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Primary hypertension is a very common disorder particularly in the aging population but hypertensive disorders can appear earlier in life, especially when obesity and unhealthy lifestyle are present. Also pregnant women can be at risk of developing gestational hypertension and/or pre-eclampsia, which causes complications in nearly 7% of pregnancies. These 'special' populations could be regarded as natural models suited to reveal mechanisms of hypertension development which are either common to other forms of hypertension, including primary hypertension or specific to these populations. Recent studies in the field of genetics of primary hypertension have used new powerful tools, such as genome-wide association studies (GWAS) and sequencing, but studies about hypertension during childhood and in pregnancy have seldom used high-throughput technologies and the knowledge in this field comes mostly from the candidate gene approach. In this review we summarize some interesting results from genetic studies conducted in childhood and adolescence and during pregnancy and underline the need to apply modern technologies in these potentially very fruitful populations. [ABSTRACT FROM AUTHOR]

Background: Endothelial nitric oxide synthase (eNOS) produces nitric oxide, which plays a role in vasodilatation and in the regulation of cell growth and apoptosis. eNOS-deficient mice have impaired cardiac development resulting in congenital heart defects (CHDs). In humans, a single nucleotide polymorphism in the gene coding for eNOS (894G>T) is associated with birth defects. Methods: We investigated the eNOS 894G>T polymorphism in relation to CHDs using a case-control study and a case-parent study. Possible interaction with maternal cigarette smoking during pregnancy and periconceptional folic acid supplementation was also investigated in a case-only approach. Results: The eNOS 894G>T polymorphism was genotyped in 170 CHD-affected children, in 161 of their mothers, 215 control children and 240 control women. For the case-parent study, 135 complete triads were available. The sum of eNOS 894 GT and TT vs. GG genotypes in children was associated with increased CHD risk [odds ratio, OR 1.5 (95% CI 1.03–2.31)]. There was no preferential transmission of the 894T allele [OR 1.2 (95% CI 0.81–1.69)]. Overall, the maternal eNOS 894 GT or TT vs. GG genotypes were not associated with increased CHD risk. The maternal 894TT genotype in combination with maternal smoking was associated with an increased risk, particularly for a subgroup of other than conotruncal heart defects [OR 3.3 (95% CI 1.00–11.1)]. No interaction with periconceptional folic acid supplementation was observed. Conclusions: Our data indicate that the eNOS 894G>T polymorphism is associated with increased CHD risk. The study also provides evidence of a possible gene-environment interaction effect on CHD risk between the maternal eNOS 894G>T variant and maternal cigarette smoking during pregnancy. This observation should be interpreted with caution because of the relatively small subgroups. Further study in a larger group of CHD subjects is required. Clin Chem Lab Med 2008;46:1369–75. [ABSTRACT FROM AUTHOR]

Cardiovascular disease is a major problem in diabetes, and risk factors presumably unrelated to diabetes, such as hyperhomocysteinaemia, may be related to the development of cardiovascular complications in diabetic individuals. Plasma homocysteine levels are usually normal in diabetes, although both lower and higher levels have been reported. Homocysteine levels in diabetes are modulated by hyperfiltration and renal dysfunction, as well as low folate status. Insulin resistance does not appear to be a major determinant of plasma homocysteine level. Hyperhomocysteinaemia has been associated with microalbuminuria and retinopathy in type 1 and type 2 diabetes. In patients with type 2 diabetes, plasma homocysteine concentration is a significant predictor of cardiovascular events and death. This relation seems to be stronger in subjects with diabetes than without. The underlying pathophysiological mechanism of this increased vascular risk remains unexplained, but may be related to worsening of endothelial dysfunction and/or structural vessel properties induced by oxidative stress. Because homocysteine and diabetes have apparent synergistic detrimental vascular effects, patients with diabetes are candidates for screening and treatment with folic acid until the results of ongoing clinical trials are available. [ABSTRACT FROM AUTHOR]