholesterol, % triglycerides, diabetes mellitus, body mass index, height, smoking habits, alcohol intake, physical activity level, and educational level on the incidence of MI. DESIGN: Prospective population based cohort study of cardiovascular risk and risk factors with follow up of MI by record linkage with the Cause of Death Register and The National Hospital Discharge Register until 1994. SETTING: The Copenhagen Centre for Prospective Population Studies, where data from three Danish studies are integrated. PARTICIPANTS: Subjects were 24,664 people aged 20-93, examined between 1976 and 1987. MAIN RESULTS: A total of 1763 new cases of MI occurred during 293,559 person years of observation. All risk factors, including family history of MI reported by 4012 subjects, were, as expected, associated with incidence of MI. With a few inconsistent exceptions we found no significant interactions between family history of MI and cardiovascular risk factors in their effect on MI. CONCLUSIONS: The familial predisposition to MI does not consistently modify the effect of other risk factors on the risk of MI. However, subjects with a family history of MI may still be regarded as an appropriate target group for screening for cardiovascular risk and intervention against other risk factors. (+info)
Smoking habits among pregnant Danish women: reliability of information recorded after delivery.
(42/3722)
STUDY OBJECTIVE: To compare recall of smoking habits during pregnancy 0.5-3 years after delivery across groups defined by recall time (5 six month periods) and pregnancy outcome (pre-eclampsia, pregnancy induced hypertension, intrauterine growth retardation, preterm or post-term delivery compared with controls). DESIGN: Case-control nested in cohort study. SETTING AND PARTICIPANTS: A subsample of 503 women from a cohort of 6347 women established between 1989 and 1991 in Aarhus University Hospital. MAIN RESULTS: Measures of agreement between concurrent and retrospective data on smoking status varied between 0.93 and 1.0 (sensitivity), 0.90 and 0.98 (specificity), and 0.79 and 0.98 (kappa). Spearman's correlation coefficients for number of cigarettes smoked/day varied between 0.87 and 0.97; mean differences were all close to zero. Accuracy of recall tended to diminish with increasing alcohol intake, particularly among women smoking > or = 10 cigarettes/day. CONCLUSIONS: Information on smoking habits could be accurately obtained retrospectively independent of recall time and the pregnancy outcomes studied here. Accuracy diminished with increasing alcohol intake, particularly among heavy smokers. (+info)
Danish National In-Vitro Fertilization Registry 1994 and 1995: a controlled study of births, malformations and cytogenetic findings.
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This paper reports data from the Danish in-vitro fertilization (IVF) registry from 1994 to 1995 including data on treatments and the results of these (perinatal outcome, cytogenetic findings and fetal malformations) in comparison with a control group matched for maternal age, parity, multiplicity and year of birth. There were 1756 deliveries of 2245 children (24.3% twins, 1.8% triplets). The rate of prematurity among IVF children was 23.8% (NS) [singletons 7. 3% (P < 0.05), twins 41.2% and triplets 93.5%], 23.6% weighed <2500 g [singletons 7% (P < 0.05), twins 42.2% and triplets 87.1%]. The perinatal mortality rate was 21.8 in the study group compared to 17. 4 in the control group (NS). In total, 13.2% of all clinical pregnancies and 15.4% of the pregnancies that resulted in a delivery had a prenatal genetic examination. Of all examined, 3.5% had an abnormal karyotype. In total, 107 (4.8%) children in the study group and 103 (4.6%) in the control group were born with malformations (NS), compared to 2.8% in the background population. Our results indicate that it is the characteristics of the patients and multiplicity of pregnancy, rather than the assisted reproductive technology that determines the fetal risks of IVF pregnancies compared to the background population. (+info)
Usefulness of spoligotyping To discriminate IS6110 low-copy-number Mycobacterium tuberculosis complex strains cultured in Denmark.
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Mycobacterium tuberculosis complex strains cultured in Denmark have been analyzed by IS6110 restriction fragment length polymorphism (RFLP) on a routine basis from 1992 and onwards. Due to the influx of immigrants with tuberculosis, the number of strains harboring only one to five copies of IS6110 has increased steadily. Since the discriminatory power of IS6110 fingerprinting for such strains is poor, we have performed additional genotyping of all low-copy-number strains by the recently described PCR-based method known as spoligotyping. A total of 311 clinical strains were typed: 14 Mycobacterium bovis BCG, 48 M. bovis, and 249 M. tuberculosis strains. Spoligotyping correctly differentiated M. bovis and M. bovis BCG from M. tuberculosis strains, but it did not differentiate M. bovis from M. bovis BCG. All M. bovis BCG strains exhibited identical spoligotype patterns. The discriminatory power of spoligotyping of low-copy-number M. tuberculosis strains was higher than that of IS6110 fingerprinting. Based on RFLP typing solely, 83% of the low-copy-number M. tuberculosis strains were found to form part of a cluster, and 75% were found to form a cluster on the basis of spoligotyping. When the two techniques were combined, the amount of clustering decreased to 55%. The combination of these two techniques might be valuable in studying the epidemiology of M. tuberculosis strains harboring few copies of the IS6110 element. (+info)
Mortality and causes of death among Danish medical doctors 1973-1992.
(45/3722)
BACKGROUND: To examine the mortality pattern of Danish doctors for the period 1973-1992. METHODS: A historical prospective cohort study based on the membership register of the Danish Medical Association. The study population consisted of 21,943 medical doctors, 6012 of whom were women. The doctors' cause-specific mortality was compared with that of the general population. RESULTS: The study covered about 277,000 person-years. A total of 2387 deaths occurred from 1 January 1973 to 31 December 1992. The doctors' mortality was lower than that of the general population. Both sexes showed a standardized mortality ratio (SMR) below one for cancer, circulatory diseases and other natural causes. Mortality due to lung cancer was particularly low. The SMR for suicide was significantly increased, 1.6 for males (95% CI: 1.4-1.9) and 1.7 for females (95% CI: 1.1-2.5). The suicide rate was increased, in particular because of an increased number of suicides by poisoning. In addition female doctors displayed a relatively high mortality due to accidents and other types of violent death. CONCLUSIONS: Compared with the general population the doctors' mortality was low, but the mortality from external causes was increased, mainly due to an excess number of suicides. (+info)
Preterm delivery and risk of breast cancer.
(46/3722)
To explore the risk of breast cancer in relation to the length of a pregnancy we tested whether a preterm delivery carries a higher risk of breast cancer than does a full-term delivery. Based on information from the Civil Registration System, and the National Birth Registry in Denmark, we established a population-based cohort of 474 156 women born since April 1935, with vital status and detailed parity information, including the gestational age of liveborn children and stillbirths. Information on spontaneous and induced abortions was obtained from the National Hospital Discharge Registry and the National Registry of Induced Abortions. Incident cases of breast cancer in the cohort (n = 1363) were identified through linkage with the Danish Cancer Registry. The period at risk started in 1978 and continued until a breast cancer diagnosis, death, emigration, or 31 December, 1992, whichever occurred first. After adjusting for attained age, parity, age at first birth and calendar period, we observed the following relative risks of breast cancer for different lengths of the pregnancy: < 29 gestational weeks = 2.11 (95% confidence interval 1.00-4.45); 29-31 weeks = 2.08 (1.20-3.60); 32-33 weeks = 1.12 (0.62-2.04); 34-35 weeks = 1.08 (0.71-1.66); 36-37 weeks = 1.04 (0.83-1.32); 38-39 weeks = 1.02 (0.89-1.17); 40 weeks = 1 (reference). Parous women who had a preterm delivery below 32 weeks gestation had a 1.72-fold (1.14-2.59) increased risk of breast cancer compared with other parous women. In conclusion, a preterm delivery of 32+ weeks gestation did not significantly increase a woman's risk of contracting breast cancer. Only for the very small group of women with preterm deliveries of less than 32 weeks gestation did we observe an increased risk. (+info)
Effects of pesticide exposure on time to pregnancy: results of a multicenter study in France and Denmark. ASCLEPIOS Study Group.
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The aim of this study was to determine whether there was a relation between male exposure to pesticides and the amount of time needed to conceive (time to pregnancy) for farmers and agricultural workers in France and Denmark. The authors used retrospective studies to compare the time to pregnancy of couples in which the man was exposed to pesticides during the year before the birth of their youngest child with that of couples in which the man was not exposed. In 1995 and 1996, the authors studied 362 French rural workers (142 exposed to pesticides and 220 not exposed), 449 Danish farmers (326 conventional farmers exposed to pesticides and 123 nonexposed organic farmers), and 121 Danish greenhouse workers exposed to pesticides. The fecundability ratio for exposure to pesticides (Cox model, before and after adjustment for confounding factors) did not differ from 1 in any of the three populations. In France, the adjusted fecundability ratio was 1.17 (95% confidence interval (CI) 0.89-1.55) for exposed and nonexposed agricultural workers. In Denmark, it was 1.09 (95% CI 0.82-1.43) for exposed and nonexposed farmers and 0.83 (95% CI 0.69-1.18) for greenhouse workers and nonexposed farmers. Thus, this study found no relation between fertility (time to pregnancy) and male exposure to pesticides. (+info)
Socioeconomic status, lung function and admission to hospital for COPD: results from the Copenhagen City Heart Study.
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This study analysed the effect of education and income on development of chronic obstructive pulmonary disease (COPD) assessing lung function and hospital admission. The study population consisted of 14,223 subjects, aged 20-90 yrs, randomly sampled from the population of Copenhagen in 1976. Association between socioeconomic factors and forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) at study entry was analysed by linear regression. The relation between socioeconomic factors and risk of admission to hospital for COPD from study entry until 1993 was assessed by register linkage. Education and income were independently associated with FEV1 and FVC. The age- and height-adjusted difference in FEV1 (mean+/-SEM) between the highest and lowest level of education and income was 259+/-31 mL in females and 400+/-39 mL in males. After additional adjustment for quantity and duration of smoking and inhalation, the difference was 220+/-31 mL and 363+/-39 mL in females and males, respectively. Results for FVC were of the same magnitude. Using a socioeconomic index which combined information on education and household income the association with lung function did not differ by age. A total of 219 females and 265 males were admitted to hospital for COPD during follow-up. Education and income were significantly associated with admission to hospital. After detailed adjustment for smoking the relative risks (95% confidence intervals) for medium and high versus low socioeconomic index in females were 0.74 (0.55-1.02) and 0.27 (0.10-0.73), respectively. Corresponding relative risks in males were 0.47 (0.36-0.63) and 0.35 (0.17-0.70). The results indicate that socioeconomic factors operating from early in life affect the adult risk of developing chronic obstructive pulmonary disease independently of smoking in both females and males. (+info)