Microvascular and macrovascular complications in type 2 diabetes Ghanaian residents in Ghana and Europe: The RODAM study.

AIMS: To compare microvascular and macrovascular complication rates among Ghanaians with type 2 diabetes (T2D) living in Ghana and in three European cities (Amsterdam, London and Berlin). METHODS: Data from the multicenter Research on Obesity and Diabetes among African Migrants (RODAM) study were analyzed. 650 Ghanaian participants with T2D (206 non-migrant and 444 migrants) were included. Logistic regression analyses were used to determine the association between migrant status and microvascular (nephropathy and retinopathy) and macrovascular (coronary artery disease (CAD), peripheral artery disease (PAD) and stroke) complications with adjustment for age, gender, socioeconomic status, alcohol, smoking, physical activity, hypertension, BMI, total-cholesterol, and HbA1c. RESULTS: Microvascular and macrovascular complications rates were higher in non-migrant Ghanaians than in migrant Ghanaians (nephropathy 32.0% vs. 19.8%; PAD 11.2% vs. 3.4%; CAD 18.4% vs. 8.3%; and stroke 14.5% vs. 5.6%), except for self-reported retinopathy (11.0% vs. 21.6%). Except nephropathy and stroke, the differences persisted after adjustment for the above-mentioned covariates: PAD (OR 7.48; 95% CI, 2.16-25.90); CAD (2.32; 1.09-4.93); and retinopathy (0.23; 0.07-0.75). CONCLUSIONS: Except retinopathy, the rates of microvascular and macrovascular complications were higher in non-migrant than in migrant Ghanaians with T2D. Conventional cardiovascular risk factors did not explain the differences except for nephropathy and stroke

Peripheral insulin resistance rather than beta cell dysfunction accounts for geographical differences in impaired fasting blood glucose among sub-Saharan African individuals: findings from the RODAM study.

AIMS/HYPOTHESIS: The aim of this study was to assess the extent to which insulin resistance and beta cell dysfunction account for differences in impaired fasting blood glucose (IFBG) levels in sub-Saharan African individuals living in different locations in Europe and Africa. We also aimed to identify determinants associated with insulin resistance and beta cell dysfunction among this population. METHODS: Data from the cross-sectional multicentre Research on Obesity and Diabetes among African Migrants (RODAM) study were analysed. Participants included Ghanaian individuals without diabetes, aged 18-96 years old, who were residing in Amsterdam (n = 1337), Berlin (n = 502), London (n = 961), urban Ghana (n = 1309) and rural Ghana (n = 970). Glucose and insulin were measured in fasting venous blood samples. Anthropometrics were assessed during a physical examination. Questionnaires were used to assess demographics, physical activity, smoking status, alcohol consumption and energy intake. Insulin resistance and beta cell function were determined using homeostatic modelling (HOMA-IR and HOMA-B, respectively). Logistic regression analysis was used to study the contribution of HOMA-IR and inverse HOMA-B (beta cell dysfunction) to geographical differences in IFBG (fasting glucose 5.6-6.9 mmol/l). Multivariate linear regression analysis was used to identify determinants associated with HOMA-IR and inverse HOMA-B. RESULTS: IFBG was more common in individuals residing in urban Ghana (OR 1.41 [95% CI 1.08, 1.84]), Amsterdam (OR 3.44 [95% CI 2.69, 4.39]) and London (OR 1.58 [95% CI 1.20 2.08), but similar in individuals living in Berlin (OR 1.00 [95% CI 0.70, 1.45]), compared with those in rural Ghana (reference population). The attributable risk of IFBG per 1 SD increase in HOMA-IR was 69.3% and in inverse HOMA-B was 11.1%. After adjustment for HOMA-IR, the odds for IFBG reduced to 0.96 (95% CI 0.72, 1.27), 2.52 (95%CI 1.94, 3.26) and 1.02 (95% CI 0.78, 1.38) for individuals in Urban Ghana, Amsterdam and London compared with rural Ghana, respectively. In contrast, adjustment for inverse HOMA-B had very minor impact on the ORs of IFBG. In multivariate analyses, BMI (β = 0.17 [95% CI 0.11, 0.24]) and waist circumference (β = 0.29 [95%CI 0.22, 0.36]) were most strongly associated with higher HOMA-IR, whereas inverse HOMA-B was most strongly associated with age (β = 0.20 [95% CI 0.16, 0.23]) and excess alcohol consumption (β = 0.25 [95% CI 0.07, 0.43]). CONCLUSIONS/INTERPRETATION: Our findings suggest that insulin resistance, rather than beta cell dysfunction, is more important in accounting for the geographical differences in IFBG among sub-Saharan African individuals. We also show that BMI and waist circumference are important factors in insulin resistance in this population

Smoking prevalence differs by location of residence among Ghanaians in Africa and Europe: The RODAM study.

BACKGROUND: Although the prevalence of smoking is low in Ghana, little is known about the effect of migration on smoking. Comparing Ghanaians living in their country of origin to those living in Europe offers an opportunity to investigate smoking by location of residence and the associations between smoking behaviours and migration-related factors. METHODS: Data on a relatively homogenous group of Ghanaians living in London (n = 949), Amsterdam (n = 1400), Berlin (n = 543), rural Ghana (n = 973) and urban Ghana (n = 1400) from the cross-sectional RODAM (Research on Obesity & Diabetes in African Migrants) study were used. Age-standardized prevalence rates of smoking by location of residence and factors associated with smoking among Ghanaian men were estimated using prevalence ratios (PR: 95% CIs). RESULTS: Current smoking was non-existent among women in rural and urban Ghana and London but was 3.2% and 3.3% in women in Amsterdam and Berlin, respectively. Smoking prevalence was higher in men in Europe (7.8%) than in both rural and urban Ghana (4.8%): PR 1.91: 95% CI 1.27, 2.88, adjusted for age, marital status, education and employment. Factors associated with a higher prevalence of smoking among Ghanaian men included European residence, being divorced or widowed, living alone, Islam religion, infrequent attendance at religious services, assimilation (cultural orientation), and low education. CONCLUSION: Ghanaians living in Europe are more likely to smoke than their counterparts in Ghana, suggesting convergence to European populations, although prevalence rates are still far below those in the host populations

Dietary patterns and type 2 diabetes among Ghanaian migrants in Europe and their compatriots in Ghana: the RODAM study.

BACKGROUND/OBJECTIVES: We aimed to study the associations of dietary patterns (DPs) with type 2 diabetes (T2D) among Ghanaian adults. SUBJECTS/METHODS: In the multi-centre, cross-sectional RODAM (Research on Obesity and Diabetes among African Migrants) study (n = 4543), three overall DPs ("mixed", "rice, pasta, meat and fish," and "roots, tubers and plantain") and two site-specific DPs per study site (rural Ghana, urban Ghana and Europe) were identified by principal component analysis. The DPs-T2D associations were calculated by logistic regression models. RESULTS: Higher adherence to the "rice, pasta, meat and fish" DP (characterized by legumes, rice/pasta, meat, fish, cakes/sweets, condiments) was associated with decreased odds of T2D, adjusted for socio-demographic factors, total energy intake and adiposity measures (odds ratio (OR)per 1 SD = 0.80; 95% confidence interval (CI) = 0.70-0.92). Similar DPs and T2D associations were discernible in urban Ghana and Europe. In the total study population, neither the "mixed" DP (whole grain cereals, sweet spreads, dairy products, potatoes, vegetables, poultry, coffee/tea, sodas/juices, olive oil) nor the "roots, tubers and plantain" DP (refined cereals, fruits, nuts/seeds, roots/tubers/plantain, fermented maize products, legumes, palm oil, condiments) was associated with T2D. Yet, after the exclusion of individuals with self-reported T2D, the "roots, tubers and plantain" DP was inversely associated with T2D (ORper 1 SD = 0.88; 95% CI = 0.69-1.12). CONCLUSION: In this Ghanaian population, DPs characterized by the intake of legumes, fish, meat and confectionery were inversely associated with T2D. The effect of a traditional-oriented diet (typical staples, vegetables and legumes) remains unclear

Food consumption, nutrient intake, and dietary patterns in Ghanaian migrants in Europe and their compatriots in Ghana.

Background: West African immigrants in Europe are disproportionally affected by metabolic conditions compared to European host populations. Nutrition transition through urbanisation and migration may contribute to this observations, but remains to be characterised. Objective: We aimed to describe the dietary behaviour and its socio-demographic factors among Ghanaian migrants in Europe and their compatriots living different Ghanaian settings. Methods: The multi-centre, cross-sectional RODAM (Research on Obesity and Diabetes among African Migrants) study was conducted among Ghanaian adults in rural and urban Ghana, and Europe. Dietary patterns were identified by principal component analysis. Results: Contributions of macronutrient to the daily energy intake was different across the three study sites. Three dietary patterns were identified. Adherence to the 'mixed' pattern was associated with female sex, higher education, and European residency. The 'rice, pasta, meat, and fish' pattern was associated with male sex, younger age, higher education, and urban Ghanaian environment. Adherence to the 'roots, tubers, and plantain' pattern was mainly related to rural Ghanaian residency. Conclusion: We observed differences in food preferences across study sites: in rural Ghana, diet concentrated on starchy foods; in urban Ghana, nutrition was dominated by animal-based products; and in Europe, diet appeared to be highly diverse

Epigenetic age acceleration in the emerging burden of cardiometabolic diseases among migrant and non-migrant African populations:the population based cross-sectional RODAM study

BACKGROUND: African populations are experiencing health transitions due to rapid urbanization and international migration. However, the role of biological aging in this emerging burden of cardiometabolic diseases (CMD) among migrant and non-migrant Africans is unknown. We aimed to examine differences in epigenetic age acceleration (EAA) as measured by four clocks (Horvath, Hannum, PhenoAge and GrimAge) and their associations with cardiometabolic factors among migrant Ghanaians in Europe and non-migrant Ghanaians. METHODS: Genome-wide DNA methylation (DNAm) data of 712 Ghanaians from cross-sectional RODAM study were used to quantify EAA. We assessed correlation of DNAmAge measures with chronological age, and then performed linear regressions to determine associations of body mass index (BMI), fasting blood glucose (FBG), blood pressure, alcohol consumption, smoking, physical activity, and one-carbon metabolism nutrients with EAA among migrant and non-migrants. We replicated our findings among 172 rural-urban sibling pairs from India migration study and among 120 native South Africans from PURE-SA-NW study. FINDINGS: We found that Ghanaian migrants have lower EAA than non-migrants. Within migrants, higher FBG was positively associated with EAA measures. Within non-migrants, higher BMI, and Vitamin B9 (folate) intake were negatively associated with EAA measures. Our findings on FBG, BMI and folate were replicated in the independent cohorts. INTERPRETATION: Our study shows that migration is negatively associated with EAA among Ghanaians. Moreover, cardiometabolic factors are differentially associated with EAA within migrant and non-migrant subgroups. Our results call for context-based interventions for CMD among transitioning populations that account for effects of biological aging. FUNDING: European Commission

An epigenome-wide association study in whole blood of measures of adiposity among Ghanaians: the RODAM study.

BACKGROUND: Epigenome-wide association studies (EWAS) have identified DNA methylation loci involved in adiposity. However, EWAS on adiposity in sub-Saharan Africans are lacking despite the high burden of adiposity among African populations. We undertook an EWAS for anthropometric indices of adiposity among Ghanaians aiming to identify DNA methylation loci that are significantly associated. METHODS: The Illumina 450k DNA methylation array was used to profile DNA methylation in whole blood samples of 547 Ghanaians from the Research on Obesity and Diabetes among African Migrants (RODAM) study. Differentially methylated positions (DMPs) and differentially methylation regions (DMRs) were identified for BMI and obesity (BMI ≥ 30 kg/m2), as well as for waist circumference (WC) and abdominal obesity (WC ≥ 102 cm in men, ≥88 cm in women). All analyses were adjusted for age, sex, blood cell distribution estimates, technical covariates, recruitment site and population stratification. We also did a replication study of previously reported EWAS loci for anthropometric indices in other populations. RESULTS: We identified 18 DMPs for BMI and 23 for WC. For obesity and abdominal obesity, we identified three and one DMP, respectively. Fourteen DMPs overlapped between BMI and WC. DMP cg00574958 annotated to gene CPT1A was the only DMP associated with all outcomes analysed, attributing to 6.1 and 5.6% of variance in obesity and abdominal obesity, respectively. DMP cg07839457 (NLRC5) and cg20399616 (BCAT1) were significantly associated with BMI, obesity and with WC and had not been reported by previous EWAS on adiposity. CONCLUSIONS: This first EWAS for adiposity in Africans identified three epigenome-wide significant loci (CPT1A, NLRC5 and BCAT1) for both general adiposity and abdominal adiposity. The findings are a first step in understanding the role of DNA methylation in adiposity among sub-Saharan Africans. Studies on other sub-Saharan African populations as well as translational studies are needed to determine the role of these DNA methylation variants in the high burden of adiposity among sub-Saharan Africans

Ideal cardiovascular health among Ghanaian populations in three European countries and rural and urban Ghana: the RODAM study.

Cardiovascular health (CVH) is a construct defined by the American Heart Association (AHA) as part of its 2020 Impact Goal definition. CVH has, until now, not been evaluated in Sub-Saharan African populations. The aim of this study was to investigate differences in the prevalence of ideal CVH and its constituent metrics among Ghanaians living in rural and urban Ghana and Ghanaian migrants living in three European countries. The AHA definition of CVH is based on 7 metrics: smoking, body mass index, diet, physical activity, blood pressure, total cholesterol, and fasting plasma glucose. These were evaluated among 3510 Ghanaian adults (aged 25-70 years) residing in rural and urban Ghana and three European cities (Amsterdam, London and Berlin) in the multi-centre RODAM study. Differences between groups were assessed using logistic regression with adjustments for gender, age, and education. Only 0.3% of all participants met all 7 metrics of the AHA's definition of ideal CVH. Compared to rural Ghana (25.7%), the proportions and adjusted odds ratio (OR) of individuals who had 6-7 CVH metrics in the ideal category were substantially lower in urban Ghana, (7.5%; OR 0.204, 95% CI 0.15-0.29), Amsterdam (4.4%; 0.13, 0.08-0.19), Berlin (2.7%; 0.06, 0.03-0.11), and London (1.7%; 0.04, 0.02-0.09), respectively. The proportion of ideal CVH for the various metrics ranged from 96% for all sites in the smoking metric to below 6% in the diet metric. The proportion of ideal CVH is extremely low in Ghanaians, especially among those living in urban Ghana and Ghanaian migrants in Europe

Food variety, dietary diversity, and type 2 diabetes in a multi-center cross-sectional study among Ghanaian migrants in Europe and their compatriots in Ghana: the RODAM study.

PURPOSE: The importance of dietary diversification for type 2 diabetes (T2D) risk remains controversial. We investigated associations of between- and within-food group variety with T2D, and the role of dietary diversification for the relationships between previously identified dietary patterns (DPs) and T2D among Ghanaian adults. METHODS: In the multi-center cross-sectional Research on Obesity and Diabetes among African Migrants (RODAM) Study (n = 3810; Ghanaian residence, 56%; mean age, 46.2 years; women, 63%), we constructed the Food Variety Score (FVS; 0-20 points), the Dietary Diversity Score (DDS; 0-7 points), and the Diet Quality Index-International (DQI-I) variety component (0-20 points). The associations of these scores, of a "rice, pasta, meat and fish" DP, of a "mixed" DP, and of a "roots, tubers and plantain" DP with T2D were calculated by logistic regression. RESULTS: The FVS was inversely associated with T2D, adjusted for socio-demographic, lifestyle, and anthropometric factors [odds ratio (OR) for T2D per 1 standard deviation (SD) increase: 0.81; 95% confidence interval (CI) 0.71-0.93]. The DDS and the DQI-I variety component were not associated with T2D. There was no association of the "mixed" DP and the "roots, tubers and plantain" DP with T2D. Yet, the "rice, pasta, meat and fish" DP is inversely associated with T2D (OR for T2D per 1 SD increase: 0.82; 95% CI 0.71-0.95); this effect was slightly attenuated by the FVS. CONCLUSIONS: In this Ghanaian population, between-food group variety may exert beneficial effects on glucose metabolism and partially explains the inverse association of the "rice, pasta, meat and fish" DP with T2D

Cardiovascular disease risk prediction in sub-Saharan African populations - Comparative analysis of risk algorithms in the RODAM study.

BACKGROUND: Validated absolute risk equations are currently recommended as the basis of cardiovascular disease (CVD) risk stratification in prevention and control strategies. However, there is no consensus on appropriate equations for sub-Saharan African populations. We assessed agreement between different cardiovascular risk equations among Ghanaian migrant and home populations with no overt CVD. METHODS: The 10-year CVD risks were calculated for 3586 participants aged 40-70years in the multi-centre RODAM study among Ghanaians residing in Ghana and Europe using the Framingham laboratory and non-laboratory and Pooled Cohort Equations (PCE) algorithms. Participants were classified as low, moderate or high risk, corresponding to 20% respectively. Agreement between the risk algorithms was assessed using kappa and correlation coefficients. RESULTS: 19.4%, 12.3% and 5.8% were ranked as high 10-year CVD risk by Framingham non-laboratory, Framingham laboratory and PCE, respectively. The median (25th-75th percentiles) estimated 10-year CVD risk was 9.5% (5.4-15.7), 7.3% (3.9-13.2) and 5.0% (2.3-9.7) for Framingham non-laboratory, Framingham laboratory and PCE, respectively. The concordance between PCE and Framingham non-laboratory was better in the home Ghanaian population (kappa=0.42, r=0.738) than the migrant population (kappa=0.24, r=0.732) whereas concordance between PCE and Framingham laboratory was better in migrant Ghanaians (kappa=0.54, r=0.769) than the home population (kappa=0.51, r=0.758). CONCLUSION: CVD prediction with the same algorithm differs for the migrant and home populations and the interchangeability of Framingham laboratory and non-laboratory algorithms is limited. Validation against CVD outcomes is needed to inform appropriate selection of risk algorithms for use in African ancestry populations