Editorial: Postprandial hypotension--the ultimate Big Mac attack

Glucose reduces the osmopressor response in connection with the tyrosine phosphorylation of focal adhesion kinase in red blood cells

Glucose ingestion attenuates the water ingestion-induced increase in the total peripheral vascular resistance and orthostatic tolerance. We investigated the gastrointestinal physiology of glucose by examining the effect of glucose ingestion on the functional expression of focal adhesion kinase (FAK) in red blood cell (RBC) membrane. This study was performed in 24 young, healthy subjects. Blood samples were collected at 5 min before and 25 min and 50 min after an ingestion of 10% glucose water 500 mL, water 500 mL, or normal saline 500 mL. We determined glucose and osmolality in plasma, and phosphorylation of aquaporin 1 (AQP1), glucose transporter 1 (Glut1), and FAK in RBC membrane. Our results showed that glucose ingestion reduced the rise of peripheral vascular resistance after water ingestion and upregulated the serine phosphorylation of Glut1. It also lowered both the serine phosphorylation of FAK and tyrosine phosphorylation of AQP1, compared with the ingestion of either water or saline. In an ex vivo experiment, glucose activated the Glut1 receptor and subsequently reduced the expression of FAK compared with 0.8% saline alone. We concluded that glucose activates Glut1 and subsequently lowers the functional expression of FAK, a cytoskeleton protein of RBCs. The functional change in the RBC membrane proteins in connection with the attenuation of osmopressor response may elucidate the pathophysiology of glucose in postprandial hypotension.

Frailty and hypertension in older adults: current understanding and future perspectives

Hypertension is an important factor affecting the health of older adults. Antihypertensives can reduce stroke, cardiovascular events, and mortality in older hypertensive patients. Blood pressure management is difficult in older adults since geriatric syndromes such as frailty and comorbidities often coexist with hypertension. Recent guidelines propose taking functional status into account when targeting blood pressure in older people. Therefore, a better understanding and control of frailty risk factors could improve the prognosis of older adults with hypertension. However, there are relatively few studies on hypertension and frailty in older adults, especially studies focused on antihypertensive treatment. The goals, target values, and choice of antihypertensive treatment for frail older adults are still disputed. We reviewed the recent literature focusing on frailty and hypertension in older adults and propose a management process for screening and assessing frailty and hypertension before the use of antihypertensives. The process can support older adults with lifestyle interventions and frailty management and help them begin taking a single antihypertensive medication.

Baroreflex function and postprandial hypotension in older adults

PURPOSE

Postprandial hypotension (PPH) is a common but poorly understood etiology for fainting in older adults. One potential mechanism is age-related baroreflex dysfunction. We examined baroreflex function in older adults with PPH and without PPH (noPPH) during a standardized meal test.

METHODS

57 adults (age ≥ 65; 24 PPH, 33 noPPH, mean age 77.9 ± 0.9 years, 54% female) were recruited and had meal tests performed. The baroreflex effectiveness index (BEI, %) and baroreflex sensitivity (BRS, ms/mm Hg) were calculated using the sequence method.

RESULTS

Baseline BEI (22 ± 2 versus 23 ± 2 percent, t = - 0.411, p = 0.682) and BRS (14.1 ± 2.4 versus 13.8 ± 2.5 ms/mm of Hg, t = - 0.084, p = 0.933) were similar in PPH and noPPH subjects. During the meal test PPH subjects showed significantly lower BEI as compared to noPPH subjects (time × PPH, F = 2.791, p = 0.042), while there was no difference in the postprandial change in BRS (time, F = 0.618, p = 0.605).

CONCLUSION

Patients with PPH demonstrated an acute postprandial decrease in baroreflex effectiveness during meal testing as compared with normal subjects, suggesting a potential contributing mechanism for this condition.

Clinical Update on Nursing Home Medicine: 2016

This is the tenth clinical update. It covers chronic kidney disease, dementia, hypotension, polypharmacy, rapid geriatric assessment, and transitional care.

Effects of the amount of rice in meals on postprandial blood pressure in older people with postprandial hypotension: a within-subjects design

AIMS AND OBJECTIVES

To determine the effect of the amount of rice carbohydrates consumed during mealtime on the extent of decrease in postprandial blood pressure in older people with postprandial hypotension.

BACKGROUND

The incidence of postprandial hypotension is as high as 74% in older people with hypertension.

DESIGN

A within-subjects repeated measures design was used.

METHODS

Thirty-nine older people in nursing homes received a full serving and a half-serving of rice on two separate days, in random order blood pressure and heart rate were measured before each meal and every 15 minutes for a total of 120 minutes after each meal. Data were analysed using repeated measures analysis of variance and the paired t-test with a Bonferroni adjustment using IBM spss version 19.0.

RESULTS

The control and intervention conditions yielded significantly different patterns in systolic blood pressure and diastolic blood pressure. Postprandial hypotension was less frequent under the intervention condition; however, decrease in rice intake did not significantly affect heart rate.

CONCLUSION

Reducing the amount of rice intake per meal prevents postprandial blood pressure decreases in the older people. Small and frequent meals with decreased carbohydrate content are recommended to prevent postprandial hypotension and its complications in the older people.

RELEVANCE TO CLINICAL PRACTICE

Patients, dieticians and caregivers of older patients should be aware of the importance of diet, especially of decreasing the amount of carbohydrate in a meal. Smaller and more frequent meals are recommended for older people to slow gastric emptying.

Medical care in the nursing home

With the advent of the graying of the baby boomers, there is an urgent need to enhance care in the nursing home. This article focuses on the areas where high-quality care can improve outcomes.

Aging male

There are several special issues that confront the physician when dealing with the older male. Physicians need to pay attention to these issues and recognize their importance to their patients. This article briefly reviews these unique challenges.

Falls, faints, fits and funny turns

In this practically oriented review, we will outline the clinical approach of patients with falls due to an impairment or loss of consciousness. Following a set of definitions, we describe the salient clinical features of disorders leading to such falls. Among falls caused by true loss of consciousness, we separate the clinical characteristics of syncopal falls (due to reflex syncope, hypovolemia, orthostatic hypotension or cardiac syncope) from falls due to other causes of transient unconsciousness, such as seizures. With respect to falls caused by an apparent loss of consciousness, we discuss the presentation of cataplexy, drop attacks, and psychogenic falls. Particular emphasis will be laid upon crucial features obtained by history taking for distinguishing between the various conditions that cause or mimic a transient loss of consciousness.

Diabetes and aging: epidemiologic overview

Diabetes mellitus has long been recognized as a cause of accelerated aging. As the understanding of the metabolic syndrome has evolved, it has been recognized that the interaction of a panoply of factors in the presence of insulin resistance results in accelerated aging. This article explores the increasing prevalence of diabetes mellitus with aging and how insulin resistance leads to accelerated frailty, disability, hospitalization, institutionalization, and death.

Insulin resistance syndrome and glucose dysregulation in the elderly

The incidence of insulin resistance in the geriatric population is growing as this population grows. The management of hyperglycemia and its associated risk factors depends on an expanding understanding of the underlying pathophysiology and progression of disease and of the currently available and future therapeutics, which are continually evolving. There is a major need for studies in the long-term care setting to determine the appropriate standard of care in prevention and treatment of metabolic dysregulation.

Oral glucose tolerance test reduces arterial baroreflex sensitivity in older adults

Although postprandial decreases in blood pressure are a common cause of syncope in the older adult population, the postprandial effects of the oral glucose tolerance test on blood pressure and the arterial baroreflex remain poorly characterized in older adults. Therefore, arterial blood pressure and the arterial baroreflex were studied in 19 healthy older adults (mean age 71.7 ± 1.1 years) who were given a standardized oral glucose load (75 g) or an isovolumetric sham drink during 2 separate sessions. All measures were taken for 120 min after treatment. Baroreflex function was assessed by using the spontaneous baroreflex method (baroreflex sensitivity, BRS). Subjects demonstrated a decrease in BRS after oral glucose that was not seen in the placebo session (two-way analysis of variance, p = 0.04). There was no significant change in systolic, mean, or diastolic blood pressure; together with a drop in BRS, this resulted in a significant tachycardia post glucose (two-way analysis of variance, p < 0.001). We conclude that healthy older adults can successfully maintain blood pressure during an oral glucose tolerance test despite a decrease in arterial BRS. Decreased BRS resulted in a tachycardic response to glucose.

Evidence rocks in long-term care, but does it roll?

This article reviews the problems with the implementation of evidence-based care in long-term care. It highlights the fact that many common practices are incompatible with evidence and that available evidence, including evidence about inadvisable and ineffective treatments, is often not followed. Often, there is a tendency to follow recommendations for younger persons (for example, the management of hypertension and elevated cholesterol), or to use questionable interventions (for example, choices for treating constipation). In many cases, the treatments used have only marginal efficacy and increased potential for side effects. This article makes recommendations for improving the approach to evidence-based care in long-term care and strongly urges the FDA to require drug studies in nursing homes.

Intensive Session: New Approaches to Medical Issues in Long-Term Care

This article, based on a series of presentations at the American Medical Directors Association, briefly highlights new advances in medical areas of interest to long-term care physicians. The areas discussed are heart failure, vitamin D, falls, new treatments for diabetes mellitus, blood pressure measurement, anemia, clinical nutrition, pressure ulcers, Clostridium difficile, insomnia, and antipsychotic therapy.

Urinary incontinence and the community-dwelling elder: a practical approach to diagnosis and management for the primary care geriatrician

Although there have been dramatic improvements in the management of incontinence since the 1940s, this area remains a major challenge to the geriatrician. Patients need to be asked regularly if they are incontinent and, after the diagnosis is made, should be given a rational treatment plan. Urodynamics should not be performed until mainstream treatments have failed.

Effect of gastric distension on cardiovascular parameters: gastrovascular reflex is attenuated in the elderly

Stretching the stomach wall in young healthy subjects causes an increase in muscle sympathetic nerve activity and in blood pressure, the gastrovascular reflex. We compared healthy elderly subjects with healthy young subjects to find out whether the gastrovascular reflex attenuates in normal ageing and we studied whether there was a difference in autonomic function or gastric compliance that could explain this possible attenuation. Muscle sympathetic nerve activity, finger blood pressure and heart rate were continuously recorded during stepwise isobaric gastric distension using a barostat in eight healthy young (6 men and 2 women, 27 +/- 3.2 years, mean +/-s.e.m.) and eight healthy elderly subjects (7 men and 1 woman, 76 +/- 1.5 years). Changes in cardiac output and total peripheral arterial resistance were calculated from the blood pressure signal. The baseline mean arterial pressure and muscle sympathetic nerve activity were higher in the elderly group (both P < 0.05) and muscle sympathetic nerve activity increase during the cold pressor test was lower in the elderly group (P = 0.005). During stepwise gastric distension, the elderly subjects showed an attenuated increase in muscle sympathetic nerve activity compared to the young subjects (P < 0.01). The older group tended to show a higher increase in mean arterial pressure (P = 0.08), heart rate (P = 0.06) and total peripheral arterial resistance (P = 0.09) The cardiac output rose slightly in both groups without significant difference between groups. The fundic compliance did not differ between groups. We conclude that stepwise gastric distension caused an increase in muscle sympathetic nerve activity in both groups, but the increase in the elderly was attenuated.