Carotid plague formation is associated with ankle-brachial index in elderly people.

AIMS: This study aimed at examining whether ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) were independently associated with carotid Intima-media thickness (CIMT) or carotid artery plaque (CAP) in elderly people. METHODS: A cross-sectional analysis was performed in 155 individuals aged over 75 years who underwent the measurements of ABI and baPWV. Low ABI was defined as ABI ≤ 1.0. High baPWV was defined as baPWV > 2000 cm/s. The CIMT and CAP were measured with a B-mode tomographic ultrasound system. RESULTS: Neither ABI nor baPWV was associated with CIMT in this elderly population. The group with low ABI (≤ 1.0) was significantly associated with a higher prevalence of carotid plaque (P = 0.001), while the relationship between baPWV and prevalence of carotid plaque was not found. Linear regression analysis showed that the value of ABI was significantly associated with the thickness of carotid plaque. Even in the full adjusted model, each 0.01unit ABI decreasing still increased 0.1663 mm of carotid plaque thickness (P = 0.004). Logistic Regression Analysis demonstrated that ABI lower than 1.0 had predictive value in the formation of carotid plaque with top quartile thickness (OR 2.834, 95% CI 1.131-7.099, P = 0.026). Furthermore, individuals with low ABI (≤ 1.0) were more likely to form hypoechoic carotid plaques according to ultrasonography. CONCLUSION: Low ABI but not high baPWV was associated with the formation of carotid plaque. Furthermore, ABI was significantly associated with the thickness and morphology of carotid plaque in elderly people.

Erythrocyte rheological properties but not whole blood and plasma viscosity are associated with severity of hypertension in older people.

OBJECTIVE: This study was carried out to determine whether changes in hemorheological parameters parallel the severity of essential hypertension. METHODS: A total of 198 older hypertensive patients were recruited and classified into 3 stages of hypertension according to the grading standard of hypertension. The whole blood viscosity (WBV) at various shear rates, plasma viscosity and erythrocyte rheology (including erythrocyte rigidity index, erythrocyte aggregation index and erythrocyte deformation index) were examined. RESULTS: Erythrocyte rheology paralleled the severity of essential hypertension and was significantly correlated to the average 24 h systolic blood pressure and diastolic blood pressure. Logistic analysis revealed that erythrocyte rigidity and the erythrocyte aggregation index were positively correlated with the severity of hypertension, while the erythrocyte deformation index was negatively correlated. No association was found between WBV, plasma viscosity and the severity of hypertension. CONCLUSION: The rheological properties of erythrocyte viscosity were correlated with the severity of hypertension in older people but the WBV and plasma viscosity were not.

GA to HbA1C ratio, but not HbA1C is associated with cognition in Chinese nondiabetic old adults.

OBJECTIVES: To investigate the relationship between glycated albumin (GA) to glycated hemoglobin (HbA1c) ratio and cognitive impairment in old age. Diabetes is associated with cognitive impairment in older people. However, the link between elevated GA/HbA1c levels and the risk of cognitive impairment in nondiabetic individuals is unclear. METHODS: A cross-sectional study of 474 old, nondiabetic adults (192 women, mean age 73.8 years ± 6.9 SD) who had been admitted to our hospital was conducted. Glycemic measures included fasting plasma glucose (FPG), 2-hour post-prandial plasmic glucose (2hPPG), GA and HbA1c. Cognitive function was assessed using Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) at the same examination visit in which the glycemic measures were determined. RESULTS: When the individuals were divided into two groups according to the median of GA/HbA1c ratio, old adults with GA/HbA1c ratio ≥ 2.53 showed lower MMSE and MoCA scores compared to those with GA/HbA1c ratio < 2.53. Univariate regression analysis showed that MMSE and MoCA scores were not correlated with HbA1c, but were inversely correlated with GA and GA/HbA1c ratio. Linear regression analysis revealed that there was a significant negative correlation between GA/HbA1c and cognitive function (ß = -0.77, P < 0.01 for MoCA and ß = -0.69, P < 0.05 for MMSE) even after adjustment for age, body mass index, systolic blood pressure, lipoprotein(a) and sex. CONCLUSION: Our results indicate that even in the absence of manifest type 2 diabetes mellitus, GA/HbA1c ratio levels exert a negative influence on cognition and it may be a better predictor for cognitive impairment in the older population.

MicroRNA-155 regulates angiotensin II type 1 receptor expression and phenotypic differentiation in vascular adventitial fibroblasts.

MicroRNAs (miRNAs), which are genomically encoded small RNAs, negatively regulate target gene expression at the post-transcriptional level. Our recent study indicated that microRNA-155 (miR-155) might be negatively correlated with blood pressure, and it has been suggested that miR-155-mediated target genes could be involved in the cardiovascular diseases. Bioinformatic analyses predict that angiotensin II type 1 receptor (AT(1)R) is a miR-155 target gene. The present study investigated the potential role of miR-155 in regulating AT(1)R expression and phenotypic differentiation in rat aortic adventitial fibroblasts (AFs). Luciferase assay demonstrated that miR-155 suppressed AT(1)R 3'-UTR reporter construct activity. miR-155 overexpression in AFs did not reduce target mRNA levels, but significantly reduced target protein expression. In addition, AFs transfected with pSUPER/miR-155 exhibited reduced Ang II-induced ERK1/2 activation. miR-155 overexpression in cells attenuated Ang II-induced α-smooth muscle actin (α-SMA, produces myofibroblast) expression, but did not transform growth factor beta-1 (TGF-ß1). This study demonstrated that miR-155 could have an important role in regulating adventitial fibroblast differentiation and contribute to suppression of AT(1)R expression.

[Differential expression of microRNAs in the aorta of spontaneously hypertensive rats].

MicroRNAs (miRNAs) are genomically encoded non-protein-encoding small RNAs, which negatively regulate target gene expression at post-transcriptional level. The present study aimed to investigate whether disorders of miRNAs system were involved in the pathogenesis of hypertension in spontaneously hypertensive rats (SHR). MiRanda, Target Scan and PicTar were utilized for predictive analysis of miRNAs and target genes. MiR-1, miR-133a, miR-155 and miR-208 were selected as the candidate miRNAs potentially related to blood pressure. The expression levels of miR-1, miR-133a, miR-155 and miR-208 in the aorta of 4-, 8-, 16- and 24-week-old SHR and age-matched Wistar-Kyoto (WKY) rats were detected by real-time RT-PCR. The mRNA levels of angiotensin II receptor type 1 (AGTR1a), angiotensin II receptor associated protein (AGTRAP), divalent metal transporter 1 (DMT1), low-density lipoprotein-related protein 1B (LRP1B), fibroblast growth factor-7 (FGF-7), protocadherin 9 precursor (PCDH9), chloride channel protein 5 (CLCN-5), small conductance calcium activated potassium channel protein 3 (KCNN3) and thyroid hormone receptor associated protein 1 (THRAP1), which were predicted to be target genes of differentially expressed miRNAs, were further detected by real-time RT-PCR. The results obtained showed that the expression levels of miR-1, miR-155 and miR-208 in the aorta were significantly different from those in the heart of WKY rats. The miR-155 level was significantly lower in aorta of 16-week-old SHR than that of age-matched WKY rats (P<0.05), but there was no difference between SHR and WKY rats in other age groups. In addition, miR-155 level was negatively correlated to blood pressure (r=-0.525, P<0.05). Both in WKY rats and SHR, miR-208 was most abundantly expressed in 4-week-old rats, but declined significantly in 8-, 16- and 24-week-old rats (P<0.05). No difference in miR-208 levels was observed between age-matched SHR and WKY rats. Moreover, miR-208 expression in aorta was negatively correlated with blood pressure (r=-0.400, P<0.05) and age (r=-0.684, P<0.0001). Neither miR-1 nor miR-133a was differentially expressed in SHR and WKY rats in different age groups. The mRNA levels of predicted target genes were not correlated to miR-155 or miR-208 levels. These results indicate that miR-155 is less expressed in the aorta of adult SHR compared with that of WKY rats and is negatively correlated with blood pressure, suggesting it is possibly involved in the development and pathologic progress of hypertension. The miR-208 expression in rat aorta declines with aging and it may play a role in the blood vessel development.

Aldosterone-induced osteopontin expression in vascular smooth muscle cells involves MR, ERK, and p38 MAPK.

Osteopontin (OPN) is known to be one of the cytokines that is involved in the vascular inflammation caused by aldosterone (Ald). Previous reports have shown that Ald increases OPN expression, and the mechanisms for this remain to be clarified. In this study, we investigated how Ald increases OPN expression in the vascular smooth muscle cells (VSMCs) of rats. Ald increased OPN expression time dependently as well as dose dependently. This increase was diminished by spironolactone, a mineralocorticoid receptor (MR) antagonist. PD98059, an inhibitor of p42/44 MAPK pathway, and SB203580, an inhibitor of p38 MAPK pathway, suppressed Ald-induced OPN expression and secretion in VSMCs. VSMCs migration stimulated by aldosterone required OPN expression. In conclusion, these data suggest that Ald-induced OPN expression in VSMC is mediated by MR and signaling cascades involving ERK and p38 MAPK. These molecules may represent therapeutic targets for the prevention of pathological vascular remodeling.