M. Bachir Tazkarji, MD, CCFP, CAQ Geriatric Medicine, Lecturer, Family Medicine Department, University of Toronto, Toronto, ON; Toronto Rehabilitation Institute, Toronto; Family Physician, Summerville Family Health Team, Mississauga, ON.

Arterial hypertension is one of the most important and preventable causes of death worldwide; therefore, adequate treatment of high blood pressure should be mandatory for patients with hypertension. Hypertension is defined on the basis of systolic and diastolic blood pressure levels and classified into stages on the basis of the degree of elevation. Normal blood pressure is widely considered as being less than 120/80 mm Hg. The presence of risk factors such as elevated blood cholesterol, smoking, diabetes, and obesity greatly increases the risk for hypertension-related morbid events.
Cardiovascular disease and stroke disproportionately affect older adults. Blood pressure is a potent modifiable target for reducing the risk for stroke and cardiovascular morbidity and mortality in older adults. In clinical trials, the number needed to treat to prevent one cardiovascular death was 79, one fatal or nonfatal stroke was 48, and one fatal or nonfatal coronary event was 64.
Key words: blood pressure, myocardial infarction, CVA, cardiovascular risk, older adults.

Kati Juva, MD, PhD, Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland.
Sari Rastas, MD, PhD, Department of Neuroscience and Neurology, University of Kuopio, Kuopio, Finland; Kauniala Disabled War Veterans’ Hospital, Espoo, Finland.
Tuula Pirttilä, PhD, Professor, Department of Neuroscience and Neurology, University of Kuopio and Kuopio University Hospital, Kuopio, Finland.

The harmful effects of high blood pressure on cardiovascular morbidity and mortality are well established. However, hypertension in the very old is an extremely complex issue. Current epidemiological data suggest that high blood pressure may be a marker of survival in the very old, and lowering blood pressure may lead to an increase in total mortality. In this review we will summarize the evidence on the association between blood pressure and mortality and discuss the implications of the data.
Key words: older adults, hypertension, survival, very old, blood pressure.

Kannayiram Alagiakrishnan, MD, MPH, FRCPC, ABIM, Associate Professor, Division of Geriatric Medicine, Department of Medicine, University of Alberta, Edmonton, AB.

Postural and postprandial hypotension are common conditions among older adults. They are causes of dizziness, syncope, and falls in older people. These conditions may result in significant morbidity, a decrease in function, and mortality. Dysregulation of blood pressure in older adults can result in postural and postprandial hypotension. Routine screening for these conditions is easy to perform and helps to diagnose and manage them appropriately. Management includes a combination of nonpharmacological and pharmacological interventions.
Key words: postural hypotension, postprandial hypotension, management, blood pressure, older adults.

An air of ambiguity surrounds the relationship between blood pressure and dementia. While some studies indicate that hypertension increases the risk of Alzheimer disease (AD) or other dementias, others seem to show that low blood pressure confers a higher dementia prevalence. The two observations are not necessarily contradictory, as demonstrated by a recent study at the Aging Research Center in Stockholm, Sweden. A community-based, longitudinal trial, the Kungsholmen Project was conducted to explore whether low blood pressure is prospectively associated with the occurrence of AD and dementia in the elderly.

The study population consisted of 1,270 dementia-free subjects (as determined by the MMSE) older than 75 years. At first follow-up of three years, 772 remained dementia-free and were tracked for the subsequent three years. During six-year follow-up, 339 of these patients developed dementia. The two groups did not differ significantly in their frequency of vascular disease or average systolic, diastolic or pulse pressures.

However, when statistically analysed, high systolic blood pressure (>180mmHg) conferred a significant increased risk for dementia (adjusted relative risk of 1.6) and for AD (adjusted relative risk of 1.5). High diastolic pressure (> 90mmHg) was not related to increased risk, but very low diastolic pressure (= 65mmHg) was related to an increased risk for both dementia and AD (adjusted relative risk of 1.5 and 1.7, respectively). Patients undergoing antihypertensive therapy at baseline were less likely to develop AD or other dementias than those who were not. Interestingly, though the use of antihypertensive medication did not significantly affect the association of dementia risk with systolic pressure, dementia risk was correlated with low diastolic pressure in patients using antihypertensive drugs.

The study confirms previous findings that high systolic blood pressure may be a risk factor for increased dementia incidence. Antihypertensive therapy appears to be largely protective against AD and dementia in the elderly. However, subjects with high systolic pressure remain in danger of developing dementia despite treatment, and subjects with low diastolic pressure may in fact be harmed cognitively by using antihypertensive drugs.

These results may reflect the contribution of high systolic and low diastolic pressure to arterial stiffness and widespread atherosclerosis, pathologies previously correlated with dementia and AD. The association between cognitive disease and low diastolic pressure may be further explained by previous studies, which have suggested that cerebral hypoperfusion may precede neurodegenerative pathological changes.

A major limitation of this study is that blood pressure was assessed only at baseline. Therefore, the results can only be used to determine whether blood pressure at a given point is a determinant of incident dementia, but not the direct effect of blood pressure fluctuations on dementia development.

In light of the observed results, antihypertensive therapy should be considered as a preventative for dementia with caution. Further studies are required to assess the precise points at which systolic and diastolic pressures most effectively minimise the risk for dementia. If such an ideal is established, perhaps the fine-tuning of blood pressure from an early stage in life can prevent cognitive decline further along the road.

Source

1. Chengxuan Q, von Strauss E, Fastbom J, et al. Low blood pressure and risk of dementia in the Kungsholmen project. Arch Neurol 2003;60:223-8.

J. George Fodor, MD, PhD, FRCPC, FAHA, Professor of Medicine, Head of Research, University of Ottawa Heart Institute Prevention and Rehabilitation Centre, Ottawa, ON.

It is worthwhile to review the issue of hypertension in the elderly not only because it will become an ever-increasing problem with our aging population, but also because of the robust database currently at our disposal concerning improved risk assessment and efficacious therapy.

The Epidemiology
Generally, the elderly are considered those above 65 years of age. Dealing with hypertension in this age group, we quickly realize that this disease is a major epidemic with far-reaching consequences for both the health status of this segment of the population as well as our health care system.

The Canadian Heart Health Survey ascertained that among people in the age group 65-74 years, 56% of males and 58% of females were hypertensive.¹ This survey defined hypertension as systolic blood pressure (SBP) > 140mmHg or diastolic blood pressure (DBP) > 90mmHg, or current treatment with a prescription antihypertension medication or non-pharmacological treatment of blood pressure (weight control or sodium/salt restriction). The problem of hypertension in the elderly will continue to increase steadily in importance.