Biomedical subjects
L Janzon
Publications and source records attributed to L Janzon.
Fruit and vegetable consumption in relation to risk factors for cancer: a report from the Malmö Diet and Cancer Study.
OBJECTIVE: To examine the associations between the consumption of fruit and vegetables and other markers of cancer risk. DESIGN: A cross-sectional survey within the population-based prospective Malmö Diet and Cancer (MDC) Study. Information on food habits was collected through the modified diet history method designed and validated for the MDC Study. Data on smoking and alcohol habits, leisure time physical activity, birth country, education, socioeconomic status and cohabitation status were collected through a questionnaire. SETTING: Malmö, the third largest city in Sweden. SUBJECTS: All subjects who entered the MDC Study during winter 1991 to summer 1994 (men and women living in Malmö, aged between 46 and 68 years), with a total of 15 173. RESULTS: Women consumed more fruit and vegetables than men. Low consumption of both fruits and vegetables was associated with unfavourable nutrient profiles: higher percentage of energy from fat and lower intakes of antioxidant nutrients and dietary fibre. Low consumption was also associated with smoking, low leisure time physical activity, low education and being born in Sweden. High age was associated with low vegetable consumption in both genders. CONCLUSION: This study indicates that several established risk markers and risk factors of cancer may be independently associated with low fruit and vegetable consumption. The findings suggest that the adverse effects of factors such as smoking, low physical activity and a high-fat diet could partly be explained by low consumption of fruit or vegetables. The implied health benefits of a low or moderate alcohol consumption may be similarly confounded by high consumption of fruit or vegetables.
Breast cancer incidence in relation to smoking cessation.
High plasma levels of oestrogens are associated with increased breast cancer risk. If smoking, as has been suggested, have both a tumour initiating mutagenic effect and a protective anti-oestrogenic effect, one would assume that smokers who give up smoking have the highest incidence of breast cancer. This was evaluated in the follow-up of a cohort of 10,902 women of whom 4,359 were premenopausal. Record-linkage with official cancer registries yielded 416 incident cases during an average follow-up of 13.6 years. The adjusted relative risk in all ex-smokers was 1.31 (1.02-1.69), as compared to never smokers, and in premenopausal ex-smokers it was 1.57 (1.07-2.30). Breast cancer incidence in premenopausal ex-smokers was inversely related to time since cessation, (p for trend = 0.01), and was highest among the women who had given-up smoking less than 12 months before screening: 2.76 (1.55-4.91). There was no significant association between current smoking and breast cancer risk. We conclude that incidence of breast cancer in premenopausal women who have given up smoking is higher than it is in smokers and never smokers. To what extent this may be related to endocrine effects associated with smoking cessation remains to be evaluated.
Comparison of different procedures to identify probable cases of myocardial infarction and stroke in two Swedish prospective cohort studies using local and national routine registers.
In prospective cohort studies, person-time time is calculated from baseline until the first definite event occurs or until censoring. A way to correctly identify and date definite events when only routine registers are available is to retrieve all hospital discharge notes and death certificates with a diagnosis of probable event and perform a consecutive revision. It is important to detect all possible hospital stays as they may contain useful information for the revision study. Furthermore, loss to follow-up can be avoided by extending the retrieval outside the specific geographical area where the cohort was defined. The aims of this study were (i) to describe a comprehensive retrieval of probable myocardial infarctions (diagnosis with International Classification of Diseases 8th and 9th revisions codes 410-414) or stroke (codes 430-438), (ii) to quantify the relative efficiency of different local and national routine registers or their combination compared with the use of all available registers together, and (iii) to audit local and national registers by comparing their outcome at the county level. The study was performed in two prospective cohorts studies i.e., 'Men-born-1914' (n = 500) from Skåne (period 1982-1993), and Skara-1 (n = 683) from Skaraborg (period 1988-1994.). All available routine registers were linked to the cohorts. The use of all available routine registers improved retrieval of both individual and hospital stays with a discharge diagnosis of probable event and gave an enhanced basis for a future validation study. Local registers were not completely covered by the national register, but the accessible combination of national inpatient and mortality registers was an efficient alternative.
Distribution and determinants of ischaemic heart disease in an urban population. A study from the myocardial infarction register in Malmö, Sweden.
OBJECTIVE: Age adjusted incidence of myocardial infarction has been found to vary substantially between the residential areas of the city of Malmö. The objective of this study was to assess the extent to which major biological risk factors and socio-economic circumstances account for the differences in incidence of and mortality from myocardial infarction. DESIGN: Ecological study of risk factor prevalence and incidence and mortality from myocardial infarction. SETTING: Seventeen administrative areas in Malmö, Sweden. SUBJECTS: Assessment of risk factor prevalence was based on 28 466 men and women, ranging from 45 to 73 years old, who were recruited as participants in the Malmö Diet and Cancer study. Information on serum lipids was available in a random subsample of 5362 subjects. Information about socio-economic level of the residential area was based on statistics from the Malmö City Council and Statistics Sweden. MAIN OUTCOME MEASURES: Weighted least square regressions between prevalence of risk factors (i.e. smoking, hypertension, obesity, diabetes, hypercholesterolemia and hypertriglyceridemia), a myocardial infarction risk score, a socio-economic score and incidence and mortality from myocardial infarction. RESULTS: The risk factor prevalence and myocardial infarction incidence was highest in areas with low socio-economic level. Prevalence of smoking, obesity and hypertension was significantly associated with myocardial infarction incidence and mortality rates amongst men (all r > 0.60). Prevalence of smoking was significantly associated with incidence and mortality from myocardial infarction amongst women (r = 0.66 and r = 0.61, respectively). A myocardial infarction risk score based on four biological risk factors explained 40-60% of the intra-urban geographical variation in myocardial infarction incidence and mortality. The socio-economic score added a further 2-16% to the explained variance. CONCLUSION: In an urban population with similar access to medical care, well-known biological cardiovascular risk factors account for a substantial proportion of the intra-urban geographical variation of incidence of and mortality from myocardial infarction. The socio-economic circumstances further contribute to the intra-urban variation in disease.
Trends in long-term survival after myocardial infarction: less favourable patterns for patients from deprived areas.
OBJECTIVE: New treatments have improved the prognosis for patients with acute myocardial infarction. However, studies on long-term survival are not unequivocally in favour of an improved long-term prognosis. This study aimed to analyse trends in 3-year survival in relation to sex, age and socioeconomic level of residential area. SETTING: The Malmö myocardial infarction register, Sweden. PARTICIPANTS: All men and women in the city who, between 1978 and 1995, were admitted for a first acute myocardial infarction (n = 11 226). MAIN OUTCOME MEASURES: Age-standardized 3-year survival rates. RESULTS: Both 28-day and 3-year survival rates improved markedly during the study period. Age-standardized 3-year survival (per 100 patients) amongst men and women who survived 28 days increased, between 1978-81 and 1991-95, from 64 to 78 in men and from 66 to 77 in women, an annual increase of 1.4% (95% CI = 1.1-1.7) and 1.2% (0.8-1.5), respectively. There were marked differences in survival between residential areas with different socioeconomic circumstances. The 3-year survival rates amongst men correlated significantly with the socioeconomic circumstances in the areas expressed in terms of a socioeconomic score (men: r = 0.60, n = 17, P = 0.01; women: r = 0.37, P = 0.15). Trends tended to be less favourable in deprived areas. CONCLUSION: Three-year survival after first myocardial infarction has continuously improved for men and women in all age groups. Prognosis was worse and trends tended to be less favourable for patients from deprived areas.
Relation between insulin resistance and carotid intima-media thickness and stenosis in non-diabetic subjects. Results from a cross-sectional study in Malmö, Sweden.
AIMS: To assess whether there is an association between insulin resistance and carotid intima-media thickness and stenosis in non-diabetic subjects free from symptomatic cardiovascular disease. METHODS: A cross-sectional population-based study in Malmö, Sweden, of 4,816 (40% men) subjects, born 1926-1945. The prevalence of insulin resistance was established by the homeostasis model assessment (HOMA) and defined as values above the 75th percentile. Criteria issued by the European Group for the Study of Insulin Resistance (EGIR) were used for the definition of the insulin resistance syndrome. Common carotid artery intima-media thickness (IMT) and carotid stenosis (> 15%) were measured by B-mode ultrasonography. RESULTS: Age and sex-adjusted common carotid IMT among subjects with the insulin resistance syndrome (12.7%) and controls was 0.812 mm, respectively, 0.778 mm (P < 0.001). The prevalence of stenosis in the two groups was 22.9 and 19.2% (P = 0.040). Insulin resistance per se was after adjustment for age and sex associated with increased IMT (0.780 mm vs. 0.754 mm, P < 0.001). This association disappeared, however, when other factors included in the insulin resistance syndrome were taken into account. CONCLUSIONS: Fasting serum insulin covaries with a number of factors and conditions known to influence the development of atherosclerosis. It is concluded that the association between insulin resistance, as assessed by the HOMA method in non-diabetic subjects, and atherosclerosis is explained by its covariance with established risk factors for cardiovascular disease of which hypertension seems to be the most significant.
Survival of women with breast cancer in relation to smoking.
OBJECTIVE: To compare survival of patients with breast cancer who had never smoked, were smokers, and who were ex-smokers. DESIGN: Observational study. SETTING: City of Malmö, Sweden. PATIENTS: 792 patients with breast cancer diagnosed between 1977-1986 in the Malmö mammographic screening trial. INTERVENTIONS: Follow-up of breast cancer cases through record-linkage with the Swedish Cause of Death Registry. MAIN OUTCOME MEASURES: Death from breast cancer. Relative risk (RR) with 95% confidence interval (CI) of death from breast cancer was calculated for different smoking groups using Cox's proportional hazards analysis. RESULTS: During a mean follow-up of 12.1 years, 145 patients died of breast cancer. Breast cancer mortality was 1347/10(5) person-years in those who had never smoked, 1941/10(5) in smokers, and 1493/10(5) in ex-smokers. The crude RR for smokers and ex-smokers, compared with those who had never smoked were 1.44 (1.01 to 2.06) and 1.13 (0.66 to 1.94), respectively. The RR associated with smoking remained significant after adjustment for age and stage at diagnosis, 2.14 (1.47 to 3.10), and other potential confounders. CONCLUSIONS: Survival after breast cancer was, as expected, strongly related to stage at diagnosis. However, stage by stage there was considerable variation between individual patients. We conclude that differences with regard to exposure to smoking contribute to this heterogeneity.
Incidence of myocardial infarction in women. A cohort study of risk factors and modifiers of effect.
STUDY OBJECTIVE: To assess whether the increased incidence of myocardial infarction and death associated with smoking, hypertension, hyperlipidaemia and diabetes varies significantly between groups defined in terms of occupation, education and marital status. SETTING: Malmö, Sweden. PARTICIPANTS: 9351 women, aged 28-55, with a mean follow up of 10.7 years. MAIN RESULTS: Smoking, hypertension (> or = 160/95 mm Hg or treatment), hyperlipidaemia (cholesterol > or = 6.5 mmol/l or triglycerides > or = 2.3 mmol/l), diabetes, low occupation and education levels were significantly more common among women who experienced a fatal or nonfatal myocardial infarction during the follow up (n = 104) than in other women (n = 9247). Exposure to smoking, hypertension and hyperlipidaemia showed substantial differences between groups defined in terms of education, occupation and marital status. The association between low occupation and myocardial infarction remained statistically significant after adjustments for several potential confounders (RR = 2.6, 95% CI 1.1, 6.0). Single women had similarly higher adjusted mortality rates than married women (RR = 1.4, 95% CI 1.1, 1.8). When other major risk factors were taken into account, the relative risk for mortality and myocardial infarction associated with smoking was 2.6 (95% CI 2.0, 3.4) and 7.8 (95% CI 4.4, 13.9), respectively. CONCLUSION: In this urban female population, short education and low occupation level were both associated with an increased prevalence of smoking, hypertension, hyperlipidaemia and diabetes. Low occupation level increases the rate of cardiac events caused by exposure to these four risk factors.
Intra-urban differences in breast cancer mortality: a study from the city of Malmö in Sweden.
STUDY OBJECTIVE: To assess whether in an urban population stage at breast cancer diagnosis is related to area of living and to what extent intra-urban differences in breast cancer mortality are related to incidence respectively stage at diagnosis. DESIGN: National registries were used to identify cases. Mortality in 17 residential areas was studied in relation to incidence and stage distribution using linear regression analysis. Areas with high and low breast cancer mortality, incidence and proportion of stage II+ tumours at diagnosis were also compared in terms of their sociodemographic profile. SETTING: City of Malmö in southern Sweden. PATIENTS: The 1675 incident breast cancer cases and 448 deaths that occurred in women above 45 years of age in Malmö 1986-96. MAIN RESULTS: Average annual age standardised breast cancer mortality ranged between residential areas, from 35/10(5) to 107/10(5), p = 0.04. Mortality of breast cancer was not correlated to incidence, r = 0.22, p = 0.39. The ratio of stage II+/0-I cancer incidence varied between areas from 0.45 to 1.99 and was significantly correlated to breast cancer mortality, r = 0.53, p = 0.03. Areas with high proportion of stage II+ cancers and high mortality/incidence ratio were characterised by a high proportion of residentials receiving income support, being foreigners and current smokers. CONCLUSIONS: Within this urban population there were marked differences in breast cancer mortality between residential areas. Stage at diagnosis, but not incidence, contributed to the pattern of mortality. Areas with high proportion of stage II+ tumours differed unfavourably in several sociodemographic aspects from the city average.
Cardiac arrhythmias and stroke: increased risk in men with high frequency of atrial ectopic beats.
BACKGROUND AND PURPOSE: With the exception of atrial fibrillation (AF), little scientific attention has been given the associations between cardiac arrhythmias and incidence of stroke. We sought to study whether atrial and ventricular arrhythmias assessed during a 24-hour ambulatory ECG registration are associated with incidence of stroke. METHODS: The population-based cohort "Men Born in 1914" was examined with 24-hour ambulatory ECG registrations at 68 years of age. Four hundred two men without previous myocardial infarction or stroke were included, and 236 of them had hypertension (>/=160/95 mm Hg or treatment). Fourteen-year rates of stroke (fatal and nonfatal) and all-cause mortality were updated from national and regional registers. Frequent or complex ventricular arrhythmias was defined as Lown class 2 to 5. A high frequency of atrial ectopic beats (AEB) was defined as the fifth quintile (ie, >/=218 AEB per 24 hours). RESULTS: Fifty-eight men suffered a first stroke during the follow-up. Stroke rates (per 1000 person-years) among men with AF (n=14), with frequent AEB (n=77), and without AF or frequent AEB (n=311) were 34.5, 19.5, and 11.6, respectively. The corresponding values among men with hypertension were 40.7, 32.3, and 14.7, respectively. Frequent AEB (compared with absence of AF and frequent AEB) was significantly associated with stroke among all men (relative risk=1.9; 95% CI, 1.02 to 3.4; P:=0.04) and among hypertensive men (relative risk=2.5; 95% CI, 1.3 to 4.8; P:=0.009) after adjustments for potential confounders. The increased stroke rates among men with Lown class 2 to 5 did not reach statistical significance. CONCLUSIONS: A high frequency of AEB is associated with an increased incidence of stroke.
Respiratory decline in smokers and ex-smokers--an independent risk factor for cardiovascular disease and death.
BACKGROUND AND OBJECTIVE: Although smoking is associated with an increased incidence of cardiovascular disease and death, many smokers remain healthy after many years of smoking. Our objective was to assess whether this variation is related to rate of decline of respiratory function. DESIGN: This was a population-based cohort study, its subjects being men born in 1914 from Malmö, Sweden. METHODS: All 291 smokers who since the baseline examination in 1969 had remained in Malmö were invited to a follow-up examination in 1982. Of the 242 participants, 199 men without history of myocardial infarction or stroke were included in the study. Eighty-four of them had quit smoking. The incidence of cardiovascular disease and death during 14 years was studied in relation to the decline in lung function [forced expiratory volume during 1 second (FEV1.0) and vital capacity] between 55 and 68 years of age. RESULTS: Fifty-nine (51%) smokers and 43 (51%) ex-smokers died. Forty-four (38%) smokers and 29 (35%) ex-smokers suffered a cardiovascular event. The mortality rate among smokers in the high, middle and low thirds with regard to the decline in FEV1.0 was 66.5, 44.0, and 37.6, respectively, per 1000 person-years (P for trend = 0.04). The corresponding figures in ex-smokers were 88.7, 42.0, and 35.1 (P for trend = 0.002). The cardiovascular event rate among smokers in these three groups was 56.0, 41.0, and 22.7 events, respectively, per 1000 person-years (P for trend = 0.01). The association remained significant after adjustments for potential confounders. A change in vital capacity was associated with a similar pattern of disease and death. CONCLUSION: Although smoking is associated with an accelerated respiratory decline, there are marked differences between smokers. The increased cardiovascular event and death rates among those whose lung function declined the most suggests that the change in respiratory function can be used as a measure of individual susceptibility.
Ventricular arrhythmias during 24-h ambulatory ECG recording: incidence, risk factors and prognosis in men with and without a history of cardiovascular disease.
OBJECTIVE: To study incidence, prognosis and risk factors of ventricular arrhythmias in men with and without asymptomatic non-invasively detected cardiovascular disease (CVD). DESIGN: Prospective cohort study with 11 years' follow-up. The subjects went through 24-h ambulatory electrocardiographic (ECG) registrations and non-invasive examinations of leg and carotid arteries at the baseline examination. SETTING: Malmö, Sweden. SUBJECTS: Four hundred and forty-three randomly selected 68-year-old men. MAIN OUTCOME MEASURES: Mortality and cardiac event rates during an 11-year period. RESULTS: Frequent or complex arrhythmias (Lown class 2-5) were common in men both with and without CVD. However, the associated prognoses were different. In men with CVD, frequent or complex arrhythmias were associated with increased cardiac event rates (P = 0.001) and increased mortality (P = 0.054). This pattern was also found in men with asymptomatic leg and carotid artery disease, although the frequency of arrhythmia in Lown class 2-5 was similar to that in men without CVD. Men with angina pectoris or previous myocardial infarction in combination with leg or carotid artery disease had the most arrhythmias and the worst prognosis. No relationship between frequent or complex arrhythmias and mortality or cardiac events was found in men without CVD. In a logistic regression, smoking and diabetes mellitus were significant and independent determinants of frequent or complex arrhythmias in men with CVD. High alcohol consumption was associated with arrhythmias in men without CVD. CONCLUSION: Ambulatory ECG recording is a feasible method to improve risk assessment in men with CVD. In this group, frequent or complex arrhythmias are associated with smoking and diabetes mellitus.
Covariance of breast cancer incidence with smoking-, oestrogen- and diet-related cancers in pre- and postmenopausal women in Sweden.
Effects of smoking on breast cancer risk remains controversial. Tar products have been claimed to increase risk, antioestrogenic effects to reduce risk. Another possibility is that associations to smoking have been confounded by diet. The increasing incidence of breast cancer from 1960 to 1994 in Sweden is parallel to that of lung cancer and the increasing proportion of female smokers. The incidence of endometrial and colon cancer was in premenopausal women negatively and in postmenopausal women positively related to the incidence of breast cancer. Possible explanations and hypotheses to the different co-variance between breast cancer and lung, endometrial and colon cancer in pre- and postmenopausal women are discussed from the perspectives of smoking, sex hormones and diet. It is concluded that the strong and specific positive relationship between breast and lung cancer in premenopausal women is compatible with the hypothesis that aromatic hydrocarbons may be involved in the causation of disease.
Hypertensive men who exercise regularly have lower rate of cardiovascular mortality.
BACKGROUND: Regular exercise has been associated in prospective studies with reduced incidence of cardiovascular disease (CVD) and death. OBJECTIVE: To assess in a cohort study whether there is a similar protective effect of regular exercise among hypertensive individuals. DESIGN: Population-based prospective cohort study. Spare time physical activity was assessed by structured interview. SETTING: Malmo, Sweden. PARTICIPANTS: Healthy men (n = 642) born in 1914. A baseline examination took place in 1969-1970. MAIN OUTCOME MEASURES: All-cause and cardiovascular mortality rates during 25 years of follow-up in relation to blood pressure and other risk factors for atherosclerosis. RESULTS: One-hundred (16%) men reported vigorous spare time physical activity. In this group, 31 had hypertension (blood pressure >160/95 mm Hg or treatment for hypertension), 47 were smokers and 39 had hyperlipidaemia. Among the 173 men with hypertension, vigorous physical activity was associated with markedly reduced rates of all-cause (17.3 versus 40.0 deaths per 1000 person-years) and cardiovascular mortality (6.3 versus 21.0 deaths per 1000 person-years). The risk reductions associated with exercise remained statistically significant after adjustment for smoking, systolic blood pressure and antihypertensive therapy. The relative risk was 0.43 (confidence interval 0.22-0.82) for total mortality and 0.33 (confidence interval 0.11 -0.94) for CVD mortality. CONCLUSION: People who regularly perform physical activity constitute a heterogeneous group with regard to their exposure to known cardiovascular risk factors. Our results support the view that regular physical activity is associated with a reduced incidence of cardiovascular disease and death and suggest that this protective effect may be enhanced among hypertensive individuals.
Long-term effects on the regulation of pancreatic secretion after gastric surgery.
BACKGROUND: Apart from smoking, known risk factors for the development of pancreatic carcinoma are few, gastric resection being proposed as one. The trophic effect of cholecystokinin (CCK) on the pancreatic gland is well known from animal experience and increased concentrations of CCK in plasma have been shown to induce pancreatic neoplasia experimentally. In several studies the release of CCK in response to food ingestion has been shown to be increased following gastric surgery. However, in those studies, the time between surgery and investigation of the CCK response was short, and methods of CCK analysis have since improved. PATIENTS AND METHODS: In patients, partially gastrectomized 8 years (median) earlier, we studied the plasma concentrations of CCK, insulin and gastrin, as well as some specific pancreatic enzymes. The findings were compared to an age-matched control group of individuals not subjected to gastric surgery. RESULTS: Basal CCK concentrations in the operated group were found to be lower, but increased postprandially to the same level as in controls. Serum levels of specific pancreatic enzymes were equal in the 2 groups. CONCLUSION: It is possible that a disturbed regulation of pancreatic secretion, or a secretory dysfunction within the gland, following partial gastrectomy, could contribute to the development of pancreatic carcinoma. However, our findings do not favor the idea of plasma CCK as a promotor of pancreatic carcinoma.
Subjective well-being associated with improved survival in smoking and hypertensive men.
BACKGROUND: Previous studies have shown that people who rate their health as poor have reduced life expectancy. The purpose of the present study was to determine to what extent self-rated perception of health modifies the survival rates in men at risk from tobacco smoking or hypertension. DESIGN: A prospective population-based study. METHODS: The baseline examination took place in 1969 and study participants were followed until 1993. The study cohort comprised 632 men born in 1914 and residing in Malmö, Sweden. Self-rated health (good, average or poor) was assessed in a structured interview in 1969. Mortality data were obtained from the Swedish National Bureau of Statistics. Subjects were stratified for smoking and hypertension. RESULTS: After adjustments for a number of medical risk factors and physical activity, health self-rated as good was significantly associated with reduced mortality in smoking (adjusted relative risk 0.63, confidence interval (CI) 0.47 to 0.84), hypertensive (adjusted relative risk 0.56, CI 0.34 to 0.91) and normotensive (adjusted relative risk 0.66, CI 0.49 to 0.91) men. CONCLUSION: We conclude that subjective well-being modifies the survival rates in hypertensive or smoking men.
Increased incidence of fractures in middle-aged and elderly men with low intakes of phosphorus and zinc.
The aim of the study was to determine dietary risk factors for fracture in men aged 46-68 years. Six thousand five hundred and seventy-six men were randomly invited using the Municipal Registry to a diet and health study. The diet was assessed using a combined 7-day menu book for hot meals, beverages and dietary supplements and a quantitative food frequency questionnaire for other foods. The fracture incidence was 103/10,000 person-years during a mean follow-up of 2.4 years. Zinc and phosphorus intake were associated with fracture risk and showed a threshold effect. The zinc intake in the lowest decentile, 10 mg daily, was associated with almost a doubled risk of fracture compared with the fourth and fifth quintiles (RR = 0.47; 95% confidence interval, 27-82) of zinc intake adjusted for energy, previous fractures, lifestyle factors and co-morbidity. Energy-adjusted phosphorus intake in the lowest quintile, mean level 1357 mg, was associated with an increased fracture risk compared with subjects in the second quintile. Smoking, martial status and physical activity were independently associated with fracture risk. Calcium, retinol and vitamin D showed no associations with fracture risk. We conclude that inadequate intakes of zinc and phosphorus are important risk factors for fracture.