Single nucleotide polymorphism (SNP) rs4291 of the angiotensin-converting enzyme (ACE) gene is associated with the response to losartan treatment in hypertensive patients.

Arterial hypertension is characterized by systolic pressure ≥ 140 mmHg and/or diastolic pressure ≥ 90 mmHg and its treatment consists of the use of antihypertensive drugs, as losartan and hydrochlorothiazide. Blood pressure is regulated by angiotensin-converting enzyme (ACE) and polymorphisms in the ACE gene are associated to a greater predisposition to hypertension and response to treatment. The aim of this study was to evaluate the association of genetic polymorphisms of ACE rs4363, rs4291 and rs4335 and the response to antihypertensive drugs in hypertensive patients from Ouro Preto/MG, Brazil. A case-control study was carried out with 87 hypertensive patients being treated with losartan and 75 with hydrochlorothiazide, who answered a questionnaire and had blood samples collected. Biochemical analyzes were performed on serum using UV/Vis spectrophotometry and identification of ACE variants rs4363, rs4291 and rs4335 was performed by real-time PCR using the TaqMan® system. Univariate logistic regression test was performed to compare categorical data in STATA 13.0 software. The results showed that there was an influence of ACE polymorphisms on the response to losartan, demonstrating that AT or TT genotypes of rs4291 were more frequent in the group of controlled AH (54.9%), indicating that these individuals are 2.8 times more likely to of being controlled AH (95% CI 1.12-6.80, p. =0.026) compared to those with AA genotype. In contrast, no influence of ACE polymorphisms on the response to hydrochlorothiazide was observed. In conclusion, the presence of the T allele of the rs4291 variant was associated to controled blood pressure when losartan was used as an antihypertensive agent. These results show the importance of pharmacogenetic studies to detect genetic characteristics, enabling therapeutic individuality and reducing costs for the healthcare system.

High molecular weight adiponectin as a biomarker of hypertension in children and adolescents with obesity.

Lower HMW (high molecular weight) adiponectin levels are associated with obesity, insulin resistance, and metabolic syndrome in children and adolescents. However, data on HMW levels in pediatric population with hypertension are lacking. This study aimed to examine the association and predictive capacity of HMW levels, HMW/HOMA-IR, and HMW/APN ratio with hypertension in obese children and adolescents. The 299 pediatric subjects were grouped in obese hypertensive (OH), obese normotensive (ON), and normal weight normotensive (NN). Plasma concentrations of HMW were investigated by ELISA. ANOVA was used to compare study groups, and a binary logistic regression analysis was used to verify if HMW, HMW/HOMA-IR, HMW/APN, APN, APN/HOMA-IR, and HOMA-IR are associated to hypertension regardless obesity in children and adolescents. To compare the strength and performance of each biomarker to classify individuals with and without hypertension, the receiver-operating characteristic (ROC) curve, area under the curve (AUC), and Youden index (J) were evaluated. Both HMW plasma levels and the HMW/HOMA-IR ratio were significantly lower in the OH group when compared to the ON group (HMW: 2.00 ± 1.33 µg/mL vs 2.48 ± 1.48 µg/mL; HMW/HOMA-IR ratio: 0.87 ± 0.95 vs 1.27 ± 1.2; P < 0.05) and NN weight groups (HMW: 2.00 ± 1.33 µg/mL vs 4.02 ± 1.99 µg/mL; HMW/HOMA-IR ratio: 0.87 ± 0.95 vs 2.62 ± 1.86; P < 0.05). Hypertension was associated with lowest HMW (OR = 4.50; 95% CI = 1.41-15.84) and HMW/HOMA-IR (OR = 12.13; 95% CI = 2.51-92.93) regardless of obesity. However, HOMA-IR or the HMW/APN was not significant (P > 0.05). In the ROC curve analyses, the HMW and HMW/HOM-IR were more sensitive to detect hypertension in children and adolescents with obesity.    Conclusion: Low levels of HMW oligomer and HMW/HOM-IR are associated with hypertension in childhood obesity. Thus, these biomarkers could be clinically useful in identifying hypertension in childhood obesity. What is Known: • HMW has previously been reported as the most biologically active isoform of adiponectin, and lower HMW concentrations are associated with obesity, insulin resistance, and metabolic syndrome in children and adolescents. • HMW/HOMA-IR ratio is a sensitive predictor for metabolic syndrome in adults. What is New: • HMW levels are associated with hypertension in children and adolescents, independently of presence of obesity. • HMW was more sensitive to detect hypertension in children and adolescents with obesity when compared to HMW/HOMA-IR, HMW/APN, APN, APN/HOMA-IR, or HOMA-IR.

Relationship between asymmetric dimethylarginine, nitrite and genetic polymorphisms: Impact on erectile dysfunction therapy.

Sildenafil is the most used treatment of erectile dysfunction, however a large part of patients do not respond to therapy. This drug enhances nitric oxide (NO) signaling, and therefore factors that alter NO production may impact this drug responsiveness. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of all NO synthases, and is metabolized by Dimethylarginine Dimethilaminohydrolase (DDAH) 1 and 2. Here we aimed to assess the relationship between plasma levels of ADMA and nitrite (marker of nitric oxide production) with Sildenafil responsiveness. We also studied genetic polymorphisms in DDAH1 and DDAH2 genes and their relation with biochemical and clinical data. Were included here 140 patients, divided in Clinical Erectile Dysfunction (CED) or Post-Prostatectomy Erectile Dysfunction (PPED) groups. Erectile function was evaluated before and after Sildenafil on-demand treatment using the International Index for Erectile Function Questionnaire. We have found that nitrite was associated with worse response to Sildenafil (r = - 0.25, P = 0.040). rs1554597 and rs18582 DDAH1 polymorphisms were associated with changes in ADMA levels in CED (B = - 0.23, P = 0.002; B = - 0.15, P = 0.017 for both variant genotypes, respectively). Finally, DDAH2 polymorphisms were associated with altered responsiveness to Sildenafil in PPED (B = +0.19, P = 0.027).

Matrix metalloproteinase (MMP)-2 and MMP-9 polymorphisms and haplotypes as disease biomarkers.

Chaudhary and colleagues observed associations of matrix metalloproteinase (MMP)-2 (-1306C/T) and MMP-9 (-1562C/T) promoter polymorphisms with head and neck squamous cell carcinoma (HNSCC), but not with oral submucous fibrosis (OSMF) in an Indian population. We suggest that they could carry out a haplotype analysis with their data on MMP-2 genotypes (-1306C/T and -168G/T) and that they consider genotyping the microsatellite -90 (CA)(14-24) in the MMP-9 promoter region in order to perform haplotype analysis in combination with their data on MMP-9 (-1562C/T) polymorphism. These suggestions could provide additional information with clinical relevance to cancer susceptibility.