A Review of the Etiology, Asssociated Comorbidities, and Treatment of Orthostatic Hypotension

Therapeutic dilemmas with benzodiazepines and Z-drugs: insomnia and anxiety disorders versus increased fall risk: a clinical review

PURPOSE

The aim of this clinical review was to summarise the existing knowledge on fall risk associated with benzodiazepines (BZDs) and Z-drugs in older people with focus on appropriate prescribing, including deprescribing.

METHODS

We conducted a literature search in June 2021 in PubMed and Embase with citation and reference checking. Personal reference libraries and international websites were also used. Keywords for the searches included "benzodiazepines", "Z-drugs", "falls", "deprescribing", "fall-risk-increasing-drugs", "inappropriate prescribing", "older people" and matching synonyms. We discuss use of BZDs and Z-drugs, potential fall-related adverse reactions, alternatives for and deprescribing of BZDs and Z-drugs in older persons.

RESULTS

BZDs and Z-drugs differ in fall-related adverse effect profile. They contribute to fall risk through orthostatic hypotension, dizziness and/or imbalance, sedation, muscular weakness, ataxia, etc. Fall incidents contribute significantly to mortality and morbidity. Therefore, there is a need for appropriate prescribing and use of BZDs and Z-drugs in older people. In practice, this means pertaining to a strict indication, strongly consider to non-pharmacological alternatives, limit use to the lowest dose and the shortest duration possible. Judicious deprescribing should be considered and encouraged as well. Practical resources, tools and algorithms are available to guide and assist clinicians in deprescribing BZDs and Z-drugs.

CONCLUSIONS

Prescribing BZDs and Z-drugs should be done in a well-considered way in fall-prone older people. A good overview and insight in the fall-related adverse effects of these drugs, as well as the availability of different strategies to increase the appropriate use, including deprescribing initiatives, can assist clinicians in clinical decision-making.

Orthostatic hypotension, falls and in-hospital mortality among elderly patients with and without type 2 diabetes

OBJECTIVES

To evaluate the association of falls and in-hospital mortality with the presence of orthostatic hypotension and type 2 diabetes mellitus (T2D). The study also aims to identify whether the orthostatic hypotension assessed at 1 min or at 3 min can predict falls and mortality, as a secondary objective to identify the predictors of fall during hospitalization.

METHODS

We performed a prospective study with patients admitted to a university hospital. The risk of falls was assessed using the Morse questionnaire and the presence of falls was verified by the patient's medical records during hospitalization. The orthostatic hypotension was determined by measuring blood pressure at three times, considering as orthostatic hypotension the reduction of at least 20 mmHg in SBP or 10 mmHg in DBP. In-hospital mortality was consulted in the medical records.

RESULTS

Patients with orthostatic hypotension were slower on Timed Up and Go test (TUG) (12.26 ± 3.16 vs. 16.08 ± 5.96 s, P = 20 s) and presence of orthostatic hypotension. After adjustments, patients with T2D and orthostatic hypotension had a 2.7 times greater risk of in-hospital falls and 1.54 times greater odds of in-hospital mortality when compared with patients without T2D and orthostatic hypotension.

CONCLUSION

In this sample, sedentary patients and those with lower TUG had a higher risk of falls. The prevalence of falls was higher in patients with T2D. The association of T2D with orthostatic hypotension significantly increased both the risk of falls and the risk of in-hospital mortality.

Geriatric Pharmacotherapy Case Series: Neurogenic Orthostatic Hypotension

This case illustrates the pharmacist’s role in the outpatient management of neurogenic orthostatic hypotension (nOH) in a community-dwelling older person. In this case, the patient has a long-standing history of asymptomatic hypotension with recent onset of falls with temporary loss of consciousness prompting initiation of pharmacologic therapy. This case reviews nonpharmacological and pharmacological treatment options for older people with symptomatic nOH.

Cerebral blood flow self-regulation in depression

BACKGROUND

Depression is a common neuropsychiatric disease with a high prevalence rate. Sleep problems, memory decline, dizziness and headaches are the most common neurological symptoms in depressed patients. Abnormality of cerebral blood flow (CBF) has been observed in depressive patients, but those patients did not have intracranial structural damage. Both of those phenomena might be related to cerebral blood flow self-regulation (CBFSR: cerebral blood flow self-regulation). CBFSR can maintain CBF relatively stable in response to changes in neurological and metabolic factors. Therefore, this review aimed to discuss CBFSR in depression.

METHODS

We searched for keywords such as "depression", "cerebral blood flow", "cerebral autoregulation", "cerebrovascular reactivity" and the words related to depression. We analyzed whether there is a change in the CBFSR in depression, further explored whether there is a relationship between the pathogenesis of depression and the CBFSR, and discussed the possible mechanism of impaired CBFSR in patients with depression.

RESULTS

Discovered by the literature review, CBFSR is significantly impaired in depressed patients. The level of circulating markers of endothelial dysfunction, nitric oxide, inflammatory cytokines, glucocorticoid and monoamine neurotransmitters is mostly abnormal in depression, which affected the CBFSR to varying degrees.

LIMITATIONS

Limitations include the small number of direct studies about depression and CBFSR mechanisms.

CONCLUSION

CBFSR is impaired in depression. The underlying mechanisms include endothelial dysfunction, overactivation of microglia and changes of cytokines, hyperactivation of the HPA axis, increased oxidative stress, monoamine neurotransmitter disorders, etc. These deepened our understanding of the clinical symptoms of depressed patients.

REM sleep behavioral disorder may be an independent risk factor for orthostatic hypotension in Parkinson's disease

PURPOSE

The purpose of this study was to evaluate the association between clinically possible rapid eye movement (REM) sleep behavioral disorder (pRBD) and orthostatic hypotension (OH) in PD patients, as well as to explore the mechanisms underlying the association.

METHODS

PD patients (n = 116) were assigned to a group with OH (PD-OH) or without OH (PD-NOH). General demographic and clinical data were collected. A series of scales were used to assess the clinical symptoms in the two groups.

RESULTS

A total of 27 patients (23.3%) had OH. The PD-OH group showed significantly higher H-Y staging score and significantly higher frequencies of pRBD, anxiety, depression, and cognitive impairment than the PD-NOH group. Binary logistic regression analysis identified the following factors as independently associated with PD-OH: H-Y staging [odds ratio (OR) 2.565, 95% confidence interval (CI) 1.160-5.673; P = 0.020], RBD (OR 7.680, 95% CI 1.944-30.346; P = 0.004), UPDRS II (OR 1.021, 95% CI 0.980-1.063; P = 0.020), depression (OR 7.601, 95% CI 1.492-38.718; P = 0.015), and cognitive impairment (OR 0.824, 95% CI 0.696-0.976; P = 0.025).

CONCLUSIONS

Our results suggest that pRBD is an independent risk factor for OH in patients with PD. We speculate that there may be a close relationship between RBD and OH, which requires attention. Early diagnosis of RBD may help predict the appearance of OH in PD patients.

Effectiveness of non-pharmacological interventions to treat orthostatic hypotension in elderly people and people with a neurological condition: a systematic review

OBJECTIVE

The objective of this review was to summarize the best available evidence regarding the effectiveness of non-pharmacological interventions to treat orthostatic hypotension (OH) in elderly people and people with a neurological condition.

INTRODUCTION

Orthostatic hypotension is common in elderly people and people with a neurological condition and can interfere with or limit rehabilitation. Non-pharmacological interventions to treat OH could allow for longer and earlier mobilization, which is recommended in national clinical guidelines for rehabilitation in the acute or sub-acute phase following stroke or other neurological conditions.

INCLUSION CRITERIA

The review considered people aged 50 years and older, and people aged 18 years and elderly people with a neurological condition. Non-pharmacological interventions to treat OH included compression garments, neuromuscular stimulation, physical counter-maneuvers, aerobic or resistance exercises, sleeping with head tilted up, increasing fluid and salt intake, and timing and size of meals. The comparator was usual care, no intervention, pharmacological interventions, or other non-pharmacological interventions. Outcome measures included systolic blood pressure, diastolic blood pressure, heart rate, cerebral blood flow, observed/perceived symptoms, duration of standing or sitting in minutes, tolerance of therapy, functional ability, and adverse events/effects.

METHODS

Databases for published and unpublished studies available in English up to April 2018 with no lower date limit were searched. Critical appraisal was conducted using standardized instruments from JBI. Data were extracted using standardized tools designed for quantitative studies. Where appropriate, studies were included in a meta-analysis; otherwise, data were presented in a narrative form due to heterogeneity.

RESULTS

Forty-three studies - a combination of randomized controlled trials (n = 13), quasi-experimental studies (n = 28), a case control study (n = 1), and a case report (n = 1) - with 1069 participants were included. Meta-analyses of three interventions (resistance exercise, electrical stimulation, and lower limb compression bandaging) showed no significant effect of these interventions. Results from individual studies indicated physical maneuvers such as leg crossing, leg muscle pumping/contractions, and bending forward improved orthostatic hypotension. Abdominal compression improved OH. Sleeping with head up in combination with pharmacological treatment was more effective than sleeping with head up alone. Eating smaller, more frequent meals was effective. Drinking 480 mL of water increased blood pressure.

CONCLUSIONS

The review found mixed results for the effectiveness of non-pharmacological interventions to treat OH in people aged 50 years and older, and people with a neurological condition. There are several non-pharmacological interventions that may be effective in treating OH, but not all have resulted in clinically meaningful changes in outcome. Some may not be suitable for people with moderate to severe disability; therefore, it is important for clinicians to consider the patient's abilities and impairments when considering which non-pharmacological interventions to implement.

Joint Hypermobility Links Neurodivergence to Dysautonomia and Pain

OBJECTIVES

Autism, attention deficit hyperactivity disorder (ADHD), and tic disorder (Tourette syndrome; TS) are neurodevelopmental conditions that frequently co-occur and impact psychological, social, and emotional processes. Increased likelihood of chronic physical symptoms, including fatigue and pain, are also recognized. The expression of joint hypermobility, reflecting a constitutional variant in connective tissue, predicts susceptibility to psychological symptoms alongside recognized physical symptoms. Here, we tested for increased prevalence of joint hypermobility, autonomic dysfunction, and musculoskeletal symptoms in 109 adults with neurodevelopmental condition diagnoses.

METHODS

Rates of generalized joint hypermobility (GJH, henceforth hypermobility) in adults with a formal diagnosis of neurodevelopmental conditions (henceforth neurodivergent group, n = 109) were compared to those in the general population in UK. Levels of orthostatic intolerance and musculoskeletal symptoms were compared to a separate comparison group (n = 57). Age specific cut-offs for GJH were possible to determine in the neurodivergent and comparison group only.

RESULTS

The neurodivergent group manifested elevated prevalence of hypermobility (51%) compared to the general population rate of 20% and a comparison population (17.5%). Using a more stringent age specific cut-off, in the neurodivergent group this prevalence was 28.4%, more than double than the comparison group (12.5%). Odds ratio for presence of hypermobility in neurodivergent group, compared to the general population was 4.51 (95% CI 2.17-9.37), with greater odds in females than males. Using age specific cut-off, the odds ratio for GJH in neurodivergent group, compared to the comparison group, was 2.84 (95% CI 1.16-6.94). Neurodivergent participants reported significantly more symptoms of orthostatic intolerance and musculoskeletal skeletal pain than the comparison group. The number of hypermobile joints was found to mediate the relationship between neurodivergence and symptoms of both dysautonomia and pain.

CONCLUSIONS

In neurodivergent adults, there is a strong link between the expression of joint hypermobility, dysautonomia, and pain, more so than in the comparison group. Moreover, joint hypermobility mediates the link between neurodivergence and symptoms of dysautonomia and pain. Increased awareness and understanding of this association may enhance the management of core symptoms and allied difficulties in neurodivergent people, including co-occurring physical symptoms, and guide service delivery in the future.

Clinical Prognostic Factors in Pediatric Patients With Orthostatic Intolerance

Midodrine is widely used for orthostatic intolerance (OI); however, little is known about the prognostic factors of OI after midodrine treatment. We retrospectively reviewed electronic medical charts to investigate clinical prognostic factors of OI on 159 OI patients aged 7 to 18 years who were treated with midodrine at a children's hospital. Logistic regression was conducted to clarify predictors for improving symptoms at the first month of the treatment. Patients with orthostatic uncomfortable feeling or fainting were significantly more likely to improve symptoms at the first month of the treatment (odds ratio [OR], 3.48; 95% confidence interval [95%CI], 1.36-8.89), but patients with underweight were significantly less likely to improve symptoms (OR, 0.19; 95%CI, 0.06-0.56). Our results suggest that predictive factors for OI by midodrine treatments are orthostatic symptoms and underweight in pediatric patients. These findings are useful to develop further studies for OI treatments.

Metformin may adversely affect orthostatic blood pressure recovery in patients with type 2 diabetes: substudy from the placebo-controlled Copenhagen Insulin and Metformin Therapy (CIMT) trial

Background

Metformin has been shown to have both neuroprotective and neurodegenerative effects. The aim of this study was to investigate the effect of metformin in combination with insulin on cardiovascular autonomic neuropathy (CAN) and distal peripheral neuropathy (DPN) in individuals with type 2 diabetes (T2DM).

Methods

The study is a sub-study of the CIMT trial, a randomized placebo-controlled trial with a 2 × 3 factorial design, where 412 patients with T2DM were randomized to 18 months of metformin or placebo in addition to open-labelled insulin. Outcomes were measures of CAN: Changes in heart rate response to deep breathing (beat-to-beat), orthostatic blood pressure (OBP) and heart rate and vibration detection threshold (VDT) as a marker DPN. Serum levels of vitamin B12 and methyl malonic acid (MMA) were analysed.

Results

After 18 months early drop in OBP (30 s after standing) was increased in the metformin group compared to placebo: systolic blood pressure drop increased by 3.4 mmHg (95% CI 0.6; 6.2, p = 0.02) and diastolic blood pressure drop increased by 1.3 mmHg (95% CI 0.3; 2.6, p = 0.045) compared to placebo. Beat-to-beat variation decreased in the metformin group by 1.1 beats per minute (95% CI − 2.4; 0.2, p = 0.10). Metformin treatment did not affect VDT group difference − 0.33 V (95% CI − 1.99; 1.33, p = 0.39) or other outcomes. Changes in B12, MMA and HbA_1c did not confound the associations.

Conclusions

Eighteen months of metformin treatment in combination with insulin compared with insulin alone increased early drop in OBP indicating an adverse effect of metformin on CAN independent of vitamin B12, MMA HbA_1c.

Trial registration The protocol was approved by the Regional Committee on Biomedical Research Ethics (H–D-2007-112), the Danish Medicines Agency and registered with ClinicalTrials.gov (NCT00657943).

Management of neurogenic orthostatic hypotension in the heart failure patient

Neurogenic orthostatic hypotension (nOH) is a common comorbidity in patients with neurodegenerative diseases. It is associated with an increased risk of falls, incident cardiovascular disease, and all-cause mortality. There are over 5 million individuals in the U.S. with heart failure (HF) with an associated 50% mortality rate at 5 years. The prevalence of nOH and HF increase with age and, as the population continues to age, will be increasingly common comorbid conditions. Thus, the effective management of these conditions has important implications for public health. The management of orthostatic hypotension in the context of congestive heart failure is challenging due to the fact that the fundamental principles of management of these disease states are in opposition to each other. In this review, we will discuss the principles of management of nOH and HF and outline strategies for the effective treatment of these comorbid conditions.

Fatigue in Parkinson's Disease Associates with Lower Ambulatory Diastolic Blood Pressure

BACKGROUND/OBJECTIVE

Fatigue is a common debilitating symptom in Parkinson's disease (PD) of unclear etiology. Hypotension and blood pressure variability are common in PD though their relationship to other non-motor symptoms is less well understood.

METHODS

We conducted a cross-sectional study to explore differences in 24-hour ambulatory blood pressure measurements in PD subjects (n = 35) with and without fatigue. Subjects underwent hourly systolic (SBP) and diastolic (DBP) blood pressure testing in their home environment. The presence of fatigue was assessed using the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part 1. We compared blood pressure measurements in fatigued vs. non-fatigued PD subjects, assessed over 4 epochs: overnight, morning, midday, and evening.

RESULTS

PD subjects with symptoms of fatigue demonstrated lower mean DBP, compared to those without fatigue (67.8±4.8 mmHg vs. 75.6±9.4 t = 2.57, p = 0.014). These intergroup differences were most notable in the morning. The two groups did not differ in scoring on the Survey of Autonomic Symptoms or on an office-based blood assessment of SBP or DBP performed on the day of 24-hour monitor initiation.

CONCLUSIONS

Fatigue in PD may be a clinical manifestation of low-grade systemic hypotension.

[Factors associated with orthostatic hypotension in adults: the ELSA-Brasil study]

This study aimed to investigate factors associated with orthostatic hypotension in 14,833 individuals 35-74 years of age. This was a cross-sectional study of baseline data (2008-2010) from the Longitudinal Study of Adult Health (ELSA-Brasil). Postural testing was performed after 20 minutes resting in supine position and active adoption of orthostatic posture. Blood pressure was measured in supine position and at 3 minutes in orthostatic position with an oscillometer (HEM 705 CP, Omron, São Paulo, Brazil). Orthostatic hypotension was defined as a drop of ≥ 20mmHg in systolic blood pressure and/or a drop of ≥ 10mmHg in diastolic blood pressure. The target covariates were sex, age bracket, race/color, schooling, nutritional status, waist circumference, alteration in the ankle-brachial index, pulse wave velocity, systolic and diastolic blood pressure, hypertension, diabetes, use of antihypertensives, cholesterol, triglycerides, Chagas disease serology, symptoms, and heart rate variation in the postural test, self-reported heart disease, acute myocardial infarction (AMI)/revascularization, and stroke. Orthostatic hypotension was significantly associated with higher age bracket, OR = 1.83 (95%CI: 1.14-2.95); alteration in the ankle-brachial index, OR = 2.8 (95%CI: 1.13-6.88); AMI/revascularization, OR = 1.70 (95%CI: 1.01-2.87); report of heart disease, OR = 3.03 (95%CI: 1.71-5.36); increased systolic blood pressure, OR = 1.012 (95%CI: 1.006-1.019); positive Chagas disease serology, OR = 2.29 (95%CI: 1.23-4.27); and occurrence of symptoms with postural change, OR = 20.81 (95%CI: 14.81-29.24). Presence of orthostatic hypotension can be a warning sign for cardiovascular disorders and thus a useful tool for screening and prevention.

The Investigation of the Cardiovascular and Sudomotor Autonomic Nervous System-A Review

The autonomic nervous system as operating system of the human organism permeats all organ systems with its pathways permeating that it is involved with virtually all diseases. Anatomically a central part, an afferent part and sympathetic and parasympathetic efferent system can be distinguished. Among the different functional subsystems of the autonomic nervous system, the cardiovascular autonomic nervous system is most frequently examined with easily recordable cardiovascular biosignals as heart rate and blood pressure. Although less widely established, sudomotor tests pose a useful supplement to cardiovascular autonomic assessment as impaired neurogenic sweating belongs to the earliest clinical signs of various autonomic neuropathies as well as neurodegenerative disorders and significantly reduces quality of life. Clinically at first, the autonomic nervous system is assessed with a detailed history of clinical autonomic function and a general clinical examination. As a lof of confounding factors can influence autonomic testing, subjects should be adequately prepared in a standardized way. Autonomic testing is usually performed in that way that the response of the autonomic nervous system to a well-defined challenge is recorded. As no single cardiovascular autonomic test is sufficiently reliable, it is recommended to use a combination of different approaches, an autonomic test battery including test to measure parasympathetic and sympathetic cardiovascular function (deep breathing test, Valsalva maneuver, tilt, or pressor test). More specialized tests include carotid sinus massage, assessment of baroreceptor reflex function, pharmacological tests or cardiac, and regional hemodynamic measurements. Techniques to measure functional integrity of sudomotor nerves include the quantitative sudomotor axon reflex sweat test, analysis of the sympathetic skin response as well as the thermoregulatory sweat test. In addition to these rather established techniques more recent developments have been introduced to reduce technical demands and interindividual variability such as the quantitative direct and indirect axon reflex testing or sudoscan. However, diagnostic accuracy of these tests remains to be determined. We reviewed the current literature on currently available autonomic cardiovascular and sudomotor tests with a focus on their physiological and technical mechanisms as well as their diagnostic value in the scientific and clinical setting.

Exercise training for patients with type 2 diabetes and cardiovascular disease: What to pursue and how to do it. A Position Paper of the European Association of Preventive Cardiology (EAPC)

Patients with type 2 diabetes mellitus suffer from dysregulation of a plethora of cardiovascular and metabolic functions, including dysglycaemia, dyslipidaemia, arterial hypertension, obesity and a reduced cardiorespiratory fitness. Exercise training has the potential to improve many of these functions, such as insulin sensitivity, lipid profile, vascular reactivity and cardiorespiratory fitness, particularly in type 2 diabetes mellitus patients with cardiovascular comorbidities, such as patients that suffered from an acute myocardial infarction, or after a coronary intervention such as percutaneous coronary intervention or coronary artery bypass grafting. The present position paper aims to provide recommendations for prescription of exercise training in patients with both type 2 diabetes mellitus and cardiovascular disease. The first part discusses the relevance and practical applicability of treatment targets that may be pursued, and failure to respond to these targets. The second part provides recommendations on the contents and methods to prescribe exercise training tailored to these treatment targets as well as to an optimal preparation and dealing with barriers and risks specific to type 2 diabetes mellitus and cardiac comorbidity.

[Arterial hypertension in old age with the focus on 80]

Untreated high blood pressure in old age increases the risk of secondary diseases, especially stroke, coronary heart disease, myocardial infarction and heart failure and should be treated according to the guidelines. For slightly frail people up to the age of 80 years, a systolic blood pressure of 130-139 mm Hg (measured in the doctors surgery) should be the aim. According to the current European guidelines the same values are recommended for those over the age of 80 years but treatment should start at a systolic blood pressure of ≥160 mm Hg. In physically disabled and very frail older people an individually tailored approach is recommended, regardless of age. The authors recommend a target systolic value <150 mm Hg but not below 130/70 mm Hg. In the event of poor tolerance the treatment should be adapted further as necessary. Antihypertensive medication should be selected under the aspects of polypharmacy. In many cases arterial hypertension in old age can be treated in accordance with the guidelines, taking multimorbidity and the interaction of medications into consideration.

Vertigo in children; a narrative review of the various causes and their management

Vertigo is a not an uncommon symptom in children, but often the treating doctors are unsure of the diagnosis and the management of these cases. This narrative review of the literature discusses the brief etiopathology, the clinical manifestations and the management algorithm of most of the conditions causing vertigo in children. The relevant information has been condensed into a table for the perusal of the readers, which would assist in the appropriate management of these children.

Blood pressure change does not associate with Center of Pressure movement after postural transition in geriatric outpatients

BACKGROUND

Orthostatic hypotension (OH), a blood pressure drop after postural change, is associated with impaired standing balance and falls in older adults. This study aimed to assess the association between blood pressure (BP) and a measure of quality of standing balance, i.e. Center of Pressure (CoP) movement, after postural change from supine to standing position in geriatric outpatients, and to compare CoP movement between patients with and without OH.

METHODS

In a random subgroup of 75 consecutive patients who were referred to a geriatric outpatient clinic, intermittent BP measurements were obtained simultaneously with CoP measurements in mediolateral and anterior-posterior direction directly after postural change during 3 min of quiet stance with eyes open on a force plate. Additional measurements of continuous BP were available in n = 38 patients. Associations between BP change during postural change and CoP movement were analyzed using Spearman correlation. Mann-Whitney-U tests were used to compare CoP movement between patients with OH and without OH, in which OH was defined as a BP drop exceeding 20 mmHg of systolic BP (SBP) and/or 10 mmHg of diastolic BP (DBP) within 3 min after postural change.

RESULTS

OH measured intermittently was found in 8 out of 75 (11%) and OH measured continuously in 22 out of 38 patients (57.9%). BP change did not associate with CoP movement. CoP movement did not differ significantly between patients with and without OH.

CONCLUSIONS

Results do not underpin the added value of CoP movement measurements in diagnosing OH in a clinical setting. Neither could we identify the role of CoP measurements in the understanding of the relation between OH and impaired standing balance.

Cerebral hemodynamics in orthostatic intolerance with normal head-up tilt test

OBJECTIVES

Orthostatic hypotension (OH) and postural orthostatic tachycardia syndrome (POTS) are well-known causes of orthostatic intolerance (OI). In addition, there are OI patients who are characterized by the symptoms of OI and lack of abnormal findings in head-up tilt (HUT) test. The aim of this study was to determine the cerebral hemodynamic changes in HUT test of OI patients with normal HUT (OINH).

MATERIALS AND METHODS

Two hundred and sixty-one OI patients and 50 healthy controls were enrolled in this study. All subjects underwent transcranial Doppler test while performing the HUT test. Forty-five patients had OH, 33 patients had POTS, and 183 patients had OINH. Blood pressures, heart rate, cerebral blood flow velocities (CBFVs), end-tidal carbon dioxide (ET-PCO2 ), cerebral critical closing pressure (CCP), cerebral perfusion pressure (CPP), and cerebral vascular resistance (CVR) were measured during HUT test. We compared the hemodynamic parameters of OINH with those of OH, POTS, and healthy controls.

RESULTS

Reduced CBFVs, CPP, and ET-PCO2 and elevated CCP were observed in the HUT test of all four groups. CVR was reduced in three OI patients. The drops in systolic CBFV, CPP, and CVR of OINH patients were greater than those of healthy controls. The changes in parameters in the HUT test of OINH group were not different from those of OH and POTS groups except prominent decrements of CPP and CVR in OH group.

CONCLUSION

Our findings suggest that OINH is true OI sharing the common pathomechanism of OH and POTS.

Clinical benefit of midodrine hydrochloride in symptomatic orthostatic hypotension: a phase 4, double-blind, placebo-controlled, randomized, tilt-table study

Objective

Midodrine hydrochloride is a short-acting pressor agent that raises blood pressure in the upright position in patients with orthostatic hypotension. The US Food and Drug Administration’s Subpart H approval, under which midodrine was initially approved, requires post-marketing studies to confirm midodrine’s clinical benefit in this indication. The purpose of this study was to evaluate the clinical benefit of midodrine with regard to symptom response.

Methods

This was a double-blind, placebo-controlled, randomized, crossover, multicenter study (NCT01518946). Following screening, patients aged ≥18 years with severe symptomatic orthostatic hypotension and on a stable dose of midodrine for at least 3 months were randomized to treatment with either their previous midodrine dose or placebo on day 1 and the respective alternate treatment on day 2. The primary endpoint measured time to syncopal symptoms or near-syncope using a 45-min tilt-table test at 1 h post-dose.

Results

Thirty-three patients were screened for inclusion: 19 received at least one dose of midodrine and had at least one post-dose measurement of the primary endpoint. The least-squares mean time to syncopal symptoms or near-syncope after tilt-table initiation (mean ± standard error) was 1626.6 ± 186.8 s for midodrine and 1105.6 ± 186.8 s for placebo (difference, 521.0 s; 95 % confidence interval 124.2–971.7 s; p = 0.0131). There were 15 adverse events in 10 patients; all of these were mild or moderate in severity, with none considered by the investigators to be related to midodrine.

Interpretation

Midodrine is a well-tolerated and clinically effective treatment for symptomatic orthostatic hypotension.

Orthostatic Hypotension and Risk of Venous Thromboembolism in 2 Cohort Studies

BACKGROUND

Although venous stasis is a risk factor for venous thromboembolism (VTE) and orthostatic hypotension (OH) can cause venous stasis, to our knowledge no study has examined the relationship between OH and VTE risk. We sought to quantify the association between OH and VTE (deep vein thrombosis or pulmonary embolism) using data from 2 large, prospective cohort studies: the Cardiovascular Health Study (CHS) and the Atherosclerosis Risk in Communities (ARIC) Study. We hypothesized that OH was positively associated with incident VTE.

METHODS

We measured OH-defined as a drop in systolic blood pressure (SBP) of at least 20 mm Hg or diastolic blood pressure (DBP) of at least 10 mm Hg within 3 minutes of standing-in participants aged 45-64 years in ARIC (n = 12,480) and ≥65 years in CHS (n = 5,027) at baseline visits (1987-1989 in ARIC; 1989-1990 and 1992-1993 in CHS), and followed participants for incident VTE (n = 568 in ARIC through 2011 and n = 148 in CHS through 2001). We calculated adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs) for incident VTE in relation to OH status.

RESULTS

In CHS, there was a positive association between OH status and incident VTE (HR for VTE = 1.74 (95% CI: 1.20-2.51)). In contrast, there was no association between OH and VTE in the ARIC study (HR for VTE = 0.97 (95% CI: 0.70-1.33)).

CONCLUSIONS

Community-dwelling older adults with OH had a moderately increased risk of VTE. These results were not seen in a population-based middle-aged cohort.

Brain oxygenation responses to an autonomic challenge: a quantitative fMRI investigation of the Valsalva manoeuvre

In late age, the autonomic nervous system (ANS) has diminished ability to maintain physiological homeostasis in the brain in response to challenges such as to systemic blood pressure changes caused by standing. We devised an fMRI experiment aiming to map the cerebral effects of an ANS challenge (Valsalva manoeuvre (VM)). We used dual-echo fMRI to measure the effective transverse relaxation rate (R2*, which is inversely proportional to brain tissue oxygenation levels) in 45 elderly subjects (median age 80 years old, total range 75-89) during performance of the VM. In addition, we collected fluid-attenuated inversion recovery (FLAIR) data from which we quantified white matter hyperintensity (WMH) volumes. We conducted voxelwise analysis of the dynamic changes in R2* during the VM to determine the distribution of oxygenation changes due to the autonomic stressor. In white matter, we observed significant decreases in oxygenation levels. These effects were predominantly located in posterior white matter and to a lesser degree in the right anterior brain, both concentrated around the border zones (watersheds) between cerebral perfusion territories. These areas are known to be particularly vulnerable to hypoxia and are prone to formation of white matter hyperintensities. Although we observed overlap between localisation of WMH and triggered deoxygenation on the group level, we did not find significant association between these independent variables using subjectwise statistics. This could suggest other than recurrent transient hypoxia mechanisms causing/contributing to the formation of WMH.

Uncontrolled hypertension and orthostatic hypotension in relation to standing balance in elderly hypertensive patients

Objective

To investigate the associations among uncontrolled hypertension, orthostatic hypotension (OH), and standing balance impairment in the elderly hypertensive patients referred to comprehensive geriatric assessment (CGA).

Methods

In a cross-sectional study, a total of 176 elderly hypertensive patients who underwent CGA were divided into OH group (n=36) and non-OH group (n=140) according to blood pressure measurement in the supine position, after immediate standing up, and after 1 minute and 3 minutes of standing position. Uncontrolled hypertension was defined as blood pressure of ≥140/90 mmHg if accompanied by diabetes mellitus (DM) or chronic kidney disease (CKD), or ≥150/90 mmHg if no DM and no CKD. Standing balance, including immediate standing balance and prolonged standing balance, was assessed in side-by-side and tandem stance.

Results

Neither uncontrolled hypertension nor OH was associated with prolonged standing balance impairment in elderly hypertensive patients (P>0.05). Blood pressure decrease after postural change was significantly associated with immediate standing balance impairment in side-by-side and tandem stance (P<0.05). Patients with OH were at greater risk of immediate standing balance impairment in both side-by-side and tandem stance than those without OH (odds ratio [OR] 3.44, 95% confidence interval [CI] 1.26–9.33, P<0.05; OR 3.14, 95% CI 1.14–8.64, P<0.01). Furthermore, uncontrolled hypertension was associated with immediate standing balance impairment in side-by-side stance (OR 2.96, 95% CI 1.31–6.68, P<0.05).

Conclusion

Uncontrolled hypertension, OH, and blood pressure decrease after postural change were associated with immediate standing balance impairment, and therefore, a better understanding of the underlying associations might have major clinical value.

Cortical Morphology in Patients with Orthostatic Intolerance

BACKGROUND

We evaluated the cortical morphology in patients with orthostatic intolerance.

METHODS

Thirty patients with orthostatic intolerance, as well as age- and sex-matched normal controls, were enrolled in this study. We divided the patients into orthostatic hypotension (n = 22) and postural tachycardia syndrome (n = 8) groups based on their response to a head-up tilt table test. We analyzed whole-brain T1-weighted MRI images using FreeSurfer 5.1. The measures of cortical morphology were compared between the groups.

RESULTS

The cortical thickness in the right hemisphere, including the medial orbitofrontal, peri-calcarine, post-central, inferior temporal, and lateral occipital cortex, and in the peri-calcarine cortex of the left hemisphere was thinned in patients with orthostatic hypotension compared to normal controls. The other measures of cortical morphology, including the surface area, volume, and curvatures, did not differ between patients with orthostatic hypotension and normal controls. However, none of the measures of cortical morphology differed between patients with postural tachycardia syndrome and normal controls.

CONCLUSIONS

We demonstrated that the cortical morphology significantly changed in patients with orthostatic hypotension but not in patients with postural tachycardia syndrome compared to normal controls. These findings support the hypothesis that orthostatic intolerance is a heterogeneous syndrome.

Drug therapies in older adults (part 2)

In this, the second of two articles, we continue our evaluation of drug therapies in older adults. Having previously described the pharmacokinetic and pharmacodynamic consequences of physiological ageing, along with the challenge of appropriate prescribing, we proposed four key questions which should be considered when prescribing for this cohort of the population. Does this agent reflect the priorities of the patient? Are there alternatives - with greater efficacy, effectiveness or tolerability - that might be considered? Are the dose, frequency and formulation appropriate? How does this prescription relate to concurrent medication? We also highlighted the reliance on subgroup analysis to demonstrate the efficacy of drug therapies for older adults in osteoporosis and the underutilisation of appropriate treatments for patients with Alzheimer's disease as a result of flawed guidelines. Here we describe current drug therapies in systolic heart failure, noting the limited inclusion of older adults in key trials, while also reviewing the pharmacological treatment of orthostatic hypotension. In doing so, we advocate the intermittent use of midodrine as a first-line treatment for orthostasis in older adults, counter to the generic guidelines produced by various learned societies, but in keeping with the scant trial data available.

Cardiac asystole during head up tilt (HUTT) in children and adolescents: is this benign physiology?

Cardiac asystole during HUTT has been described by some investigators as a benign finding with no major sequelae. Our aim in this study is to correlate the severity of clinical symptoms and physiologic findings prior and during the asystole occurrence. This is a retrospective study review of 536 patients who underwent HUTT for dysautonomia symptoms for the last 3 years. HUTT in our institution consists of 10 min in supine, 30 min of head up at 70°, and recline to supine for 10 min. Physiologic parameters recorded include continuous heart rate, BP, cardiac stroke volume, brain blood flow by near-infra red spectroscopy, sympathetic and parasympathetic tones. Patients' complaints and signs during HUTT were recorded. Follow-up was conducted up to 34 months. Cardiac asystole was defined as the absence of ventricular activity for ≥3 s with cessation of BP signal for the same period on the monitor. Of the 536 patients studied, 25 patients developed cardiac asystole (4.7%). The asystolic group age was 15.1 + 3.8 years and weighed 56.7 + 21 kg. All the patients fainted and were not able to complete the test with average head up time of 13.8 + 7.1 min. The cardiac asystole duration was 9.2 + 5.8 s. Sixteen patients developed convulsions during the asystole. There was sudden intense vagal tone prior to and during the asystole. Brain perfusion was significantly decreased in all the patients after head up and sharply dropped by 20-35% in patients who developed convulsions. All patients completely recovered their consciousness after reposition to supine. During recovery, there was overshoot of the brain perfusion above the baseline for several minutes and the HR returned to baseline. Follow-up of these patients: only one patient had a single lead pacemaker, otherwise the 24 patients had no cardiac pacing and were treated by medical therapy. During mean follow-up of 19 + 10 months, five patients developed syncope which resolved after optimizing medical therapy. Cardiac asystole due to neurocardiogenic syncope and dysautonomia has high association with brain anoxia that can lead to convulsions. Such patients require intense medical therapy and close observation with possible intervention by cardiac pacing if prolonged asystole occurs. There is a concern of consequence future brain function.

Nonpharmacologic management of orthostatic hypotension: a systematic review

OBJECTIVE

To systematically review the literature on nonpharmacologic treatment of orthostatic hypotension.

DATA SOURCES

MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane Central Register of Controlled Trials, and SPORTDiscus were searched for human studies written in the English language between January 1980 and April 2013. Reference lists of relevant articles were reviewed for citations to expand the data set.

STUDY SELECTION

Prospective experimental studies assessing nonpharmacologic interventions for management of orthostatic drop in blood pressure in various patient populations were included. All studies identified through the literature search were reviewed independently in duplicate. Of the 642 studies, 23 met the selection criteria.

DATA EXTRACTION

Two reviewers independently extracted data for analysis, including systolic and diastolic blood pressure and orthostatic symptoms in response to postural challenge before and after the intervention. All 23 studies were assessed in duplicate for risk of bias using the Physiotherapy Evidence Database scale for randomized controlled trials and the Downs and Black tool for nonrandomized trials.

DATA SYNTHESIS

There were 8 identified nonpharmacologic interventions for management of orthostatic hypotension under 2 general categories: physical modalities (exercise, functional electrical stimulation, compression, physical countermaneuvers, compression with physical countermaneuvers, sleeping with head up) and dietary measures (water intake, meals). Owing to the clinically diverse nature of the studies, statistical comparison (meta-analysis) was deemed inappropriate. Instead, descriptive comparisons were drawn. Levels of evidence were assigned.

CONCLUSIONS

Strong levels of evidence were found for 4 of the 8 interventions: functional electrical stimulation in spinal cord injury, compression of the legs and/or abdomen, physical countermaneuvers in various patient populations, and eating smaller and more frequent meals in chronic autonomic failure. However, this conclusion is based on a limited number of studies with small sample sizes. Further research into all interventions is warranted.