Corticotropin-releasing hormone receptor 1 (CRH-R1) polymorphisms are associated with irritable bowel syndrome and acoustic startle response.

BACKGROUND: Corticotropin-releasing hormone receptor 1 (CRH-R1) in the amygdala and the stria terminalis plays an important role in the activation of central stress circuits. Genetic factors may contribute to the hyperresponsiveness of these circuits in irritable bowel syndrome (IBS). AIMS: To determine if CRH-R1 SNPs are associated with: (1) a diagnosis of IBS, (2) gastrointestinal (GI) symptoms, and (3) acoustic startle response (ASR) to threat, which is mediated by the amygdala via CRH. METHODS: Three CRH-R1 SNPS (rs110402, rs242924, and rs7209436) were genotyped using salivary DNA from IBS and healthy control subjects (HCs). Eye blink ASR was obtained during safe (no shock), anticipation (abdominal shock may soon occur) and threat (abdominal shock likely) conditions in a subset of subjects. Associations between each SNP with IBS status, clinical traits and ASR were measured. RESULTS: 235 IBS patients (mean age 37.5 yrs, 74% F) and 264 HCs (mean age 32.1 yrs, 70% F) were studied. Of these, 57 IBS and 41 HCs underwent the ASR protocol. The presence of IBS was associated with the major allele for all three CRH-R1 SNPs (p=0.009-0.025). Within IBS, the major allele for all three SNPs (p=0.017-0.065) was associated with GI symptom anxiety scores. Within subjects with at least one copy of the major allele for the CRH-R1 SNPs, IBS had significantly lower ASR compared to HCs during threat conditions (p=0.001-0.002). Within IBS, CRH-R1 SNPs were associated with a graded increase in ASR to threat (p=0.007-0.008). CONCLUSION: These findings support that CRH-R1 contributes to the dysregulated stress responsiveness in IBS.

Are there differences in all-cause and coronary heart disease mortality between immigrants in Sweden and in their country of birth? A follow-up study of total populations.

BACKGROUND: Mortality from cardiovascular diseases is higher among immigrants than native Swedes. It is not clear whether the high mortality persists from the country of birth or is a result of migration. The purpose of the present study was to analyse whether all-cause and coronary heart disease mortality differ between immigrants in Sweden and in the country of birth. METHODS: Two cohorts including the total population from Swedish national registers and WHO were defined. All-cause and CHD mortality are presented as age-adjusted incidence rates and incidence density ratios (IDR) in eight immigrant groups in Sweden and in their country of birth. The data were analysed using Poisson regression. RESULTS: The all-cause mortality risk was lower among seven of eight male immigrant groups (IDR 0.39-0.97) and among six of eight female immigrant groups (IDR 0.42-0.81) than in their country of birth. The CHD mortality risk was significantly lower in male immigrants from Norway (IDR = 0.84), Finland (IDR = 0.91), Germany (IDR = 0.84) and Hungary (IDR = 0.59) and among female immigrants from Germany (IDR = 0.66) and Hungary (IDR = 0.54) than in their country of birth. In contrast, there was a significantly higher CHD mortality risk in male immigrants from Southern Europe (IDR = 1.23) than in their country of birth. CONCLUSION: The all-cause mortality risk was lower in the majority of immigrant groups in Sweden than in their country of birth. The differences in CHD mortality risks were more complex. For countries with high CHD mortality, such as Finland and Hungary, the risk was lower among immigrants in Sweden than in their country of birth. For low-risk countries in South Europe, the risk was higher in immigrants in Sweden than in South Europe.

Do immigrants have an increased prevalence of unhealthy behaviours and risk factors for coronary heart disease?

BACKGROUND: Although previous research has demonstrated a high risk of coronary disease in immigrants, the prevalence of unhealthy behaviours and risk factors is less known. The aim of this study was to investigate whether unhealthy behaviours and risk factors for coronary disease are more common in immigrants than in Swedish-born individuals. METHODS: Between 1 January 1996 and 31 December 2002 a simple random sample of the population was drawn and interviewed face to face. Eight immigrant groups in Sweden and a Swedish-born reference group, aged between 27 and 60 years, were studied. A log-binomial model was used to analyse the cross-sectional association between country of birth and unhealthy behaviours as well as coronary disease risk factors. RESULTS: Many of the immigrant groups showed higher risks of smoking, of physical inactivity and of obesity than Swedish-born individuals in age-adjusted models. On also adjusting for the level of education, occupational status and social network, the differences in risk persisted in the majority of groups. However, the over-risks of physical inactivity in Finnish and south European immigrant men and of diabetes in Finnish and Turkish immigrant women disappeared. CONCLUSIONS: The high prevalence of unhealthy behaviours and risk factors for coronary disease in many immigrant groups might be a lifestyle remnant from their country of birth or might be brought about by a stressful migration and acculturation into a new social and cultural environment. Nevertheless, it is important in primary healthcare to be aware of a possible preventable increased risk of unhealthy behaviours and risk factors for coronary disease in some immigrants.