Gun Wingren

A pooled analysis of case–control studies of thyroid cancer: cigarette smoking and consumption of alcohol, coffee, and tea

Objective: To analyze the role of smoking, alcohol, coffee and tea in relation to thyroid cancer, we conducted a pooled analysis of 14 case–control studies conducted in the United States, Europe, and Asia. Methods: The sample consisted of 2725 thyroid cancer cases (2247 females, 478 males) and 4776 controls (3699 females, 1077 males). Conditional logistic regression with stratification on study, age at diagnosis, and gender was used to compute odds ratios and 95% confidence intervals. Results: Thyroid cancer risk was reduced in persons who had ever smoked. The relationship was more pronounced in current smokers (OR = 0.6, 95% CI = 0.6–0.7) than former smokers (OR = 0.9, 95% CI = 0.8–1.1). There were significant trends of reduced risk with greater duration and frequency of smoking. For consumption of wine and beer, there was a significant trend of decreasing thyroid cancer risk (p = 0.02) that was not maintained after adjustment for current smoking (p = 0.12). Thyroid cancer risk was not associated with consumption of coffee or tea. These findings were consistent in both gender-specific and histology-specific (papillary and follicular) analyses. Conclusions: Pooled analyses of these geographically diverse case–control data indicate a reduced thyroid cancer risk associated with current smoking. A reduced risk associated with alcohol was eliminated after adjustment for smoking, and caffeinated beverages did not alter thyroid cancer risk.

Factors associated with pelvic floor dysfunction with emphasis on urinary and fecal incontinence and genital prolapse: an epidemiological study

Objective.  To describe a general population of women with regard to factors associated with urinary and fecal incontinence and genital prolapse symptoms.

A pooled analysis of case-control studies of thyroid cancer II. Menstrual and reproductive factors

Objective: It has been suggested that female hormones, and hence menstrual and reproductive factors, play a role in thyroid cancer etiology. Epidemiological data, however, are limited and inconsistent, partly because of the small number of cases included in each study. To clarify the etiology of thyroid cancer, we conducted a pooled analysis of original data from 14 case-control studies, 4 from the United States, 2 from Asia, and 8 from Europe.Methods: This analysis included a total of 2,247 female cases of thyroid cancer (80% papillary) and 3,699 control women. Pooled odds ratios (OR) were estimated using logistic regression, conditioning on study and (i) matching sets for individually matched studies, or (ii) quinquennia of age for the other studies. Additional terms for age and history of radiation exposure were included in the regression equations.Results: The OR per year of later menarche was 1.04 (95% confidence interval (CI) 1.0–1.1). Compared to pre-menopausal women, the OR was 1.3 for women with natural menopause, and 1.8 for those with artificial menopause, but the studies were heterogeneous and the association may be due, at least in part, to diagnostic or ascertainment bias. Parity, spontaneous or induced abortions and history of infertility were not associated with thyroid cancer risk. The OR was above unity in women reporting later age at first birth (OR=1.1, 95% CI 1.0–1.3 for 5-year delay) and higher in the first years after a birth.Conclusions: The associations of menstrual and reproductive factors with thyroid cancer risk were generally weak, but appeared stronger among women diagnosed with thyroid cancer at younger ages.

A POOLED ANALYSIS OF CASE-CONTROL STUDIES OF THYROID CANCER. IV. BENIGN THYROID DISEASES

Objective: To obtain more precise estimates of the association between thyroid cancer and benign thyroid diseases and to elucidate the role of potential confounders or effect modifiers.Methods: The original data from 12 case–control studies from the United States, Asia, and Europe were pooled. Based on 2094 women and 425 men with cancer of the thyroid and, respectively, 3248 and 928 control subjects, odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were obtained by conditional regression models, conditioning on study and age at diagnosis, and adjusting for age and radiotherapy.Results: A history of hypothyroidism was not associated with cancer risk (pooled ORs = 0.9, 95% confidence interval, CI: 0.7–1.3 in women and 1.7, 95% CI: 0.3–11.7 in men). ORs for hyperthyroidism were 1.4 (95% CI: 1.0–2.1) in women and 3.1 (95% CI: 1.0–9.8) in men. In women, however, risk was lower in the absence of or after allowance for history of goiter. Pooled ORs for a history of goiter were 5.9 (95% CI: 4.2–8.1) in women and 38.3 (95% CI: 5.0–291.2) in men. Risk for a history of benign nodules/adenomas was especially high (OR = 29.9, 95% CI: 14.5–62.0, in women; 18 cases versus 0 controls in men). The excess risk for goiter and benign nodules/adenomas was greatest within 2–4 years prior to thyroid cancer diagnosis, but an elevated OR was present 10 years or more before cancer.Conclusions: Goiter and benign nodules/adenomas are the strongest risk factors for thyroid cancer, apart from radiation in childhood.

Comorbidity and lifestyle, reproductive factors, and environmental exposures associated with rheumatoid arthritis

OBJECTIVE To evaluate the influence of lifestyle, reproduction, and some external factors on the development of rheumatoid arthritis (RA) and to describe its comorbidity. METHODS Cases were identified retrospectively from 1980 to 1995 at the University Hospital in Linköping, Sweden. The study comprised 422 cases and 859 randomly selected population referents. Data on possible aetiological factors and comorbidity were collected by postal questionnaire. RESULTS The response rates were 67% among cases and 59% among referents. A decrease in the occurrence of atopic allergy was seen in the cases (odds ratio (OR) 0.6, 95% confidence interval (CI) 0.4 to 1.0). There was a positive association between RA and insulin treatment (OR 10.2, 95% CI 1.7 to 60.8) in women, and women with a short fertile period had an increased risk of RA (OR 2.5, 95% CI 1.1 to 5.4). Current and previous smoking were associated with increased risks for RA in both sexes, and in men a dose-response relationship was found with number of tobacco pack years (p for trend <0.005). The risk for RA decreased with increasing level of education in both men and women. Increased risks were seen in men born into households with private wells (OR 2.8, 95% CI 1.5 to 5.2), residentially exposed to mould (OR 4.6, 95% CI 1.1 to 20.2), or exposed to farm animals (OR 3.3, 95% CI 0.7 to 16.6). In women there were positive associations between RA and reporting a previous joint injury (OR 2.5, 95% CI 1.0 to 6.6) and prolonged exposure to hair dyes (OR 1.9, 95% CI 0.8 to 4.5). CONCLUSIONS RA, a disease with features of T helper 1 (Th1) dominated immune response, was inversely associated with atopic allergy, a Th2 dominated condition, while there were indications of a strong positive association with Th1 related diabetes mellitus. The results support a causal relationship between smoking and RA. The level of education was inversely associated with RA, while there was a positive association between RA and certain residential factors in men and a short fertile period in women.

A pooled analysis of thyroid cancer studies. V. Anthropometric factors

AbstractObjective: To assess the relation between anthropometric factors and thyroid cancer risk in a pooled analysis of individual data from 12 case–control studies conducted in the US, Japan, China and Europe. Methods: 2056 female and 417 male cases, 3358 female and 965 male controls were considered. Odds ratios (OR) were derived from logistic regression, conditioning on age, A-bomb exposure (Japan) and study, and adjusting for radiotherapy. Results: Compared to the lowest tertile of height, the pooled OR was 1.2 for females for the highest one, and 1.5 for males, and trends in risk were significant. With reference to weight at diagnosis, the OR for females was 1.2 for the highest tertile, and the trend in risk was significant, whereas no association was observed in males. Body mass index (BMI) at diagnosis was directly related to thyroid cancer risk in females (OR = 1.2 for the highest tertile), but not in males. No consistent pattern of risk emerged with BMI during the late teens. Most of the associations were observed both for papillary and follicular cancers, and in all age groups. However, significant heterogeneity was observed across studies. Conclusions: Height and weight at diagnosis are moderately related to thyroid cancer risk.

A pooled analysis of case-control studies of thyroid cancer. III. Oral contraceptives, menopausal replacement therapy and other female hormones.

Objective: The relations between oral contraceptives (OC), hormone replacement therapy (HRT) for menopause, and other female hormone use and thyroid cancer risk was analyzed using the original data from 13 studies from North America, Asia and Europe.Methods: Based on 2,132 cases and 3,301 controls, odds ratios (OR) and the corresponding 95% confidence intervals (CI) were obtained by conditional regression models, conditioning on study and age at diagnosis, and adjusting for age, radiation exposure and parity.Results: Overall, 808 (38%) cases versus 1,290 (39%) controls had ever used OCs, corresponding to an OR of 1.2 (95% CI 1.0 to 1.4). There was no relation with duration of use, age at first use, or use before first birth. The OR was significantly increased for current OC users (OR=1.5, 95% 1.0 to 2.1), but declined with increasing time since stopping (OR=1.1 for >10 years since stopping). The association was stronger for papillary cancers (OR=1.6 for current users) than for other histologic types. No significant heterogeneity was observed across studies or geographic areas. Eight studies had data on HRT, for a total of 1,305 cases and 2,300 controls: 110 (8%) cases and 205 (9%) controls reported ever using HRT (OR=0.8; 95% CI 0.6 to 1.1). The ORs were 1.6 (95% to 0.9 to 2.9) for use of fertility drugs, and 1.5 (95% CI 1.1 to 2.1) for lactation suppression treatment.Conclusions: The studies considered in these analyses include most of the epidemiological data on the role of exogenous hormone use in the etiology of thyroid cancer, and they provide reassuring evidence on the absence of an association of practical relevance. The moderate excess risk in current OC users, if not due to increased surveillance for thyroid masses among OC users, is similar to that described for breast cancer, and would imply a role of female hormones on thyroid cancer promotion. There was no indication of increased thyroid cancer risk 10 or more years after discontinuing OC use.

Child physical abuse and concurrence of other types of child abuse in Sweden—Associations with health and risk behaviors

OBJECTIVE To examine the associations between child physical abuse executed by a parent or caretaker and self-rated health problems/risk-taking behaviors among teenagers. Further to evaluate concurrence of other types of abuse and how these alone and in addition to child physical abuse were associated with bad health status and risk-taking behaviors. METHODS A population-based survey was carried out in 2008 among all the pupils in 2 different grades (15 respectively 17 years old) in Södermanland County, Sweden (n=7,262). The response rate was 81.8%. The pupils were asked among other things about their exposure to child physical abuse, exposure to parental intimate violence, bullying, and exposure to being forced to engage in sexual acts. Adjusted analyses were conducted to estimate associations between exposure and ill-health/risk-taking behaviors. RESULTS Child physical abuse was associated with poor health and risk-taking behaviors with adjusted odds ratios (OR) ranging from 1.6 to 6.2. The associations were stronger when the pupils reported repeated abuse with OR ranging from 2.0 to 13.2. Also experiencing parental intimate partner violence, bullying and being forced to engage in sexual acts was associated with poor health and risk-taking behaviors with the same graded relationship to repeated abuse. Finally there was a cumulative effect of multiple abuse in the form of being exposed to child physical abuse plus other types of abuse and the associations increased with the number of concurrent abuse. CONCLUSIONS This study provides strong indications that child abuse is a serious public health problem based on the clear links seen between abuse and poor health and behavioral problems. Consistent with other studies showing a graded relationship between experiences of abuse and poor health/risk-taking behaviors our study shows poorer outcomes for repeated and multiple abuse. Thus, our study calls for improvement of methods of comprehensive assessments, interventions and treatment in all settings where professionals meet young people.

Occupations and exposures in the work environment as determinants for rheumatoid arthritis

Background and Aims: Several occupational categories have been associated with rheumatoid arthritis (RA); this study was conducted to further evaluate these associations. Methods: Lifelong occupational history together with exposure experiences were collected through a postal questionnaire answered by 293 incident cases and 1346 population based referents. Occupational determinants were evaluated through stratified and multivariate analyses; pooled analyses with previously gathered data on 422 prevalent cases and 858 referents were also performed. Results: In both materials, significantly increased logistic odds ratios (LORs) were seen for male conductors, freight and transport workers (LOR 17.8, 95% CI 1.5 to 207.8 and LOR 4.7, 95% CI 1.4 to 16.3, respectively), and farmers and farm workers (LOR 2.4, 95% CI 1.1 to 5.2, and LOR 2.2, 95% CI 1.3 to 3.5, respectively). Among women, increased LORs were seen in the separate and the pooled material for printmakers and process engravers (LOR 5.5, 95% CI 0.9 to 32.6, and LOR 3.0, 95% CI 0.9 to 10.3, respectively). Increased risks were seen in both materials for men exposed to asbestos (LOR 2.5, 95% CI 1.0 to 6.8, and LOR 1.6, 95% CI 0.8 to 3.3, respectively), and vibrations (LOR 2.0, 95% CI 0.9 to 4.4, and LOR 2.2, 95% CI 1.3 to 3.8, respectively). The risk for RA increased with increasing duration of exposure to vibrations and mineral dust, respectively. Conclusions: There was evidence of a causal relation between exposures to vibrations and mineral dust and development of RA among men. Occupational factors seem to be aetiologically more important for men, and most occupations at risk involve multiple exposures. Several exposures associated with an increased risk for RA are frequent among farmers, and some of the occupations at risk include exposure to organic dust.

Prevalence and characteristics of child physical abuse in Sweden - findings from a population-based youth survey.

Aim:  To examine prevalence rates of child physical abuse perpetrated by a parent/caretaker, abuse characteristics and the extent of disclosures.