Association of tea and coffee consumption and biliary tract cancer risk: The Biliary Tract Cancers Pooling Project.

BACKGROUND AND AIMS: Tea and coffee are widely consumed beverages worldwide. We evaluated their association with biliary tract cancer (BTC) incidence. APPROACH AND RESULTS: We pooled data from 15 studies in the Biliary Tract Cancers Pooling Project to evaluate associations between tea and coffee consumption and biliary tract cancer development. We categorized participants as nondrinkers (0 cup/day), moderate drinkers (>0 and <3 cups/day), and heavy drinkers (≥3 cups/day). We estimated multivariable HRs and 95% CIs using Cox models. During 29,911,744 person-years of follow-up, 851 gallbladder, 588 intrahepatic bile duct, 753 extrahepatic bile duct, and 458 ampulla of Vater cancer cases were diagnosed. Individuals who drank tea showed a statistically significantly lower incidence rate of gallbladder cancer (GBC) relative to tea nondrinkers (HR=0.77; 95% CI, 0.64-0.91), and intrahepatic bile duct cancer (IHBDC) had an inverse association (HR=0.81; 95% CI, 0.66-1.00). However, no associations were observed for extrahepatic bile duct cancer (EHBDC) or ampulla of Vater cancer (AVC). In contrast, coffee consumption was positively associated with GBC, with a higher incidence rate for individuals consuming more coffee (HR<3 cups/day =1.29; 95% CI, 1.01-1.66; HR≥3 cups/day =1.49; 95% CI, 1.11-1.99, Ptrend=0.01) relative to coffee nondrinkers. However, there was no association between coffee consumption and GBC when restricted to coffee drinkers. There was little evidence of associations between coffee consumption and other biliary tract cancers. CONCLUSIONS: Tea consumption was associated with a lower incidence of GBC and possibly IHBDC. Further research is warranted to replicate the observed positive association between coffee and GBC.

Gestational age at birth and type 1 diabetes in childhood and young adulthood: a nationwide register study in Finland, Norway and Sweden.

AIMS/HYPOTHESIS: Children and adults born preterm have an increased risk of type 1 diabetes. However, there is limited information on risk patterns across the full range of gestational ages, especially after extremely preterm birth (23-27 weeks of gestation). We investigated the risk of type 1 diabetes in childhood and young adulthood across the full range of length of gestation at birth. METHODS: Data were obtained from national registers in Finland, Norway and Sweden. In each country, information on study participants and gestational age was collected from the Medical Birth Registers, information on type 1 diabetes diagnoses was collected from the National Patient Registers, and information on education, emigration and death was collected from the respective national register sources. Individual-level data were linked using unique personal identity codes. The study population included all individuals born alive between 1987 and 2016 to mothers whose country of birth was the respective Nordic country. Individuals were followed until diagnosis of type 1 diabetes, death, emigration or end of follow-up (31 December 2016 in Finland, 31 December 2017 in Norway and Sweden). Gestational age was categorised as extremely preterm (23-27 completed weeks), very preterm (28-31 weeks), moderately preterm (32-33 weeks), late preterm (34-36 weeks), early term (37-38 weeks), full term (39-41 weeks; reference) and post term (42-45 weeks). HRs and 95% CIs from country-specific covariate-adjusted Cox regression models were combined in a meta-analysis using a common-effect inverse-variance model. RESULTS: Among 5,501,276 individuals, 0.2% were born extremely preterm, 0.5% very preterm, 0.7% moderately preterm, 4.2% late preterm, 17.7% early term, 69.9% full term, and 6.7% post term. A type 1 diabetes diagnosis was recorded in 12,326 (0.8%), 6364 (0.5%) and 16,856 (0.7%) individuals at a median age of 8.2, 13.0 and 10.5 years in Finland, Norway and Sweden, respectively. Individuals born late preterm or early term had an increased risk of type 1 diabetes compared with their full-term-born peers (pooled, multiple confounder-adjusted HR 1.12, 95% CI 1.07, 1.18; and 1.15, 95% CI 1.11, 1.18, respectively). However, those born extremely preterm or very preterm had a decreased risk of type 1 diabetes (adjusted HR 0.63, 95% CI 0.45, 0.88; and 0.78, 95% CI 0.67, 0.92, respectively). These associations were similar across all three countries. CONCLUSIONS/INTERPRETATION: Individuals born late preterm and early term have an increased risk of type 1 diabetes while individuals born extremely preterm or very preterm have a decreased risk of type 1 diabetes compared with those born full term.

Female reproductive histories and the risk of chronic obstructive pulmonary disease.

BACKGROUND: Female reproductive factors may influence the development of chronic obstructive pulmonary disease (COPD) through the female hormonal environment, but studies on this topic are limited. This study aimed to assess whether age at menarche, number of children, infertility, miscarriage, stillbirth and age at natural menopause were associated with the risk of COPD. METHODS: Women from three cohorts with data on reproductive factors, COPD and covariates were included. Cause specific Cox regression models were adjusted for birth year, race, educational level, body mass index and pack years of smoking, stratified by asthma, and incorporating interaction between birth year and time. Between cohort differences and within cohort correlations were taken into account. RESULTS: Overall, 2 83 070 women were included and 10 737 (3.8%) developed COPD after a median follow-up of 11 (IQR 10-12) years. Analyses revealed a U shaped association between age at menarche and COPD (≤11 vs 13: HR 1.17, 95% CI 1.11 to 1.23; ≥16 vs 13: HR 1.24, 95% CI 1.21 to 1.27). Women with three or more children (3 vs 2: HR 1.14, 95% CI 1.12 to 1.17; ≥4 vs 2: HR 1.34, 95% CI 1.28 to 1.40), multiple miscarriages (2 vs 0: HR 1.28, 95% CI 1.24 to 1.32; ≥3 vs 0: HR 1.36, 95% CI 1.30 to 1.43) or stillbirth (1 vs 0: HR 1.38, 95% CI 1.25 to 1.53; ≥2 vs 0: HR 1.67, 95% CI 1.32 to 2.10) were at a higher risk of COPD. Among postmenopausal women, earlier age at natural menopause was associated with an increased risk of COPD (<40 vs 50-51: HR 1.69, 95% CI 1.63 to 1.75; 40-44 vs 50-51: HR 1.42, 95% CI 1.38 to 1.47). CONCLUSIONS: Multiple female reproductive factors, including age at menarche, number of children, miscarriage, stillbirth, and age at natural menopause were associated with the risk of COPD.

Preterm delivery and maternal obesity remain common complications in pregnancies with type 1 diabetes-A nationwide study in Sweden.

AIM: A primary goal of obstetric care of women with type 1 diabetes (T1D) is to reduce the risks of preterm birth (PTB). Besides hyperglycaemia, maternal obesity is an important risk factor for PTB in T1D. However, it's unclear if public health efforts decreased risks of maternal obesity and PTB in pregnancies with T1D. We examined time-trends over the last 20 years in the distribution of gestational ages at birth (GA) in offspring of women with T1D in Sweden, and in maternal BMI in the same mothers. METHODS: Population-based cohort study, using data from national registries in Sweden. To capture differences not only in the median values, we used quantile regression models to compare the whole distributions of GA's and early pregnancy BMI between deliveries in 1998-2007 (P1) and 2008-2016 (P2). Multivariable models were adjusted for differences in maternal age, smoking and education between periods 1 and 2. RESULTS: The study included 7639 offspring of women with T1D between 1998 and 2016. The 10% percentile GA, increased with 0.09 days (95% CI: -0.11 to 0.35) between P1 and P2. The 90% percentile for BMI was 1.20 kg/m2 higher (95% CI: 0.57 to 1.83) in P2. Risks of PTB remained stable over time also when adjusting for maternal BMI. CONCLUSION: Despite modern diabetes management, the distribution of GA, and consequently the risk of PTB in T1D, remained unchanged from 1998 to 2016. During the same time, maternal BMI increased, particularly in the already obese.

Association of infertility and recurrent pregnancy loss with the risk of dementia.

Emerging evidence has shown the association between female reproductive histories (e.g., menarche age, parity, premature and early menopause) and the risk of dementia. However, little attention has been given to infertility and pregnancy loss. To examine the associations of infertility, recurrent miscarriages, and stillbirth with the risk of dementia, this study used data from four cohorts in the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events. Women with data on at least one of the reproductive exposures of interest, dementia, and all covariates were included. Histories of infertility, miscarriage, and stillbirth were self-reported. Dementia (including Alzheimer's disease) was identified through surveys, aged care, pharmaceutical, hospital, and death registry data. Cause-specific Cox regression models were used to estimate the hazard ratios of dementia, accounting for well-established risk factors of dementia, study variability, and within-study correlation. Overall, 291,055 women were included at a median (interquartile range) age of 55.0 (47.0-62.0) at baseline. During the median (interquartile range) follow-up period of 13.0 (12.0-14.0) years, 3334 (1.2%) women developed dementia. Compared to women without stillbirth, a history of recurrent stillbirths (≥ 2) was associated with 64% higher risk of dementia (adjusted hazard ratio = 1.64, 95% confidence interval: 1.46-1.85). Compared to women without miscarriage, women with recurrent miscarriages (≥ 3) were at 22% higher risk of dementia (adjusted hazard ratio = 1.22, 95% confidence interval: 1.19-1.25). These findings suggest that recurrent stillbirths is a risk factor for dementia and may need to be considered in risk assessment of dementia in women.

Paternal and maternal psychiatric history and risk of preterm and early term birth: A nationwide study using Swedish registers.

BACKGROUND: Women with psychiatric diagnoses are at increased risk of preterm birth (PTB), with potential life-long impact on offspring health. Less is known about the risk of PTB in offspring of fathers with psychiatric diagnoses, and for couples where both parents were diagnosed. In a nationwide birth cohort, we examined the association between psychiatric history in fathers, mothers, and both parents and gestational age. METHODS AND FINDINGS: We included all infants live-born to Nordic parents in 1997 to 2016 in Sweden. Psychiatric diagnoses were obtained from the National Patient Register. Data on gestational age were retrieved from the Medical Birth Register. Associations between parental psychiatric history and PTB were quantified by relative risk (RR) and two-sided 95% confidence intervals (CIs) from log-binomial regressions, by psychiatric disorders overall and by diagnostic categories. We extended the analysis beyond PTB by calculating risks over the whole distribution of gestational age, including "early term" (37 to 38 weeks). Among the 1,488,920 infants born throughout the study period, 1,268,507 were born to parents without a psychiatric diagnosis, of whom 73,094 (5.8%) were born preterm. 4,597 of 73,500 (6.3%) infants were born preterm to fathers with a psychiatric diagnosis, 8,917 of 122,611 (7.3%) infants were born preterm to mothers with a pscyhiatric diagnosis, and 2,026 of 24,302 (8.3%) infants were born preterm to both parents with a pscyhiatric diagnosis. We observed a shift towards earlier gestational age in offspring of parents with psychiatric history. The risks of PTB associated with paternal and maternal psychiatric diagnoses were similar for different psychiatric disorders. The risks for PTB were estimated at RR 1.12 (95% CI [1.08, 1.15] p < 0.001) for paternal diagnoses, at RR 1.31 (95% CI [1.28, 1.34] p < 0.001) for maternal diagnoses, and at RR 1.52 (95% CI [1.46, 1.59] p < 0.001) when both parents were diagnosed with any psychiatric disorder, compared to when neither parent had a psychiatric diagnosis. Stress-related disorders were associated with the highest risks of PTB with corresponding RRs estimated at 1.23 (95% CI [1.16, 1.31] p < 0.001) for a psychiatry history in fathers, at 1.47 (95% CI [1.42, 1.53] p < 0.001) for mothers, and at 1.90 (95% CI [1.64, 2.20] p < 0.001) for both parents. The risks for early term were similar to PTB. Co-occurring diagnoses from different diagnostic categories increased risk; for fathers: RR 1.10 (95% CI [1.07, 1.13] p < 0.001), 1.15 (95% CI [1.09, 1.21] p < 0.001), and 1.33 (95% CI [1.23, 1.43] p < 0.001), for diagnoses in 1, 2, and ≥3 categories; for mothers: RR 1.25 (95% CI [1.22, 1.28] p < 0.001), 1.39 (95% CI [1.34, 1.44] p < 0.001) and 1.65 (95% CI [1.56, 1.74] p < 0.001). Despite the large sample size, statistical precision was limited in subgroups, mainly where both parents had specific psychiatric subtypes. Pathophysiology and genetics underlying different psychiatric diagnoses can be heterogeneous. CONCLUSIONS: Paternal and maternal psychiatric history were associated with a shift to earlier gestational age and increased risk of births before full term. The risk consistently increased when fathers had a positive history of different psychiatric disorders, increased further when mothers were diagnosed and was highest when both parents were diagnosed.

Hypertensive conditions of pregnancy, preterm birth, and premenopausal breast cancer risk: a premenopausal breast cancer collaborative group analysis.

PURPOSE: Women with preeclampsia are more likely to deliver preterm. Reports of inverse associations between preeclampsia and breast cancer risk, and positive associations between preterm birth and breast cancer risk are difficult to reconcile. We investigated the co-occurrence of preeclampsia/gestational hypertension with preterm birth and breast cancer risk using data from the Premenopausal Breast Cancer Collaborative Group. METHODS: Across 6 cohorts, 3096 premenopausal breast cancers were diagnosed among 184,866 parous women. We estimated multivariable hazard ratios (HR) and 95% confidence intervals (CI) for premenopausal breast cancer risk using Cox proportional hazards regression. RESULTS: Overall, preterm birth was not associated (HR 1.02, 95% CI 0.92, 1.14), and preeclampsia was inversely associated (HR 0.86, 95% CI 0.76, 0.99), with premenopausal breast cancer risk. In stratified analyses using data from 3 cohorts, preterm birth associations with breast cancer risk were modified by hypertensive conditions in first pregnancies (P-interaction = 0.09). Preterm birth was positively associated with premenopausal breast cancer in strata of women with preeclampsia or gestational hypertension (HR 1.52, 95% CI: 1.06, 2.18), but not among women with normotensive pregnancy (HR = 1.09, 95% CI: 0.93, 1.28). When stratified by preterm birth, the inverse association with preeclampsia was more apparent, but not statistically different (P-interaction = 0.2), among women who did not deliver preterm (HR = 0.82, 95% CI 0.68, 1.00) than those who did (HR = 1.07, 95% CI 0.73, 1.56). CONCLUSION: Findings support an overall inverse association of preeclampsia history with premenopausal breast cancer risk. Estimates for preterm birth and breast cancer may vary according to other conditions of pregnancy.

Direct additive genetics and maternal effect contribute to the risk of Tourette disorder.

BACKGROUND: Risk for Tourette disorder, and chronic motor or vocal tic disorders (referenced here inclusively as CTD), arise from a combination of genetic and environmental factors. While multiple studies have demonstrated the importance of direct additive genetic variation for CTD risk, little is known about the role of cross-generational transmission of genetic risk, such as maternal effect, which is not transmitted via the inherited parental genomes. Here, we partition sources of variation on CTD risk into direct additive genetic effect (narrow-sense heritability) and maternal effect. METHODS: The study population consists of 2 522 677 individuals from the Swedish Medical Birth Register, who were born in Sweden between 1 January 1973 and 31 December 2000, and followed for a diagnosis of CTD through 31 December, 2013. We used generalised linear mixed models to partition the liability of CTD into: direct additive genetic effect, genetic maternal effect and environmental maternal effect. RESULTS: We identified 6227 (0.2%) individuals in the birth cohort with a CTD diagnosis. A study of half-siblings showed that maternal half-siblings had twice higher risk of developing a CTD compared with paternal ones. We estimated 60.7% direct additive genetic effect (95% credible interval, 58.5% to 62.4%), 4.8% genetic maternal effect (95% credible interval, 4.4% to 5.1%) and 0.5% environmental maternal effect (95% credible interval, 0.2% to 7%). CONCLUSIONS: Our results demonstrate genetic maternal effect contributes to the risk of CTD. Failure to account for maternal effect results in an incomplete understanding of the genetic risk architecture of CTD, as the risk for CTD is impacted by maternal effect which is above and beyond the risk from transmitted genetic effect.

Familial clustering of psychiatric disorders and low IQ.

BACKGROUND: Although the ICD and DSM differentiate between different psychiatric disorders, these often share symptoms, risk factors, and treatments. This was a population-based, case-control, sibling study examining familial clustering of all psychiatric disorders and low IQ, using data from the Israel Draft-Board Registry on all Jewish adolescents assessed between 1998 and 2014. METHODS: We identified all cases with autism spectrum disorder (ASD, N = 2128), severe intellectual disability (ID, N = 9572), attention-deficit hyperactive disorder (ADHD) (N = 3272), psychotic (N = 7902), mood (N = 9704), anxiety (N = 10 606), personality (N = 24 816), or substance/alcohol abuse (N = 791) disorders, and low IQ (⩾2 SDs below the population mean, N = 31 186). Non-CNS control disorders were adolescents with Type-1 diabetes (N = 2427), hernia (N = 29 558) or hematological malignancies (N = 931). Each case was matched with 10 age-matched controls selected at random from the Draft-Board Registry, with replacement, and for each case and matched controls, we ascertained all full siblings. The main outcome measure was the relative recurrence risk (RRR) of the sibling of a case having the same (within-disorder RRR) or a different (across-disorder RRR) disorder. RESULTS: Within-disorder RRRs were increased for all diagnostic categories, ranging from 11.53 [95% confidence interval (CI): 9.23-14.40] for ASD to 2.93 (95% CI: 2.80-3.07) for personality disorders. The median across-disorder RRR between any pair of psychiatric disorders was 2.16 (95% CI: 1.45-2.43); the median RRR between low IQ and any psychiatric disorder was 1.37 (95% CI: 0.93-1.98). There was no consistent increase in across-disorder RRRs between the non-CNS disorders and psychiatric disorders and/or low IQ. CONCLUSION: These large population-based study findings suggest shared etiologies among most psychiatric disorders, and low IQ.

Maternal rheumatoid arthritis and risk of autism in the offspring.

BACKGROUND: Maternal Rheumatoid Arthritis (RA) is suggested to increase the risk of Autism Spectrum Disorder (ASD) in the offspring, mainly through inflammation/autoimmunity, but the association is unclear. A prospective population-based cohort study was implemented to examine the association between maternal RA and offspring ASD. METHODS: We included all children born alive in Sweden from 1995 to 2015, followed up through 2017. Diagnoses of ASD and RA were clinically ascertained from National Patient Register. We quantified the association by hazard ratios (HR) and two-sided 95% confidence intervals (CI), from Cox regression after detailed adjustment for potential confounders. We examined RA serostatus, etiological subgroups and the timing of exposure. To closer examine the underlying mechanism for the association, we included a negative control group for RA, arthralgia, with similar symptomology as RA but free from inflammation/autoimmunity. RESULTS: Of 3629 children born to mothers with RA, 70 (1.94%) were diagnosed with ASD, compared to 28 892 (1.92%) of 1 503 908 children born to mothers without RA. Maternal RA before delivery was associated with an increased risk of offspring ASD (HR = 1.43, 95% CI 1.11-1.84), especially for seronegative RA (HR = 1.61, 95% CI 1.12-2.30). No similar association was observed for paternal RA, maternal sisters with RA, or RA diagnosed after delivery. Maternal arthralgia displayed as high risks for offspring ASD as did maternal RA (HR = 1.41, 95% CI 1.24-1.60). CONCLUSIONS: In Sweden, maternal RA before delivery was associated with an increased risk of offspring ASD. The comparable association between maternal arthralgia and ASD risk suggests other pathways of risk than autoimmunity/inflammation, acting jointly or independently of RA.

Dietary omega-3 fatty acids and endometrial cancer risk in the Epidemiology of Endometrial Cancer Consortium: An individual-participant meta-analysis.

BACKGROUND: Limited data from prospective studies suggest that higher dietary intake of long-chain omega-3 polyunsaturated fatty acids (LCn3PUFA), which hold anti-inflammatory properties, may reduce endometrial cancer risk; particularly among certain subgroups characterized by body mass and tumor pathology. MATERIALS AND METHODS: Data from 12 prospective cohort studies participating in the Epidemiology of Endometrial Cancer Consortium were harmonized as nested case-control studies, including 7268 endometrial cancer cases and 26,133 controls. Habitual diet was assessed by food frequency questionnaire, from which fatty acid intakes were estimated. Two-stage individual-participant data mixed effects meta-analysis estimated adjusted odds ratios (OR) and 95% confidence intervals (CI) through logistic regression for associations between study-specific energy-adjusted quartiles of LCn3PUFA and endometrial cancer risk. RESULTS: Women with the highest versus lowest estimated dietary intakes of docosahexaenoic acid, the most abundant LCn3PUFA in diet, had a 9% increased endometrial cancer risk (Quartile 4 vs. Quartile 1: OR 1.09, 95% CI: 1.01-1.19; P trend = 0.04). Similar elevated risks were observed for the summary measure of total LCn3PUFA (OR 1.07, 95% CI: 0.99-1.16; P trend = 0.06). Stratified by body mass index, higher intakes of LCn3PUFA were associated with 12-19% increased endometrial cancer risk among overweight/obese women and no increased risk among normal-weight women. Higher associations appeared restricted to White women. The results did not differ by cancer grade. CONCLUSION: Higher dietary intakes of LCn3PUFA are unlikely to reduce endometrial cancer incidence; rather, they may be associated with small to moderate increases in risk in some subgroups of women, particularly overweight/obese women.

Is there a link between infertility, miscarriage, stillbirth, and premature or early menopause? Results from pooled analyses of 9 cohort studies.

BACKGROUND: Some reproductive factors (such as age at menarche and parity) have been shown to be associated with age at natural menopause, but there has been little quantitative analysis of the association between infertility, miscarriage, stillbirth, and premature (<40 years) or early menopause (40-44 years). In addition, it has been unknown whether the association differs between Asian and non-Asian women, although the age at natural menopause is younger among Asian women. OBJECTIVE: This study aimed to investigate the association of infertility, miscarriage, and stillbirth with age at natural menopause, and whether the association differed by race (Asian and non-Asian). STUDY DESIGN: This was a pooled individual participant data analysis from 9 observational studies contributing to the InterLACE consortium. Naturally postmenopausal women with data on at least 1 of the reproductive factors (ie, infertility, miscarriage, and stillbirth), age at menopause, and confounders (ie, race, education level, age at menarche, body mass index, and smoking status) were included. A multinomial logistic regression model was used to estimate relative risk ratios and 95% confidence intervals for the association of infertility, miscarriage, and stillbirth with premature or early menopause, adjusting for confounders. Between-study difference and within-study correlation were taken into account by including study as a fixed effect and indicating study as a cluster variable. We also examined the association with number of miscarriages (0, 1, 2, ≥3) and stillbirths (0, 1, ≥2), and tested whether the strength of association differed between Asian and non-Asian women. RESULTS: A total of 303,594 postmenopausal women were included. Their median age at natural menopause was 50.0 years (interquartile range, 47.0-52.0). The percentages of women with premature and early menopause were 2.1% and 8.4%, respectively. The relative risk ratios (95% confidence intervals) of premature and early menopause were 2.72 (1.77-4.17) and 1.42 (1.15-1.74) for women with infertility; 1.31 (1.08-1.59) and 1.37 (1.14-1.65) for women with recurrent miscarriages; and 1.54 (1.52-1.56) and 1.39 (1.35-1.43) for women with recurrent stillbirths. Asian women with infertility, recurrent miscarriages (≥3), or recurrent stillbirths (≥2) had higher risk of premature and early menopause compared with non-Asian women with the same reproductive history. CONCLUSION: Histories of infertility and recurrent miscarriages and stillbirths were associated with higher risk of premature and early menopause, and the associations differed by race, with stronger associations for Asian women with such reproductive history.

Gestational age and cancer risk up to young adulthood in Swedish population born 1974 to 2013: A population-based cohort study.

We examined the association between gestational age and risk of any primary cancer and observed whether the risk patterns differed by sex, birth weight for gestational age categories, cancer site and age of onset. All people live-born in Sweden 1974 to 2013 were prospectively followed up from birth until 2016 using national registers. Gestational age was extracted from the Medical Birth Register and primary malignant cancer diagnoses were from the Swedish cancer register. The adjusted hazard ratios (aHR) for any primary cancer according to weekly gestational age and gestational age categories were determined using cox proportional hazards models adjusted for birth year and parental age. The study included 3 137 691 people; 180 363 (5.8%) born preterm and 254 790 (8.1%) born postterm. They were followed up for 71 691 112 person-years, to a maximum of 43 years and recorded 22 604 new cancers. Although aHRs for the predefined GA categories were only increased for moderate to late preterm delivery (aHR 1.07, 95% CI 1.01-1.14), gestational week-specific aHRs were increased for gestational weeks 30 to 35, with greatest aHR observed for 31 weeks (aHR 1.18, 95% CI 1.05-1.32). Increased cancer risk related to shorter gestational ages were observed particularly for women, those born small for gestational age, childhood cancers and for cancers originating at certain sites (eg, testicular and liver cancer). We provide the first evidence that those born between 30 and 35 weeks gestation may have increased risk of any primary malignant cancer up to young adulthood. Additionally, increasing gestational ages may reduce the risk of testicular and liver cancer.

Psychometric properties of the Swedish translation of the Obsessive-Compulsive Inventory-Revised and the population characteristics of the symptom dimensions of OCD.

PURPOSE: EGOS is an epidemiological obsessive-compulsive disorder (OCD) cohort in Sweden. Individuals contributed DNA for genotyping and sequencing and completed a Swedish translation of the Obsessive-Compulsive Inventory-Revised (OCI-R), a self-report questionnaire for assessing the severity of OCD. This study aimed first to evaluate the psychometric properties of the Swedish translation of the OCI-R and then shed light on the frequency, severity, and symptom dimensions of OCD comorbid with other psychiatric disorders. METHODS: OCI-R data were available for 1010 individuals diagnosed with OCD, and 124 individuals diagnosed with chronic tic disorders without OCD used as a comparison group. We first performed a confirmatory factor analysis to confirm the six-factor structure of OCI-R. Then, we estimated Cronbach's α coefficient and the generalizability coefficient to evaluate the internal consistency of the OCI-R. We linked the data from the Swedish national registries to access and analyze psychiatric comorbidities of OCD. RESULTS: The Swedish translation of OCI-R demonstrated internal consistency and clear agreement with the OCI-R six-factor model. The mean total OCI-R score for females was significantly higher than for males. The most comorbid psychiatric condition to OCD were anxiety disorders (13.6%) and major depression (12%). CONCLUSION: The Swedish translation of OCI-R was a valid and reliable measure for assessing the severity of OCD. We observed that individuals with OCD frequently had additional comorbid psychiatric disorders and that the severity of OCD was significantly higher in individuals with at least one additional psychiatric comorbidity as compared to individuals with no psychiatric comorbidity.

Cancer risk in individuals with intellectual disability in Sweden: A population-based cohort study.

BACKGROUND: A knowledge gap exists about the risk of cancer in individuals with intellectual disability (ID). The primary aim of this study was to estimate the cancer risk among individuals with ID compared to individuals without ID. METHODS AND FINDINGS: We conducted a population-based cohort study of all children live-born in Sweden between 1974 and 2013 and whose mothers were born in a Nordic country. All individuals were followed from birth until cancer diagnosis, emigration, death, or 31 December 2016 (up to age 43 years), whichever came first. Incident cancers were identified from the Swedish Cancer Register. We fitted Cox regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) as measures of cancer risk in relation to ID after adjusting for several potential confounders. We analyzed ID by severity, as well as idiopathic ID and syndromic ID separately. We performed a sibling comparison to investigate familial confounding. The study cohort included a total of 3,531,305 individuals, including 27,956 (0.8%) individuals diagnosed with ID. Compared with the reference group (individuals without ID and without a full sibling with ID), individuals with ID were in general more likely to be male. The median follow-up time was 8.9 and 23.0 years for individuals with ID and individuals without ID, respectively. A total of 188 cancer cases were identified among individuals with ID (incidence rate [IR], 62 per 1,000 person-years), and 24,960 among individuals in the reference group (IR, 31 per 1,000 person-years). A statistically significantly increased risk was observed for any cancer (HR 1.57, 95% CI 1.35-1.82; P < 0.001), as well as for several cancer types, including cancers of the esophagus (HR 28.4, 95% CI 6.2-130.6; P < 0.001), stomach (HR 6.1, 95% CI 1.5-24.9; P = 0.013), small intestine (HR 12.0, 95% CI 2.9-50.1; P < 0.001), colon (HR 2.0, 95% CI 1.0-4.1; P = 0.045), pancreas (HR 6.0, 95% CI 1.5-24.8; P = 0.013), uterus (HR 11.7, 95% CI 1.5-90.7; P = 0.019), kidney (HR 4.4, 95% CI 2.0-9.8; P < 0.001), central nervous system (HR 2.7, 95% CI 2.0-3.7; P < 0.001), and other or unspecified sites (HR 4.8, 95% CI 1.8-12.9; P = 0.002), as well as acute lymphoid leukemia (HR 2.4, 95% CI 1.3-4.4; P = 0.003) and acute myeloid leukemia (HR 3.0, 95% CI 1.4-6.4; P = 0.004). Cancer risk was not modified by ID severity or sex but was higher for syndromic ID. The sibling comparison showed little support for familial confounding. The main study limitations were the limited statistical power for the analyses of specific cancer types, and the potential for underestimation of the studied associations (e.g., due to potential underdetection or delayed diagnosis of cancer among individuals with ID). CONCLUSIONS: In this study, we found that individuals with ID showed an increased risk of any cancer, as well as of several specific cancer types. These findings suggest that extended surveillance and early intervention for cancer among individuals with ID are warranted.

Mediterranean Dietary Pattern at Middle Age and Risk of Parkinson's Disease: A Swedish Cohort Study.

BACKGROUND: The Mediterranean diet has been proposed to protect against neurodegeneration. OBJECTIVES: The aim of this study was to assess the association of adherence to Mediterranean dietary pattern (MDP) at middle age with risk for Parkinson's disease (PD) later in life. METHOD: In a population-based cohort of >47,000 Swedish women, information on diet was collected through a food frequency questionnaire during 1991-1992, from which adherence to MDP was calculated. We also collected detailed information on potential confounders. Clinical diagnosis of PD was ascertained from the Swedish National Patient Register through 2012. RESULTS: We observed an inverse association between adherence to MDP and PD, multivariable hazard ratio of 0.54 (95% confidence interval: 0.30-0.98), comparing high with low adherence. The association was noted primarily from age 65 years onward. One unit increase in the adherence score was associated with a 29% lower risk for PD at age ≥ 65 years (95% confidence interval: 0.57-0.89). CONCLUSION: Higher adherence to a Mediterranean diet at middle age was associated with lower risk for PD. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Maternal health around pregnancy and autism risk: a diagnosis-wide, population-based study.

BACKGROUND: Many studies have reported an increased risk of autism spectrum disorder (ASD) associated with some maternal diagnoses in pregnancy. However, such associations have not been studied systematically, accounting for comorbidity between maternal disorders. Therefore our aim was to comprehensively test the associations between maternal diagnoses around pregnancy and ASD risk in offspring. METHODS: This exploratory case-cohort study included children born in Israel from 1997 to 2008, and followed up until 2015. We used information on all ICD-9 codes received by their mothers during pregnancy and the preceding year. ASD risk associated with each of those conditions was calculated using Cox proportional hazards regression, adjusted for the confounders (birth year, maternal age, socioeconomic status and number of ICD-9 diagnoses during the exposure period). RESULTS: The analytic sample consisted of 80 187 individuals (1132 cases, 79 055 controls), with 822 unique ICD-9 codes recorded in their mothers. After extensive quality control, 22 maternal diagnoses were nominally significantly associated with offspring ASD, with 16 of those surviving subsequent filtering steps (permutation testing, multiple testing correction, multiple regression). Among those, we recorded an increased risk of ASD associated with metabolic [e.g. hypertension; HR = 2.74 (1.92-3.90), p = 2.43 × 10-8], genitourinary [e.g. non-inflammatory disorders of cervix; HR = 1.88 (1.38-2.57), p = 7.06 × 10-5] and psychiatric [depressive disorder; HR = 2.11 (1.32-3.35), p = 1.70 × 10-3] diagnoses. Meanwhile, mothers of children with ASD were less likely to attend prenatal care appointment [HR = 0.62 (0.54-0.71), p = 1.80 × 10-11]. CONCLUSIONS: Sixteen maternal diagnoses were associated with ASD in the offspring, after rigorous filtering of potential false-positive associations. Replication in other cohorts and further research to understand the mechanisms underlying the observed associations with ASD are warranted.

Mediterranean diet and depression: a population-based cohort study.

BACKGROUND: Depression imposes immense public health burden, demonstrating an urgent need of the identification of modifiable risk factors. Only a few cohort studies have analyzed the association between Mediterranean dietary pattern (MDP) and depression but with mixed results. We examined the impact of MDP on clinically ascertained depression in a large population-based dataset. METHODS: In 1991/92, detailed information on diet, using a food frequency questionnaire, and potential confounding factors (body weight, height, educational attainment, smoking, previous diabetes and hypertension, and physical activity) was collected, in a random sample of 49,261 Swedish women aged 29-49. Adherence to MDP was calculated. Clinical depression was extracted from the National Patient Register. Study participants were followed up through 2012. RESULTS: During an average follow-up of 20.4 years, 1677 incident cases of depression were diagnosed. We observed a lower risk of depression for medium (score 4-5) and high (6-9) adherence to MDP, compared with low (0-3) adherence (Medium: hazard ratio (HR) = 0.90, 95% confidence interval (CI) = 0.81-1.00; High: HR = 0.82, 95%CI = 0.71-0.94). Per unit increase of adherence, the risk of depression was reduced by 5% (HR = 0.95, 95%CI = 0.92-0.98). The association became stronger when restricting to severe form of depression (HR = 0.51, 95%CI = 0.33-0.76). The HRs were higher from age 50 onward both over the first and the second 10-year follow-up period, compared with before age 50, indicating stronger association with increasing age. Results remained after extensive sensitivity analyses. CONCLUSION: Higher adherence to a Mediterranean diet at middle age was associated with a lower risk of depression later in life among Swedish women.

Lifestyle changes and risk of cancer: experience from the Swedish women's lifestyle and health cohort study.

BACKGROUND: The impact of lifestyle changes on cancer risk is yet to be elucidated. We investigated this issue in the Swedish Women's Lifestyle and Health Cohort Study. MATERIAL AND METHODS: We measured changes by comparing two questionnaires, filled in 1991/92 and 2003. We followed women for cancer from 2003 until 2012. We used Cox regression models to assess the effect of changes in smoking, alcohol consumption, body mass index (BMI), physical activity and a lifestyle score on the risk of lifestyle-related cancer. One point was added to the lifestyle score for each of these: non-smoking, alcohol consumption ≤12 grams/day, BMI <25 kg/m2 and high level of physical activity. RESULTS: We included 29,930 women. From 1991/92 to 2003, median age changed from 40.0 to 51.7 years, alcohol consumption from 2.5 to 4.7 grams/day, BMI from 22.7 to 24.5 kg/m2, proportion of current smokers from 31.0 to 20.6% and women reporting high physical activity from 27.2 to 37.0%. Women who quit smoking had lower risk of smoking-related cancers compared to women who continued (hazard ratio (HR) 0.74, 95% confidence interval (CI) 0.55-1.00). Women who reduced their weight by more than 5%, compared to women with stable weight, had lower risk of breast cancer (HR 0.49, 95% CI 0.31-0.78). Among women with score of 0-2 in 1992/93, those who improved to 3-4 had lower risk of lifestyle-related cancers compared to women who did not (HR 0.81, 95% CI 0.66-0.99). CONCLUSIONS: Healthy lifestyle changes, particularly smoking cessation and weight reduction, were associated with a decreased risk of cancer.

Maternal Influenza A(H1N1) Immunization During Pregnancy and Risk for Autism Spectrum Disorder in Offspring : A Cohort Study.

BACKGROUND: There are concerns that influenza vaccine exposure during pregnancy may be associated with increased risk for autism spectrum disorder (ASD). OBJECTIVE: To examine the risk for ASD in offspring of mothers who were vaccinated against influenza A(H1N1)pdm09 ("swine flu") during pregnancy. DESIGN: Population-based cohort study using nationwide registers. SETTING: Seven health care regions in Sweden. PARTICIPANTS: Live births between October 2009 and September 2010, with follow-up through December 2016. In total, 39 726 infants were prenatally exposed to H1N1 vaccine (13 845 during the first trimester) and 29 293 infants were unexposed. MEASUREMENTS: Cox regression was used to estimate hazard ratios (HRs) for the primary outcome, ASD, before and after adjustment for potential confounders. The secondary outcome was autistic disorder (AD). RESULTS: Mean follow-up was 6.7 years in both unexposed and exposed children. During follow-up, 394 (1.0%) vaccine-exposed and 330 (1.1%) unexposed children had a diagnosis of ASD. In adjusted analyses, prenatal exposure to H1N1 vaccination was not associated with a later diagnosis of ASD (adjusted HR [aHR], 0.95 [95% CI, 0.81 to 1.12]) or AD (aHR, 0.96 [CI, 0.80 to 1.16]). The 6-year standardized cumulative incidence difference between the unexposed and exposed children was 0.04% (CI, -0.09% to 0.17%) for ASD and 0.02% (CI, -0.09% to 0.14%) for AD. Restricting the analysis to vaccination in the first trimester of pregnancy did not influence risk estimates (aHR, 0.92 [CI, 0.74 to 1.16] for ASD and 0.91 [CI, 0.70 to 1.18] for AD). LIMITATION: Data on H1N1 influenza infection are lacking. CONCLUSION: This large cohort study found no association between maternal H1N1 vaccination during pregnancy and risk for ASD in the offspring. PRIMARY FUNDING SOURCE: Swedish Research Council.