Does baseline hypotension predict incident depression in a cohort of community-dwelling older people? Data from The Irish Longitudinal Study on Ageing (TILDA)

Background

hypotension is now recognised as a risk factor for syncope, cardiovascular events and mortality, but it may also represent a risk factor for late life depression (LLD). The aim of this study was to clarify the longitudinal relationship between hypotension and incident LLD.

Methods

this is a longitudinal study involving community-dwelling participants aged ≥50 years, using data from The Irish Longitudinal Study on Ageing. The Centre for Epidemiological Studies Depression Scale (CES-D) was administered at baseline and at follow-up 2 years later. Blood pressure (BP) was measured at baseline. Participants with a CES-D score ≥16 at baseline and those taking antidepressants were excluded and considered to have a current diagnosis of depression. A score of ≥16 at follow-up was used to define incident depression.

Results

about 4,525 participants were included and 200 participants had diagnosis of incident LLD. The incident depression group had lower systolic BP at baseline than the non-depressed group (132.8 ± 1.43 mm Hg vs. 136.0 ± 0.30 mm HG, P = 0.025). Logistic regression showed those with systolic BP <130 mm HG had an unadjusted odds ratio of 1.31 (1.01-1.68) for incident depression. This persisted after adjustment for confounding factors.

Conclusion

systolic BP <130 mm Hg increased the likelihood of incident depression in a cohort of community-dwelling older adults. These findings are important because systolic hypotension may represent a potentially modifiable risk factor for LLD. They are also relevant in the context of BP treatment targets for older people.

Affective impairment in chronic low blood pressure

OBJECTIVE

Physical complaints such as faintness, dizziness, cold limbs and headaches have been well-established in chronic low blood pressure (hypotension). This study investigated the occurrence of adverse emotional states and the symptoms of depression in this condition. As autonomic dysregulation, particularly diminished sympathetic tone, is believed to be involved in the etiology of hypotension, the impact of different facets of autonomic cardiovascular control on mood and depressive symptoms was also explored.

METHODS

Forty individuals with chronic hypotension and forty normotensive control persons were presented with the Mood Scale and Beck Depression Inventory. Stroke volume, cardiac output, pre-ejection period, Heather index and aortic peak blood flow velocity were recorded under resting conditions as indices of beta-adrenergic inotropic drive. Respiratory sinus arrhythmia and baroreflex sensitivity were additionally obtained.

RESULTS

Hypotensive individuals scored markedly higher on both questionnaire scales than controls, indicating an adversely affected emotional state and more severe depressive symptoms. In the entire sample, cardiac output, Heather index, and aortic peak blood flow velocity correlated negatively with the questionnaire scores; according to regression analysis, the Heather index explained the largest proportion of test score variance.

CONCLUSION

Although hypotension does not constitute a serious medical condition, the findings of an adverse affective state and increased burden with depressive symptoms corroborate the view that it can have a considerable impact on wellbeing and quality of life. The correlations of the beta-adrenergic indices with the questionnaire scales indicate that cardiac sympathetic regulation plays a key role in the psychophysiological mediation of hypotension-related mood impairment.

Determinants of altered sensorium at presentation with diabetic ketoacidosis

AIM

The aim of this paper was to determine the prevalence of altered sensorium and their determinants in diabetic ketoacidosis (DKA).

METHODS

Retrospective review of medical records for diabetic ketoacidosis admissions over a two year period.

RESULTS

A total of 94 admissions for DKA in 89 patients were reviewed. Majority of admissions were female related. The mean age of the subjects was 39.1±18.5 years. The prevalence of altered sensorium defined as Glasgow coma scale (GCS) below 15 was 47.9%. In Model 1, systolic blood pressure (SBP) <90 mmHg (odds ratio [OR] 17.5 95% Confidence Interval (CI) 2.1-142.9; P=0.008 and calculated effective serum osmolality >320 mosmol/Kg (OR 3.6 95% CI 1.4-12.2; P=0.043 were independently associated with altered sensorium. In Model 2 where serum osmolality was substituted with uncorrected serum sodium, SBP <90 mmHg OR 19.6 95% CI 2.2-100; P=0.007, uncorrected serum sodium >150 mmol/L OR 18.5 95% CI 2.1-100; P=0.0009 and white cell count >25 x 106/L OR 3.6 95% CI 1.03-13.5; P=0.05 were independently associated with altered sensorium.

CONCLUSION

Systolic blood pressure <90 mmHg, calculated effective serum osmolality >320 mosmol/Kg, uncorrected serum sodium >150 mmol/L and white bood count >25 x 106/L were independently associated with altered sensorium.

Better cognitive and physical performance is associated with higher blood pressure in centenarians

OBJECTIVES

Knowledge of rational, evidence based health care in the hundred-year-old is still poor. The aim of the study was to evaluate health and functional state in hundred-year-old inhabitants of Upper Silesia, Poland, with a focus on the heart and vascular function.

PARTICIPANTS

Medical and nursing assessment at places of residence was performed in thirty five 100.7±1.4 (mean±SD) year-old subjects, 28 women, and 7 men.

MEASUREMENTS

The protocol included Mini-Mental State Examination (MMSE), Barthel Index (BI) and laboratory tests. A telephone follow-up was performed 180 days after the initial examination.

RESULTS

Most subjects had increased systolic blood pressure (BP), diminished albumin and folate serum levels as well as decreased Glomerular Filtration Rate. According to the quadratic polynomial regression model MMSE and BI were dependent on BP. Higher BP was associated with better performance and survival. Those who survived more than 180 days had lower levels of CRP and VCAM-1 and higher level of sCD40L.

CONCLUSION

The relationships between functional scales, survival and blood pressure suggest a beneficial effect of elevated BP on both mental and physical performance in centenarians. Further studies should determine an optimal balance between risk and benefits of elevated blood pressure in the oldest old people.

Haemodialysis course is associated to changes in pain threshold and in the relations between arterial pressure and pain

ANTECEDENTS

Arterial pressure is negatively associated to pain perception.

OBJECTIVES

In this study, pain and the relations between arterial pressure and pain threshold were compared at the beginning and end of the haemodialysis.

METHODS

14 patients with chronic renal disease participated in the study. Pain thresholds were evaluated with pressure algometry bilaterally at two tender points: the second rib and the knee. Arterial pressure and pain thresholds were assessed twice: 1) 15 min alter dialysis onset and 2) 30 min before dialysis ended.

RESULTS

Arterial pressure remains unchanged through the dialysis. The course of dialysis was associated to a decrease in pain threshold in the second left rib and left and right knees. At the beginning of dialysis arterial pressure were uncorrelated with pain, while at the end of the dialysis both systolic and diastolic arterial pressure were strongly associated to pain thresholds (rs between 0.552 and 0.806): increased arterial pressure was associated to lower pain in terms of increased threshold.

CONCLUSIONS

Haemodialysis is associated to changes in pain sensitivity and in the relationships between arterial pressure and pain, suggesting a modification in the ascending pain inhibition system arising from the cardiovascular system. Possible explanations of this effect include the changes produced by haemodialysis in cognitive-perceptive functions, in autonomic cardiovascular regulation, and in the habituation of stress-related variables.

The effect of Camphor-Crataegus berry extract combination on blood pressure and mental functions in chronic hypotension--a randomized placebo controlled double blind design

A number of studies have provided evidence for reduced cognitive performance due to chronically low blood pressure. The present studies explored whether these deficits can be reduced by pharmacological blood pressure elevation. Effects of the Camphor-Crataegus berry extract combination (Korodin(®)) were investigated in two studies with 40 and 48 hypotensive women based on a randomized, placebo controlled double blind design. The participants were presented with different tasks assessing performance in attention and cognition. Blood pressure was measured repeatedly during the experiment. The administration of the drug led to positive and differential effects on blood pressure and cognitive performance as compared to placebo. These effects were already visible within the time range of 2-5 min. A positive correlation between blood pressure increase and performance enhancement could be demonstrated for two of the four tasks. The results show that the application of Korodin(®) results in beneficial effects on resting blood pressure and cognitive performance. The positive association between the increase in blood pressure and cognitive enhancement suggests that blood pressure plays a causal role in the cognitive deficits in hypotension and underlines that they can be reduced through antihypotensive treatment.

Nocebo effects with antidepressant clinical drug trial placebos

We describe an individual who experienced unusual negative effects while taking a placebo during a clinical drug trial. A 26-year-old male took 29 inert capsules, believing he was overdosing on an antidepressant. Subsequently, he experienced hypotension requiring intravenous fluids to maintain an adequate blood pressure until the true nature of the capsules was revealed. The adverse symptoms then rapidly abated. The nocebo effect (undesirable symptoms following administration of an inert substance that the patient believes to be an active drug) may have significant negative impacts on certain patients. Further research is warranted to better understand this phenomenon.

Prevention of dialysis hypotension episodes using fuzzy logic control system

BACKGROUND

Automatic systems for stabilizing blood pressure (BP) during dialysis are few and only control those variables indirectly related to BP. Due to complex BP regulation under dynamic dialysis conditions, BP itself appears to be the most consistent input parameter for a device addressed to preventing dialysis hypotension (DH).

METHODS

An automatic system (ABPS, automatic blood pressure stabilization) for BP control by fluid removal feedback regulation is implemented on a dialysis machine (Dialog Advanced, Braun). A fuzzy logic (FL) control runs in the system, using instantaneous BP as the input variable governing the ultrafiltration rate (UFR) according to the BP trend. The system is user-friendly and just requires the input of two data: critical BP (individually defined as the possible level of DH risk) and the highest UFR applicable (percentage of the mean UFR). We evaluated this system's capacity to prevent DH in 55 RDT hypotension-prone patients. Sessions with (treatment A) and without (treatment B) ABPS were alternated one-by-one for 30 dialysis sessions per patient (674 with ABPS vs 698 without).

RESULTS

Despite comparable treatment times and UF volumes, severe DH appeared in 8.3% of sessions in treatment A vs 13.8% in treatment B (-39%, P=0.01). Mild DH fell non-significantly (-12.3%). There was a similar percentage of sessions in which the planned body weight loss was not achieved and dialysis time was prolonged.

CONCLUSIONS

In conclusion, FL may be suited to interpreting and controlling the trend of a determined multi-variable parameter like BP. The medical knowledge of the patient and the consequent updating of input parameters depending on the patient's clinical conditions seem to be the main factors for obtaining optimal results.

Enhancement of cerebral blood flow and cognitive performance following pharmacological blood pressure elevation in chronic hypotension

Previous research has demonstrated reduced cognitive performance and diminished cerebral blood flow in the case of chronic hypotension. We investigated whether these deficits can be reduced by pharmacological blood pressure elevation. Effects of the sympathomimetic midodrine were examined in 50 hypotensive individuals based on a randomized, placebo-controlled double-blind design. A paper-pencil test assessing performance in selective attention was presented. By means of transcranial Doppler sonography, blood flow velocities were recorded in both middle cerebral arteries at rest and during the execution of a cued reaction time task. The administration of midodrine led to an increase in blood flow velocities at rest as well as enhanced attentional performance. The degree of rise in flow velocities was positively correlated with performance enhancement. The increase in flow velocities observed during the execution of the reaction time task was stronger following drug administration.

Lower blood pressure correlates with poorer performance on visuospatial attention tasks in younger individuals

The relationship between low blood pressure and cognitive function among younger individuals is not fully understood. While a number of studies have examined hypertensive and hypotensive individuals, particularly in older populations, little attention has been devoted to healthy, young populations. We tested 105 healthy young individuals whose blood pressure levels naturally fell in the below normal-to-normal range. Our primary finding was a positive relation between blood pressure and cognition, as measured by two visuospatial attention tasks. This relation appears to be specific to visuospatial skills, as no relationship was observed between recognition memory and blood pressure. We discuss possible explanations for this positive relationship, such as structural neural mechanisms, and how they apply to the overall blood pressure-cognition relationship.

Cognitive performance and cerebral blood flow in essential hypotension

In the present study cerebral blood flow was assessed in 40 subjects with chronically low blood pressure and 40 normotensive controls at resting conditions and during the execution of a cued reaction time task. Blood flow velocities were recorded by means of transcranial Doppler sonography in both middle cerebral arteries. In hypotensives flow velocity at rest was reduced bilaterally. During the anticipation of the stimuli, which the subjects had to respond to, a predominantly right hemispheric increase of flow velocity was observed in both groups. This increase was significantly less pronounced in the hypotensive group. Hypotensives showed longer reaction times, and there was a negative correlation between the extent of the flow velocity increase and the reaction times. This study is the first to demonstrate a reduced cerebral perfusion and maladaption of blood flow to cognitive demands due to essential hypotension.

Nonlinear relations of blood pressure to cognitive function: the Baltimore Longitudinal Study of Aging

This investigation examined cross-sectional and longitudinal relations, both linear and nonlinear, of blood pressure (BP) and its interaction with demographic and lifestyle variables to a broad spectrum of cognitive functions. Eight hundred forty-seven participants (503 men and 344 women) from the Baltimore Longitudinal Study of Aging completed tests of verbal and nonverbal memory, attention, perceptuo-motor speed, executive functions, and confrontation naming, and clinical assessment of BP on 1 to 7 occasions over 11 years. Mixed-effects regression models, adjusted for age, education, gender, alcohol consumption, smoking status, depression scores, and use of antihypertensive medications, revealed nonlinear relations of systolic BP with longitudinal change on tests of nonverbal memory and confrontation naming; cognitive decline was apparent among older (80 years) individuals with higher systolic BP. Cross-sectional findings, across testing sessions, indicated moderated U- and J-shaped relations between BP and cognitive function. Both high and low diastolic BP were associated with poorer performance on tests of executive function and confrontation naming among less-educated persons; with tests of perceptuo-motor speed and confrontation naming among nonmedicated (antihypertensives) individuals; and with executive function among older individuals. Cross-sectional linear relations included higher systolic BP and poorer nonverbal memory in nondrinkers, and higher diastolic BP and poorer working memory among less-educated individuals. Results indicate that cross-sectional and longitudinal relations of BP to cognitive function are predominantly nonlinear and moderated by age, education, and antihypertensive medications. Careful monitoring and treatment of both high and low BP levels may be critical to the preservation of cognitive function.

Reduced cognitive performance and prolonged reaction time accompany moderate hypotension

The aim of the present study was to investigate the impact of hypotension on attentional and motor performance. Twenty-six moderately hypotensive subjects (mean systolic blood pressure = 108.8 mmHg) were compared to 29 normotensive controls (mean systolic blood pressure = 123.5 mmHg). The participants were presented with two standard German tests of attention ("Aufmerksamkeits-Belastungs-Test", Test d2; "Zahlen-Verbindungs-Test", ZVT). Additionally, reaction times to acoustic signals were measured. The hypotensive group showed significantly prolonged reaction times (p = 0.007) as well as reduced performance speed (p = 0.004) and lower concentration capacity (p = 0.014) in the test d2. In the ZVT as well a slightly poorer performance in hypotensives was observed (p = 0.088). Moreover, significant partial correlations between systolic blood pressure and the performance measures with age as covariate were found (performance speed: r = 0.28; concentration capacity: r = 0.22; reaction time: r = 0.33). A lowered cerebral perfusion in hypotensives and an altered activity of baroreceptors located in the carotid sinus are discussed as possible underlying psychophysiological processes mediating the relationship between blood pressure and cognitive performance. This study is the first to provide empirical evidence for the relation between attentional deficits and even moderately lowered blood pressure.

The Effect of Meals at Different Mealtimes on Blood Pressure and Symptoms in Geriatric Patients With Postprandial Hypotension

BACKGROUND

The variability of postprandial hypotension (PPH) during the day in elderly patients is unknown. We examined the effect of meals administered at different mealtimes on postprandial blood pressure (BP) responses in geriatric patients.

METHODS

In 14 geriatric patients (6 men and 8 women, aged 66-97) previously diagnosed with PPH, standardized liquid test meals were given in random order at breakfast, lunchtime, or dinnertime on 3 separate days. Systolic BP (SBP), diastolic BP (DBP), and heart rate (HR) were measured with an ambulatory BP device every 10 minutes from 20 minutes before until 90 minutes after each meal. Postprandial symptoms were observed continuously.

RESULTS

Significant decreases in SBP and DBP were present after each meal (p <.050). The maximum SBP decrease was significantly smaller at dinnertime (-18 +/- 3 mmHg) than at breakfast (-29 +/- 2 mmHg) or lunchtime (-34 +/- 4 mmHg) (p <.005 between groups). Eight patients showed no PPH in the evening, whereas all patients had PPH after breakfast and lunch. The duration of PPH was significantly shorter (p <.001), and postprandial symptoms were less frequent and less severe after dinner compared to breakfast and lunch.

CONCLUSIONS

In geriatric patients, postprandial BP responses show a variation during the day, with significantly less PPH and fewer symptoms in the evening. Clinical implication is that, in the diagnostic process and management of PPH, the variation of the occurrence of PPH during the day should be taken into account. Through adjustment of BP decreasing activities to the time PPH is least prevalent, the risk of developing symptomatic PPH can be reduced.

High vibration perception threshold and autonomic dysfunction in hemodialysis patients with intradialysis hypotension

BACKGROUND

Intradialysis hypotension is a common problem among hemodialysis patients. Some studies have shown that autonomic neuropathy could be a major cause of intradialysis hypotension, whereas others have not. Furthermore, whether there are parallel changes in the autonomic nervous system and somatic nerves remains unclear.

METHODS

We investigated the autonomic and peripheral nervous functions of 12 chronic hemodialysis patients who suffered from intradialysis hypotension, and of 12 age- and sex-matched hemodialysis patients who had stable blood pressure during hemodialysis. We used spectral analysis of their heart rate variability and systemic vascular resistance to evaluate autonomic functions. Vibrameter and nerve conduction studies to assess peripheral nervous function were also performed. Low-frequency/high-frequency ratio power index was used as a surrogate of sympathovagal balance.

RESULTS

The power index rose progressively in the control group and reached significantly high levels at hour 4 compared to the basal values (3.7 +/- 0.5 vs. 2.1 +/- 0.3; P < 0.05). However in the group prone to hypotension, the power index remained almost unchanged. In addition, their systemic vascular resistance was lower than that in the control group (13.7 +/- 1.8 vs. 22.3 +/- 2.6 Wood units; P < 0.05). The vibration perception thresholds of the index finger and great toe were significantly higher in the group prone to hypotension (4.7 +/- 0.7 vs. 2.2 +/- 0.3 vibration units and 3.1 +/- 0.4 vs. 1.5 +/- 0.2 vibration units, respectively; both P < 0.05).

CONCLUSION

We found that more severe damage to autonomic and peripheral nervous system occurred in patients prone to hypotension.

The memory effects of general anesthesia persist for weeks in young and aged rats

Studies demonstrate lasting cognitive impairment in elderly persons after anesthesia and surgery. We tested the hypothesis that general anesthesia contributes to this cognitive impairment. Six- and 18-mo-old Fischer 344 rats were trained in a 12-arm radial arm maze and were then randomized to anesthesia for 2 h with 1.2% isoflurane/70% nitrous oxide/30% oxygen or a control treatment consisting of 30% oxygen. Rats recovered for 24 h and then were tested daily on the radial arm maze for 8 wk. Performance of young control rats was stable throughout the experiment. In contrast, aged control rats improved their performance as measured by time to complete the maze but not by error rate. After anesthesia, time to complete the maze did not change in young rats, but error rate decreased (P < 0.05 at 1 and 3 wk), indicating improved performance. In contrast, previously anesthetized aged rats failed to improve with repeated testing and took longer to complete the maze than aged control rats (P < 0.05 at 1 and 3 wk). These data demonstrate that general anesthesia with isoflurane and nitrous oxide improves the memory performance on an established spatial memory task in young rats, but in aged rats it attenuates the improvement in performance that otherwise occurs with repeated testing. Therefore, isoflurane and nitrous oxide anesthesia produces a sustained learning impairment in aged rats.

IMPLICATIONS

This study demonstrates that general anesthesia with isoflurane and nitrous oxide improves spatial memory in young rats but impairs it in aged rats for at least 3 wk, indicating that it can influence memory for much longer than previously recognized and may adversely affect memory processes in the aged.

Association of hypotension with positive and negative affect and depressive symptoms in the elderly

BACKGROUND

Previous research associating hypotension with depression has produced inconsistent results. A possible reasons is that depressive symptom scales reflect both high negative affect and low positive affect.

AIMS

To examine the association of hypotension with depressive symptoms, negative affect and positive affect.

METHOD

Community survey of 340 elderly persons aged 77-99 years.

RESULTS

Diastolic hypotension had a weak association with depression, no association with negative affect and a strong inverse association with positive affect. Systolic hypertension was associated with positive affect. Use of antihypertensive medication was independently associated with lower positive affect.

CONCLUSIONS

Diastolic hypotension shows a specific association with low positive affect. This association may explain the weak and inconsistent results of earlier studies relating hypotension to depression.

[Postoperative cognition disorders in elderly patients. The results of the "International Study of Postoperative Cognitive Dysfunction" ISPOCD 1)]

OBJECTIVE

Cognitive dysfunction is a known problem after operations and may be especially relevant in the elderly. The aim of this international multicentre study was to investigate short- and long-term cognitive dysfunction in elderly patients and to elucidate the relevance of hypoxaemia and hypotension as causative factors.

METHODS

1218 patients aged 60 years and older and scheduled for major non-cardiac surgery under general anaesthesia were investigated. Oxygen saturation was measured by continuous pulse oximetry before surgery and throughout the day of and the first 3 nights after surgery. Blood pressure was recorded every 3 minutes during the operation and every 15-30 min for the rest of that day and night. Cognitive testing was performed before and 1 week and 3 months after the operation. Cognitive dysfunction was identified with neuropsychological tests compared with controls recruited from the UK (n = 176) and the same countries as study centres (n = 145).

RESULTS

Postoperative cognitive dysfunction was present in 25.8% of patients 1 week after surgery and in 9.9% 3 months after surgery, compared with 3.4% and 2.8%, respectively, of the UK controls. Increasing age and duration of anaesthesia, little education, a second operation, postoperative infections, and respiratory complications were the risk factors for early postoperative cognitive dysfunction, but only age was a risk factor for long-term postoperative cognitive dysfunction. Hypoxaemia and hypotension were not significant risk factors at any time.

CONCLUSION

With this investigation long-term cognitive dysfunction could be proven definitively for elderly patients after major operations under general anaesthesia. No factors with prophylactic or therapeutic influence were detectable so that aetiology and pathophysiology of POCD could not be further determined.

Low blood pressure associated with low mood: a red herring?

OBJECTIVE

Several reports have discussed a relationship between blood pressure (BP) and psychological well-being scales. Lower BP readings were associated with higher levels of psychological distress and fatigue. This study sought to replicate the association found by previous secondary analyses of epidemiological surveys.

DESIGN

Cross-sectional study.

SETTING

Academic Family Medicine Department in Toronto, Canada.

SUBJECTS

214 practice attenders. STUDY MEASURES: Extent of psychological abnormalities with the General Health Questionnaire (GHQ), self-reported fatigue, in-clinic and home BP measurements.

RESULTS

No significant relationship between blood pressure levels and GHQ-score or fatigue could be demonstrated. This applies to clinic and home measurements for systolic and diastolic pressure. Neither adjustment for age or sex nor for several confounders through multiple linear regression produced significant associations in the postulated direction. No nonlinear relationship could be shown either. The study had a power of 95% to detect a correlation of r = 0.22 (alpha = 0.05, one-sided).

CONCLUSION

The study specifically addressing the possible link between blood pressure and psychological dysfunction/fatigue, could not confirm the previously reported association. Problems related to type-I error in epidemiological research are discussed.

The influence of low blood pressure and baroreceptor activity on pain responses

The influence of baroreceptor modulation on pain perception has been extensively studied in normal and hypertensive subjects, but not in hypotensive subjects. The present experiment was performed to verify the following hypotheses: 1. Hypotensive subjects exhibit an increased pain response following baroreceptor activation compared to normals; 2. unlike the hypotensives, normal subjects, with normal baroreceptor reflexes, would learn to choose more often the baroreceptor activation condition compared to the opposite condition, during painful stimulation; 3. sensory and pain thresholds are correlated with blood pressure. The subjects (39 men), divided according to low and normal blood-pressure groups, participated in an experiment in which electrically-induced pain ratings and pain-evoked potentials were measured. Baroreceptor manipulation was performed by means of the PRES procedure. Whereas hypotensive subjects did not perceive any pain difference between the two baroreceptor conditions, activation and inhibition, normotensive men were able to perceive the baroreceptor activation condition as less painful. Similarly to subjective ratings, pain-evoked potentials of the low blood-pressure group showed a reversed trend compared to normals: larger somatosensory evoked potentials (N150-P260) to the baroreceptor activation condition and the opposite to the baroreceptor deactivation condition. Furthermore, results showed a negative correlation between diastolic blood pressure and sensory perception threshold, and a positive correlation between systolic pressure and pain threshold. Contrary to expectations, the rate of choice of baroreceptor conditions during painful stimulation did not show, in either group, any preference for baroreceptor activation.

Patient refusal of care in the out-of-hospital setting

A case vignette of out-of-hospital refusal of emergency care is reported with accompanying discussion. This case illustrates the challenges faced by out-of-hospital emergency care personnel in these scenarios and provides guidance to the emergency physician and emergency medical technician. Recommendations are provided for preparing the emergency medical services system to handle these cases.

Blood pressure as a risk factor for depression in elderly people: a prospective study

A total of 1070 men and women aged 65 years and over living in the community in Liverpool were interviewed using the Geriatric Mental State. Diagnoses of depression at case and subcase level were made using the GMS-AGECAT package from an initial interview and at follow-up three years later. Data relating to blood pressure at year 0 was available on 748 subjects. Men not taking anti-hypertensives or antidepressants with diastolic blood pressure greater than 85 mmHg were significantly less likely to be subcases than men with low or normal diastolic pressure. People in this group were also significantly less likely to be cases 3 years later. There were no other significant findings. These results do not support an association between low blood pressure and coincidental or future subcase- or case-level depressive illness.

Hypotension--does it make sense in family practice?

In general practice many diagnostic labels are used that are related to cultural background rather than a scientific basis. To estimate the use of diagnoses like 'hypotension' and depression, a cross-sectional survey in German and British GPs' surgeries was performed. Prevalence of related symptoms, sociodemographic and medical data were recorded as well as actual and previous blood pressure levels. In German general practice, where 'hypotension' is an established entity, 17% of all patients attending were reported as hypotensive either by their doctor or by themselves. The proportion was twice as high among women than among men. It was more common among the young. One-quarter of these patients were on medication to raise their blood pressure. Actual and previous blood pressure levels failed to explain the occurrence of symptoms like tiredness, dizziness, headache etc. Demographic characteristics of patients diagnosed as depressed were similar in both countries. Presumably for economic reasons there is a tendency for German GPs to use more diagnostic labels of any kind. It was concluded that diagnostic labels attached to vague but frequently presented symptoms vary considerably between countries. They often lack a physiologic rationale. Nevertheless they often support the tendency to somatize common problems.

Low systolic blood pressure and self perceived wellbeing in middle aged men

OBJECTIVE

To examine the relation between systolic blood pressure and self perceived wellbeing in 50 year old men.

DESIGN

Cross sectional population study of data derived from questionnaires and physical examination as a part of a cardiovascular risk factor survey.

SETTING

City of Gothenburg, Sweden.

STUDY POPULATION

776 men from a random population sample of 1016 men aged 50.

METHODS

Self perceived wellbeing according to the Gothenburg quality of life questionnaire, which is an assessment of social, physical, and mental wellbeing in 15 different areas.

MAIN RESULTS

Low systolic blood pressure was significantly (p < 0.05) related to impaired social wellbeing in four areas: work, home and family, financial situation, and housing. Of the items dealing with physical wellbeing, health, memory, and appetite were significantly related to blood pressure. As regards mental wellbeing, energy and self confidence were significantly related to systolic blood pressure. Diastolic blood pressure was significantly related to housing, memory, energy, patience, and self confidence. In multiple regression analyses that controlled for smoking, stress, physical activity, social activity, and emotional support, poor social, physical, and mental wellbeing were all significantly related to low systolic blood pressure independently of other factors. Low diastolic blood pressure was independently associated with poor physical and mental, but not social, wellbeing.

CONCLUSION

Low systolic blood pressure was associated with poor perception of wellbeing in several areas. The cause is unclear.

Effects of arterial pressure on drinking and urinary responses to intracerebroventricular angiotensin II

These experiments examined the dipsogenic responses of rats to intracerebroventricularly administered angiotensin II (ANG II) under normotensive and hypotensive conditions. Intravenous infusion of the vasodilator drug minoxidil (25 micrograms.kg-1.min-1), combined with the angiotensin converting enzyme inhibitor captopril (0.33 mg/min), both reduced blood pressure and prevented endogenous ANG II formation. Central infusions with ANG II (4 or 16 ng/h) began 60 min later, and the intravenous and intracerebroventricular infusions ran concurrently for another 90 min. Mean arterial pressure (MAP), water intake, urine volume (UV) and electrolyte excretion were measured throughout. Water intakes to both doses of intracerebroventricular ANG II were increased, and UV and electrolyte excretion were reduced during hypotensive conditions compared with normotensive conditions. Thus the increased water intakes occurred despite increased fluid retention. It is concluded that arterial hypotension enhances the dipsogenic effects of centrally administered ANG II, possibly through baroreceptor-mediated mechanisms.

Low blood pressure, low mood?

OBJECTIVE

To determine whether a set of physical symptoms is associated with low blood pressure and to investigate the possible role of psychological factors in their occurrence.

DESIGN

Analysis of data collected by questionnaire and physical screening from the first phase of the Whitehall II study, a cohort study of an employed population.

SETTING

23 civil service departments in London.

SUBJECTS

10,314 male and female London based civil servants aged between 35 and 55.

MAIN OUTCOME MEASURES

Symptoms of dizziness-giddiness and unexplained tiredness; psychological functioning as measured by the 30 item general health questionnaire in which the response "no more than usual" to an item about disease was scored as indicating chronic illness.

RESULTS

Dizziness-giddiness in men and unexplained tiredness in both men and women were significantly related to low systolic blood pressure. There was a highly significant inverse relation between general health questionnaire score and systolic blood pressure for both men and women, which persisted after controlling for potentially confounding variables, including age, body mass index, drug treatment, physical illness, and exercise. This association of low blood pressure with physical symptoms was no longer significant when general health questionnaire score was controlled for.

CONCLUSIONS

There seems a strong relation between low systolic blood pressure and minor psychological dysfunction. Associated physical symptoms seem to be secondary to the primary disturbance in mental state.

Electrodermal responsivity in young hypotensive and hypertensive men

Electrodermal responses were recorded during the presentation of 16 moderately intense (1000 Hz, 90dB) tones in three groups of young men: borderline hypertensives (138/79 mmHg), normotensives (112/65 mmHg), and hypotensives (104/63 mmHg). Electrodermal response habituation was measured as a decline in response over trials, number of trials to a response criterion of three successive nonresponses, and number of inversions of response amplitude (larger responses following smaller responses) in the stimulus sequence. Habituation was fastest in hypotensives. Nonspecific electrodermal responses at rest and during tone presentations were most frequent in borderline hypertensives, least frequent in the hypotensive group, with the normotensive group falling in between. There were no significant differences in electrodermal level. The rapid habituation rate in hypotensives is discussed in terms of cursory information processing associated with impulsive behaviour. The higher nonspecific electrodermal activity in borderline hypertensives is interpreted to indicate increased sympathetic nervous system activity.

[Conditioning treatment in hypotonia with complications]

The social-medical significance of hypotension is in general underestimated. For females between the 18th and 35th year of age it has the same significance for the number of patients as the arterial hypertension. The hospital conditioning is the therapy of choice. About half the affected persons needs psychotherapy. Changes of the functional parameters could not be proved after single treatment, but ameliorations of the general condition and improvements in the patients' physical health could be made evident in the region of psychological tests.

Taste sensitivity for sodium chloride in hypotensive, normotensive and hypertensive subjects

The taste sensitivity for sodium chloride was examined in 103 normotensive, 55 hypertensive and 36 hypotensive subjects. The examination was performed on five areas of the tongue using four different concentrated NaCl solutions (2.5, 5.0, 7.5 and 15%). The results indicate that hypotensive subjects show a much higher salt sensitivity compared to normotensive or hypertensive subjects. The enhanced sensitivity of hypotensives to sodium chloride may reflect a regulatory factor tending to normalize blood pressure. In contrast, the lower sensitivity of hypertensives points to a salt dependency of high blood pressure in these patients.

Duration versus degree of hypotension as critical conditions of brain infarction in the albino rat

In 41 anesthetized, spontaneously breathing male adult albino rats, cerebral hypotension of precisely defined duration and magnitude was induced by means of controlled arterial hemorrhage. One common carotid artery was occluded throughout the hypotensive period, and the target pressure was monitored in the ipsilateral internal carotid artery. Regional brain infarcts developed in all 16 animals with a target pressure of 14 mm Hg maintained for 90 minutes and in all five animals with a target pressure of 12 mm Hg maintained for 70 minutes. However, the brains of all 10 rats with a target pressure of 17 mm Hg maintained for 80 minutes remained intact. In two further groups of five animals each with target pressures of 15 mm Hg for 80 minutes and 16 mm Hg for 90 minutes the incidence of infarct was about 30%. There were no marked differences between the five groups of rats in body weight, body temperature, heart rate, respiratory rate, PaO2, PaCO2, arterial pH, or hematocrit. The data suggest that, in the rat, the clear-cut threshold for the induction of brain infarcts is a function of the severity and duration of arterial hypotension. Evidence is presented indicating that this function is distinctly species-dependent, due to species differences in the dilatory capacity of the arteries supplying the brain rather than species differences in brain vulnerability.

[Social perception of arterial hypertension from a transcultural perspective]

From ethnological and psychological inquiries, during an ordinary elaboration of methodology (between France and West Africa that took place in Ivory Coast) the author emphasizes the differential value of the terms hypertension or hypotension with a systematic claim of a take of blood pressure in Europe. This uncommon fact in West Africa becomes integrated into the notion of a medical technology and raises the problem of evolution of society (non migration, new forms of alimentation, work and urbanization...). While in France the inquiry is dependent on an image of an hypertensive, his body, his personality, his problems; in Ivory Coast people refer to a body language, the psychosomatic damage including the existential malaise politics, cultural confrontations, stress pathology ... all this with periods of high or low tension internal or external pressures, getting out of the medical act consisting in a take of blood pressure or a particular psychic state testing, the nervous break down or anxiety for example. In a methodological field, the author from different levels of view points (sociological, statistical, ethnological and clinical) is in search of an adapted synthetic formula in anthropology for situations of substitution and social differences.

Fainting on exposure to phobic stimuli

Two patients with phobias for medical procedures and trauma developed "vasovagal syncope" with hypotension and bradycardia while viewing a videotape of a venous cutdown. Eleven hours of exposure therapy per patient eliminated both the phobic and fainting responses. These facts support existing hypotheses that phobias of this type and vasovagal fainting are associated and that vasovagal syncope is a diphasic response. They do not support hypotheses that vasovagal syncope follows sudden cessation of anxiety, that that counter-conditioning is necessary for successful treatment, or that novel symptoms emerge following behavioral treatment of these phobias.

Life events and elevated blood pressure in young men

The study group was recruited from a population of 18-yr-old men who were subjected to blood pressure screening. Subjects with blood pressure elevation from this group were compared with two samples from the same population, one normotensive and one hypotensive, with regard to self-reported life events. A detailed interview regarding life events during the total life span revealed no significant differences in total mean number of events between the groups. However, there were significant differences with regard to reports of positive life events. More positive events were reported during the later years in the hypotensive group. An analysis of particular events related to separation from family revealed no instances of reported divorce in the families of the hypertensive subjects in contrast to two divorces in the normotensive and four in the hypotensive families. The hypertensive group was divided into two subgroups, those who during an interview session showed consistent vasoconstriction--with more sustained and severe blood pressure elevation--and those who did not--with a less stable blood pressure elevation. These subgroups differed as to mean number of life events and life events perceived as negative. As a parallel to the findings in the main groups, the subgroup with more sustained blood pressure elevation had the smallest number of reported events. The psychosocial differences between the subgroups within the hypertensive group found in the present study is a further indication to the existence of different psychosomatic mechanisms operating.

Ethanol consumption in genetically selected hypertensive and hypotensive mice

Hypertensive mice drank more alcohol than did hypotensive animals over a wide range of concentrations. The intake was not related to blood pressure phenotype in a causal manner, nor was age a factor in the results.