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A Ekbom

Publications and source records attributed to A Ekbom.

At least 55 records · Page 3Linked to original sources
PubMed2002

Supplementary oxygen and risk of childhood lymphatic leukaemia.

AIM: Childhood leukaemia has been linked to several factors, such as asphyxia and birthweight, which in turn are related to newborn resuscitation. Based on the findings from a previous study a population-based case-control study was performed to investigate the association between childhood leukaemia and exposure to supplementary oxygen and other birth-related factors. METHODS: Children born in Sweden and diagnosed with lymphatic leukaemia between 1973 and 1989 (578 cases) were individually matched by gender and date of birth to a randomly selected control. Children with Down's syndrome were excluded. Exposure data were blindly gathered from antenatal, obstetric and other standardized medical records. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated by conditional logistic regression. RESULTS: Resuscitation with 100% oxygen with a facemask and bag immediately postpartum was significantly associated with an increased risk of childhood lymphatic leukaemia (OR = 2.57, 95% Cl 1.21-6.82). The oxygen-related risk further increased if the manual ventilation lasted for 3 min or more (OR = 3.54, 95% CI 1.16-10.80). Low Apgar scores at 1 and 5 min were associated with a non-significantly increased risk of lymphatic leukaemia. There were no associations between lymphatic leukaemia and supplementary oxygen later in the neonatal period or other birth-related factors. CONCLUSION: Resuscitation with 100% oxygen immediately postpartum is associated with childhood lymphatic leukaemia, but further studies are warranted to confirm the findings.

Adolescent↗
PubMed2002

Correlates of pregnancy oestrogen, progesterone and sex hormone-binding globulin in the USA and China.

The objective of this study is to examine perinatal correlates of oestradiol (E2), oestriol (E3), progesterone and sex hormone-binding globulin (SHBG) among pregnant women in the USA and China. Three hundred and four Caucasian women in Boston and 335 Chinese women in Shanghai were studied. Levels of E2, E3, progesterone and SHBG were measured in maternal blood at weeks 16 and 27 of gestation, and correlated with maternal, gestational and perinatal characteristics. Height, weight and body mass index (BMI) before pregnancy is inversely associated with E2 and SHBG, whereas E3 is inversely associated with height and progesterone is inversely associated with weight and BMI. A previous live birth is associated with lower E2 and SHBG in the index pregnancy. Total gestation duration is inversely associated with E2, E3 and progesterone, whereas weight gain during pregnancy is inversely associated with progesterone and SHBG. In the US, pregnancies with female fetuses are characterized by significantly reduced progesterone. Pregnancy hormones are associated with several maternal, gestational and neonatal characteristics.

Adult↗
PubMed2002

Alcohol abuse and the risk of pancreatic cancer.

BACKGROUND: Although most epidemiological studies do not support a role for alcohol in the aetiology of pancreatic cancer, an increased risk among heavy drinkers cannot be excluded. METHODS: In a retrospective cohort based on the Swedish Inpatient Register, we analysed the risk of pancreatic cancer among patients admitted to hospital for alcoholism (n=178 688), alcoholic chronic pancreatitis (n=3500), non-alcoholic chronic pancreatitis (n=4952), alcoholic liver cirrhosis (n=13 553), or non-alcoholic liver cirrhosis (n=7057) from 1965 to 1994. Follow up through to 1995 was accomplished by linkage to nationwide registers. Standardised incidence ratios (SIRs) express the relative risks by taking the general Swedish population as reference. To minimise the possible influence of selection bias, we excluded the first year observations. RESULTS: Alcoholics had only a modest 40% excess risk of pancreatic cancer (SIR 1.4, 95% confidence interval (CI) 1.2-1.5). Overrepresented smokers among alcoholics might confound a true SIR of unity among alcoholics to approximately 1.4. SIR among alcoholic chronic pancreatitis patients (2.2, 95% CI 0.9-4.5) was considerably lower than that among non-alcoholic chronic pancreatitis patients (8.7, 95% CI 6.8-10.9), and decreased with increasing duration of follow up in both groups, indicating that most of the excess might be explained by reversed causation from undiagnosed cancers. Among patients with alcoholic liver cirrhosis, the increased risk of pancreatic cancer was also moderate (SIR 1.9, 95% CI 1.3-2.8) while no significant excess risk was found among non-alcoholic liver cirrhosis patients (SIR 1.2, 95% CI 0.6-2.2). CONCLUSIONS: The excess risk for pancreatic cancer among alcoholics is small and could conceivably be attributed to confounding by smoking.

Adult↗
PubMed2001

Birthweight, early environment, and genetics: a study of twins discordant for acute myocardial infarction.

BACKGROUND: Epidemiological studies that used birthweight as a crude marker of fetal growth have suggested that low birthweight is associated with increased risk of coronary heart disease. Through investigation of this association within same-sexed twin pairs, confounding by genetic and early environmental factors can be greatly decreased. We undertook a case-control study in twins discordant for acute myocardial infarction (AMI). METHODS: The case-control study was nested within the population-based Swedish Twin Registry and linked with the national cause-of-death and hospital-discharge registries. We manually retrieved birth records containing information on birth and maternal characteristics for 132 same-sexed twin pairs discordant for AMI and 118 individually matched control twin pairs. FINDINGS: In comparisons between AMI cases and external matched control twins, cases had significantly lower birthweight (mean 2556 [SD 500] vs 2699 [530] g, p=0.04), birth length (47.1 [2.8] vs 47.9 [2.7] cm, p=0.04), and head circumference (33.0 [1.8] vs 33.5 [2.0] cm, p=0.03) than controls. In within-pair comparisons between AMI cases and healthy co-twins, no significant differences in birth measurements were found (birthweight 2458 [510] vs 2534 [530] g, p=0.73; birth length 47.1 [2.8] vs 47.2 [2.8] cm, p=0.91; head circumference 33.0 [1.7] vs 33.0 [1.8] cm, p=0.92). INTERPRETATION: The lack of an association between birth characteristics and AMI within twin pairs suggests that previously reported associations may be influenced by genetic and early environmental factors, or possibly, by unmeasured maternal factors that operate independently of birthweight.

Birth Weight↗
PubMed2001

[Prevention and early diagnosis of cancer. What do we know? What do we think? Reports from the Lakardagarna in Orebro].

Läkardagarna (physician days) in Orebro is an annual course arranged by the Orebro Society of Medicine in collaboration with The Swedish Society of Medicine. In the year 2000 the title was "Prevention and early diagnosis of cancer. What do we know? What do we believe? What do we do?" With general practitioners as the target audience, the course covered basic biological science, risk factors, screening, ethical questions and the general practitioner's dilemma. This article reviews four selected contributions: 1) What is cancer? 2) Possible importance of the fetal stage for later risk of cancer; 3) Infections as a cause of cancer; and 4) Screening for cancer.

Health Knowledge, Attitudes, Practice↗
PubMed2001

Appendectomy and protection against ulcerative colitis.

BACKGROUND: A history of appendectomy is rare in patients with ulcerative colitis. This suggests a protective effect of appendectomy or that appendicitis and ulcerative colitis are alternative inflammatory responses. We sought to characterize this inverse relation further. METHODS: We studied a cohort of 212,963 patients who underwent appendectomy before the age of 50 years between 1964 and 1993 and a cohort of matched controls who were identified from the Swedish Inpatient Register and the nationwide census. The cohort was followed until 1995 for any subsequent diagnosis of ulcerative colitis. RESULTS: Patients who underwent appendectomy for appendicitis and mesenteric lymphadenitis had a low risk of ulcerative colitis (for patients with perforated appendicitis, the adjusted hazard ratio was 0.58 [95 percent confidence interval, 0.38 to 0.87]; for those with nonperforated appendicitis it was 0.76 [95 percent confidence interval, 0.65 to 0.90]; and for those with mesenteric lymphadenitis it was 0.57 [95 percent confidence interval, 0.36 to 0.89]). In contrast, patients who underwent appendectomy for nonspecific abdominal pain had the same risk of ulcerative colitis as the controls (adjusted hazard ratio, 1.06; 95 percent confidence interval, 0.74 to 1.52). For the patients who had appendicitis, an inverse relation with the risk of ulcerative colitis was found only for those who underwent surgery before the age of 20 years (P<0.001). CONCLUSIONS: Appendectomy for an inflammatory condition (appendicitis or lymphadenitis) but not for nonspecific abdominal pain is associated with a low risk of subsequent ulcerative colitis. This inverse relation is limited to patients who undergo surgery before the age of 20 years.

Abdominal Pain↗
PubMed2001

Time trends in first admissions for schizophrenia and paranoid psychosis in Stockholm County, Sweden.

Several studies have reported decreasing time trends in first diagnosed schizophrenia patients. The aim of this study was to analyze time trends for first admissions with a diagnosis of schizophrenia or a diagnosis of either schizophrenia or paranoid psychosis during 1978-1994 in Stockholm County, Sweden, with a population of around 1.8million. Information about first psychiatric admission with the diagnosis schizophrenia or paranoid psychosis for residents of Stockholm County was obtained from the Swedish population-based psychiatric inpatient register. Age-adjusted average yearly changes in first hospitalization rates were estimated in a Poisson regression model. Time trends in first admission rates were calculated from 1978 to 1994, while admissions during 1971 to 1977 were observed only to eliminate later re-admissions. First admissions for schizophrenia declined by 1.9% annually for females and by 1.3% for males, while first admissions for schizophrenia and paranoid psychosis together were unchanged over the study period for both genders. Our results indicate that the incidence of schizophrenia and paranoid psychosis taken together was essentially the same over the studied time period in Stockholm County, and that the apparent decline in first admission rates for schizophrenia may be an effect of changes in clinical diagnosis over time.

Adolescent↗
PubMed2001

Long-term tobacco smoking and colorectal cancer in a prospective cohort study.

Tobacco smoking has consistently been associated with colorectal adenomas, precursors of cancer, but the association with colorectal cancer itself has not been consistent. If colorectal cancer emerges only after a 35-year induction period, an association would unlikely be detected in studies where exposure assessment is of shorter duration. Most previous studies do not examine smoking of such duration and therefore do not account for the hypothesized 35-year induction period. By using the Cox proportional hazards models to estimate relative risks, we studied the association of long-term smoking and colorectal cancer risk in a population-based prospective cohort of 17,118 Swedish twins with up to 30 years of follow-up and information on smoking habits prior to baseline exposure assessment. Long-term heavy smoking was associated with a statistically significant 3-fold increased risk of colorectal cancer compared with never smoking (relative risk 3.1, 95% CI 1.4- 7.1). Examining colorectal cancer sub-sites separately, a non-significant 60% increased risk of colon cancer was observed only for heavy smokers and a statistically significant 5-fold increased risk was observed for rectal cancer. Our data lend some support to the hypothesis that heavy long-term cigarette smoking is associated with increased risk of colorectal cancer. Further elucidation of this association would be valuable from both etiologic and public health perspectives.

Adult↗
PubMed2001

Colorectal cancer rates among first-degree relatives of patients with inflammatory bowel disease: a population-based cohort study.

BACKGROUND: Inflammatory bowel disease (IBD) and colorectal cancer might share a common cause and, therefore, relatives of patients with IBD could be at increased risk of this malignant disease. We aimed to assess cancer rates among first-degree relatives of patients with IBD to try to determine whether an association between the two diseases exists. METHODS: In a population-based study, we identified 114,102 first-degree relatives by registry linkage and followed them up for cancer occurrence. We used standardised incidence ratio (SIR) of cancer as relative risk. FINDINGS: 560 colorectal cancers were identified among relatives. First-degree relatives of patients with Crohn's disease or ulcerative colitis were not at increased risk of cancer (SIR 0.90, 95% CI 0.82-0.97). The relative risk was 0.96 (0.87-1.06, n=379) for colon cancer and 0.78 (0.68-0.91, 181) for rectal cancer. The SIRs were not affected by age, relation to patient, or type or extent of IBD in the patient. Relatives of patients with both IBD and colorectal cancer had an 80% increased risk of colorectal cancer. INTERPRETATION: Our results do not endorse a common cause of IBD and colorectal cancer. The slightly decreased relative risk for colorectal cancer among relatives could indicate the proportion of all colorectal cancer cases attributable to IBD.

Adult↗
PubMed2001

Birth characteristics and breast cancer risk: a study among like-sexed twins.

High birth weight has been proposed to increase the risk of breast cancer. Birth weight and gestational age are positively associated with intrauterine estrogen exposure, which may initiate the carcinogenic process in mammary gland tissue and determine mammary gland cell mass later in life. In the present case-control study, we retrieved birth records for 96 female twin pairs where one twin had developed breast cancer. We used two control groups. In the external comparison, we used aged-matched twins as the control group, and in the within-pair comparison the control group included the healthy twin sisters. Odds ratio (OR) was used to estimate the relative risk, using 95% confidence intervals (CI). Compared with twins with gestational age less than 33 weeks, twins with gestational age of more than 40 weeks were at increased risk of breast cancer (OR = 8.4; 95% CI 1.3-54.4). In the within-pair comparison, mean birth weight and ponderal index were higher among cases compared with their co-twins (p = 0.07 and p = 0.05, respectively). The risk of breast cancer increased with birth weight. Compared with women with birth weight of less than 2,000 g, women with birth weight of at least 3,000 g had a nonsignificant increase in risk of developing breast cancer (OR = 3.5; 95% CI 0.7-18.5). The results give some support to the hypothesis that the fetal environment influences adult breast cancer risk.

Adult↗
PubMed2001

Incidence of ovarian cancer among alcoholic women: a cohort study in Sweden.

Linkage of nationwide databases in Sweden allowed us to evaluate the incidence of ovarian cancer among 36,856 women diagnosed with alcoholism between 1965 and 1994. Mean duration of follow-up was 9.6 years, for a total of 317,518 person-years at risk. The expected number of cases of ovarian cancer was calculated by multiplying the number of person-years by 5-year age group and calendar year-specific incidence rates of ovarian cancer in Sweden. The effect measure was the standardized incidence ratio (SIR), with 95% confidence intervals (CIs). Our results indicate an overall deficit of cases of ovarian cancer of about 14% among women with a diagnosis of alcoholism. This deficit is particularly strong and statistically significant among alcoholic women younger than 60 years (SIR = 0.76, 95% CI 0.58-1.00). This deficit is compatible with the reported reduction of gonadotrophin levels among alcoholic women younger than 60 years and with the hypothesis invoking these gonadotrophins in the etiology of ovarian cancer.

Adult↗
PubMed2001

Risk of non-Hodgkin's lymphoma following tuberculosis.

To study the association between chronic infections and non-Hodgkin's lymphoma (NHL), we assessed the risk of NHL in a Swedish cohort of 5050 individuals with tuberculosis 1939-1960. The overall relative risk was moderately increased, largely accounted for by high risks following severe tuberculosis diagnosed a long time ago.

Cause of Death↗
PubMed2001

Excess mortality in bipolar and unipolar disorder in Sweden.

BACKGROUND: Selected groups of patients with bipolar and unipolar disorder have an increased mortality rate from suicide and natural causes of death. However, there has been no population-based study of mortality of patients followed up from the onset of the illness. METHODS: All patients with a hospital diagnosis of bipolar (n = 15 386) or unipolar (n = 39 182) disorder in Sweden from 1973 to 1995 were identified from the inpatient register and linked with the national cause-of-death register to determine the date and cause of death. Overall and cause-specific standardized mortality ratios (SMRs) and numbers of excess deaths were calculated by 5-year age classes and 5-year calendar periods. RESULTS: The SMRs for suicide were 15.0 for males and 22.4 for females with bipolar disorder, and 20.9 and 27.0, respectively, for unipolar disorder. For all natural causes of death, SMRs were 1.9 for males and 2.1 for females with bipolar disorder, and 1.5 and 1.6, respectively, for unipolar disorder. For bipolar disorder, most excess deaths were from natural causes, whereas for unipolar disorder, most excess deaths were from unnatural causes. The SMR for suicide was especially high for younger patients during the first years after the first diagnosis. Increasing SMR for suicide during the period of study was found for female patients with unipolar disorder. CONCLUSIONS: This population-based study of patients treated in the hospital documented increased SMRs for suicide in patients with bipolar and unipolar disorder. The SMR for all natural causes of death was also increased, causing about half the excess deaths.

Adolescent↗
PubMed2001

Caffeine metabolism and the risk of spontaneous abortion of normal karyotype fetuses.

OBJECTIVE: To investigate whether the rate of caffeine metabolism influences spontaneous abortion risk. METHODS: We studied 101 women with normal karyotype spontaneous abortions and 953 pregnant women at 6-12 gestational weeks. Participants reported on caffeine intake and provided urine for phenotyping cytochrome P4501A2 (CYP1A2) activity and blood for genotyping N-acetylation (NAT2) status. We calculated odds ratios (OR) and 95% confidence intervals (CI) to evaluate the association between each of the two metabolic indices and spontaneous abortion risk and also the potential interaction between caffeine intake and metabolic activity on such risk. In calculating the associations between the metabolic indices and risk of spontaneous abortion, we had 80% power to detect an OR of 2.1, with a Type I error of 0.05. RESULTS: Slow acetylators had a nonsignificantly increased risk for spontaneous abortion (OR 1.36, 95% CI 0.84, 2.21) and recurrent spontaneous abortion (OR 2.51, 95% CI 0.81, 7.76). In contrast, low CYP1A2 activity was associated with a significantly decreased risk for spontaneous abortion (OR 0.35, 95% CI 0.20, 0.63). Caffeine was a risk factor for spontaneous abortion among women with high, but not low, CYP1A2 activity (OR 2.42, 95% CI 1.01, 5.80 for 100-299 mg/day; OR 3.17, 95% CI 1.22, 8.22 for 300 mg/day or more, among women with high CYP1A2 activity). CONCLUSION: The findings indicate that high CYP1A2 activity may increase the risk of spontaneous abortion, independently or by modifying the effect of caffeine. The results regarding NAT2 are less conclusive but suggest that slow acetylators may be at elevated risk of spontaneous abortion.

Abortion, Spontaneous↗
PubMed2001

Cause-specific mortality in a cohort of patients with diabetes mellitus: a population-based study in Sweden.

A cohort of patients with diabetes mellitus hospitalised in Sweden from 1965 to 1983 was followed up until 1989, by linkages of population-based registers. Standardised mortality ratios (SMR), adjusted for confounding variables, and 95% confidence intervals (CIs) were calculated. After exclusion of the first year of follow-up (to reduce the effect of selection bias), the cohort consisted of 144,427 patients, of whom 92,248 patients died during follow-up. The SMR for all causes of death combined was 2.62 (95% CI 2.58-2.67) among men and 3.23 (95% CI 3.18-3.28) among women. The excess mortality was still evident 20 years after first hospitalisation, but became less marked with longer follow-up time. Patients with presumably insulin-dependent diabetes mellitus (IDDM) had the highest SMRs (10.2; CI 9.5-11.0); however, there was a significant (34%) improvement over time in their mortality risk. We conclude that excess mortality persisted throughout all calendar periods and at all ages, indicating the need for health care prevention measures.

Adult↗
PubMed2001

Trends in lung cancer incidence in Sweden with special reference to period and birth cohorts.

OBJECTIVE: Sweden has one of the largest population-based cancer registers in the world that provides an opportunity to examine the trend of lung cancer incidence during a 35-year period. The primary aim of the present study was to estimate the effects of birth cohort, year of diagnosis (period), and age on the time trends of lung cancer incidence rates, and to analyze the gender-specific incidence of different histopathological types of lung cancer. RESULTS: Among men the age-standardized incidence rate increased steadily up to 1982, when a peak of 49 cases per 100,000 person-years was reached. Among women the incidence rate was lower and showed a monotonic increase throughout the observation period. The fastest rate of increase was noted among the youngest women. In women, but not in men, there was a steady increase in risk with each successive birth cohort. For both sexes there were large changes in the histopathological distributions of cases. The most notable was a major increase in adenocarcinomas. CONCLUSIONS: The overall age-adjusted incidence rate of lung cancer in Sweden has stabilized in men during the past two decades while rates are still increasing in women. In view of the continued high prevalence of smoking among young women, a future definite increase in the overall number of lung cancer cases in women can be expected.

Adenocarcinoma↗