Sympathetic Overactivity and 24-Hour Blood Pressure Pattern in Hypertensives with Chronic Renal Failure

Abstract

In order to assess the activity of the sympathetic system and to evaluate the 24-h blood pressure pattern in hypertensives with chronic renal failure (CRF), 12 CRF patients and 16 essential hypertensives (EHs) were studied. In all subjects, plasma samples for catecholamines and renin activity were obtained both in the basal condition and after standing, and 24-h blood pressure monitoring (ABPM) was performed. The 24-h mean blood pressure results were quite similar between CRFs and EHs. In 50% of the CRFs, ABPM showed a nighttime decrease in diastolic BP (DBP) greater than 10%, while in the remaining 50% the ABPM indicated a nondipper blood pressure pattern. Of the 16 EHs, 4 had a nighttime decrease in DBP < 10%, that is, nondippers. The study of circulating catecholamines showed no significant differences in plasma epinephrine between CRFs and EHs, while plasma norepinephrine (NE) was significantly higher in hypertensives with CRF than in EHs, both at rest and after standing (p < 0.05 and 0.02, respectively). Among dipper hypertensives, subjects with CRF showed greater values of basal plasma NE than EHs (535 +/- 67 vs. 412 +/- 24.5 pg/mL, p < 0.05); the comparison between dipper and nondipper CRFs showed no differences in circulating NE levels (535 vs. 516 pg/mL). The present study shows that CRFs are characterized by higher values of plasma NE than EHs, and that there are no differences in sympathetic activity between dipper and nondipper hypertensives with CRF.

Sympathetic Activity and Blood Pressure Pattern in Autosomal Dominant Polycystic Kidney Disease Hypertensives

“…Moreover, our finding of no difference in the dipping behavior between the two groups of ADPKD patients subdivided according to renal function, seems to be in accordance with our previous results obtained in patients with chronic renal failure, where no relationship between serum creatinine level and percentage day-night blood pressure difference was observed [43].…”

“…Whatever the reason, it is noteworthy that our finding seems to be in keeping with a growing body of evidence that suggests that renal impulses from an injured kidney may increase sympathetic nervous system activity and contribute to hypertension in renal diseases [43,[47][48][49][50][51][52]. Actually, the kidney is a sensory organ richly innervated, endowed with afferent nerves and two main types of sensory receptors: mechanoreceptors, which increase their firing in response to changes in renal perfusion and intrarenal pressure, and chemoreceptors that are activated by ischemic metabolites, such as adenosine, or uremic toxins.…”

“…In fact, we found higher levels of plasma catecholamines in ADPKD patients when compared with matched essential hypertensives. It is interesting to note that increased plasma concentrations of adrenaline and noradrenaline were observed also in the subset of ADPKD patients with normal renal function, that can affect catecholamines' plasma levels as demonstrated also by our group [43].…”

Blood pressure and progression of chronic kidney disease: Importance of systolic, diastolic, or diurnal variation

“…Similarly, Jensen and Pedersen [39] studied patients with essential hypertension (n = 61), secondary hypertension (n = 32), and chronic renal failure (n = 32) matched with healthy control subjects (n = 35), and demonstrated that nighttime BP was higher among the chronic renal failure patients than in the control group, and the nightly fall in BP was reduced. Similar data about the lack of nocturnal BP decline in patients with chronic renal insufficiency have been reported in other studies [40,41]. Most hypertensive ESRD patients demonstrate a "non-dipper" profile [42][43][44].…”

Decline of Renal Function Is Associated with Proteinuria and Systolic Blood Pressure in the Morning in Diabetic Nephropathy

“…An implication of elevation of blood pressure in the moming is considered to have two effects: one is loss of the physiological noctumal decline in blood pressure and the other is so called "morning surge." Several studies using ambulatory hlood pressure monitoring revealed that patients with chronic renal diseases have a blunted blood pressure profile, mainly due to extracellular iluid volume expansion and/or hyperactivity of the renin-angiotensin system (17)(18)(19)(20). Moreover, our recent study has indicated that elevation of blood i36 H. Suzuki et al pressure in the moming had a close association with a decline of GFR in the patients with nondiahetic chronic kidney diseases (10).…”