Arterial Stiffness, Cognitive Dysfunction and Adherence to Antihypertensive Agents. Is there a Link to Hypertensive Patients?

The incidence of hypertension (HTN) and its cardiovascular (CV) complications are increasing throughout the world. Blood pressure (BP) control remains unsatisfactory worldwide. Medical inertia and poor adherence to treatment are among the factors that can partially explain, why BP control rate remains low. The introduction of a method for measuring the degree of adherence to a given medication is now a prerequisite. Complex treatment regimes, inadequate tolerance and frequent replacements of pharmaceutical formulations are the most common causes of poor adherence. In contrast, the use of stable combinations of antihypertensive drugs leads to improved patient adherence. We aim to review the relationships between arterial stiffness, cognitive function and adherence to medication in patients with HTN. Large artery stiffening can lead to HTN. In turn, arterial stiffness induced by HTN is associated with an increased CV and stroke risk. In addition, HTN can induce disorders of brain microcirculation resulting in cognitive dysfunction. Interestingly, memory cognitive dysfunction leads to a reduced adherence to drug treatment. Compliance with antihypertensive treatment improves BP control and arterial stiffness indices. Early treatment of arterial stiffness is strongly recommended for enhanced cognitive function and increased adherence.

Arterial damage and cognitive decline in chronic kidney disease patients.

In the general population aortic stiffening, assessed by carotid femoral pulse wave velocity (cf-PWV), is associated with cognitive dysfunction (CO/DY). Data in chronic kidney disease (CKD) are limited. This study tests the hypothesis that large artery stiffness and microvascular damage in CKD patients are related to the damage of brain microcirculation reflected by impaired cognitive function. A cross-sectional study enrolled 151 patients (mean age 58.4 years; 64.5% males; 44 patients with CKD stage 1; 47 with stage 2; 25 with stage 3; and 35 with stage 4). Cognitive impairment, assessed by the Mini Mental State Examination (MMSE), the Clock - drawing test (Clock-test), and the Instrumental Activity of Daily Living (IADL), was considered as primary outcome. We measured systolic and pulse pressures at the brachial and aortic sites and cf-PWV. Our patients revealed a significant linear deterioration in all the domains of cognitive function according to CKD stages. High values of cf-PWV (P = 0.029) and aortic pulse pressure (aPP) (P < 0.026) were independent determinants of cognitive decline assessed by the MMSE. The present trial supports the hypothesis of an interaction between the kidney, large artery damage, central pressure pulsatility, and the injury of brain microcirculation. In clinical practice, cf-PWV and aPP measurements may help to predict cognitive decline. Whether the reduction in aortic stiffness following an aggressive treatment translates into improved cognitive outcomes remains to be determined.

Albuminuria as a marker of arterial stiffness in chronic kidney disease patients.

AIM: To access the association between albuminuria levels and arterial stiffness in non-diabetic patients with hypertension and chronic kidney disease (CKD) stages 1-2, treated with renin angiotensin blockade agents plus other hypertensive drugs when needed. METHODS: One hundred fifteen patients [median age 52 years (68% males)] were consequently enrolled in the study. For each patient, we recorded gender, age, body mass index (BMI), peripheral systolic blood pressure (pSBP), peripheral diastolic blood pressure, peripheral pulse pressure, central systolic blood pressure (cSBP), central diastolic blood pressure (cDBP), central pulse pressure (cPP), hematocrit, hemoglobin, hsCRP, total cholesterol triglycerides, high-density lipoprotein-C, low-density lipoprotein-C, calcium, phosphorus, parathormone, and albumin, as well as 24 h urine albumin excretion. According to 24-h urine albumin collection, patients were then classified as those with moderately increased albuminuria (formerly called macroalbuminuria) (≤ 300 mg/d) and those with severely increased albuminuria (formerly called macroaluminuria (> 300 mg/d). We considered aortic stiffness (AS) indices [carotid femoral pulse wave velocity (PWVc-f) and augmentation index (AIx)] as primary outcomes of the study. We explored potential correlations between severely increased albuminuria and AS indices using a multiple linear regression model. RESULTS: Fifty-eight patients were included in the moderately increased albuminuria group and 57 in the severely increased albuminuria. Blood pressure measurements of the study population were 138 ± 14/82 ± 1.3 mmHg (systolic/diastolic). There were no significant differences in age, sex, and BP measurements between the two groups. Patients with severely increased albuminuria had higher PWV and AIx than patients with moderately increased albuminuria (P < 0.02, P < 0.004, respectively). In addition these patients exhibited higher BMI (P < 0.03), hsCRP (P < 0.001), and fibrinogen levels (P < 0.02) compared to patients with moderately increased albuminuria. In multivariate linear regression analysis, severely increased albuminuria (ß = 1.038, P < 0.010) pSBP (ß = 0.028, P < 0.034) and Ht (ß = 0.171, P = 0.001) remained independent determinants of the increased PWVc-f. Similarly, severely increased albuminuria (ß = 4.385, P < 0.012), cSBP (ß = 0.242, P < 0.001), cPP (ß = 0.147, P < 0.01) and Ht levels (ß = 0.591, P < 0.013) remained independent determinants of increased AIx. CONCLUSION: These findings demonstrate an independent association between AS indices and severely increased albuminuria in non-diabetic, hypertensive patients with CKD stages 1-2 treated with renin angiotensin aldosterone system blockers.

Efficacy of aliskiren and valsartan in hypertensive patients with albuminuria: a randomized parallel-group study.

INTRODUCTION: Blockade of the renin-angiotensin system (RAS) is a critical approach to the management of hypertension, especially in proteinuric patients. It is well proven that the direct renin inhibitor aliskiren shows comparable clinical efficacy to the angiotensin II receptor blocker valsartan on blood pressure control and albuminuria. However, there is only limited data on the hand-to-hand effectiveness of these two RAS blockers in improving arterial stiffness. We tested whether aliskiren or valsartan would improve arterial stiffness in hypertensive patients with albuminuria who are already on antihypertensive therapy. MATERIAL AND METHODS: Thirty-four patients with hypertension and albuminuria < 1 g, after a wash-out period of three weeks, were randomized to aliskiren or valsartan in a 24-week randomized parallel-group study. RESULTS: A nonsignificant difference in blood pressure was seen between the two treatment groups. Albuminuria was significantly reduced in both groups (56% for the aliskiren group, p < 0.05, and 38% for the valsartan group, p < 0.05). Only valsartan but not aliskiren significantly reduced carotid-femoral pulse wave velocity (-1.1 ± 0.8 m/s (p = 0.02) for valsartan and +0.1 ± 0.7 m/s (ns) for aliskiren). CONCLUSION: The results of our study showed that valsartan improves arterial stiffness to a significantly greater extent than aliskiren, despite a similar antihypertensive and antiproteinuric effect.

Risk factors for cognitive dysfunction in CKD and hypertensive subjects.

PURPOSE: Cognitive dysfunction (CO/DY) in chronic kidney disease (CKD) patients has long been recognized. Hypertension is also associated with CO/DY. The study describes associated factors with CO/DY in CKD patients compared to hypertensive subjects. METHODS: Ninety-six hypertensive subjects without CKD, 19 patients with CKD stages I-II, 33 with CKD III, 42 with CKD stage IV, 33 on hemodialysis (HD) and 33 on peritoneal dialysis (PD) were included in our study. Cognitive impairment measured by MMSE, clock-drawing test and IADL was considered as primary outcome. RESULTS: In all groups tested, age was significantly associated with CO/DY by almost all cognitive function tests. Among CKD patients, CKD stage and DM were significantly associated with CO/DY by all three cognitive function tests. PTH levels were also associated with CO/DY by MMSE and clock-drawing tests. In hypertensives, pulse pressure (PP) was associated with CO/DY by clock-drawing and IADL tests, while those receiving CCBs as monotherapy were less likely to have CO/DY by IADL test. For dialysis patients, DM was significantly related to CO/DY by MMSE and clock-drawing tests. In the same group of patients Hb <11 g/dl was significantly correlated with CO/DY by MMSE, dialysis modality and Kt/V >1.2 by IADL test. PD patients were less likely to present with CO/DY by clock-drawing test. CONCLUSIONS: In every CKD stage, the risk of CO/DY increased significantly. Low Hb levels (Hb <11 g/dl) and increased serum PTH levels were associated with CO/DY while DM plays also a significant role in cognitive function deterioration. Among hypertensive subjects, those with PP ≤60 mmHg or receiving CCBs showed a better executive function.