Life-course perspective on socioeconomic differences in carotid atherosclerosis

OBJECTIVE

Socioeconomic status (SES) in adulthood is known to be related to carotid atherosclerosis. However, few studies have tried to assess its association with SES from a life-course perspective.

METHODS AND RESULTS

We examined the relationship between SES in childhood and in adulthood and carotid atherosclerosis in a general population of Swedish men and women. Carotid stenosis was determined by B-mode ultrasound. Results showed that women whose fathers' occupations involved unskilled manual labor had higher odds of carotid stenosis than did women whose fathers' occupations involved high- or medium-level nonmanual labor, even after adjustment for adult occupational status and risk factors (odds ratio 1.8, 95% CI 1.1 to 2.8). No such association appeared in men. Furthermore, the impact of life-course SES on atherosclerosis was examined by using an additive measure of one's combined SES during childhood and adulthood. Among women, the odds of carotid stenosis increased with a rise in exposure to low SES during the life-course (P for trend <0.001). In men, no such trend was found.

CONCLUSIONS

The results indicate that the total life-course exposure to low SES, with contributions from childhood and adulthood, seems to play a role in atherogenesis in women. Such a pattern of association could not be shown in men.

Incidence of cardiovascular disease, cancer and death in postmenopausal women affirming use of hormone replacement therapy

AIM

The goal of this study was to evaluate the incidence of myocardial infarction, cancer and death in relation to use of hormone replacement therapy (HRT).

METHODS

Nine years' follow up of an urban cohort of peri-/postmenopausal women was undertaken. Local and national registers were used for retrieval of events.

RESULTS

The incidence of myocardial infarction per 1.000 person-years in users and non-users was 0.61 (5/962) and 2.20 (92/4759) respectively, adjusted relative risk (RR) 0.37; 95% confidence interval 0.15-0.90. Rates of mortality from cardiovascular disease and cancer were 0.36 and 1.10, p= 0.058, and 2.60 and 2.09, p=0.360 respectively. In terms of all-cause mortality the adjusted RR was 1.02; 0.69-1.52, incidence of cancer 1.28; 1.01-1.64, breast cancer 1.52; 1.01-2.28 and endometrial cancer 3.61; 1.54-8.46.

CONCLUSIONS

Women affirming use of HRT had a lower incidence of myocardial infarction. Further studies are needed to assess whether the absence of effect on total mortality may be accounted for by an increased cancer risk.

Smoking as a modifier of the systolic blood pressure-induced risk of cardiovascular events and mortality: a population-based prospective study of middle-aged men

OBJECTIVE

To examine to what degree smoking habits modulate the relationship between systolic blood pressure (SBP) and risk for cardiovascular morbidity (first event) and mortality in middle-aged men.

DESIGN AND METHODS

In all, 22 444 middle-aged men were recruited from a population-based screening study (mean attendance rate 71%). Risk factor intervention was offered to about 20% of participants. Subjects were followed in local and national registers for cardiovascular morbidity and mortality during more than 17 years of follow-up. Life-style variables were investigated at baseline, including smoking habits. Event rates were calculated in relation to quintiles (Q1-Q5) of baseline SBP in untreated subjects, subdivided into categories of smoking habits, but also for 915 previously known, treated hypertensive (tHT) patients at baseline.

RESULTS

We found an increasing incidence of first cardiovascular event (CE) with increasing SBP levels, ranging from 63.5 CE/10 000 person-years (Q1) to 62.3, 70.5, 82.3 and 115.1 CE/10 000 person-years (Q2-Q5). The corresponding figure in tHTs was 153 CE/10 000 person-years. If further subdivided into smokers/ex-smokers/non-smokers, the relative risks (RR) of smokers were 1.9 [95% confidence interval (CI): 1.5-2.4], 2.1 (1.8-2.5), 2.3 (1.8-2.9), 1.8 (1.5-2.1), and 1.7 (1.5-2.0) compared to present non-smokers, in relation to SBP (Q1-Q5). In tHTs the RR was 1.4 (1.1-1.8). Cardiovascular mortality rates differed in relation to SBP and smoking habits, from 40.3 (present non-smokers) and 70.7 (smokers) deaths/10 000 person-years in Q1, to 54.2 and 134.0 deaths/10 000 person-years in Q5. In tHTs the corresponding figures were 81.6 and 149.4 deaths/10 000 person-years, respectively. No difference in risk was found for never-smokers compared to ex-smokers in relation to SBP. The risk in moderate/heavy smokers ( 10 cigarettes/day) compared to other smokers (<or= 10 cigarettes/day) was significantly ( 0.005) increased only in Q5.

CONCLUSION

Increasing systolic blood pressure levels in middle-aged men is associated with an increasing risk of future cardiovascular events and mortality, an association modified by smoking habits. Patients with treated hypertension in the 1970-1980s were also at an increased risk in spite of healthcare efforts. This calls for a more comprehensive multiple risk factor approach for the management and reduction of cardiovascular risk in these patients.

Influence of obesity on cardiovascular risk. Twenty-three-year follow-up of 22,025 men from an urban Swedish population

OBJECTIVE

To assess to what extent the incidence of coronary events and death related to smoking, hypertension, hyperlipidemia and diabetes is modified by obesity.

DESIGN

Prospective cohort study.

SUBJECTS

A total of 22 025 men aged 27 to 61-y-old at entry.

MEASUREMENTS

Incidence of coronary events (CE, ie acute myocardial infarctions and deaths due to chronic ischaemic heart disease) and death during 23 y of follow-up was studied in relation to body mass index (BMI), heart rate, blood pressure, blood lipids, glucose and insulin, lifestyle factors, history of angina pectoris, history of cancer, self-reported health and socio-economic conditions.

RESULTS

At the end of follow-up 20% of the obese men were no longer alive, and 13% had had a coronary event. Incidence of CE was 16% lower (RR (relative risk) 0.84; 95% confidence interval (CI) 0.65-1.10) among underweight (n=1171), 24% higher (RR 1.24; CI 1.12-1.37) among overweight (n=7773), and 76% higher (RR 1.76; 95% CI 1.49-2.08) among obese men (n=1343) than it was among men with normal BMI (n=11 738). The risk associated with overweight and obesity remained statistically significant after adjustment for potential confounders (RR 1.18; CI 1.07-1.31; and 1.39; 1.17-1.65, respectively). The association between BMI and mortality was J-shaped. In all, 1.7% of the obese men were smokers with hypertension, hyperlipidaemia and diabetes, 16.3% were not exposed to any of these risk factors. The cardiovascular risk associated with obesity was small in the absence of other risk factors. Between smoking and obesity there was a statistically significant synergistic effect.

CONCLUSIONS

Obesity is associated with an increased incidence of coronary events and death. The risk associated with obesity is substantially increased by exposure to other atherosclerotic risk factors, of which smoking seems to be the most important. The preventive potential of these associations should be evaluated in controlled trials.

Invitation to a population-based cohort study: differences between subjects recruited using various strategies

AIM

The present study compares subjects recruited to a population-based prospective cohort study by community versus personal invitation, and subjects responding late versus early to personal invitation. Subjects were compared with respect to sociodemographic characteristics, selected lifestyle factors, cancer incidence and mortality.

METHODS

The Malmö Diet and Cancer Study recruited a total of 28,098 subjects between 1991 and 1996. Entire birth-year cohorts, born 1923-50, were recruited using community directed (passive) invitation, and a personal letter of invitation (active recruitment). Information on sociodemography and lifestyle was obtained using a self-administered questionnaire. Anthropometric measurements were assessed at a physical examination. Cancer incidence and cause of death were retrieved using record linkage with national registries.

RESULTS

Subjects responding to community directed invitation were older, and more often females, than participants recruited using personal invitation. Furthermore, participants recruited through passive invitation had a comparably more favourable situation with regard to sociodemographic and lifestyle factors. They also had a lower frequency of prevalent disease, lower incidence of cancer and lower mortality. Contrary to this, men were more likely to respond late to a personal letter of invitation and late responders were also older, as compared with subjects responding early to personal invitation. Furthermore, those who responded late had a comparatively unfavourable socioeconomic situation and were characterized by a high prevalence of current smoking, obesity, weight change, and prevalent disease.

CONCLUSIONS

Subjects who are recruited using different strategies in population-based cohort studies may have different sociodemographic and lifestyle characteristics, and may vary with regard to prevalent disease, cancer incidence and subsequent mortality.

The enigma of increased non-cancer mortality after weight loss in healthy men who are overweight or obese

OBJECTIVE

To study effects on non-cancer mortality of observational weight loss in middle-aged men stratified for body mass index (BMI), taking a wide range of possible confounders into account.

DESIGN

Prospective, population based study.

SETTING

Male population of Malmö, Sweden.

PARTICIPANTS

In all 5722 men were screened twice with a mean time interval of 6 years in Malmö, southern Sweden. They were classified according to BMI category at baseline (<21, 22-25, overweight: 26-30, and obesity: 30+ kg m(-2)) and weight change category until second screening (weight stable men defined as having a baseline BMI +/- 0.1 kg m(-2) year-1 at follow-up re-screening).

MAIN OUTCOME MEASURES

Non-cancer mortality calculated from national registers during 16 years of follow-up after the second screening. Data from the first year of follow-up were excluded to avoid bias by mortality caused by subclinical disease at re-screening.

RESULTS

The relative risk (RR; 95% CI) for non-cancer mortality during follow-up was higher in men with decreasing BMI in all subgroups: RR 2.64 (1.46-4.71, baseline BMI <21 kg m(-2)), 1.39 (0.98-1.95, baseline BMI 22-25 kg m(-2)), and 1.71 (1.18-2.47, baseline BMI 26+ kg m(-2)), using BMI-stable men as reference group. Correspondingly, the non-cancer mortality was also higher in men with increasing BMI, but only in the obese group (baseline BMI 26+ kg m(-2)) with RR 1.86 (1.31-2.65). In a subanalysis, nonsmoking obese (30+ kg m(-2)) men with decreased BMI had an increased non-cancer mortality compared with BMI-stable obese men (Fischer's test: P=0.001). The mortality risk for nonsmoking overweight men who increased their BMI compared with BMI-stable men was also significant (P=0.006), but not in corresponding obese men (P=0.094). CONCLUSIONS. Weight loss in self-reported healthy but overweight middle-aged men, without serious disease, is associated with an increased non-cancer mortality, which seems even more pronounced in obese, nonsmoking men, as compared with corresponding but weight-stable men. The explanation for these observational findings is still enigmatic but could hypothetically be because of premature ageing effects causing so-called weight loss of involution.

Insulin resistance in non-diabetic subjects is associated with increased incidence of myocardial infarction and death

AIMS

To compare the incidence of myocardial infarction and death in non-diabetic subjects with and without insulin resistance.

METHODS

Population-based prospective cohort study, in Malmö, Sweden, of 4748 non-diabetic subjects (60% women), aged 46-68 years, with no history of myocardial infarction or stroke. The prevalence of insulin resistance was established by the homeostasis model assessment (HOMA) and defined as values above the sex-specific 75th percentile (1.80 for women and 2.12 for men). Incidence of myocardial infarction and death is based on record linkage with local and national registers. Cox's proportional hazards model was used to assess the influence of insulin resistance after adjustment for age, sex, hyperglycaemia, raised arterial blood pressure, dyslipidaemia, central obesity, smoking and leisure-time physical activity.

RESULTS

Sixty-two subjects suffered a coronary event, and 93 subjects died during the 6-year follow-up period. Insulin resistance was after adjustment for other factors included in the insulin resistance syndrome and other potential confounders, associated with an increased incidence of coronary events (relative risk (RR) 2.18; 95% confidence interval (CI) 1.22-3.87; P = 0.008) and deaths (RR 1.62; 1.03-2.55; P = 0.038).

CONCLUSIONS

Insulin resistance, as assessed by the HOMA method, was in this cohort of middle-aged non-diabetic subjects associated with an increased incidence of myocardial infarction and death. This risk remained when smoking, low physical activity and factors included in the insulin resistance syndrome were taken into account in a stepwise regression model.

A prospective study of adiposity and all-cause mortality: the Malmö Diet and Cancer Study

OBJECTIVE

This study aims to examine the association between various measures of adiposity and all-cause mortality in Swedish middle-aged and older men and women and, additionally, to describe the influences of age and sex on these associations.

RESEARCH METHODS AND PROCEDURES

A prospective analysis was performed in a cohort of 10,902 men and 16,814 women ages 45 to 73 years who participated in the Malmö Diet and Cancer Study in Sweden. Baseline examinations took place between 1991 and 1996, and 982 deaths were documented during an average follow-up of 5.7 years. All-cause mortality was related to the following variables measured at baseline: body mass index (BMI), percentage of body fat, lean body mass (LBM), and waist-to-hip ratio (WHR), with adjustment for age and selected covariates. Body composition data were derived from bioelectrical impedance analysis.

RESULTS

The association between percentage of body fat and mortality was modified by age, particularly in women. For instance, fatness was associated with excess mortality in the younger women but with reduced mortality in the older women. Weaker associations were seen for BMI than for percentage of body fat in both sexes. Placement in the top quintiles of waist-to-hip ratio, independent of overall body fat, was a stronger predictor of mortality in women than in men. The observed associations could not be explained by bias from early death or antecedent disease.

DISCUSSION

The findings reveal sex and age differences for the effects of adiposity and WHR on mortality and indicate the importance of considering direct measures of adiposity, as opposed to BMI, when describing obesity-related mortality risks.

Prospective study of IGF-I, IGF-binding proteins, and breast cancer risk, in northern and southern Sweden

OBJECTIVE

To examine the possible relationships of breast cancer risk to prediagnostic plasma levels of insulin; insulin-like growth factor-I (IGF-I); and IGF-binding proteins -1, -2, and -3.

METHODS

Within two prospective cohorts in Umeå and Malmö we measured plasma concentrations of insulin, IGF-I, and IGFBPs for a total of 513 incident breast cancer cases and 987 matched controls.

RESULTS

Globally, risk was unassociated with levels of IGF-I, IGFBP-3, or IGF-I adjusted for IGFBP-3. When breaking down the analysis by subgroups of age at blood donation, an increase in risk was observed for increasing levels of IGF-I in women aged 55 or older, in the Umeå cohort only (odds ratios of 1.00, 1.73, 1.76, 1.90; Ptrend = 0.05). This effect weakened, however, when the analysis was restricted to subjects who did not use exogenous hormones for the treatment of menopausal symptoms. Levels of IGF-I and IGFBP-3 were not related to risk in younger women, recruited before age 50, contrary to observations from previous studies. In a subcohort where blood samples had been collected after at least four hours of fasting, breast cancer risk showed no clear associations with levels of insulin, IGFBP-1, or IGFBP-2.

CONCLUSIONS

Our results do not confirm earlier findings of an association of plasma IGF-I levels with breast cancer risk especially in young women, but suggest a possible association with postmenopausal breast cancer risk, possibly among ERT/HRT users only. Our results do not support the hypothesis that elevated plasma insulin levels, and reduced levels of IGFBP-I and IGFBP-2, are associated with increased breast cancer risk.

Costs for screening, intervention and hospital treatment generated by the Malmö Preventive Project: a large-scale community screening programme

OBJECTIVES

The purpose of this study was to estimate retrospectively the costs of health care resources used in the Malmö Preventive Project, Sweden and estimate the costs of in-patient care that were avoided because of early intervention.

SETTING AND SUBJECTS

A large-scale community intervention programme was conducted from 1974 to 1992 in Malmö, Sweden with the aim of reducing morbidity and mortality of cardiovascular diseases (CVD), alcohol related illnesses, and breast cancer. Between 1974 and 1992, 33 336 male and female subjects were screened for hypertension, hyperlipidaemia, type-2 diabetes and alcohol abuse. Intervention programmes that included life-style modifications, follow-up visits with physicians and nurses and drug therapy were offered to about 25% of screened subjects.

METHODS

Recruitment costs were generated through out the screening period. Intervention costs were estimated for 5 years after screening. Excess in-patient care costs were estimated by subtracting hospital consumption for an unscreened, matched cohort from that of the screened cohort over follow-up periods of 13-19 years. Intervention and excess in-patient care costs were estimated until 1996.

RESULTS

The net expenditures for recruitment and intervention was SEK253 million and saved costs for in-patient care of SEK143 millions (1998 prices). Considering the opportunity cost of the resources used in the study, the net cost rises to about SEK200 millions.

CONCLUSIONS

The results suggest that only part of the intervention costs were offset by reduction in future morbidity health care costs. This is in line with results from prospective analyses of other primary prevention programmes.

Food patterns and components of the metabolic syndrome in men and women: a cross-sectional study within the Malmö Diet and Cancer cohort

This study examined the relations between food patterns and five components of the metabolic syndrome in a sample of Swedish men (n = 2,040) and women (n = 2,959) aged 45-68 years who joined the Malmö Diet and Cancer study from November 1991 to February 1994. Baseline examinations included an interview-administered diet history, a self-administered questionnaire, blood pressure and anthropologic measurements, and blood samples donated after an overnight fast. Cluster analysis identified six food patterns for which 43 food group variables were used. Logistic regression analysis was used to examine the risk of each component (hyperinsulinemia, hyperglycemia, hypertension, dyslipidemia, and central obesity) and food patterns, controlling for potential confounders. The study demonstrated relations, independent of specific nutrients, between food patterns and hyperglycemia and central obesity in men and hyperinsulinemia in women. Food patterns dominated by fiber bread provided favorable effects, while food patterns high in refined bread or in cheese, cake, and alcoholic beverages contributed adverse effects. In women, food patterns dominated by milk-fat-based spread showed protective relations with hyperinsulinemia. Relations between risk factors and food patterns may partly depend on gender differences in metabolism or food consumption and on variations in confounders across food patterns.

Sleep disturbance in association with elevated pulse rate for prediction of mortality--consequences of mental strain?

OBJECTIVES

Sleep deprivation has experimentally been shown to adversely influence glucose metabolism, endocrine function and sympathovagal balance in young men without known serious disease. We investigated the impact of sleep problems and resting heart rate in a large sample of self-reported, healthy middle-aged men and women on long-term mortality.

METHODS

In all 22,444 men and 10,902 women participated in a population-based health screening (71% mean attendance), including blood sampling and examination of blood pressure (BP) and pulse rate after 10 min supine rest, as well as a self-administered questionnaire on sleep problems. Mortality was assessed from national death registers.

RESULTS

Sleep disturbances were related to increased cardiovascular risk factor levels at baseline in both sexes, and predicted total and cause-specific mortality after a mean of 12 years (women) and 17 years (men) of follow-up. In men, self-reported healthy at baseline, total mortality during follow-up was independently predicted by both sleep problems and increased resting heart rate, also after adjustment for smoking, body mass index (BMI), systolic BP, cholesterol, smoking and problematic alcohol drinking habits. A step-wise increased total mortality was shown in men reporting successively worse sleep problems and higher heart rate, highest hazard ratio 2.7 [95% confidence interval (CI) = 2.1-3.4] after adjustments, compared with men free from sleep problems and with normal heart rate.

CONCLUSIONS

Sleep disturbance is a predictor of total and cause-specific mortality in both sexes, but only interacts with increased resting heart rate for this prediction in healthy men. Sleep problems correlated cross-sectional with disturbances in lipid and glucose metabolism, even after adjustment for degree of obesity and smoking. Sleep disturbance is a symptom for a biological pathway that is correlated to premature mortality. One possible explanation would be that it acts in concert with sympathetic nervous activation (SNA), both being consequences of chronic stress exposure.

The Malmö Diet and Cancer Study: representativity, cancer incidence and mortality in participants and non-participants

In order to investigate potential selection bias in population-based cohort studies, participants (n = 28098) and non-participants (n = 40807) in the Malmö Diet and Cancer Study (MDCS) were compared with regard to cancer incidence and mortality. MDCS participants were also compared with participants in a mailed health survey with regard to subjective health, socio-demographic characteristics and lifestyle. Cancer incidence prior to recruitment was lower in non-participants, Cox proportional hazards analysis yielded a relative risk (RR) with a 95% confidence interval of 0.95 (0.90-1.00), compared with participants. During recruitment, cancer incidence was higher in non-participants, RR: 1.08 (1.01-1.17). Mortality was higher in non-participants both during, 3.55 (3.13-4.03), and following the recruitment period, 2.21 (2.03-2.41). The proportion reporting good health was higher in the MDCS than in the mailed health survey (where 74.6% participated), but the socio-demographic structure was similar. We conclude that mortality is higher in non-participants than in participants during recruitment and follow-up. It is also suggested that non-participants may have a lower cancer incidence prior to recruitment but a higher incidence during the recruitment period.

Helicobacter pylori infection is associated with a decreased risk of developing oesophageal neoplasms

BACKGROUND

The role of Helicobacter pylori infection in the development of oesophageal malignancies was investigated through a multivariate conditional logistic regression analysis in a nested case-control study.

METHODS

Blood samples and a questionnaire on smoking and alcohol habits were collected from a cohort of 32,906 city residents during a health-screening programme between 1974 and 1992. Forty-four cases of oesophageal cancer and 149 matched controls were selected. The mean interval between screening and cancer diagnosis was 11.9 years. H. pylori seropositivity was determined by an enzyme-linked immunosorbant assay measuring IgG. Occupation was included in the statistical analysis as an indicator of socio-economic status.

RESULTS

Helicobacter pylori seropositivity was present in 10 of the cases (22.7%) and 67 of the controls (45.0%). In a multivariate model, with adjustment for occupation, tobacco and alcohol consumption, the odds ratio for developing an oesophageal malignancy when infected with H. pylori was 0.29 (95% confidence interval (CI): 0.12-0.67). Current smokers had an odds ratio of 17.3 (95% CI: 3.0-99.4) and the odds ratio for ex-smokers was 5.9 (95% CI: 1.15-29.9). High alcohol consumption was no longer significantly associated with oesophageal neoplasms after tobacco smoking was included into the model, odds ratio 1.22 (95% CI: 0.46-3.2). The protective effect of H. pylori was more pronounced for oesophageal adenocarcinoma (seven cases, odds ratio 0.16, 95% CI: 0.00-1.06) than for squamous-cell carcinoma (29 cases, odds ratio 0.41, 95% CI: 0.14-1.2).

CONCLUSIONS

Helicobacter pylori infection is associated with a decreased risk of developing an oesophageal malignancy. Current smokers and ex-smokers have instead a definite increased risk of oesophageal neoplasms.

Reduced utilisation of specialist care among elderly cancer patients: a randomised study of a primary healthcare intervention

The aim of this study was to evaluate the effect of an individual support (IS) intervention including intensified primary healthcare on the utilisation of specialist care among cancer patients, and to investigate if such an effect was modified by the patient's age (less than 70 years or 70 years and more). Newly diagnosed cancer patients (n=416) were randomised between the intervention and a control condition, and data were collected on the utilisation of specialist care within 3 months from inclusion. Intensified primary healthcare comprised extended information from the specialist clinics, and education and supervision in cancer care for general practitioners (GPs) and home-care nurses. The support given also included interventions designed to diminish problems of weight loss and psychological distress. The intervention reduced the number of admissions (NoA) and the days of hospitalisation (DoH) after adjustment for weight loss and psychological distress, but only for older patients. Older patients randomised to the intervention (n=82) experienced 393 fewer DoH than the older control patients (n=79). In addition, the proportion of older patients in the IS group who utilised acute specialist care was smaller compared with older control patients group. The conclusion is that older cancer patients' utilisation of specialist care may be reduced by intensified primary healthcare services.

Diastolic blood pressure and area of residence: multilevel versus ecological analysis of social inequity

STUDY OBJECTIVES

To study geographical differences in diastolic blood pressure and the influence of the social environment (census percentage of people with low educational achievement) on individual diastolic blood pressure level, after controlling for individual age and educational achievement. To compare the results of multilevel and ecological analyses.

DESIGN

Cross sectional analysis performed by multilevel linear regression modelling, with women at the first level and urban areas at the second level, and by single level ecological regression using areas as the unit of analysis.

SETTING

Malmö, Sweden (population 250 000).

PARTICIPANTS

15 569 women aged 45 to 73, residing in 17 urban areas, who took part in the Malmö Diet and Cancer Study (1991-1996).

MAIN RESULTS

In the "fixed effects" multilevel analysis, low educational achievement at both individual (beta=1.093, SE=0.167) and area levels (beta=2.966, SE=1.250) were independently associated with blood pressure, although in the "random effects" multilevel analysis almost none of the total variability in blood pressure across persons was attributable to areas (intraclass correlation=0.3%). The ecological analysis also found an association between the area educational variable and mean diastolic blood pressure (beta=4.058, SE=1.345).

CONCLUSIONS

The small intraclass correlation found indicated very marginal geographical differences and almost no influence of the urban area on individual blood pressure. However, these slight differences were enough to detect an effect of the social environment on blood pressure. The ecological study overestimated the associations found in the "fixed" effects multilevel analysis, and neither distinguished individual from area levels nor provided information on the intraclass correlation. Ecological analyses are inadequate to evaluate geographical differences in health.

Nonattendance in mammographic screening: a study of intraurban differences in Malmö, Sweden, 1990-1994

Mammographic screening may reduce breast cancer mortality. Not all women, however, come for examination. The objective in this study from Malmö has been to assess extent to which the rate of nonattendance varies between residential areas with different sociodemographic profiles. The study is based on 32,605 women, 45 to 68 years old and living in 17 areas, who between 1990 and 1994 were invited to screening. Between age groups, the age-specific nonattendance rate ranged from 31% to 35 % (P < .01). The nonattendance rate was highest for women 65 years or older. Between residential areas, age-adjusted nonattendance rates ranged from 23% to 43% (P < .01). A socioeconomic score was developed to express the socioeconomic circumstances in the residential areas and ranged from -7.18 in the most deprived area to 5.01 in the least. Nonattendance covaried in an inverse fashion with the socioeconomic score (r = -0.78; P < .01). One of three women in this urban population did not accept the invitation to mammographic screening. Our conclusion is that women in areas with less favorable circumstances seem to be less willing to participate.

Increased incidence of small and well-differentiated breast tumours in post-menopausal women following hormone-replacement therapy

Exposure to hormone-replacement therapy (HRT) has consistently been associated with an increased incidence of breast cancer, particularly of small tumours. Other tumour characteristics in relation to HRT have received less scientific attention. Our aim in this population-based prospective cohort study was to assess whether HRT is associated with an increased incidence of breast-cancer subgroups defined in terms of stage, type (according to the WHO system), Nottingham grade and the Nottingham Prognostic Index (NPI). Evaluation was based on a cohort of 5,865 post-menopausal women followed for an average of 9.8 years. Twenty percent of women reported current use of HRT at the time of the baseline interview. Record linkage with the Swedish Cancer Registry and local clinical registries identified 141 incident invasive breast-cancer cases. All tumours were reclassified by 1 pathologist. The incidence of breast cancer in HRT users was 377/10(5) and in non-users 221/10(5) person-years [relative risk (RR) = 1.72, 95% confidence interval (CI) 1.17-2.52]. This risk remained statistically significant after adjustment for established risk factors in a Cox proportional hazards analysis (RR = 1.66, 95% CI 1.12-2.45). Among HRT users, there was over-representation of cases with stage I tumours (adjusted RR = 2.33, 95% CI 1.44-3.76), of lobular carcinomas (RR = 4.38, 95% CI 1.60-12.0) and of tubular tumours (RR = 4.81, 95% CI 1.37-16.8). Nottingham grade I/II carcinomas (RR = 2.02, 95% CI 1.29-3.16) and cases with NPI < or = 3.4 (RR = 2.29, 95% CI 1.41-3.72) were similarly over-represented among HRT users. Incidence of breast cancer was increased in post-menopausal women who used HRT at baseline. Among HRT users, there was over-representation of tumours that, with regard to stage, type and grade, are associated with a favourable prognosis.

Breast cancer incidence in ex-smokers in relation to body mass index, weight gain and blood lipid levels

According to several studies breast cancer is more common among former smokers. This study explores whether this association has any relationship with anthropometric measurements or blood lipid levels. The 2082 ex-smokers (mean age 49.9 years) in the Malmö Preventive Cohort were followed for an average of 13.3 years using official cancer registries. This yielded 93 incident breast cancer cases. Oestrogen receptor (ER) status was assessed by an immunological method. Incidence of breast cancer covaried with height, body mass index, weight gain and cholesterol levels. None of these associations reached statistical significance. Incidence of breast cancer increased over quartiles of serum triglycerides, Ptrend: 0.02, relative risk (RR) for triglycerides as a continuous variable: 1.46 (1.21-1.77). Nineteen tumours were ER negative; this subgroup was similarly related to high triglycerides, 1.76 (1.40-2.21). All results were similar when BMI and cholesterol levels were entered into the model. It is concluded that breast cancer incidence covaries with triglyceride levels in ex-smokers.

Fat intake is more strongly associated with lifestyle factors than with socio-economic characteristics, regardless of energy adjustment approach

OBJECTIVE

To compare how three different energy adjustment approaches influence the ranking of individuals on fat intake, and to examine the relation between fat intake and socio-economic, demographic and lifestyle characteristics for each energy adjustment approach.

DESIGN

A cross-sectional analysis project, using a sub-sample (7055 women and 3240 men) from the Malmö Diet and Cancer Study. Dietary habits were assessed with an interview based diet history method. Fat intake was, depending on energy-adjustment method, defined as absolute intake (FATg), percentage energy from fat (FAT%), and residuals from total fat regressed on total energy (FATres). Cross-classification compared categorisation into fat intake quintiles. Logistic regression estimated, separately for each of the three approaches, the associations between high fat intake and socio-economic, demographic and lifestyle characteristics.

RESULTS

Agreement in individuals' ranking was high between FAT% and FATres, but FATg differed substantially from the others. Current smoking, low level of leisure time physical activity and low alcohol intakes were, in multivariate analysis, consistently associated with risk of high fat consumption regardless of energy adjustment method. However, the associations with socio-economic characteristics varied with energy adjustment method and gender groups.

CONCLUSIONS

The similarities between FAT% and FATres, in the ranking of individuals and in the association with lifestyle factors and socio-economic characteristics implies that it is possible to translate results obtained with FATres to recommendations using FAT%. The consistent lifestyle pattern across fat intake definitions (in energy adjusted models) may indicate that fat consumption is more strongly related to lifestyle factors than to socio-economic characteristics.

Effect of endocrine treatment on sexuality in premenopausal breast cancer patients: a prospective randomized study

PURPOSE

To study the sexual effects of the 2-year adjuvant goserelin (Zoladex [Zeneca AB, Södertälje, Sweden]) alone, tamoxifen alone, and Zoladex and tamoxifen in combination (ZT) versus no adjuvant endocrine therapy among premenopausal breast cancer patients with or without chemotherapy in a controlled clinical trial (a European multicenter trial: Zoladex in Premenopausal Breast Cancer Patients).

PATIENTS AND METHODS

This prospective study examined several aspects of sexuality through the use of self-administered questionnaires, which were completed by patients at seven points of assessment for 3 years after randomization.

RESULTS

Patients treated with chemotherapy had a higher level of sexual dysfunction than did patients who received no systemic treatment. The addition of endocrine treatment did not alter this result. In contrast, among patients who did not receive chemotherapy, Zoladex and ZT produced a significantly higher level of dysfunction from 1 to 2 years after inclusion, as compared with those who received no endocrine treatment. Tamoxifen alone did not produce side effects. After termination of endocrine treatment, sexual dysfunction began to diminish. Those with chemotherapy had high and frequently increasing levels of dysfunction even after 2 to 3 years of independent of endocrine treatment. Zoladex had a negative effect on sexual fear, which was reduced by the addition of tamoxifen.

CONCLUSION

Zoladex increased sexual dysfunction during treatment among patients without chemotherapy, but the disturbances of sexual functioning were reversible. The use of adjuvant chemotherapy was associated with continued sexual problems, even at 3 years after randomization.