Dynamics of the circadian blood pressure profiles after renal transplantation

BACKGROUND: Abnormalities of diurnal blood pressure (BP) rhythm ("nondipping") are well-described in dialysis patients, and have prognostic importance. It is controversial whether successful renal transplantation (RTx) improves diurnal BP rhythm. To date, no study has attempted to define and model the evolution of diurnal BP rhythm profiles from dialysis to engraftment, focusing on the immediate (4-6 weeks) and medium-term (>1 year) postengraftment periods. METHODS: To test if kidney transplantation normalizes the BP profile, ambulatory blood pressure monitoring (ABPM) was performed in 20 living related transplants (age, 30.3+/-5.1 years; 11 males, on dialysis for 25.6 months) 1 month preRTx and repeated 1 month and >1 year (ABPM3) after successful RTx. Dipping was defined as a sleep-to-awake ratio>0.92 (for systolic BP) and >0.90 (for diastolic BP). RESULTS: PreRTx only 15% patients were dippers. At 1 month postRTx (creatinine clearance, 65.8 ml/min), all patients were complete nondippers. However, after >1 year postRTx (creatinine clearance, 70.4 ml/min), 40% were now dippers. Most importantly, overall, 30% of the patients improved significantly their circadian rhythm (35.3% of the initial preRTx nondippers). Despite successful renal transplantation, 55% patients maintained unchanged their nondipping profile throughout all three ABPM recordings. The only determinants of "long-term" postRTx circadian rhythm are the contemporary level of the renal function and the baseline, dialysis dipping profile: SBP3 sleep-to-awake ratio is related with serum creatinine3 (r=0.58, P=0.001), creatinine clearance (r=-0.41, P=0.036) and SBP1 sleep-to-awake ratio (r=0.48, P=0.034); similarly DBP3 sleep-to-awake ratio is related with serum creatinine3 (r=0.63, P=0.001), creatinine clearance (r=-0.471, P=0.036) and SBP1 sleep-to-awake ratio (r=0.53, P=0.016). In all, 57% of the variance in dipping status can be attributed and explained by the contribution of renal function and initial circadian variability. CONCLUSIONS: Half of the nondipper dialysis patients maintain a permanently abnormal circadian rhythm, despite successful RTx. In the short term, RTx is associated with a highly abnormal diurnal profile, exclusively related to ciclosporin dose and levels. However, in the longer term, renal transplantation leads to a significant improvement of the circadian blood pressure profile, influenced by the renal function level and by the pretransplantation dipping profile.     

Ambulatory blood pressure monitoring in nephrology: focus on BP variability.

As accurate assessment of hypertension in renal patients must be the cornerstone of better prevention of its deleterious effects, ambulatory blood pressure monitoring (ABPM) has become an essential clinical and research procedure in day to day nephrological practice. However, despite numerous studies in the renal literature, a consensus is needed for normal (desirable?!) ambulatory daytime and nighttime BP levels and for defining normal sleep BP dipping. Nevertheless, blunted sleep BP fall appears to be a ubiquitous finding in renal disease (primary renal conditions, chronic renal failure pre-dialysis, peritoneal and hemodialysis, and renal transplantation). Abnormal diurnal variability should be considered as an important contributor to cardiac and general morbidity as it is clearly associated with a faster decline in renal function and also with more cardiac structural and functional abnormalities - especially left ventricular dilatation. Several mechanisms have been proposed to explain the reduced BP circadian rhythm, but the majority of the supporting evidence is still contradictory. A novel, unifying hypothesis to be tested in future studies, is linking the common diurnal rhythm abnormalities with functional disturbances in aortic and carotid baroreflexes caused by uraemia-related large arterial structural changes (arterial intima and media thickening, arterial calcifications and increased arterial stiffness).     

Nighttime blood pressure fall in renal disease patients

OBJECTIVE: There are controversial reports in the prevalence of abnormal nighttime blood pressure fall in renal patients. It has been evaluated nocturnal BP in renal patients using 24 h blood pressure monitoring (ABPM) in comparison with nontreated control subjects either normotensives or hypertensives. DESIGN: AND METHODS: It has been reviewed 137 ABPM studies performed in renal patients (47.8 +/- 15.4 years, 76 men and 61 women). The control group includes 119 subjects without kidney disease, 65 were normotensives, and 49 were hypertensives, aged 46.8 +/- 12.1 years, 59 men and 60 women. The ambulatory BP was measured noninvasively for 24h by the SpaceLabs 90207 device programmed to measure BP every 15 min during daytime and every 20 min during nighttime. The definition of daytime and nighttime was made on the basis of wakefulness and sleep or bed rest periods, obtained from a diary kept by each subject. RESULTS: SBP, but not DBP, was higher (133.9/81.7) in renal disease patients when compared to nonrenal subjects (127.9/80.8, p < 0.01). When the control group was split into normotensive and hypertensive patients there were still significant differences, but hypertensives had higher BP than renal disease patients (139.0/89.7, p < 0.05). Nocturnal SBP fall in renal disease patients was reduced (5.8%, p < 0.001) and so was DBP fall (11.1%, p < 0.001) compared with the overall nonrenal patients sample (SBP 10.8; DBP 15.3%). The frequency of nondipper status in renal disease patients (39.6%) was higher than in control patients (18.4%, p < 0.001). Nontreated normotensive renal disease patients did not show any difference in either SBP or DBP nighttime fall with respect to control normotensives. Neither do nontreated hypertensive renal patients as compared with control hypertensives. There were not differences between proteinuric and nonproteinuric patients in nocturnal BP fall. The same result was obtained when hypertensive and normotensive nontreated renal patients were compared. The presence of renal failure did not induce a reduction of nocturnal BP fall. Most of treated renal patients were mainly receiving drug therapy during the morning and frequently this was the single daily dose. CONCLUSIONS: Altered diurnal rhythm should not be considered as a usual complication of renal disease. Inadequate antihypertensive pharmacotherapy could be related to the abnormalities of nighttime BP fall when it is detected.     

How reproducible is diurnal blood pressure rhythm in patients with secondary (renal) hypertension?

Abnormalities (reduction in/absence of) in diurnal bp rhythm are much more commonly seen in patients with chronic uremia than in patients with primary hypertension or in normal subjects. Target-organ damage is greater in these patients. However, the extent to which these diurnal bp rhythm changes are consistent or variable is untested. We retrospectively examined 223 ambulatory blood pressure monitoring (ABPM) traces in 92 patients with chronic uremia who had undergone ABPM at least twice (mean 2.3 ABPM traces/patient) over the period 1991-1997. ABPM technique and analysis were constant over this period. We found that for patients with chronic declining renal function but not yet on dialysis therapy, 67% retained the same diurnal rhythm from one ABPM recording to the next; if the known tendency for declining renal function to accompanied by a greater prevalence of "non-dipping" is taken into account, 82% of all patients had a "predictable" diurnal pattern. 79% of transplant patients, 87% of haemodialysis patients and 100% of CAPD patients retained the diurnal rhythmicity from one ABPM session to the next. Non-dipping was much more frequent than dipping (67% vs 33%). We conclude that abnormalities of diurnal BP rhythm are reasonably consistent in patients with renal hypertension, especially as renal function declines and patients enter the renal replacement therapy programme.     

Non-dipping is a potent predictor of cardiovascular mortality and is associated with autonomic dysfunction in haemodialysis patients.

BACKGROUND: Lack of nocturnal blood pressure (BP) fall (non-dipping) is common among haemodialysis (HD) patients, but much less is known regarding its association with cardiovascular (CV) disease morbidity and mortality. METHODS: Eighty HD patients initially underwent 24 h ambulatory BP monitoring (ABPM), and then they were defined as either 'dippers' (n=24, nocturnal BP fall > or = 10%) or 'non-dippers' (n=56, fall <10%). Coronary angiography was performed in the patients who had signs and/or symptoms of coronary artery disease (CAD). Twenty-four hour ambulatory ECG was recorded in 20 dippers and 20 non-dipper HD patients, and in 20 normal subjects. All patients were followed for up to 5.8 years (33.0+/-19.1 months). The outcome events studied were the hospitalisations due to CV diseases and CV death. RESULTS: Compared with dippers, non-dippers initially had a higher incidence of coronary artery stenosis (P<0.05) along with left ventricular asynergy (both Ps<0.01). The circadian rhythm of autonomic function was impaired in non-dippers. The incidences of CV events and CV deaths were 3.5 and 9 times higher in non-dippers than in dippers. The cumulative CV event-free survival and CV survival rates were lower in non-dippers than in dippers (P=0.02 and P=0.005, respectively). Based on Cox analysis, non-dipping was associated positively with CV events and CV mortality [hazard ratio (HR) 2.46, 95% CI 1.02-5.92, P=0.038 and HR 9.62, 95% CI 1.23-75.42, P=0.031, respectively]. Meanwhile, nocturnal systolic BP fall, diurnal systolic BP and diurnal pulse pressure were negatively associated with CV event/death. The clinic BP was not associated with CV event/death. CONCLUSIONS: The non-dipping phenomenon is closely related to a high incidence of CV diseases, a poor long-term survival and profound autonomic dysfunction. ABPM is useful in predicting long-term CV prognosis in HD patients.     

Ultradian but not circadian blood pressure rhythms correlate with renal dysfunction in children with chronic renal failure

Whereas the diurnal fall of BP (dipping) is an important prognostic marker in patients with chronic renal failure (CRF), the integrity of physiologic ultradian (i.e., shorter than 24 h) cardiovascular rhythms in patients with CRF is unknown. Also, the relationship between conventional dipping analysis and Fourier spectral rhythm analysis has not been examined in renal hypertension. The prevalence and dimensions of the circadian and three ultradian (12, 8, and 6 h) cardiovascular rhythms were studied by ambulatory BP monitoring in 214 children (aged 3 to 18 yr) with CRF (stage 2 to 4 chronic kidney disease) and no antihypertensive treatment compared with 938 healthy control subjects, and the relationship of rhythm characteristics to conventional dipping parameters, renal function, proteinuria, and serum electrolytes was assessed. The CRF cohort exhibited significantly reduced amplitudes of the circadian and all ultradian cardiovascular rhythms studied (all P < 0.01). Moreover, all BP and most heart rate rhythms showed significantly delayed acrophases (time of peak; P < 0.01). Whereas conventional BP dipping parameters (day/night difference, day/night ratio) and the 24-h BP amplitude were independent of renal function, the 8-h BP amplitude was positively correlated with GFR (r = 0.3, P = 0.01) and inversely correlated with the urinary protein/creatinine ratio (r = -0.27, P < 0.05), and the 6-h BP amplitude was inversely correlated with proteinuria (r = -0.3, P < 0.02). Children who displayed 24- or 12-h cardiovascular rhythms had significantly lower serum calcium levels than children without these rhythms. In summary, children with CRF display not only blunted circadian but also blunted ultradian cardiovascular rhythms. Ultradian but not circadian rhythms or conventional dipping parameters are quantitatively associated with renal function and proteinuria.     

Nighttime Blood Pressure Fall in Renal Disease Patients

Objective.?There are controversial reports in the prevalence of abnormal nighttime blood pressure fall in renal patients. It has been evaluated nocturnal BP in renal patients using 24 h blood pressure monitoring (ABPM) in comparison with nontreated control subjects either normotensives or hypertensives. Design and Methods.?It has been reviewed 137 ABPM studies performed in renal patients (47.8 ± 15.4 years, 76 men and 61 women). The control group includes 119 subjects without kidney disease, 65 were normotensives, and 49 were hypertensives, aged 46.8 ± 12.1 years, 59 men and 60 women. The ambulatory BP was measured noninvasively for 24 h by the SpaceLabs 90207 device programmed to measure BP every 15 min during daytime and every 20 min during nighttime. The definition of daytime and nighttime was made on the basis of wakefulness and sleep or bed rest periods, obtained from a diary kept by each subject. Results.?SBP, but not DBP, was higher (133.9/81.7) in renal disease patients when compared to nonrenal subjects (127.9/80.8, p<0.01). When the control group was split into normotensive and hypertensive patients there were still significant differences, but hypertensives had higher BP than renal disease patients (139.0/89.7, p<0.05). Nocturnal SBP fall in renal disease patients was reduced (5.8%, p<0.001) and so was DBP fall (11.1%, p<0.001) compared with the overall nonrenal patients sample (SBP 10.8; DBP 15.3%). The frequency of nondipper status in renal disease patients (39.6%) was higher than in control patients (18.4%, p<0.001). Nontreated normotensive renal disease patients did not show any difference in either SBP or DBP nighttime fall with respect to control normotensives. Neither do nontreated hypertensive renal patients as compared with control hypertensives. There were not differences between proteinuric and nonproteinuric patients in nocturnal BP fall. The same result was obtained when hypertensive and normotensive nontreated renal patients were compared. The presence of renal failure did not induce a reduction of nocturnal BP fall. Most of treated renal patients were mainly receiving drug therapy during the morning and frequently this was the single daily dose. Conclusions.?Altered diurnal rhythm should not be considered as a usual complication of renal disease. Inadequate antihypertensive pharmacotherapy could be related to the abnormalities of nighttime BP fall when it is detected.     

慢性肾脏病患者血压昼夜节律异常的研究

目的 观察慢性肾脏病(CKD)患者24 h血压动态变化，探讨昼夜节律异常与肾功能损害的关系。方法 随机选择本院肾脏科CKD患者236例，高血压科原发性高血压住院患者43例。病例分组:正常对照组(NC)14例；原发性高血压组(EHC)43例；CKD血压正常组(NCKD)130例；CKD伴血压升高组(HCKD)106例。动态血压监测(ABPM)采用携带式的动态血压检测仪，ABP Report Mangement System Version 1.03.03进行数据分析。夜间血压下降率:(白昼平均值-夜间平均值)/白昼平均值，下降率≥10%，称勺型血压；<10%，称非勺型血压。结果 在血压正常的患者中，NCKD组的平均夜间收缩压和舒张压数值均高于NC组[(111.2±10.8)比 (91.6±7.5)，(68.7±9.5) 比 (56.2±4.6)mm Hg，P < 0.05]；而日间收缩压和舒张压无明显差异。在高血压患者中，HCKD组患者夜间收缩压和舒张压数值均高于EHC组[(141.9±16.5) 比(118.6±16.4)， (84.5±10.6)比(73.0±11.1)mm Hg， P < 0.05]。CKD患者无论血压正常或升高，其心率均较其对照组明显加快，尤其是夜间心率无明显下降。NCKD组、HCKD组与NC组、EHC组相比，夜间收缩压和舒张压下降数值较小，尤其是CKD伴血压升高组，呈典型的非勺型血压模式。NC组血压节律消失者占7.14%，EHC组为37.2%，NCKD组为70.0%，HCKD组为81.6%。结论 CKD患者无论血压正常或升高，夜间收缩压和舒张压下降减少或消失，呈典型的非勺型血压；血压昼夜节律异常率明显高于原发性高血压患者。在积极降低血压值的同时，还需降低血压负荷和调整血压昼夜节律，以延缓肾功能恶化。     

Clinical and pathological significance of circadian blood pressure rhythm change in IgA nephropathy patients with hypertension

Objective To investigate whether the clinical and pathological injury of kidney in IgA nephropathy (IgAN) patients with hypertension is associated with circadian blood pressure rhythm change, particularly with elevated nocturnal blood pressure (BP). Methods This study was a retrospective cross-sectional study. Clinic and renal histopathological injury data were obtained from 83 IgAN patients with hypertension. First, 24 h ambulatory BP monitoring (ABPM) data were analyzed. Second, all these IgAN patients were divided into two groups, elevated nocturnal BP group and nocturnal normotensive BP group, and the clinical and pathological differences between this two groups were analyzed. Third, logistic regression analysis was used to analyze the influencing factors of renal tubulointerstitial injury in IgAN patients with hypertension. At last, all these IgAN patients were divided into two groups according to the level of estimated glomerular filtration rate (eGFR), group of patients with eGFR≥60 ml?min-1?(1.73 m2)-1 and the other group with eGFR＜60 ml?min-1?(1.73 m2)-1, and the 24 h ABPM data were compared. Results (1) The proportion of non-dipper circadian rhythm of BP in IgAN patients with hypertension was 79.5%. (2) Compared with nocturnal normotensive BP group, patients in elevated nocturnal BP group had significantly higher levels of 24-hour urinary protein quantity and blood uric acid (both P＜0.05), and lower eGFR and urine osmotic pressure clinically (both P＜0.05). Index of interstitial fibrosis and tubular atrophy was significantly higher in nocturnal normotensive BP group (P＜0.05), while the proportion of glomerular ischemia lesion was not significantly different between two groups. (3) Multivariate logistic regression analysis showed that elevated nocturnal BP was an independent risk factor for severe tubulointerstitial injury of IgAN (OR=1.113, 95%CI 1.038-1.192, P=0.002). (4) Compared with the group of eGFR≥60 ml?min-1?(1.73 m2)-1, 24-hour systolic blood pressure (SBP) and diastolic blood pressure (DBP), daytime SBP and DBP, nocturnal SBP and DBP were significantly higher in group of eGFR＜60 ml?min-1?(1.73 m2)-1 (all P＜0.05). Conclusion The proportion of non-dipper circadian rhythm of BP in IgAN patients with hypertension is as high as 79.5%. Elevated nocturnal BP is associated with the severity of renal damage, and elevated nocturnal BP is an independent risk factor for severe tubulointerstitial injury in IgAN patients with hypertension. Therefore, 24 h ABPM should be emphasized, and elevated nocturnal BP should be well controlled to slow the progression of IgAN.     

Ambulatory blood pressure and left ventricular mass in normotensive patients with autosomal dominant polycystic kidney disease

Higher left ventricular mass (LVM) has been found in early stages of autosomal dominant polycystic kidney disease (ADPKD). The mechanisms involved in the increase of LVM are unknown. To investigate whether LVM in ADPKD may be influenced by abnormal diurnal BP variations, the 24-h ambulatory BP profile was analyzed in a group of young normotensive ADPKD patients. Ambulatory BP monitoring and two-dimensional echocardiography were performed in 26 young normotensive ADPKD with normal renal function and in 26 healthy control subjects. LVM index was higher in ADPKD patients than in controls (90.8+/-19.6 g/m2 versus 73.9+/-16.1 g/m2, P = 0.001). Average 24-h and daytime systolic, diastolic, and mean BP were similar in both groups. Nighttime diastolic and mean BP, but not systolic BP, were greater in ADPKD patients. The average and percent nocturnal decrease of systolic BP was lower in ADPKD patients than in control subjects (10.0 mm Hg [-3 to 24] versus 15.5 mm Hg [-4 to 31], P = 0.009, and 9.0% [-2 to 22] versus 14.2% [-2 to 25], P = 0.016, respectively). On the basis of their profile BP patterns, 54% of ADPKD subjects and 31% of controls were classified as nondippers (P = 0.092). There were no differences between dippers and nondippers in left ventricular wall thickness, chamber dimensions, and mass indexes. In ADPKD patients, simple regression analysis showed that LVM index was correlated with 24-h, daytime, and nighttime systolic BP. On multiple regression analysis, the 24-h systolic BP was the only variable linked to LVM index. It is concluded that young normotensive ADPKD patients have higher LVM that is closely related to the ambulatory systolic BP. The nocturnal fall in BP is attenuated in these patients, although it is not associated with the higher LVH that they present.     

慢性肾脏病患者血压非勺型节律与左心室肥厚之间的关系

目的 探讨24 h动态血压（ABPM）非勺型节律与慢性肾脏病（CKD）患者左心室肥厚（LVH）之间的关系。 方法 共有257例CKD 1~5期患者入选,根据肾功能分为两组：CKD1~3期组和CKD4~5期组。采用GE Marquette Tonoport V Eng动态血压计测定各组患者动态血压参数和昼夜节律;心脏彩色多普勒超声了解心脏结构的改变,并探讨血压非勺型节律与LVH之间的关系。 结果 CKD患者血压正常的生理节律丧失的现象普遍,总体血压非勺型昼夜节律发生率达75.4％,即使在血压正常者中也达到71.3%,随着肾功能下降血压非勺型昼夜节律的发生率也在上升。CKD患者血压非勺型节律组的心脏结构改变较勺型组明显,LVH的发生率也较高。相关性分析显示左室心肌质量指数（LVMI）与血压水平、非勺型的昼夜节律等相关。多元逐步回归分析显示24 h-收缩压（SBP）（β = 0.417,P < 0.01）、三酰甘油 （β = -0.132,P = 0.007）、血红蛋白（Hb）（β = -0.394,P = 0.016）及性别（β = 0.158,P = 0.039）是影响LVMI的独立危险因素。 结论 CKD患者的血压非勺型昼夜节律现象普遍,并随着肾功能的下降其发生率逐渐升高。血压非勺型节律患者心脏结构改变更明显,LVH的发生率高。非勺型节律与LVMI密切相关。     

Ambulatory blood pressure monitoring in patients receiving long, slow home haemodialysis.

BACKGROUND: Good blood pressure (BP) control has been reported previously in haemodialysis (HD) patients receiving 8-h dialysis sessions. Home HD allows patients to dialyze for long periods, but there are few data on the BP control achieved by these patients. We studied BP control, using ambulatory blood pressure monitoring (ABPM), in our home-HD patients who were receiving long-hours dialysis. METHODS: Twenty-four patients aged 52.7+/-11 years underwent ABPM. They had been on home HD for 52.9+/-39 months and dialysed for 7.2+/-1.1 h thrice weekly. Two patients were taking antihypertensive drugs. Historical data on BP and weight gains were obtained from the patients' own records. Left ventricular (LV) mass was assessed by echocardiography and total body water (TBW) by bioelectrical impedance. RESULTS: The mean 24-h BP was 129+/-17 mmHg (systolic) and 83+/-14 mmHg (diastolic). The daytime BP was 131+/-17 mmHg (systolic) and 84+/-14 mmHg (diastolic), while the night-time BP was 126+/-22 mmHg (systolic) and 81+/-17 mmHg (diastolic). Six patients (25%) had a normal circadian BP rhythm, but the rest showed a subnormal fall or an increase in BP at night. Mean 24-h BP did not correlate significantly with time on dialysis, dialysis session length, Kt/V, haemoglobin, interdialytic weight gain, or TBW. Twenty-one patients (87%) had LV hypertrophy and 16 of these had diastolic dysfunction. LV mass index was inversely correlated with nocturnal BP fall (r=-0.54, P=0.03). Non-dippers had been treated longer than dippers (29 vs 59.2 months, P=0.03) but they were similar in respect to age, dialysis session length or Hb concentration. CONCLUSIONS: Long, slow haemodialysis at home provides satisfactory daytime BP control in the majority of patients without the need for antihypertensive drugs but abnormal circadian BP rhythm and LV hypertrophy remain common.     

Nighttime blood pressure control in hypertensive chinese chronic kidney disease patients

Objective To evaluate the nighttime blood pressure(BP) control status of hypertensive Chinese chronic kidney disease (CKD) patients and related risk factors. Methods This cross - sectional study enrolled 337 hypertensive CKD in - patients. The clinical and ambulatory BP monitoring (ABPM) data were retrieved from the electronic database of the hospital. High ambulatory BP were defined as >130/80 mmHg (average 24 - hour BP) and >135/85 mmHg (daytime) />120/70 mmHg (nighttime), respectively. Multivariable analysis was used to evaluate the risk factors for lack of nighttime BP control and circadian rhythm. Results There were 38.6% of the whole population had average 24-hour BP controlled. But only 22.8% of them achieved nighttime BP control, which was far less than the 50.7% of daytime BP control (P＜0.01). Even among those patients who achieved average 24 - hour BP control shown by ABPM, there were still 44.6% of them with uncontrolled nighttime BP. Multiple analyses showed urinary protein excretion (OR: 1.151, 95%CI: 1.035-1.279) was independent risk factor for lack of nighttime BP control. About 80% of patients presented with non- dipping BP pattern, among whom 37.3% were presented with reverse-dipper pattern. Lack of nighttime BP control was independent risk factor for lack of normal circadian rhythm (both P＜0.001). Conclusions Lack of nighttime BP control was common in hypertensive CKD patients and contributed to the abnormal circadian rhythm. ABPM should be performed more commonly in clinical practice to help nighttime BP control in the future.     

Autonomic dysfunction and ambulatory blood pressure in renal transplant recipients

BACKGROUND: Abnormal circadian blood pressure (BP) rhythm (nondipping) and autonomic dysfunction are both common in end-stage renal disease (ESRD). It is not known whether these abnormalities are related or if they are associated with greater left ventricular hypertrophy. METHODS: Nineteen renal transplantation (RT) recipients, aged 22-67 years, who were transplanted at least 12 months (1-29 years) previously, were studied with 24-hr ambulatory blood pressure monitoring (ABPM). Autonomic function was tested by automated analysis of heart rate variations and echocardiography was used to estimate left ventricular mass index (LVMI). RESULTS: Thirteen patients (68%) were nondippers. Although seven (37%) patients had significant parasympathetic dysfunction, this was not related to dipper status. Neither abnormality showed a tendency to diminish with time after RT. Systolic hypertension, diagnosed by ABPM, occurred in 5% of patients during the awake period and in 52% during sleep, whereas diastolic hypertension occurred in 47% when awake and in 63% when asleep. Awake systolic BP was the strongest predictor of LVMI (r=0.7, P<0.001), and was considerably better than systolic BPs recorded at the clinic (r=0.48, P<0.05). CONCLUSIONS: Nondipping is common after RT but is not related to the degree of autonomic dysfunction. These findings suggest that autonomic dysfunction is not a major contributor to nondipping in ESRD. In RT patients, ABPM is a more sensitive measure of hypertension and a stronger predictor of LVMI than clinic BP.     

Arterial hypertension in liver transplant recipients

Hypertension is an important cardiovascular risk factor that influences patient survival. This study sought to evaluate hypertension incidence and circadian rhythms of blood pressure (BP) among liver transplant recipients during the first posttransplant month. We also compared hypertension incidence according to clinical and automated blood pressure monitoring methods. BP was determined by clinical blood pressure monitoring (CBPM) methods and by automated blood pressure monitoring (ABPM) using the SpaceLabs device. We also assessed blood biochemistry, particularly kidney function parameters and immunosuppressive drug blood trough levels, among 32 white subjects (10 women and 22 men) of average age 47.58 ± 14.19 years. The leading cause for transplantation was liver insufficiency due to viral hepatitis B and/or C infection (43.75%). The majority (93.75%) of patients was prescribed immunosuppressive treatment with tacrolimus. Although we observed hypertension in 28 patients (87.5%) by ABPM measurements and in 25 (78.12%) using CBPM method, the difference did not reach statistical significance. However, BP control was inadequate in 28 patients (87.5%) by ABPM assessment versus 3 (9.38%) according to CBPM readings (P = .025). The BP circadian rhythm was altered in 30 patients (93.75%) including 15 with higher nighttime BP readings. There was no correlation between tacrolimus blood levels and BP values or with kidney function as assessed by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. We concluded that prevalence of arterial hypertension among liver transplant recipients within 1 month after transplantation is high. The majority of the patients show disturbed circadian rhythms in the early period after liver transplantation with loss or even reversal of the normal nocturnal decrease in BP. Owing to the fact that ABPM enables more adequate daily assessment of BP values, it is an optimal method to adjust antihypertensive therapy to optimal levels.     

Circadian rhythm of blood pressure in patients with benign prostatic hyperplasia

OBJECTIVE: Nocturia, a common and bothersome symptom of benign prostatic hyperplasia (BPH), may cause sleep disturbances. Patients with nocturia may have difficulty returning to their normal sleep after repeated episodes of waking and voiding. Therefore, nocturia may have an impact on the circadian rhythm of blood pressure (BP). The association between nocturia and the circadian rhythm of BP was investigated in this study. MATERIAL AND METHODS: A total of 100 male patients who had been diagnosed with BPH and 53 healthy male subjects were included in the study. Nocturnal urinary frequency was assessed by means of a questionnaire and recorded in both groups. Ambulatory BP monitoring was performed in all patients over a 24-h period. RESULTS: Patient characteristics and laboratory parameters were similar in both groups. Seventy-five patients (75%) in the BPH group and 20 subjects (37.7%) in the control group were non-dippers, i.e. they did not have a normal nocturnal fall in BP, and this difference was statistically significant (p=0.001). Eighty-nine patients in the BPH group and 13 in the control group had nocturia. Seventy-one patients (79.8%) with nocturia were non-dippers and the difference compared to the patients without nocturia in the BPH group was significant (p=0.003), whereas four patients with nocturia (30.8%) were non-dippers in the control group. CONCLUSIONS: Our findings indicate that non-dipping was more prevalent in elderly men with BPH and nocturia. BPH and nocturia may be etiological factors in the pathogenesis of non-dipping, which is an indicator of early cardiovascular disease. Further studies must focus on this relationship and, especially, on whether treatment of nocturia and BPH helps to treat non-dipping or not.     

Ambulatory blood pressure monitoring in children: a large center’s experience

Ambulatory blood pressure monitoring (ABPM) is well established in adults and is becoming common in children. We reviewed 190 ABPM studies retrospectively (since 1990) to assess the failure rate, and analyzed the data from 97 patients 5–19 years old (1992–1996) to review the experience gained from the use of this technique in children and adolescents. Seventeen percent (32/190) of studies failed. Most children accepted ABPM, provided it was clearly explained in advance. There were differences between day and night readings of systolic blood pressure (BP), diastolic BP, and heart rate. BP did not correlate with height or weight. ”White coat” effect apparently exists in children: clinic systolic BPs were higher than daytime systolic ABPM (no difference in diastolic). Eighty-nine percent (86/97) had an elevated BP load (>30% of readings >95th percentile). The antihypertensive medications of 16% (16/97) of patients were changed after ABPM. The nocturnal fall in BP (expressed as a percentage of the individual mean daytime values) was approximately normally distributed and was independent of age and height. Nocturnal systolic and diastolic dipping were closely correlated. Attenuation of nighttime dipping was observed in children with kidney disease and those with organ transplants. There is a need for normative data for ABPM for North American children. In our study, the technique was useful in selected cases, such as borderline or secondary hypertension, and for therapeutic monitoring when BP control is difficult. Received: 1 March 1999 / Revised: 24 November 1999 / Accepted: 28 November 1999     

Ambulatory blood pressure monitoring after renal transplantation in children

Hypertension occurs commonly following renal transplantation and may cause end organ damage, such as cardiac hypertrophy. This study seeks to determine which features of hypertension are related to cardiac hypertrophy in children after renal transplantation. Ambulatory blood pressure monitoring (ABPM) was performed in 45 pediatric patients, 4.9+/-3.0 years after renal transplantation. ABPM data were related to clinical features and echocardiographic measurements. Hypertension was demonstrated in 33% of patients by casual blood pressure (BP) measurement and in 40% by ABPM. The mean percentage nighttime decline in BP (dipping) was 8.9+/-5.0% for systolic and 13.9+/-7.7% for diastolic BP. Abnormal dipping (<10%) was seen in 58% of patients. BP load (percentage of BP recordings above 95th percentile) was >30% in 44% of patients. Patients taking antihypertensive medication had more abnormal dipping and greater nighttime BP load. The prevalence of left ventricular hypertrophy was 72% before transplantation, 75% after transplantation, and 54% near to ABPM. Left ventricular mass (LVM) indexed to height(3) decreased significantly after transplantation. (40.2+/-14.7 vs. 35.0+/-8.3 g/m(3), P=0.0002). There was no significant relationship between ABPM data and LVM. ABPM was not able to differentiate those patients with persistently elevated LVM. The results suggest that hypertension is not always associated with cardiac hypertrophy following pediatric renal transplantation.     

Ambulatory blood pressure monitoring in renal transplant patients: modifiable parameters after active antihypertensive treatment

BACKGROUND: Hypertension (HT) accounts for nearly 60% to 80% of renal transplant patients (RT). It is one of the most important risk factors for cardiovascular diseases and may cause chronic graft dysfunction. Therefore, it is important to accurately detect and treat HT. We aimed to evaluate the changes in ambulatory blood pressure monitoring (ABPM) parameters among hypertensive RT after active treatment compared with baseline values. METHODS: Thirty seven RT (25 men, 12 women, aged 49.4 +/- 11.2 year) diagnosed with mild to moderate HT underwent 24-hour ABPM after a 4-week washout period (W0). For the 23 RT with confirmed HT of a second 24-hour ABPM was recorded after 4 weeks of treatment with doxazosin GITS (-4 mg once daily in the morning), a new formulation of an alpha1-receptor inhibitor (W4). Nondippers were considered when mean blood pressure (BP) showed a < or = 10% reduction during sleep. Statistical analyses included Saphiro-Wilks test, Student t test, and ANOVA. RESULTS: After active treatment systolic, diastolic, and mean BP (SBP, DBP, MBP) significantly decreased during diurnal and 24 hours but not the nocturnal period. No significant change was observed for heart rate nor for pulse pressure during any period. The prevalence dippers increased from 0% to 17% after treatment. After placebo administration 8 among 37 RT with HT diagnosed according to casual BP remained hypertensive at nighttime (but not at daytime) according to 24-hour ABPM. CONCLUSIONS: Diurnal and 24-hour periods of ABPM showed significant changes in SBP, DBP, and MBP after active treatment with doxazosin GITS. No significant BP changes were observed in the nocturnal period or in dipper status. Further studies using ABPM must be undertaken to determine the optimal dosage and time of administration of antihypertensive drugs in RT.     

Ambulatory blood pressure in hypertensive patients with autosomal dominant polycystic kidney disease

Background: Ambulatory blood pressure is more closely correlated with various indices of hypertensive target-organ damage, and is a better prognostic predictor of cardiovascular morbidity and mortality than conventional methods of blood pressure measurement. Autosomal dominant polycystic kidney disease (ADPKD) is complicated by hypertension, progressive renal failure, and an increased risk of cardiovascular mortality. This study investigated the 24-h ambulatory blood pressure profile in patients with ADPKD in view of the sparsity of such data in these patients and the possibility that abnormal diurnal blood pressure variations may have prognostic consequences. Methods: Ambulatory blood pressure was measured over a 24-h period by the oscillometric method with an automatic non-invasive recorder (SpaceLabs 90207 system) in matched groups of 25 hypertensive patients with ADPKD and 25 patients with essential hypertension. Results: Both groups showed a nocturnal decrease in blood pressure, but this was significantly smaller in patients with ADPKD. There was no evidence of enhanced lability of blood pressure in ADPKD. Conclusion: The nocturnal fall in blood pressure was attenuated in patients with ADPKD. Further studies are required to assess the importance of this finding and its possible contribution to the progression of renal failure or increased cardiovascular mortality in these patients.