Postural hypotension in hypertensive patients

BACKGROUND: The association between orthostatic hypotension and supine hypertension (Hypo-Hyper) has been reported in previous studies on selected populations. The present longitudinal study aimed to characterize the haemodynamic patterns, comorbidity, prognostic implications and eventual effect of therapy in patients with the Hypo-Hyper pattern. METHODS: Ambulatory blood pressure monitoring (AMAP) and clinical evaluation were performed on 615 consecutive patients recruited from the Hypertension Clinics of five Italian Hospitals: 34 patents were identified as Hypo-Hyper, and underwent 10-month follow-up. RESULTS: The incidence of the Hypo-Hyper pattern was 5.5% in the hypertensives studied. Hypo-Hyper was more frequent in the elderly (mean age 58 years), and the affected population exhibited different kinds of underlying pathologies. Multivariate analysis showed no association between antihypertensive treatment and Hypo-Hyper pattern. Patients with AMAP features of higher blood pressure values at night-time than at daytime displayed higher rates of myocardial hypertrophy and pacemaker implantation during the follow-up. CONCLUSIONS: Although the study design did not aim to identify any pathophysiological mechanism for Hypo-Hyper pattern, these first data show that the Hypo-Hyper association is the effect of a particular subtype of hypertension, with significantly different prognostic implications.     

Postural hypotension and postural dizziness in patients with non-insulin-dependent diabetes.

BACKGROUND: Postural hypotension with a decline of 20 mm Hg or more in systolic blood pressure on standing is considered a potentially dangerous hypotensive response. Postural dizziness is often strongly associated with postural hypotension. However, there is conflicting evidence, and previous studies have been confined to the elderly, not specifically to patients with diabetes. Thus, we evaluated the association between postural hypotension and postural dizziness, and determined the factors most likely related to postural hypotension in patients with diabetes. METHODS: The subjects were 204 consecutive noninsulin-dependent patients with diabetes and 408 age- and sex-matched control subjects. Postural hypotension was defined as a decline of 20 mm Hg or more in systolic blood pressure 1 minute after standing. Postural dizziness was any feelings of dizziness, lightheadedness, or faintness that occurred while standing during the examination. RESULTS: The prevalence of postural hypotension and postural dizziness in patients with diabetes was higher than in control subjects. Those patients with both diabetes and postural hypotension were older and had higher supine systolic blood pressures and higher plasma glycosylated hemoglobin and fasting glucose levels. They had higher prevalence of postural dizziness, hypertension, and cerebrovascular disease, and lower standing systolic blood pressures than those without postural hypotension. They also were more often being treated with antihypertensive agents. Only 32.8% of patients with diabetes with postural hypotension suffered from postural dizziness. Postural dizziness, hypertension, cerebrovascular disease, and plasma glycosylated hemoglobin levels were independently associated with postural hypotension in patients with diabetes. CONCLUSIONS: Postural dizziness, glycemic control, hypertension, and cerebrovascular disease were important determinants of postural hypotension in patients with diabetes. Postural hypotension was associated with postural dizziness, but it cannot be determined clinically just from the presence of postural dizziness because the sensitivity for diagnosis of postural hypotension is low.     

Postural hypotension: its meaning and management in the elderly

Aging is associated with a considerable number of alterations in function of the autonomic nervous system and with systems involved in the control of cardiovascular response to postural changes. However, these alterations themselves do not generally lead to symptomatic orthostatic hypotension. In combination with other factors, older patients can develop marked problems with orthostatic hypotension--notably, certain drug regimens, some degree of underlying heart failure, or such common geriatric illnesses as parkinsonism and diabetes. Treatment regimens must be designed to minimize side effects. While aggressive pharmacologic treatment may be helpful for young patients, among the elderly physical therapy or behavioral maneuvers may promote the most benefit with least risk. The simplest first step, however, is to focus on possible iatrogenic causes and eliminate them.     

Postural hypotension and labile blood pressure associated with severe hypophosphatemia

We present a patient with postural hypotension and labile blood pressure due to severe hypophosphatemia. There was no evidence for other causes of postural hypotension in our patient. The blood pressure abnormalities responded to phosphate replacement.     

The orthostatic hypotension in patients treated with antihypertensive drugs (author's transl)]

Occasional or recurrent episodes of orthostatic hypotension were observed in 58 out of 584 hypertensive patients treated with alpha-methyldopa, beta-blockers and clonidine alone or associated with diuretics and/or hydralazine and/or reserpine. They occurred more frequently in the elderly. In none dicardial ischaemia. In only 3 cases it caused drowsiness and in 2 transient T wave inversion. These results suggest that postural hypotension does not contraindicate the continuation of antihypertensive treatment.     

Orthostatic hypotension and novel blood pressure-associated gene variants: Genetics of Postural Hemodynamics (GPH) Consortium

Aims Orthostatic hypotension (OH), an independent predictor of mortality and cardiovascular events, strongly correlates with hypertension. Recent genome-wide studies have identified new loci influencing blood pressure (BP) in populations, but their impact on OH remains unknown. Methods and results A total of 38 970 men and women of European ancestry from five population-based cohorts were included, of whom 2656 (6.8%) met the diagnostic criteria for OH (systolic/diastolic BP drop ≥20/10 mmHg within 3 min of standing). Thirty-one recently discovered BP-associated single nucleotide polymorphisms (SNPs) were examined using an additive genetic model and the major allele as referent. Relations between OH, orthostatic systolic BP response, and genetic variants were assessed by inverse variance-weighted meta-analysis. We found Bonferroni adjusted (P < 0.0016) significant evidence for association between OH and the EBF1 locus (rs11953630, per-minor-allele odds ratio, 95% confidence interval: 0.90, 0.85-0.96; P = 0.001), and nominal evidence (P < 0.05) for CYP17A1 (rs11191548: 0.85, 0.75-0.95; P = 0.005), and NPR3-C5orf23 (rs1173771: 0.92, 0.87-0.98; P= 0.009) loci. Among subjects not taking BP-lowering drugs, three SNPs within the NPPA/NPPB locus were nominally associated with increased risk of OH (rs17367504: 1.13, 1.02-1.24; P = 0.02, rs198358: 1.10, 1.01-1.20; P = 0.04, and rs5068: 1.22, 1.04-1.43; P = 0.01). Moreover, an ADM variant was nominally associated with continuous orthostatic systolic BP response in the adjusted model (P= 0.04). Conclusion The overall association between common gene variants in BP loci and OH was generally weak and the direction of effect inconsistent with resting BP findings. These results suggest that OH and resting BP share few genetic components.     

Postural hypotension following N-type Ca2+ channel blockade is amplified in experimental hypertension

OBJECTIVE: To determine the relative importance of the cardiac and vascular sympathetic components of the orthostatic response to 90 degrees head-up tilt after N-type calcium-channel blockade in normotensive (sham renal cellophane wrap) and hypertensive (renal wrap) conscious rabbits. METHODS: The effects of N-type calcium-channel blockade with omega-conotoxin GVIA (omega-CTX, 10 microg/kg i.v. bolus) were assessed in the absence or presence of cardiac block by propranolol and methscopolamine. These were contrasted with the effects of alpha1-adrenoceptor antagonism (prazosin 0.5 mg/kg i.v. bolus, in the presence of cardiac block) or ganglion blockade (mecamylamine 4 mg/kg i.v. bolus). RESULTS: In vehicle (0.9% saline) treatment groups, the response to tilt consisted of a small pressor effect (4 +/- 2 and 7 +/- 1 mmHg) and tachycardia (29 +/- 6 and 17 +/- 6 beats/min) in sham (n = 6) and wrap (n = 5) rabbits, respectively. After prazosin administration (with cardiac block), there were significant falls in MAP of 3 +/- 1 and 7 +/- 2 mmHg in sham (n = 7) and wrap (n = 6) rabbits, respectively, in response to tilt omega-CTX caused postural hypotensive responses of 8 +/- 2 and 13 +/- 2 mmHg in sham (n = 6) and wrap (n = 7) rabbits, respectively, and 7 +/- 1 and 14 +/- 2 mmHg in sham (n = 7) and wrap (n = 7) rabbits with prior cardiac block. Similarly, mecamylamine caused falls in MAP of 8 +/- 1 and 10 +/- 2 mmHg in response to tilt in sham (n = 6) and wrap (n = 9) animals, respectively. CONCLUSION:Sympathetic vasoconstrictor effectors are primarily responsible for maintaining blood pressure during tilt in conscious rabbits. The postural hypotension caused by sympatholytic agents is about double in hypertensive rabbits, and N-type calcium-channel blockade is as effective as ganglion blockade at inducing this syndrome.     

Huge price variations in generic drugs

Huge, secret price variations create huge profits for the well connected, raising prices for patients and the public. One drug with an "average wholesale price" of $2.66 per pill was actually sold to pharmacies for 5 cents per pill.     

Seasonal variations in office and home blood pressures in hypertensive patients treated with antihypertensive drugs

OBJECTIVE: To analyze various factors influencing season variations in blood pressure under ordinary circumstances. METHODS: We examined home and office blood pressures in 315 outpatients with essential hypertension. The majority (88%) were being administered antihypertensived drugs. Their office and home blood pressures were recorded in 1993. The patients were 156 men and 159 women, aged 60.8 +/- 0.6 years (mean +/- SEM). The office blood pressure was measured monthly by the same physicians. The home blood pressure was measured every day by the patients, in the morning and evening. RESULTS: The home blood pressures both in men and in women exhibited significant seasonal variations, to a similar extent. The winter-summer difference in home blood pressure was 3.9 +/- 0.5 mmHg systolic and 1.7 +/- 0.3 mmHg diastolic for the men and 4.6 +/-0.5 mmHg systolic and 2.4 +/- 0.3 mmHg diastolic for the women. The office blood pressure of the men also exhibited significant seasonal variation. There was no seasonal variation in office systolic blood pressure in the women. The levels of home blood pressure in the men and women were similar during each season, whereas the office systolic blood pressure of the women was significantly higher than that of men throughout the year. For the total group of patients, the winter-summer differences in home systolic blood pressure was positively correlated to age. The seasonal variations in blood pressure were not affected by body mass index, smoking status, and administration of antihypertensive medication.CONCLUSIONS: Seasonal variations in blood pressure existed both for male and for female hypertensive patients and occurred even for subjects being treated with antihypertensive drugs. However, there was no seasonal variation in the office systolic blood pressure of women, suggesting that the differences between the office and home blood pressures and between thermoregulatory mechanisms for the sexes may have obscured it.