Biomedical subjects
Publications and source records attributed to E Prescott.
In a prospective cohort study in Denmark of 8736 randomly selected people, no evidence was found among 1011 subjects who developed cancer that self-reported stressful major life events had increased their risk for cancer.
OBJECTIVE: To investigate the associations of birth weight, body mass index (BMI) during childhood and youth, and current BMI with adult lung function. DESIGN: Population-based longitudinal study of juvenile obese and non-obese men, who were identified at draft board examination (age range: 19-27 y) and who participated in a follow-up examination in 1981-1983 (age range: 25-48 y). Birth weight, childhood weight and height measurements from 7 to 13 y of age were obtained from school health records. Current BMI and lung function were assessed at follow-up. SETTING: Copenhagen and adjacent regions, Denmark. SUBJECTS: In total, 193 juvenile obese men at draft board examination and 205 randomly selected nonobese controls from the same population. MAIN OUTCOME MEASURES: Lung function measured by forced expiratory volume in 1 s (FEV(1)) and forced vital capacity (FVC), adjusted for age and height. RESULTS: After adjusting for current BMI, smoking and education, birth weight was positively related to FEV(1), although only with borderline statistical significance. BMI at age 7 y was positively associated with both FEV(1) and FVC, whereas BMI at later ages in childhood and in youth was not associated with these measures. There was a strong negative linear relation between current BMI and lung function among those currently overweight and obese (BMI 25 kg/m(2)), whereas no association was seen in the non-obese (BMI <25 kg/m(2)). CONCLUSION: Our findings confirm the detrimental effect of high current BMI on adult lung function, and further suggest that early childhood growth has a protective influence.
The associations between physical activity in leisure time with special focus on jogging and the level of mental stress and life dissatisfaction were studied in 12 028 randomly selected men and women aged 20-79 years. The associations were similar in men and women; thus, results are given for pooled data. The odds ratios (ORs) are presented as adjusted for sex, age, body mass index, smoking, alcohol consumption, education and income. With increasing physical activity in leisure time, there was a decrease in high level of stress, between sedentary persons and joggers, OR=0.30 (95% confidence interval (CI) from 0.16 to 0.56). With increasing physical activity there was also a decrease in life dissatisfaction, between sedentary persons and joggers, OR=0.30 (95% CI from 0.18 to 0.52). Although there was a dose-response effect between physical activity and psychosocial well-being the most pronounced difference with regard to the level of stress and dissatisfaction was seen between the group with low and the group with moderate physical activity, e.g., 2-4 h of walking per week. In conclusion, we recommend that increased well-being should be a key argument in future campaigns for increased leisure-time physical activity.
AIM: To investigate whether the effect of socioeconomic position on risk of myocardial infarction (MI) is mediated by differential exposure or differential susceptibility to psychosocial work environment. METHODS: Data were used from three prospective population studies conducted in Copenhagen. A total of 16 214 employees, 44% women, aged 20-75 years, with initial examination between 1974 and 1992 were followed until 1996 for incident (hospital admission or death) MI. Register based information on job categories was used. Psychosocial job exposures were measured indirectly by means of a job exposure matrix based on the Danish Work Environment Cohort Study 1990. RESULTS: During follow up, 731 subjects were diagnosed with an MI: 610 men and 121 women (35% fatal). The hazards by socioeconomic position showed a graded effect with a hazard ratio (HR) of 1.57 (95% CI 1.23 to 2.03) for unskilled workers compared to executive managers. Despite a strong and graded association in risk of MI related to decision authority and skill discretion, only skill discretion mediated the effect of socioeconomic position. The HR for unskilled workers was reduced to 1.47 (0.93 to 2.31) after adjustment for decision authority and other cardiovascular risk factors, and to 1.07 (0.72 to 1.60) after adjustment for skill discretion and cardiovascular risk factors. No sign of synergy was found. CONCLUSIONS: Decision authority and skill discretion were strongly related to socioeconomic position; and the effect on risk of MI was partially mediated by skill discretion. Improvements in psychosocial work environment, especially possibilities for skill discretion, might contribute to reducing the incidence of MI and social inequality in MI.
STUDY OBJECTIVE: To examine the educational level in the area of living as a determinant of all cause mortality, controlling for individual and other correlated contextual factors. DESIGN: Pooled data from two population based cohort studies were linked to social registers to obtain selected socioeconomic information at parish and individual level. A total of 18 344 men and women were followed up from 1980 until October 1999. SETTING: Copenhagen, Denmark. MAIN OUTCOME MEASURE: All cause mortality. RESULTS: During follow up 2614 men and women died. Educational status both at parish (hazard ratio (HR): 0.87 (95% CI 0.77 to 0.98) and individual level (HR: 0.76 (95% CI 0.64 to 0.88) were inversely associated with mortality, when comparing the higest educated groups with the least educated. However, at parish level the effect was only present, when information on subject's income, behaviour (smoking, exercise, alcohol use, and body mass index) and contextual factors (local area unemployment, income share, and household composition) were included in the Cox model. CONCLUSION: In this study the educational level of an area influenced subject's mortality, but first after adjustment for behavioural and other contextual risk factors. Neighbourhood education is one of different characteristics of adverse social conditions in an area increasing mortality.
OBJECTIVE: To analyse the effects of smoking reduction and smoking cessation on incidence of myocardial infarction after adjustment for established cardiovascular risk factors. DESIGN: Prospective cohort study with record linkage to mortality and hospital registers. The association of individual change in smoking with myocardial infarction was examined in Cox proportional hazard analyses with continuous heavy smokers (> or =5 cigarettes/day) as reference. SETTING: Pooled data from three population studies conducted in Copenhagen, Denmark. PARTICIPANTS: 10 956 men and 8467 women with complete information on smoking habits at two examinations five to ten years apart were followed up from the second examination for a first hospital admission or death from myocardial infarction. Mean duration of follow up was 13.8 years. MAIN RESULTS: A total of 643 participants who were heavy smokers at baseline reduced their daily tobacco consumption by at least 50% without quitting between first and second examination, and 1379 participants stopped smoking. During follow up 1658 men and 521 women experienced a fatal or non-fatal myocardial infarction. After adjustment for cardiovascular risk factors, people who stopped smoking had a decreased risk of myocardial infarction, hazard ratio 0.71 (95% confidence intervals 0.59 to 0.85). Smoking reduction was not associated with reduced risk of myocardial infarction, hazard ratio 1.15 (95% confidence intervals 0.94 to 1.40). These associations remained unchanged after controlling for baseline illness in different ways. CONCLUSIONS: Smoking cessation in healthy people reduces the risk of a subsequent myocardial infarction, whereas this study provides no evidence of benefit from reduction in the amount smoked.
AIMS: To examine the relation between unemployment rates in area of residence and all-cause mortality, taking the individuals' unemployment experience and a number of social and behavioural factors into account. METHODS: Prospective cohort study with record linkage to mortality and unemployment registers. Data were pooled data from two population studies conducted in Copenhagen, Denmark. The association between unemployment at parish level and mortality was examined in Cox proportional hazard analysis. A total of 15 980 men and women, aged 20-67 years and employed at 1 January 1980, were studied. All-cause mortality was followed from January 1981 to December 1998. RESULTS: The unemployment rate in the area of residence was associated with increased mortality (hazard ratio(highest v lowest quartile) 1.35:0.14-1.60) even after adjustment for individuals' unemployment experience in 1980, which was also a risk factor (hazard ratio(yes/no) 1.38:1.16-1.64). These estimates attenuated somewhat when other social and behavioural covariates were taken into account. The effects were similar in men and women, but the influence of individuals' unemployment experience during one and five years decreased gradually with increasing age. CONCLUSION: This prospective study suggests that high local unemployment and individuals' experience of unemployment increase mortality risk, even after adjustment for other social and behavioural factors.
Although social differences in respiratory diseases are considerable, few studies have focused on this disease entity using mortality as an outcome. Does mortality from respiratory disease, including chronic obstructive pulmonary disease (COPD) differ with social position measured by education, income, housing and employment grade? The study population consisted of 26,392 males and females from pooling of two population studies in the Copenhagen area. Data was linked with information from social registers in Statistics Denmark. The relationship between socioeconomic factors and risk of death from respiratory disease and COPD was assessed with an average duration of follow-up of 12 yrs. Education was strongly associated with respiratory mortality in both sexes. The association was stronger in later birth cohorts comparing the highest level of education (>11 yrs) with the lowest (<8 yrs). Although smoking rates were inversely associated with the level of education, the social gradient was not affected by adjustment for smoking. In males, but not in females, there was an additional effect of other indicators of social position, i.e. employment grade (white collar versus blue collar), household income, housing conditions (less than one person per room versus more), and cohabitation (cohabiting versus living alone). Similar results were found for mortality from COPD. The results confirm the existence of a strong social gradient in respiratory mortality and chronic obstructive pulmonary disease, which is independent of smoking and is stronger in males. Social disadvantage is a potentially avoidable cause of death from respiratory disease and further research is needed to explain the excess risk in the socioeconomically disadvantaged.
Chronic obstructive pulmonary disease has been associated with a high frequency of arrhythmias. Few studies have analysed the role of reduced lung function in predicting atrial fibrillation (AF). The aim of the present study was to investigate the relationship between forced expiratory volume in one second (FEV1) and risk of first episode of AF in a prospective study. Data from 13,430 males and females without previous myocardial infarction, who participated in the Copenhagen City Heart Study, were analysed. New AF was assessed at re-examination after 5 yrs and by hospital admission for AF during a period of 13 yrs. Multivariate analyses were used with adjustment for cardiopulmonary risk factors. There were 62 new cases of AF at 5-yr follow-up (0.58%) and 290 cases (2.20%) diagnosed at hospitalisations. Risk of new AF at re-examination was 1.8-times higher for FEV1 between 60-80% of predicted compared with FEV1 > or = 80% after adjustment for sex, age, smoking, blood pressure, diabetes and body mass index. The risk of AF hospitalisation was 1.3-times higher for FEV1 between 60-80% and 1.8-times higher for FEV1 < 60% compared with FEV1 > or = 80%, when additional adjustment was made for education, treatment with diuretics and chest pain at activity. The authors conclude that reduced lung function is an independent predictor for incident atrial fibrillation.
STUDY OBJECTIVE: To determine risk of myocardial infarction (MI) and all cause mortality associated with light smoking and inhalation habits in men and women. DESIGN: Prospective cohort study with follow up of MI and all cause mortality through record linkage. SETTING: The Copenhagen City Heart Study, a cardiovascular study based on a sample of the general population established in 1976. PARTICIPANTS: 6505 women and 5644 men followed up until 1998 for first MI and for death from all causes. MAIN RESULTS: During follow up 476 women and 872 men suffered a MI whereas 2305 women and 2883 men died. After adjusting for major cardiovascular risk factors there was a dose-response relation between smoking with and without inhaling and both MI and all cause mortality. Among inhaling smokers significantly increased risks were found in women at a consumption of only 3-5 grams of tobacco per day with relative risks (RR) of MI and all cause mortality of 2.14 (95% CI 1.11 to 4.13) and 1.86 (95% CI 1.37 to 2.51), respectively. In men increased risks were seen when smoking 6-9 grams per day with RR of MI and all cause mortality of 2.10 (95% CI 1.40 to 3.14) and 1.76 (95% CI 1.39 to 2.23), respectively. Risks were also increased in non-inhaling smokers, although in men only significantly so for all cause mortality. After adjusting for inhalation and quantity smoked, cigarette smokers had a higher risk of all cause mortality (RR 1.16 (95% CI 1.07 to 1.26)) but not of MI (RR 1.11 (95% CI 0.95 to 1.30)). The RR associated with smoking were significantly higher in women than in men for both MI and all cause mortality. CONCLUSIONS: Smoking as little as 3-5 grams of tobacco per day or not inhaling the smoke was shown to carry a significantly increased risk of developing MI and of all cause mortality with higher RR found in women than in men. The study emphasises the importance of recognising that even very limited tobacco consumption has detrimental health effects.
BACKGROUND: Little is known about the effects of changes in smoking habits on the subsequent risk of chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate the relationship between smoking cessation and reduction and admission to hospital for COPD in a general population sample. METHODS: A total of 19,709 participants from three prospective population studies in Copenhagen were followed with record linkage for date of first hospital admission for COPD until 1998 (mean follow up 14 years). Heavy smokers (>/=15 cigarettes/day) who reduced their tobacco consumption by at least 50% between the two initial examinations without quitting and smokers who stopped smoking during this time were compared with continuous heavy smokers using a Cox proportional hazards model. RESULTS: During the follow up period 1,260 subjects (741 men and 519 women) were admitted to hospital for COPD. After multivariate adjustment, quitting smoking was associated with a significant reduction in the risk of hospital admission. The relative hazard (HR) was 0.57 (95% confidence interval (CI) 0.33 to 0.99). Those who reduced smoking did not show a significantly lower risk of hospitalisation than continuing heavy smokers (HR 0.93 (95% CI 0.73 to 1.18)). Exclusion of events during the first 5 study years, detailed adjustment for lung function, or restriction of analyses to participants with impaired pulmonary function did not reverse the observed trend. CONCLUSIONS: Self-reported smoking cessation is associated with a reduction in the risk of COPD morbidity of approximately 40%; the benefit of smoking reduction is questionable.
An association between low body mass index (BMI) and poor prognosis in patients with chronic obstructive pulmonary disease (COPD) has been found in a number of studies. The prevalence and prognostic importance of weight change in unselected subjects with COPD was examined. Subjects with COPD, defined as forced expiratory volume in one second/forced vital capacity < 0.7 in the Copenhagen City Heart Study and who attended two examinations 5 yrs apart, were followed for 14 yrs for COPD-related and all-cause mortality. The proportion of subjects who lost > 1 unit BMI (approximately 3.8 kg) between the two examinations was significantly associated with level of COPD, reaching approximately 30% in subjects with severe COPD. After adjusting for age, smoking habits, baseline BMI and lung function, weight loss was associated with higher mortality in both persons with and without COPD (rate ratio (RR) for weight loss > 3 BMI units 1.71 (95% confidence interval (CI): 1.32-2.23) and 1.63 (95% CI 1.38-1.92), respectively). Weight gain was associated with increased mortality, but not significantly so in subjects with COPD. Risk of COPD-related death increased with weight loss (RR 2.14 (95% CI 1.18-3.89)), but not with weight gain (RR 0.95 (95% CI 0.43-2.08)). In subjects without COPD or with mild-to-moderate COPD, the effect of weight change was the same irrespective of initial weight. In subjects with severe COPD, there was a significant risk ratio modification (p=0.045) between effect of baseline BMI and weight change: in the normal-to-underweight (BMI < 25), best survival was seen in those who gained weight, whereas for the overweight and obese (BMI > or = 25), best survival was seen in stable weight. A high proportion of subjects with chronic obstructive pulmonary disease experienced a significant weight loss, which was associated with increased mortality. The results support further intervention studies that aim at avoiding weight loss in normal-to-underweight chronic obstructive pulmonary disease patients.
Twin studies suggest that genetic factors influence smoking behavior. However, in these studies, genetic and environmental influences may be confounded. We examined whether smoking behavior of adoptees is associated with smoking behavior in adoptive and biological relatives in a design in which this confounding is minimized. Data on smoking status were collected using a mailed questionnaire in a sample of 840 adoptive families from the Danish Adoption Register including all non-familial adoptions from 1924 through 1947. Smoking data were available for 706 adoptees, 451 biological fathers, 580 biological mothers, 641 adoptive fathers, 693 adoptive mothers, 199 biological full-siblings, 684 maternal half-siblings, and 576 paternal half-siblings. Adoptees' status as ever, current, heavy, or former (ex-)smokers was related to their relatives' smoking status. Adoptees ever smoking was associated with their full-siblings' status as ever smokers (OR = 3.6 [1.5-8.7]). Adoptees' current smoking was also associated with their full-siblings' ever (OR = 3.2 [1.5-7.7]) and current (OR = 2.6 [1.3-5.0]) smoking, whereas adoptees' heavy smoking was associated with their full-siblings ever (OR = 5.5 [2.1-14.3]), current (OR = 4.0[1.9-8.6]) and heavy (OR = 2.0[1.0-4.2]) smoking. Compared with current smokers, adoptee ex-smokers had full-siblings who were ex-smokers more often (OR = 3.5 [1.0-11.6]), current (OR = 0.4 [0.2-0.8]), and heavy (OR = 0.3 [0.1-0.9]) smokers less often. Adoptees' smoking behavior was not associated with adoptive or biological parents' status as current smokers. This study of smoking behavior in adult adoptees and their biological and adoptee family supports the finding in twin studies of a genetic influence on smoking within the same generation.
BACKGROUND: The aim of this study was to examine the extent and gender distribution of unassisted tobacco reduction and cessation in a cohort of moderate and heavy smokers and to identify possible predictor variables associated with these changes in smoking behavior. METHODS: This was a prospective population study of 3,791 moderate and heavy smokers, 15 g tobacco/day or more, who were enrolled in the Copenhagen City Heart Study in 1976-1978 and attended a reexamination 5 years later. Data on smoking behavior were collected at baseline and follow-up. Smoking reduction was defined as a decrease in mean daily tobacco consumption of 10 g or more. Using multivariate logistic regression, subjects who reported reduced smoking or who reported smoking cessation were compared with subjects who continued the habit unchanged. RESULTS: After 5 years 13% of the men and 9% of the women had reduced their tobacco consumption, and 9 and 7%, respectively, had quit altogether. Smoking reduction was strongly associated with high tobacco consumption (25+ g/day) at baseline and also with severely impaired lung function (FEV(1) <50% predicted) and overweight (BMI >25). Predictors of smoking cessation included impaired lung function and a tobacco consumption of 15-24 g/day. Additional determinants of smoking reduction and cessation such as inhalation habits and sociodemographic variables differed by gender. CONCLUSIONS: Several predictors of smoking reduction and cessation were identified, indicating that these subgroups of smokers differ substantially from continuing smokers. This should be taken into account when assessing potential health benefits from these changes in smoking behavior.
AIMS: To develop and validate a non-invasive method for measuring myocardial iron in order to allow diagnosis and treatment before overt cardiomyopathy and failure develops. METHODS AND RESULTS: We have developed a new magnetic resonance T2-star (T2*) technique for the measurement of tissue iron, with validation to chemical estimation of iron in patients undergoing liver biopsy. To assess the clinical value of this technique, we subsequently correlated myocardial iron measured by this T2* technique with ventricular function in 106 patients with thalassaemia major. There was a significant, curvilinear, inverse correlation between iron concentration by biopsy and liver T2* (r=0.93, P<0.0001). Inter-study cardiac reproducibility was 5.0%. As myocardial iron increased, there was a progressive decline in ejection fraction (r=0.61, P<0.001). All patients with ventricular dysfunction had a myocardial T2* of <20 ms. There was no significant correlation between myocardial T2* and the conventional parameters of iron status, serum ferritin and liver iron. Multivariate analysis of clinical parameters to predict the requirement for cardiac medication identified myocardial T2* as the most significant variable (odds ratio 0.79, P<0.002). CONCLUSIONS: Myocardial iron deposition can be reproducibly quantified using myocardial T2* and this is the most significant variable for predicting the need for ventricular dysfunction treatment. Myocardial iron content cannot be predicted from serum ferritin or liver iron, and conventional assessments of cardiac function can only detect those with advanced disease. Early intensification of iron chelation therapy, guided by this technique, should reduce mortality from this reversible cardiomyopathy.
BACKGROUND: Reduced lung function has been shown to be a significant predictor of non-fatal ischaemic heart disease, and of mortality due to cardiovascular disease. Fewer studies have analysed the relationship between lung function and risk of fatal or non-fatal stroke. The present study presents results on the relation between forced expiratory volume in one second (FEV1) and risk of incident and fatal first-ever stroke. SUBJECTS AND METHODS: The analyses are based on prospective cohort data from 12 878 eligible men and women aged 45-84 years, who participated in the first health examination of the Copenhagen City Heart Study in 1976-1978. The subjects were followed from day of entry until 31 December 1993. During that period 808 first-ever strokes occurred of which 153 were fatal within 28 days. Risk of incident and fatal stroke was estimated by means of Cox hazard regression. The analyses included adjustment for potential confounders: sex, age, smoking, inhalation, body mass index, systolic blood pressure, triglycerides, physical activity in leisure time, education, diabetes mellitus, and antihypertensive treatment. RESULTS: We found an inverse association between FEV1 and risk of first-time stroke. For each 10% decrease in FEV1 in percentage of expected, the relative risk (RR) increased 1.05 (95% CI : 1.00-1.09, P = 0.03). This represents an approximately 30% higher risk of stroke in the group of people with the lowest lung function as compared to the group with the highest lung function. The association between lung function and risk of fatal stroke resembled that of risk of incident stroke (fatal and non-fatal). The RR was 1.11 (95% CI : 1.03-1.19) for each 10% decrease in FEV1 in percentage of expected. This represents approximately a doubling of the risk between the highest and lowest lung function groups. CONCLUSIONS: This study shows that reduced lung function measured in percentage of predicted FEV1 is a predictor of first-time stroke and fatal stroke independent of smoking and inhalation. The high risk of fatal first-ever stroke in the group of people with low lung function may be of significance in both the design and interpretation of clinical trials.
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BACKGROUND: Recent evidence suggests a role for hormonal factors in the aetiology of asthma. METHODS: Data from a large study of women selected from the general population were used to relate treatment with oral hormonal contraceptives (OCP) and postmenopausal hormone replacement therapy (HRT) to the following asthma indicators: self-reported asthma, wheezing, cough at exertion, and use of medication for asthma. The study sample comprised 1536 premenopausal and 3016 postmenopausal women who participated in the third round of the Copenhagen City Heart Study in 1991-4. A total of 377 women were taking OCP (24.5% of premenopausal women) and 458 were on HRT (15.2% of postmenopausal women). RESULTS: In premenopausal women 4.8% reported having asthma. The prevalence of self-reported asthma, wheeze, use of asthma medication, and cough at exertion was not significantly related to use of OCP. In postmenopausal women the prevalence of self-reported asthma was 6.2%. A weak but consistent association was observed between HRT and self-reported asthma (OR 1.42 (95% CI 0.95 to 2.12)), wheeze (OR 1.29 (95% CI 1.02 to 1.64)), cough at exertion (OR 1.34 (95% CI 1.01 to 1.77)), and use of asthma medication (OR 1.45 (95% CI 0.97 to 2.18)). CONCLUSIONS: In this study of the general population no relationship was found between the use of OCP and asthma. Although an association was observed between HRT and asthma and asthma-like symptoms, this was relatively weak and it is concluded that there is no necessity to change present prescription practice.