Tahereh Moradi

Type 2 diabetes incidence and socio-economic position: a systematic review and meta-analysis

BACKGROUND We conducted a systematic review and meta-analysis, the first to our knowledge, summarizing and quantifying the published evidence on associations between type 2 diabetes incidence and socio-economic position (SEP) (measured by educational level, occupation and income) worldwide and when sub-divided into high-, middle- and low-income countries. METHODS Relevant case-control and cohort studies published between 1966 and January 2010 were searched in PubMed and EMBASE using the keywords: diabetes vs educational level, occupation or income. All identified citations were screened by one author, and two authors independently evaluated and extracted data from relevant publications. Risk estimates from individual studies were pooled using random-effects models quantifying the associations. RESULTS Out of 5120 citations, 23 studies, including 41 measures of association, were found to be relevant. Compared with high educational level, occupation and income, low levels of these determinants were associated with an overall increased risk of type 2 diabetes; [relative risk (RR) = 1.41, 95% confidence interval (CI): 1.28-1.51], (RR = 1.31, 95% CI: 1.09-1.57) and (RR = 1.40, 95% CI: 1.04-1.88), respectively. The increased risks were independent of the income levels of countries, although based on limited data in middle- and low-income countries. CONCLUSIONS The risk of getting type 2 diabetes was associated with low SEP in high-, middle- and low-income countries and overall. The strength of the associations was consistent in high-income countries, whereas there is a strong need for further investigation in middle- and low-income countries.

The independent contribution of individual-, neighbourhood-, and country-level socioeconomic position on attitudes towards intimate partner violence against women in sub-Saharan Africa: a multilevel model of direct and moderating effects.

We examined associations between country, neighbourhood, and individual socioeconomic position (SEP) and attitudes towards intimate partner violence against women (IPVAW). We applied multivariable multilevel logistic regression analysis on Demographic and Health Survey data for 165,983 women and 68,501 men nested within 7465 communities from 17 countries in sub-Saharan Africa collected between 2003 and 2007. Contrary to expectation women were 34% more likely to justify IPVAW than men. We found that sex moderates associations of individual-, neighbourhood-, and country-level SEP with attitudes towards IPVAW. There was a significant positive interaction effect between sex and education attainment; women with no education were more likely to justify IPVAW than men with no education. Negative sex interaction with household wealth status indicates that differences in attitude are less pronounced among women. Unemployed men were more likely to justify IPVAW. Interaction effects indicate that the association of neighbourhood socioeconomic disadvantage with attitudes was more pronounced among women than among men. The association of country-level SEP with attitudes towards IPVWA was inconclusive. There was some evidence that neighbourhood modified the association between individual SEP and attitudes towards IPV. Also, there was cross-level interaction between country and neighbourhood SEP. Neighbourhood and individual SEP were independently associated with attitudes towards IPVAW. The relationship with country-level SEP was inconclusive. The findings underscore the need to implement public health prevention/intervention strategies not only at the level of individual SEP but also at the neighbourhood level.

Socioeconomic position and incidence of acute myocardial infarction: a meta-analysis

Background A negative socioeconomic gradient is established for coronary heart disease (CHD) mortality and survival, while socioeconomic patterning of disease incidence is less well investigated. To study socioeconomic inequalities in the incidence of acute myocardial infarction (AMI), the major component of CHD, a meta-analysis was undertaken to summarise existing evidence on the issue. Methods A systematic search was performed in PubMed and EMBASE databases for observational studies on AMI incidence and socioeconomic position (SEP), published in English to April 2009. A random-effects model was used to pool the risks estimates from the individual studies. Results Among 1181 references, 70 studies fulfilled the inclusion criteria. An overall increased risk of AMI among the lowest SEP was found for all three indicators: income (pooled RR 1.71, 95% CI 1.43 to 2.05), occupation (pooled RR 1.35, 95% CI 1.19 to 1.53) and education (pooled RR 1.34, 95% CI 1.22 to 1.47). The strongest associations were seen in high-income countries such as USA/Canada and Europe, while the results were inconsistent for middle and low-income regions. Conclusion AMI incidence is associated with low SEP. The nature of social stratification at the level of economic development of a country could be involved in the differences of risk of AMI between social groups.

Breast cancer risk and lifetime leisure-time and occupational physical activity (Sweden).

AbstractObjective: To clarify whether type and timing of physical activity affect postmenopausal breast cancer risk. Methods: In a population-based case–control study within the Swedish female population 50–74 years of age, 3347 women with invasive, postmenopausal breast cancer (84% of all eligible) and 3455 controls (82% of all selected) reported on past leisure-time physical activity. Record linkage to decennial census data (1960–1990) provided estimates of their occupational physical activity. Odds ratios with 95% confidence intervals were estimated by multivariate logistic regression. Results: After adjustment for potential confounders, women in sedentary occupations during their reproductive years (25–44 years of age) had a 50% higher risk for postmenopausal breast cancer, compared to those with the physically most demanding jobs. Only the most recent leisure-time physical activity was associated with a significant risk reduction. Women with the combination of sedentary jobs and lack of leisure-time exercise had a three-fold higher risk of breast cancer, compared to the physically most active both inside and outside the workplace. Conclusion: Effects of occupational and leisure-time physical activity on breast cancer risk appear to have different latency times, and/or to be effect-modified by age or reproductive status. Although chance might explain our findings, it is advisable to consider type and timing of physical activity in future studies.

Socioeconomic differences in lung cancer incidence: a systematic review and meta-analysis

ObjectiveTo investigate the associations between various socioeconomic indicators and lung cancer incidence.MethodsWe searched PubMed and EMBASE databases for studies on socioeconomic position (SEP) and lung cancer incidence published through October 2007. Random-effect model was used to pool the risk estimates from the individual studies. We stratified the analysis by adjustment strategy to investigate the influence of smoking on socioeconomic gradient in lung cancer incidence.ResultsOut of 3,288 citations, we identified 64 studies eligible for inclusion. Compared to the highest SEP level, we observed an overall increased risk in lung cancer incidence among people with low educational SEP (61%), low occupational SEP (48%), and low income-based SEP (37%). The negative social gradient for lung cancer incidence remained for most of the possible sets of pooled estimates obtained in subgroup analyses for occupational and educational SEP with less consistency for SEP based on income in studies adjusted and unadjusted for smoking. No evidence of publication bias was apparent.ConclusionLung cancer incidence was associated with low educational, occupational, and income-based SEP. The association, adjusted or unadjusted for smoking, points out the importance of social position to be addressed in all discussions on cancer preventive measures.

Physical activity and risk for breast cancer a prospective cohort study among Swedish twins

The epidemiologic association between physical activity and breast cancer has been corroborated in many studies. Some inconsistencies remain, possibly due to variation in life periods for exposure assessment, confounding and undetected effect modification. In our cohort study, we address some of these questions by taking into account physical activity in different periods of life and by investigating effect modification by birth cohort and body mass index (BMI). Altogether 9,539 same‐sex twin women aged 42–70 years who answered a questionnaire about their work and leisure‐time physical exercise from ages 25 to 50 during 1967 and 1970 were included in our cohort. During follow‐up, 506 breast cancer cases occurred through 1997. We used multivariate Cox models to estimate relative risk (RR) with 95% confidence interval (CI). We found no associations between physical activity and breast cancer overall. Women born between 1901 and 1917 (aged 51–70 at baseline) who reported regular leisure‐time activity had a borderline significant 40% lower risk compared with those who reported no activity (RR 0.6; 95% CI 0.4–1.0; test for trend, p = 0.07). This association appeared to be confined to women with a low BMI after the age of 50 and to women with a high BMI during the premenopausal period. We found no evidence that work activity reduces risk for breast cancer. The importance of physical activity for breast cancer risk seems to depend on birth cohort. The association may be limited to normal‐weight postmenopausal women and overweight premenopausal women.

Occupational physical activity and risk for prostate cancer in a nationwide cohort study in Sweden

We investigated effects of occupational physical activity on relative risk for prostate cancer. From Swedish nationwide censuses in 1960 and 1970, we defined two cohorts of men whose occupational titles allowed classification of physical activity levels at work in 1960 (n=1 348 971) and in 1970 (n=1 377 629). A third cohort included only men whose jobs required a similar level of physical activity in both 1960 and 1970 (n=673 443). The incidence of prostate cancer between 1971 and 1989 was ascertained through record linkage to the Swedish Cancer Register. A total of 43 836, 28 702, and 19 670 prostate cancers, respectively, occurred in the three cohorts. In all three cohorts, the relative risk for prostate cancer increased with decreasing level of occupational physical activity (P<0.001), using Poisson regression. Among men with the same physical activity levels in 1960 and 1970, the rate ratio was 1.11 for men with sedentary jobs as compared with those whose jobs had very high/high activity levels after adjustment for age at follow-up, calendar year of follow-up and place of residence (95% CI 1.05–1.17; P for trend <0.001). There was no association between occupational activity and prostate cancer mortality. Since we had no data on other potential risk factors the observed associations for both incidence and mortality might have been confounded. Further studies are needed to better understand the potential role of physical activity for prostate cancer.

Physical activity and postmenopausal endometrial cancer risk (Sweden)

AbstractObjectives:To examine the hypothesis that sedentary women have an increased risk of endometrial cancer compared to physically active women. Methods:This is a population-based case–control study in the entire Swedish female population aged 50–74 years in 1994–1995. We obtained self-reported information on leisure-time physical activity during childhood, at ages 18–30, and recently from 709 incident case women with endometrial cancer and 3368 population controls. Occupational physical activity was estimated through record linkage to the Swedish census data from 1960, 1970, 1980, and 1990. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for different activity levels by multivariate logistic regression, taking into account potential confounders. Results:Comparing lowest to highest (reference) levels of physical exercise, we observed statistically significant associations with risk of endometrial cancer for leisure-time activity at age 18–30 years (multivariate OR = 1.4; 95% CI = 1.0–1.8; p for trend 0.01) and in recent years (multivariate OR=1.3; 95% CI = 1.0–1.7; p for trend 0.01). We found similar associations comparing lowest to highest (reference) levels of occupational activity assessed at the censuses in 1980 (multivariate OR = 1.4; 95% CI = 1.0–1.9; p for trend 0.03) and 1990 (multivariate OR = 1.3; 95% CI = 0.9–1.9, p for trend 0.05), but a less consistent association with censuses in 1960 and 1970. The increased risk associated with low level of occupational physical activity was confined to women who were not obese and to women who were smokers. Conclusion:Our data, in conjunction with past epidemiological studies, indicate that both occupational and leisure-time physical activity may reduce the risk for postmenopausal endometrial cancer.

Sex disparities in attitudes towards intimate partner violence against women in sub-Saharan Africa: a socio-ecological analysis.

BackgroundAttitudes towards intimate partner violence against women (IPVAW) has been suggested as one of the prominent predictor of IPVAW. In this study, we take a step back from individual-level variables and examine relationship between societal-level measures and sex differences in attitudes towards IPVAW.MethodsWe used meta-analytic procedure to synthesize the results of most recent data sets available from Demographic and Health Survey (DHS) of 17 countries in sub-Saharan Africa conducted between 2003 and 2007. Pooled odds ratio (OR) and 95% confidence intervals (CI) were computed for all countries. Test of heterogeneity, sensitivity analysis, and meta-regression were also carried out.ResultsWomen were twice as likely to justify wife beating than men (pooled OR = 1.97; 95% CI 1.53- 2.53) with statistically significant heterogeneity. The magnitude in sex disparities in attitudes towards IPVAW increased with increasing percentage of men practicing polygamy in each country. Furthermore, magnitude in sex disparities in attitudes towards IPVAW decreased monotonically with increasing adult male and female literacy rate, gender development index, gross domestic product and human development index.ConclusionThis meta-analysis has provided evidence that women were more likely to justify IPVAW than men in sub-Saharan Africa. Our results revealed that countrys socio-economic factors may be associated with sex differential in attitudes towards IPVAW.

Occupational physical activity and risk for cancer of the colon and rectum in Sweden among men and women by anatomic subsite

Inverse association between physical activity and colon cancer is well established, at least in men. We investigated the association of occupational physical activity with subsite-specific colorectal cancer risk. On the basis of occupational titles from the Swedish nationwide censuses in 1960 and 1970, we defined a cohort of women and men with the same work-related physical demands in 1960 and 1970. Incidence of colon and rectum cancer during 1971–1989 was ascertained through linkages to the Cancer Register. Relative risks (RRs) were estimated through Poisson regression. The risk for colon cancer increased with decreasing occupational physical activity. RR among sedentary women and men was 1.2 and 1.3 (P for trend=0.08 and <0.001). For men, the risks for proximal and distal colon cancer increased by 20 and 40% (P for trend=0.005 and <0.001). Inactivity seemed to be particularly associated with descending colon cancer (RR =2.4, P for trend<0.001). In women, the inverse association with activity was concentrated to proximal parts of colon; RR for cancer in the proximal and transverse colon among sedentary women was 1.4 and 2.0 (P for trend <0.07 and <0.01). Cancer of the rectum was not associated with activity in either sex. We confirmed the well-known inverse relationship between activity and risk of colon cancer but not rectal cancer in both sexes. Data suggest that the physical activity-related variation in risk among women is greatest in the proximal and middle parts of the colon, whereas the corresponding peak in men seems to be more distal. Sex-specific anatomic and motility differences of the colon might contribute to this subsite difference.