Renal function and its association with blood pressure in Middle Eastern immigrants and native Swedes

Comparison of Framingham 10-year cardiovascular risks in Sweden- and foreign-born primary health care patients in Sweden

BACKGROUND

The prevalence of cardiovascular disease around the world varies by ethnicity and region of birth. Immigrants living in Sweden may have a higher prevalence of cardiovascular diseases than native-born Swedes, but little is known about their actual cardiovascular risk. This study aimed to examine the relationship in Sweden between 10-year cardiovascular risk and birthplace.

METHOD

This cross-sectional study was based on cardiovascular risk factor data obtained from the 4D Diabetes Project, a Programme 4D subproject in Sweden. Participants were recruited from two primary healthcare centres in Stockholm without a history of diabetes or pre-diabetes. The outcome variable was 10-year cardiovascular risk based on the calculation of a Framingham Risk Score with six risk factors: age, sex, LDL, HDL, BP, diabetes and smoking for each participant. Multiple linear regression was performed to generate β-coefficients for the outcome.

RESULTS

There was an average of 8.86% cardiovascular risk over 10 years in Sweden-born participants and a 5.45% 10-year risk in foreign-born, (P < 0.0001). Foreign-born participants were about 10 years younger (mean age 46 years vs. 56 years, P < 0.001), with a significantly higher proportion of smokers (23.9% vs. 13.7%; P = 0.001). To be born in Sweden (with parents born in Sweden) was significantly associated with a 10-year cardiovascular risk in the crude model (β- coefficient = 3.40, 95% CI 2.59-4.22; P < 0.0001) and when adjusted for education and alcohol consumption (β- coefficient = 2.70 95% CI 1.86-3.54; P < 0.0001). Regardless of the birthplace, 10-year cardiovascular risk was lower for those with higher education compared to those with less than 10 years of education.

CONCLUSION

This study found a relationship between 10-year calculated cardiovascular risk and place of birth. Sweden-born participants had a higher association with 10-year cardiovascular risk than foreign-born participants. These results contradict previous reports of higher rates of CVD in residents of Middle-Eastern countries and Middle-Eastern immigrants living in Sweden.

GWAS in people of Middle Eastern descent reveals a locus protective of kidney function-a cross-sectional study

BACKGROUND

Type 2 diabetes is one of the leading causes of chronic kidney failure, which increases globally and represents a significant threat to public health. People from the Middle East represent one of the largest immigrant groups in Europe today. Despite poor glucose regulation and high risk for early-onset insulin-deficient type 2 diabetes, they have better kidney function and lower rates of all-cause and cardiovascular-specific mortality compared with people of European ancestry. Here, we assessed the genetic basis of estimated glomerular filtration rate (eGFR) and other metabolic traits in people of Iraqi ancestry living in southern Sweden.

METHODS

Genome-wide association study (GWAS) analyses were performed in 1201 Iraqi-born residents of the city of Malmö for eGFR and ten other metabolic traits using linear mixed-models to account for family structure.

RESULTS

The strongest association signal was detected for eGFR in CST9 (rs13037490; P value = 2.4 × 10^-13), a locus previously associated with cystatin C-based eGFR; importantly, the effect (major) allele here contrasts the effect (minor) allele in other populations, suggesting favorable selection at this locus. Additional novel genome-wide significant loci for eGFR (ERBB4), fasting glucose (CAMTA1, NDUFA10, TRIO, WWC1, TRAPPC9, SH3GL2, ABCC11), quantitative insulin-sensitivity check index (METTL16), and HbA1C (CAMTA1, ME1, PAK1, RORA) were identified.

CONCLUSIONS

The genetic effects discovered here may help explain why people from the Middle East have better kidney function than those of European descent. Genetic predisposition to preserved kidney function may also underlie the observed survival benefits in Middle Eastern immigrants with type 2 diabetes.

Pro-Enkephalin and its association with renal function in Middle Eastern immigrants and native Swedes

Iraqi-born immigrants residing in Sweden exhibit lower blood pressure as well as better renal function despite an overall worse metabolic risk profile in comparison with native Swedes. This may indicate the presence of cardiorenal protective mechanisms in the Middle Eastern population. Hence, the aim of this study was to investigate whether the association between renal function and Pro-Enkephalin (PENK), a biomarker predictive of both acute and chronic kidney dysfunction, differs across ethnicities. The MEDIM population-based study including a cohort of women and men, born in Iraq or Sweden, aged 30-75 years was conducted in Malmö, Sweden, from 2010 to 2012. The study included fasting blood samples, physical examinations and self-administrated questionnaires. Despite significantly better renal function assessed by creatinine-based eGFR in the Iraqi group, levels of PENK did not differ between the groups, (70.0 pmol/L, born in Iraq (n = 1263) vs 71.1, born in Sweden (n = 689), p = .4). However, the association between PENK and renal function was relatively weaker in the Iraqi born group, as supported by a significant interaction between PENK and country of birth (P_Interaction= Country of birth x PENK = 0,010). This observational study suggests that the association between renal function and PENK was weaker in Middle Eastern immigrants. This is of interest as PENK may exhibit a direct effect on renal function, however further research is needed including studies on causality.

Adult-onset diabetes in Middle Eastern immigrants to Sweden: Novel subgroups and diabetic complications-The All New Diabetes in Scania cohort diabetic complications and ethnicity

BACKGROUND

Middle Eastern immigrants to Europe represent a high risk population for type 2 diabetes. We compared prevalence of novel subgroups and assessed risk of diabetic macro- and microvascular complications between diabetes patients of Middle Eastern and European origin.

METHODS

This study included newly diagnosed diabetes patients born in Sweden (N = 10641) or Iraq (N = 286), previously included in the All New Diabetes in Scania cohort. The study was conducted between January 2008 and August 2016. Patients were followed to April 2017. Incidence rates in diabetic macro- and microvascular complications were assessed using cox-regression adjusting for the confounding effect of age at onset, sex, anthropometrics, glomerular filtration rate (eGFR) and HbA1c.

FINDINGS

In Iraqi immigrants versus native Swedes, severe insulin-deficient diabetes was almost twice as common (27.9 vs. 16.2% p < 0.001) but severe insulin-resistant diabetes was less prevalent. Patients born in Iraq had higher risk of coronary events (hazard ratio [HR] 1.84, 95% CI 1.06-3.12) but considerably lower risk of chronic kidney disease (CKD) than Swedes (HR 0.19; 0.05-0.76). The lower risk in Iraqi immigrants was partially attributed to better eGFR. Genetic risk scores (GRS) showed more genetic variants associated with poor insulin secretion but lower risk of insulin resistance in the Iraqi than native Swedish group.

INTERPRETATION

People with diabetes, born in the Middle East present with a more insulin-deficient phenotype and genotype than native Swedes. They have a higher risk of coronary events but lower risk of CKD. Ethnic differences should be considered in the preventive work towards diabetes and its complications.

Country of birth and mortality risk in hypertension with and without diabetes: the Swedish primary care cardiovascular database

OBJECTIVES

Hypertension and diabetes are common and are both associated with high cardiovascular morbidity and mortality. We aimed to investigate associations between mortality risk and country of birth among hypertensive individuals in primary care with and without concomitant diabetes, which has not been studied previously. In addition, we aimed to study the corresponding risks of myocardial infarction and ischemic stroke.

METHODS

This observational cohort study of 62 557 individuals with hypertension diagnosed 2001-2008 in the Swedish Primary Care Cardiovascular Database assessed mortality by the Swedish Cause of Death Register, and myocardial infarction and ischemic stroke by the National Patient Register. Cox regression models were used to estimate study outcome hazard ratios by country of birth and time updated diabetes status, with adjustments for multiple confounders.

RESULTS

During follow-up time without diabetes using Swedish-born as reference, adjusted mortality hazard ratios per country of birth category were Finland: 1.26 (95% confidence interval 1.15-1.38), high-income European countries: 0.84 (0.74-0.95), low-income European countries: 0.84 (0.71-1.00) and non-European countries: 0.65 (0.56-0.76). The corresponding adjusted mortality hazard ratios during follow-up time with diabetes were high-income European countries: 0.78 (0.63-0.98), low-income European countries: 0.74 (0.57-0.96) and non-European countries: 0.56 (0.44-0.71). During follow-up without diabetes, the corresponding adjusted hazard ratio of myocardial infarction was increased for Finland: 1.16 (1.01-1.34), whereas the results for ischemic stroke were inconclusive.

CONCLUSION

In Sweden, hypertensive immigrants (with the exception for Finnish-born) with and without diabetes have a mortality advantage, as compared to Swedish-born.

Metabolite profiling paradoxically reveals favorable levels of lipids, markers of oxidative stress and unsaturated fatty acids in a diabetes susceptible group of Middle Eastern immigrants

AIMS

The population of immigrants from the Middle East in Sweden show a higher prevalence of type 2 diabetes (T2D) compared to native Swedes. The exact reason for this is unknown. Here, we have performed metabolite profiling to investigate these differences.

METHODS

Metabolite profiling was conducted in Iraqi immigrants (n = 93) and native Swedes (n = 77) using two complementary mass spectrometry-based platforms. Differences in metabolite levels were compared after adjustment for confounding anthropometric, diet and clinical variables.

RESULTS

The Iraqi immigrant population were more obese (44.1 vs 24.7%, p < 0.05), but had a lower prevalence of hypertension (32.3 vs 54.8%, p < 0.01) than the native Swedish population. We detected 140 metabolites, 26 of which showed different levels between populations (q < 0.05,) after adjustment for age, sex, BMI, T2D and use of metformin. Twenty-two metabolites remained significant after further adjustment for HOMA-IR, HOMA-beta or insulin sensitivity index. Levels of polyunsaturated acylcarnitines (14:2 and 18:2) and fatty acid (18:2) were higher, whereas those of saturated and monounsaturated acylcarnitines (14:0, 18:1, and 8:1), fatty acids (12:0, 14:0, 16:0, and 18:1), uremic solutes (urate and quinate) and ketone bodies (beta-hydroxybutyrate) were lower in Iraqi immigrants. Further, levels of phospholipids were generally lower in the Iraqi immigrant population.

CONCLUSIONS

Our result suggests an overall beneficial lipid profile in Iraqi immigrants, despite a higher risk to develop T2D. Higher levels of polyunsaturated fatty acids may suggest differences in dietary pattern, which in turn may reduce the risk of hypertension.

Metabolically Healthy Obesity (MHO)-New Research Directions for Personalised Medicine in Cardiovascular Prevention

PURPOSE OF REVIEW

To discuss new findings on the heterogeneity of obesity and associated risks.

RECENT FINDINGS

Obesity is a public health problem of immense importance on a global scale. However, epidemiological findings and clinical studies have revealed that obesity is a heterogeneous phenotype and that not all obese subjects run the same risk for complications. Current research has tried to describe so-called metabolically healthy obesity (MHO), defined by lack of risk factors included in the metabolic syndrome. These subjects will not escape long-term complications, but mortality risk is not increased. However, a new definition of MHO has recently been proposed, based on the lack of hospitalisation for somatic disease for decades in middle life. MHO subjects defined in this way are characterised by being "fat and fit" and also run a lower risk of long-term complications. If MHO could be better understood, this could contribute to a more diverse clinical approach to obesity based on personalised medicine.