Aetiological research on the health of migrants living in Germany: a systematic literature review.

BACKGROUND: Germany has become an important immigration country and health services need to adopt to meet the needs of an increasingly multicultural population. For public health planning, it is essential to understand the aetiology of health problems among migrant populations. The main objective was to systematically identify, evaluate and synthesise population-based studies that investigated exposure-outcome relationships among migrant groups in Germany. METHODS: In November 2019, we searched PubMed and LIVIVO, and updated this search in November 2020, to identify peer-reviewed publications that fulfilled our eligibility criteria: English or German language; study on disease aetiology among major migrant groups in Germany, according to the latest microcensus; publication date from inception to 01 November 2020 and observational or experimental study designs. For quality appraisal, we used the Critical Appraisal Skills Programme checklists. Outcomes under investigation were categorised according to the WHO major disease groups, and their associations with risk factors were synthesised as a heat map. RESULTS: Out of 2407 articles retrieved, we included 68 publications with a total number of 864 518 participants. These publications reported on cross-sectional data (n=56), cohort studies (n=11) and one intervention study. The population groups most frequently studied were from the Middle East (n=28), Turkey (n=24), sub-Saharan Africa (n=24), Eastern Europe (n=15) and the former Soviet Union (n=11). The outcomes under study were population group specific. There were consistent associations of demographic and socioeconomic factors with ill health among migrants in Germany. DISCUSSION: In this systematic review, we observed low risk of bias in two-thirds of the studies. There is an increasing body of evidence for aetiological research on migrants' health in Germany. Still, the directions of associations between a wide range of risk factors and major disease groups seem only partially understood. PROSPERO REGISTRATION NUMBER: CRD42018085074.

Reduced Rank Regression-Derived Dietary Patterns Related to the Fatty Liver Index and Associations with Type 2 Diabetes Mellitus among Ghanaian Populations under Transition: The RODAM Study.

The Fatty Liver Index (FLI) is a proxy for the steatotic component of non-alcoholic fatty liver disease (NAFLD). For sub-Saharan African populations, the contribution of dietary factors to the development of NAFLD in the etiology of type 2 diabetes mellitus (T2DM) remains to be clarified. We identified sex-specific dietary patterns (DPs) related to the FLI using reduced ranked regression (RRR) and evaluated the associations of these DPs with T2DM. This analysis used data from the RODAM, a multi-center cross-sectional study of Ghanaian populations living in Ghana and Europe. The daily intake frequencies of 30 food groups served as the predictor variables, while the FLI was the response variable. The odds ratios and 95% confidence intervals for T2DM were calculated per one standard deviation increase in the DP score using logistic regression. In males, the DP score explained 9.9% of the variation in their food intake and 16.0% of the variation in the FLI. This DP was characterized by high intakes of poultry, whole-grain cereals, coffee and tea, condiments, and potatoes, and the chance of T2DM was 45% higher per 1 DP score-SD (Model 2). Our results indicate that the intake of modernized foods was associated with proxies of NAFLD, possibly underlying the metabolic pathways to developing T2DM.

Metabolic-associated Fatty Liver Disease as Assessed by the Fatty Liver Index Among Migrant and Non-migrant Ghanaian Populations.

BACKGROUND AND AIMS: Metabolic-associated fatty liver disease (MAFLD) is driven by high caloric intake and sedentary lifestyle. Migration towards high income countries may induce these driving factors; yet, the influence of such on the prevalence of MAFLD is clearly understudied. Here, we investigated the Fatty Liver Index (FLI), a proxy of steatosis in MAFLD, after migration of Ghanaian subjects. METHODS: Cross-sectional data of 5282 rural, urban and migrant participants from the Research on Obesity and Diabetes among African Migrants (also known as RODAM) study were analyzed with logistic regression for geographical differences in FLI and associations with type 2 diabetes mellitus (T2DM), waist-to-hip ratio, and 10-year predicted risk of atherosclerotic cardiovascular disease (ASCVD). RESULTS: Both FLI and the proportion with an FLI indicative of MAFLD steatosis (FLI ≥60) were higher in migrants compared with non-migrants. Prevalence of elevated FLI (FLI ≥60) in non-migrant males was 4.2% compared to 28.9% in migrants. For females, a similar gradient was observed, from 13.6% to 36.6% respectively. Compared to rural residents, the odds for a FLI ≥60 were higher in migrants living in urban Europe (odds ratio [OR] 9.02, 95% confidence interval [CI]: 5.02-16.20 for men, and 4.00, 95% CI: 3.00-5.34 for women). Compared to controls, the ORs for FLI ≥60 were 2.43 (95% CI: 1.73-3.41) for male T2DM cases and 2.02 (95% CI: 1.52-2.69) for female T2DM cases. One-unit higher FLI was associated with an elevated (≥7.5%) 10-year ASCVD risk (OR: 1.051, 95% CI: 1.041-1.062 for men, and 1.020, 95% CI: 1.015-1.026 for women). CONCLUSIONS: FLI as a proxy for MAFLD increased stepwise in Ghanaians from rural areas, through urban areas, to Europe. Our results clearly warrant awareness for MAFLD in migrant population as well as confirmation with imaging modalities.