Gallstones, Body Mass Index, C-Reactive Protein, and Gallbladder Cancer: Mendelian Randomization Analysis of Chilean and European Genotype Data.

BACKGROUND AND AIMS: Gallbladder cancer (GBC) is a neglected disease with substantial geographical variability: Chile shows the highest incidence worldwide, while GBC is relatively rare in Europe. Here, we investigate the causal effects of risk factors considered in current GBC prevention programs as well as C-reactive protein (CRP) level as a marker of chronic inflammation. APPROACH AND RESULTS: We applied two-sample Mendelian randomization (MR) using publicly available data and our own data from a retrospective Chilean and a prospective European study. Causality was assessed by inverse variance weighted (IVW), MR-Egger regression, and weighted median estimates complemented with sensitivity analyses on potential heterogeneity and pleiotropy, two-step MR, and mediation analysis. We found evidence for a causal effect of gallstone disease on GBC risk in Chileans (P = 9 × 10-5 ) and Europeans (P = 9 × 10-5 ). A genetically elevated body mass index (BMI) increased GBC risk in Chileans (P = 0.03), while higher CRP concentrations increased GBC risk in Europeans (P = 4.1 × 10-6 ). European results suggest causal effects of BMI on gallstone disease (P = 0.008); public Chilean data were not, however, available to enable assessment of the mediation effects among causal GBC risk factors. CONCLUSIONS: Two risk factors considered in the current Chilean program for GBC prevention are causally linked to GBC risk: gallstones and BMI. For Europeans, BMI showed a causal effect on gallstone risk, which was itself causally linked to GBC risk.

ABCB1/4 gallbladder cancer risk variants identified in India also show strong effects in Chileans.

BACKGROUND: The first large-scale genome-wide association study of gallbladder cancer (GBC) recently identified and validated three susceptibility variants in the ABCB1 and ABCB4 genes for individuals of Indian descent. We investigated whether these variants were also associated with GBC risk in Chileans, who show the highest incidence of GBC worldwide, and in Europeans with a low GBC incidence. METHODS: This population-based study analysed genotype data from retrospective Chilean case-control (255 cases, 2042 controls) and prospective European cohort (108 cases, 181 controls) samples consistently with the original publication. RESULTS: Our results confirmed the reported associations for Chileans with similar risk effects. Particularly strong associations (per-allele odds ratios close to 2) were observed for Chileans with high Native American (=Mapuche) ancestry. No associations were noticed for Europeans, but the statistical power was low. CONCLUSION: Taking full advantage of genetic and ethnic differences in GBC risk may improve the efficiency of current prevention programs.

Statin use and all-cause mortality in people living with HIV: a systematic review and meta-analysis.

BACKGROUND: It is unknown whether statin use among people living with HIV results in a reduction in all-cause mortality. We aimed to evaluate the effect of statin use on all-cause mortality among people living with HIV. METHODS: We conducted comprehensive literature searches of Medline, Embase, CINAHL, the Cochrane Library, and cross-references up to April 2018. We included randomised, quasi-randomised trials and prospective cohort studies that examined the association between statin use and cardio-protective and mortality outcomes among people living with HIV. Two reviewers independently abstracted the data. Hazard ratios (HRs) were pooled using empirical Bayesian random-effect meta-analysis. A number of sensitivity analyses were conducted. RESULTS: We included seven studies with a total of 35,708 participants. The percentage of participants on statins across the studies ranged from 8 to 35%. Where reported, the percentage of participants with hypertension ranged from 14 to 35% and 7 to 10% had been diagnosed with diabetes mellitus. Statin use was associated with a 33% reduction in all-cause mortality (pooled HR = 0.67, 95% Credible Interval 0.39 to 0.96). The probability that statin use conferred a moderate mortality benefit (i.e. decreased risk of mortality of at least 25%, HR ≤ 0.75) was 71.5%. Down-weighting and excluding the lower quality studies resulted in a more conservative estimate of the pooled HR. CONCLUSION: Statin use appears to confer moderate mortality benefits in people living with HIV.

Breast cancer diagnosis and mortality by tumor stage and migration background in a nationwide cohort study in Sweden.

INTRODUCTION: Survival in breast cancer patients has steadily increased over the years, but with considerable disparities between individuals with different migration background and social position. We explored differences in diagnosis and all-cause mortality in breast cancer patients by stage of disease at the time of diagnosis and by country of birth, while considering the effect of comorbidity, regional and socio-demographic factors. METHODS: We used Swedish national registers to follow a cohort of 35,268 patients (4232 foreign-born) with breast cancer between 2004 and 2009 in Sweden. We estimated relative risk ratio (RRR) for diagnosis, hazard ratio (HR) for all-cause mortality and relative excess rate (RER) for breast cancer mortality using multinomial logistic regression models, multivariable Cox proportional hazard, and Poisson regression, respectively. RESULTS: We observed 4178 deaths due to any causes. Among them 418 women were born abroad. Foreign-born patients were on average 3 years younger at the time of breast cancer diagnosis and had higher risk of stage II tumors compared with Sweden-born women (RRR = 1.09, 95% CI 1.00-1.19). Risk of dying was 20% higher in foreign-born compared with Sweden-born breast cancer patients, if the tumor was diagnosed at stages III-IV after adjustment for age at diagnosis, education, county of residence and Charlson's comorbidity index (HR = 1.20, 95% CI 0.95-1.51 and RER = 1.21, 95% CI 0.95-1.55). CONCLUSIONS: The worse prognosis in foreign-born patients with advanced tumors compared with Sweden-born patients is not explained by educational level or comorbidity. The reasons behind the observed disparities should be further studied.

Influence of socioeconomic position and gender on current cigarette smoking among people living with HIV in sub-Saharan Africa: disentangling context from composition.

BACKGROUND: Smoking is still gaining ground in Sub-Saharan Africa, especially among socially disadvantaged groups. People living with HIV represent a subgroup with a significantly elevated prevalence of cigarette smoking. The objective of the study was to examine the influence of individual-, neighbourhood- and country-level socioeconomic position on current cigarette smoking among people living with HIV in Sub-Saharan Africa. METHODS: We applied multivariable multilevel logistic regression analysis on Demographic and Health Survey data collected between 2003 and 2012 in sub-Saharan Africa. We identified 31,270 individual living with HIV (Level 1) nested within 7,054 neighbourhoods (Level 2) from 19 countries (Level 3). RESULTS: After adjustment for individual-, neighbourhood- and country-level factors, respondents, the following significant independent risk factors for increasing odds of being a current cigarette smokers among people living with HIV: male gender (odds ratio [OR] = 62.49; 95 % credible interval [CrI] 45.93 to 78.28), from the poorer households (OR = 1.62, 95 % CrI 1.38 to 1.90); living in urban areas (OR = 1.24, 95 % CrI 1.09 to 1.41), from neighbourhoods with low poverty rate (OR = 1.25, 95 % CrI 1.09 to 1.43), illiteracy rate (OR = 1.28, 95 % CrI 1.14 to 1.42), low unemployment rate (OR = 1.11, 95 % crI 1.01 to 1.43); and from countries with low socio-economic deprivation (OR = 1.53, 95 CrI 1.08 to 1.96). About 3.4 % and 39.4 % variation in cigarette smoking behaviour among people living with HIV is conditioned by differences between neighbourhoods and countries. CONCLUSIONS: Gender, education and socioeconomic context are independently associated with current cigarette smoking among people living with HIV in sub-Saharan Africa.

Heterozygosis deficit of polymorphic markers linked to the ß-globin gene cluster region in the Iranian population.

OBJECTIVES: Iran is considered as one of the high-prevalence areas for ß-thalassemia with a rate of about 10% carrier frequency. Molecular diagnosis of the disease is performed both by direct sequencing and indirectly by the use of polymorphic markers present in the beta globin gene cluster. However, to date there is no reliable information on the application of the markers in the Iranian population. Here we report the results of an extended molecular analysis of five RFLP markers, XmnI, HindIIIA, HindIIIG, RsaI and HinfI, located within the ß-globin gene cluster region in four subpopulations of Iran. MATERIALS AND METHODS: A total of 552 blood samples taken from the Iranian subpopulations including Isfahan, Chaharmahal-O-Bakhtiari, Khuzestan and Hormozgan were genotyped using PCR-RFLP and sequencing. The allele frequency, the expected and observed heterozygosity, and Shannon's information index (I) of these markers were calculated. RESULTS: Distribution of the allele frequencies for XmnI, HindIIIA, HindIIIG, RsaI and HinfI polymorphic markers did not differ significantly among the subpopulations examined. Overall observed heterozygosity ranged from 0.1706 for HindIIIA to 0.4484 for RsaI. The Shannon index was <1 for all the polymorphic markers in the populations studied. The data indicated that heterozygosity of these markers was low in the Iranian population. CONCLUSION: The results suggested that genotyping of these markers is not informative enough once used as single markers for prenatal diagnosis and carrier detection of ß-thalassemia in the Iranian population. However, haplotyping of these markers may provide more useful data in linkage analysis and prenatal diagnosis as well as carrier detections for ß-thalassemia in Iranians.

Trends in mortality after cancer diagnosis: A nationwide cohort study over 45 years of follow-up in Sweden by country of birth.

BACKGROUND: Survival has steadily improved for major cancer types in most parts of the world. We compared all-cause mortality between foreign-born and Sweden-born residents of Sweden who were diagnosed with cancer of the colon, lung, stomach, prostate, breast, cervix, and all site. METHODS: We used Swedish national vital status and health registers to follow a cohort of 1,556,108 patients 45 years of age and older diagnosed with cancer between 1961 and 2009 in Sweden. Among them, 109,915 were born abroad. We estimated hazard ratios (HR) and 95% confidence interval (CI) using multivariable Cox proportional hazard models. RESULTS: We identified 604,035 and 540,138 deaths among men and women, respectively. Among them 33,595 men and 34,174 women were born abroad. At the time of diagnosis, patients born abroad were on average 4 years younger than patients born in Sweden. All-cause mortality was generally lower in the former than in the latter group of patients before 1990 but higher after 2000. The mortality trend was similar for prostate and breast cancer. CONCLUSIONS: Whilst national policy in Sweden aims at achieving equal access to health care, the mortality trend observed among cancer patients born in Sweden was different from that observed among patients born elsewhere. Mortality after diagnosis of major types of cancer has worsened among foreign-born after the year 2000. The possible determinants of disparities need be identified and investigated.

Maternal overweight and obesity are associated with increased risk of type 1 diabetes in offspring of parents without diabetes regardless of ethnicity.

AIMS/HYPOTHESIS: The incidence of type 1 diabetes in children is increasing in Sweden, as is the prevalence of maternal overweight/obesity. Therefore, the aim of this study was to investigate if maternal overweight/obesity increases the risk of type 1 diabetes in offspring of parents with and without diabetes, and of different ethnicities. METHODS: The study cohort comprised 1,263,358 children, born in Sweden between 1992 and 2004. Children were followed from birth until diagnosis of type 1 diabetes, emigration, death or end of follow-up in 2009, whichever occurred first. First trimester maternal BMI was calculated (kg/m(2)). Poisson regression was used to calculate incidence rate ratios (IRRs) with 95% CI for type 1 diabetes in the offspring. RESULTS: The risk of type 1 diabetes was increased in offspring of parents with any type of diabetes regardless of parental ethnicity. High first trimester maternal BMI was associated with increased risk of type 1 diabetes only in offspring of parents without diabetes (IRR 1.33 [95% CI 1.20, 1.48]). CONCLUSIONS/INTERPRETATION: Increasing incidence of type 1 diabetes in children with non-diabetic parents may partly be explained by increasing prevalence of maternal overweight/obesity.

Differences in undergoing cardiac procedures within three months after first myocardial infarction by country of birth in women and men: a Swedish national cohort study.

OBJECTIVE: To examine the relationship between country of birth and the utilization of coronary angiography, percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) after a first-time myocardial infarction (MI). DESIGN, SETTING AND PATIENTS: 117,494 MI patients of all ages who were admitted to coronary care units between 2001 and 2009 in Sweden were followed-up for three months after admission. MAIN OUTCOME MEASURES: Undergoing coronary angiography, PCI or CABG after first-time MI. RESULTS: proportion of patients undergoing angiography and PCI increased whereas proportion of patients undergoing CABG also delay time for all three procedures decreased over the study period. The proportion of women undergoing any of the three procedures was markedly lower and delay time longer than those of men regardless of study period and migration background. Overall foreign-born first MI patients had higher rate of angiography (HR = 1.30, 95% CI: 1.27-1.33), PCI (HR = 1.27, 95% CI: 1.24-1.30) and CABG (HR = 1.21, 95% CI: 1.15-1.28) compared with Sweden born first MI patients. After controlling for potential confounding factors in multivariable models, the overall differences vanished for angiography and reduced markedly for PCI and CABG. However, multivariable stratified analysis by specific country of birth yielded higher rate of angiography among men born in Uganda (HR = 2.11, 95% CI: 1.00-4.43) and Peru (HR = 1.98, 95% CI: 1.07-3.68) and lower rate among men born in Croatia (HR = 0.71, 95% CI: 0.52-0.99) and women born in Thailand (HR = 0.49, 95% CI: 0.35-0.94). PCI adjusted rates were higher among women born in Palestine state (HR = 2.44, 95% CI: 1.15-5.16), Iraq (HR = 1.34, 95% CI: 1.04-1.74) and Poland (HR = 1.21, 95% CI: 1.02-1.44) and rate of CABG was higher among immigrants from some parts of Asia, including men born in Sri Lanka (HR = 3.19, 95% CI: 1.43-7.12), India (HR = 1.95, 95% CI: 1.21-3.14), Vietnam (HR = 2.65, 95% CI: 1.32-5.33), Palestine State (HR = 2.11, 95% CI: 1.06-4.24), and women born in Syria (HR = 2.36, 95% CI: 1.25-4.45), Iraq (HR = 1.74, 95% CI: 1.02-2.94), and Turkey (HR = 1.70, 95% CI: 1.03-2.79). CONCLUSIONS: The observed high rate of CABG for immigrants and particularly those born in some Asian countries was not explained by the potential confounding factors. A more severe coronary disease in this population might explain this high rate but needs further research. Awareness and subsequent intervention at earlier stage of coronary disease among immigrants could prolong their life and reduce the healthcare costs.

Recommended drug use after acute myocardial infarction by migration status and education level.

PURPOSE: The purpose of this study is to investigate the association between migration status and education level and the use of recommended drugs after first acute myocardial infarction (MI). METHODS: A nationwide cohort study performed in Sweden from January 1, 2006 to August 1, 2008. The cohort consisted of 49,037 incident cases of first acute MI. In total, 37,570 individuals survived 180 days after MI, of whom 4782 (12.7%) were foreign-born. We used logistic regression to estimate the odds ratio (OR) with 95% confidence interval (CI) of the association between migration status and education level and prescribed drugs after MI. RESULTS: One third of the patients who were not on any recommended cardiovascular drugs before MI continued to be without recommended cardiovascular drugs after MI. Among those with no cardiovascular drugs before MI, we found no difference in recommended drug use after MI by migration status (OR 1.00, 95% CI 0.89-1.12). Among those with some but not all recommended cardiovascular drugs before MI, foreign-born cases had a slightly non-significant lower use of recommended drugs (OR 0.92, 95% CI 0.83-1.03). Foreign-born patients with low education had a slightly lower use of recommended drug compared to Sweden-born. Women with low education had a lower use of drugs after MI (Sweden born, OR 0.85; 95% CI 0.74-0.96 and foreign born OR 0.51; 95% CI 0.34-0.77). CONCLUSION: There is no apparent difference between foreign-born and Sweden-born in recommended drug use after MI. However, our study reveals an inequity in secondary prevention therapy after myocardial infarction by education level.

The risk of type 1 diabetes among offspring of immigrant mothers in relation to the duration of residency in Sweden.

OBJECTIVE: The risk for type 1 diabetes mellitus (T1DM) is increased in the second compared with the first generation of immigrants in Sweden. We investigated the effect of the mother's duration of stay in Sweden on the risk of T1DM in the offspring. RESEARCH DESIGN AND METHODS: Using data from national registries, we identified all subjects with T1DM among 984,798 children born in Sweden (aged 0-18 years) between 1992 and 2009. Incidence rate ratios (IRRs) with 95% CI were estimated using Poisson regression. RESULTS: Offspring of mothers living in Sweden for up to 5 years had a 22% lower risk of T1DM (adjusted IRR 0.78, 95% CI 0.63-0.96) compared with offspring of mothers living in Sweden for 11 years or more. The risk increased with the mother's duration of stay in Sweden. CONCLUSIONS: Our findings support the hypothesis that immigration to Sweden is associated with exposure to new environmental factors that contribute to the development of T1DM in genetically susceptible individuals.

Body mass index development from birth to early adolescence; effect of perinatal characteristics and maternal migration background in a Swedish cohort.

BACKGROUND: Well documented diversity in risk of developing overweight and obesity between children of immigrant and of native mothers, might be explained by different body mass index (BMI) development trajectories in relation to maternal and perinatal characteristics of offspring. OBJECTIVES: To assess BMI development trajectories among children born to immigrant and to Swedish mothers from birth to adolescence in relation to perinatal characteristics. METHODS: A cohort of 2517 children born in Stockholm during 1994 to 1996 was followed with repeated measurement of height and weight at eleven time points until age 12 years. We estimated changes over time for BMI in relation to maternal and perinatal characteristics of offspring using mixed linear model analysis for repeated measure data. RESULTS: We observed a significant BMI change over time in children and time interaction with maternal migration status (P<0.0001). Estimated BMI over time adjusted for maternal and perinatal characteristics of offspring, showed slower BMI growth before age of 5, followed by an earlier plateau and steeper BMI growth after 5 years among children of immigrant mothers compared with children of Swedish mothers. These differences in BMI growth were more prominent among children with mothers from outside Europe. CONCLUSION: Beside reinforcing early childhood as a crucial period in development of overweight, the observed slower BMI development at early childhood among children of immigrants followed by a steeper increase in BMI compared with children of Swedish mothers is important for further studies and for planning of preventive public health programs.

Effect of parental migration background on childhood nutrition, physical activity, and body mass index.

BACKGROUND: Poor nutrition, lack of physical activity, and obesity in children have important public health implications but, to date, their effects have not been studied in the growing population of children in Sweden with immigrant parents. METHODS: We estimated the association between parental migration background and nutrition, physical activity, and weight in 8-year-old children born in Stockholm between 1994 and 1996 of immigrants and Swedish parents (n = 2589). Data were collected through clinical examination and questionnaires filled out by parents. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using multivariable logistic regression. RESULTS: Children of immigrants complied more closely with Nordic Nutrition Recommendations compared with those of Swedes (OR = 1.35, 95% CI 1.11-1.64). They had higher intake of dietary fibre, vitamins C, B6, and E, folic acid, and polyunsaturated fatty acids (omega-3 and omega-6) reflecting higher consumption of foods of plant origin, but lower intake of vitamins A and D, calcium, and iron reflecting lower consumption of dairy products. Children of immigrants had higher intake of sucrose reflecting higher consumption of sugar and sweets. Furthermore, these children had a higher risk of having low physical activity (OR = 1.31, 95% CI 1.06-1.62) and being overweight (OR = 1.33, 95% CI 1.06-1.65) compared with children of Swedish parents. The odds of having low physical activity and being overweight were even higher in children whose parents were both immigrants. A low level of parental education was associated with increased risk of low physical activity regardless of immigration background. CONCLUSIONS: Culturally appropriate tools to capture the diverse range of ethnic foods and other lifestyle habits are needed. Healthcare professionals should be aware of the low levels of physical activity, increased weight, and lack of consumption of some important vitamins among children of immigrants.

Risk and predictors of attempted and completed suicide in patients with hematological malignancies.

BACKGROUND: Hematological malignancies can cause high levels of distress, but few studies have assessed risk of suicidal behavior among these patients. METHODS: We evaluated risk of attempted and completed suicide in a cohort of 46,309 patients diagnosed with malignant lymphoma, myeloma and leukemia in Sweden 1992 to 2009 and 107,736 cancer-free subjects, using Poisson regression. RESULTS: In all, 146 suicide attempts and 63 completed suicides occurred during a median follow up of 3.1 years (maximum 19 years). The risk of completed suicide was 3.5-fold increased among patients with myeloma [incidence rate ratio (IRR) = 3.52, 95% confidence interval (CI) = 2.05-6.03] and 1.9-fold increased among patients with lymphoma (IRR = 1.87, 95% CI = 1.31-2.67) but not significantly increased among patients with leukemia. Risk of attempted suicide was increased among patients with myeloma (IRR = 2.13, CI = 1.39-3.26) and lymphoma (IRR = 1.34, 95% CI = 1.07-1.69). Both male and female patients were at increased risk of attempted as well as completed suicide. A pre-malignant history of mental disorders conferred 15-fold to 30-fold increased risks, but elevated risks were also observed among patients without such history. CONCLUSIONS: Suicidal actions in patients with hematological malignancies have high suicidal intent, and that subgroups of patients should be monitored for suicidal ideation.

Cancer mortality by country of birth, sex, and socioeconomic position in Sweden, 1961-2009.

In 2010, cancer deaths accounted for more than 15% of all deaths worldwide, and this fraction is estimated to rise in the coming years. Increased cancer mortality has been observed in immigrant populations, but a comprehensive analysis by country of birth has not been conducted. We followed all individuals living in Sweden between 1961 and 2009 (7,109,327 men and 6,958,714 women), and calculated crude cancer mortality rates and age-standardized rates (ASRs) using the world population for standardization. We observed a downward trend in all-site ASRs over the past two decades in men regardless of country of birth but no such trend was found in women. All-site cancer mortality increased with decreasing levels of education regardless of sex and country of birth (p for trend <0.001). We also compared cancer mortality rates among foreign-born (13.9%) and Sweden-born (86.1%) individuals and determined the effect of education level and sex estimated by mortality rate ratios (MRRs) using multivariable Poisson regression. All-site cancer mortality was slightly higher among foreign-born than Sweden-born men (MRR = 1.05, 95% confidence interval 1.04-1.07), but similar mortality risks was found among foreign-born and Sweden-born women. Men born in Angola, Laos, and Cambodia had the highest cancer mortality risk. Women born in all countries except Iceland, Denmark, and Mexico had a similar or smaller risk than women born in Sweden. Cancer-specific mortality analysis showed an increased risk for cervical and lung cancer in both sexes but a decreased risk for colon, breast, and prostate cancer mortality among foreign-born compared with Sweden-born individuals. Further studies are required to fully understand the causes of the observed inequalities in mortality across levels of education and countries of birth.

Downward trend in the risk of second myocardial infarction in Sweden, 1987-2007: breakdown by socioeconomic position, gender, and country of birth.

BACKGROUND: Second myocardial infarction (SMI) is a significant health problem. There are no nationwide studies on SMI among foreign-born populations that include detailed information about country of birth. DESIGN: Nationwide cohort study of 331,748 men and 186,755 women aged 30-84, living in Sweden, and diagnosed with first myocardial infarction (FMI) between January 1987 and December 2007. METHODS: Trends in, and risk of, SMI after day 28 of FMI association with gender, educational level, and country of birth were analysed. A hazard ratio (HR) with a 95% confidence interval (CI) yielded a risk estimate of SMI among FMI patients based on the Cox proportional hazard model. RESULTS: Men had a higher risk of SMI than women (HR 1.14, 95% CI 1.12-1.55) with a downward trend over time, regardless of country of birth (p-trend <0.0001). Low educational level increased the HR of SMI irrespective of gender or country of birth. Foreign-born men and women had a slightly increased HR than Sweden-born. Men born in India, Palestine, Uganda, Algeria, and Tunisia and women born in India, Palestine, and Lebanon had approximately a 2-fold risk. Men born in the Netherlands had the lowest risk (HR 0.65, 95% CI 0.44-0.94). Foreign-born who had lived in Sweden for less than 35 years had a higher risk than those that had lived there for 35 years or longer. CONCLUSIONS: Although the risk of SMI continued to decrease over time, low socioeconomic position independent of country of birth and gender remained an important risk indicator deserving further attention.

The trends and the risk of type 1 diabetes over the past 40 years: an analysis by birth cohorts and by parental migration background in Sweden.

OBJECTIVE: To investigate the trends and the risk of developing type 1 diabetes in the offspring of Swedes and immigrants by specific parental migration background, age, sex and birth cohort. DESIGN: Registry-based cohort study. SETTING: Using Swedish nationwide data we analysed the risk of developing type 1 diabetes in 3 457 486 female and 3 641 304 male offspring between 0 and 30 years of age, born to native Swedes or immigrants and born and living in Sweden between 1969 and 2009. We estimated incidence rate ratios (IRRs) with 95% CIs using Poisson regression models. We further calculated age-standardised rates (ASRs) of type 1 diabetes, using the world population as standard. RESULTS: We observed a trend of increasing ASRs among offspring below 15 years of age born to native Swedes and a less evident increase among offspring of immigrants. We further observed a shift towards a younger age at diagnosis in younger birth cohorts in both groups of offspring.Compared with offspring of Swedes, children (0-14 years) and young adults (15-30 years) with one parent born abroad had an overall 30% and 15-20% lower IRR, respectively, after multivariable adjustment. The reduction in IRR was even greater among offspring of immigrants if both parents were born abroad. Analysis by specific parental region of birth revealed a 45-60% higher IRR among male and female offspring aged 0-30 years of Eastern Africa. CONCLUSIONS: Parental country of birth and early exposures to environmental factors play an important role in the aetiology of type 1 diabetes.

Socioeconomic position and incidence of gastric cancer: a systematic review and meta-analysis.

BACKGROUND: Low socioeconomic position (SEP) has been associated with increased risks of morbidity and mortality from many diseases. We investigated the associations between gastric cancer incidence and education, occupation and income as indicators for SEP. METHODS: We searched the PubMed and EMBASE databases for studies on SEP and gastric cancer incidence published from 1966 through February 2013. We used a random-effect model to pool the risk estimates from the individual studies. The relative indexes of inequality (RIIs) with their 95% CIs were used as summary estimates. We stratified the analysis by SEP indicators, sex, country's income group, geographical area, level of adjustment for an established risk factor, publication year, study design, type of control and length of follow-up. RESULTS: Of 1549 citations, 36 studies met our inclusion criteria. We observed an increased risk of gastric cancer among the lowest SEP categories in education (RII=2.97; 95% CI 1.923 to 4.58), occupation (RII=4.33; 95% CI 2.57 to 7.29) and combined SEP (RII=2.64; 95% CI 1.05 to 6.63) compared with the highest SEP categories. Although the association between the incidence of gastric cancer and the level of income is evident, it did not reach a statistically significant level (RII=1.25; 95% CI 0.93 to 1.68). CONCLUSIONS: We found that the risk of gastric cancer incidence is higher among low SEP groups.