What Causes Low Blood Pressure in the Elderly?

What Causes Low Blood Pressure in the Elderly? This review reviews the main characteristics of orthostatic hypo tension that occurs in the elderly. It is a little studied and little detected pathology in Primary Care consultations. We want to highlight its enormous prevalence, the need for systematic detection, the difficulty in the diagnostic study, its importance as a vascular risk factor in the group of patients aged 65 years or more, and we want to give guidelines for approach and treatment from the Care Primary.

ABSTRACT

In this review is presented the main features of orthostatic hypotension that occurred in the elderly patients. I

Key words: Orthostatic hypotension. Primary Health Care. Age.

Acceptance: 04-07-02

CONCEPT

The Consensus Committee of the American Society for Autonomic Diseases and the American Academy of Neurology define orthostatic hypotension (HO) as a drop in systolic blood pressure (SBP) greater than or equal to 20 millimeters of mercury (mmHg) or diastolic blood pressure (DBP) greater than or equal to 10 mmHg that occurs within 3 minutes of going from supine to upright position. 1-5

Although this is the most accepted definition, there is a great disparity in criteria around this concept. Some authors are based solely on PAS, leaving aside the PAD 6 . Others reduce the observation time from 3 to 1 minute 7. Finally, there are authors who deviate considerably from this definition, using the patient’s previous arterial pressure (BP) drops, either by 5% or more or by 10% or more, when moving from the supine position to the position. upright 8 , they also use any decrease in BP that is accompanied by symptoms 9 , as well as any SBP in the standing position of less than 95 mmHg 10 .

EPIDEMIOLOGY AND PREVALENCE

At the time of quantifying the prevalence of HO we find a great problem: the great variability of BP. First of all, this marked variability may be due to errors or inadequate measurements of the BP figures. It is known that, depending on the type of measuring device, the tension figures can fluctuate 11 .

It is also important to say that the magnitude of BP is an intrinsically variable parameter, and that it depends on many factors 11 : age, time of day of measurement, food, drugs, etc.

The prevalence also varies according to the type of population we study, depending on age and various associated pathologies.

An estimate can be made based on epidemiological data that would place the prevalence between 4 and 33% of the elderly population 5,7-10,12-13 . In a recent article published in our country, the prevalence of HO in hypertensive elderly in the Primary Care setting was 14.6% 13 . In this population group it has found that BP control influences the prevalence 14 . In diabetic patients a prevalence that can reach 19% 7 has been seen , although the highest prevalence of HO has been observed in Parkinson’s patients, with figures of 60% 12,15 .

In primary highlights a little known, called syndrome Bradbury-Eggleston or pure autonomic failure 18. It was described in 1925 by Bradbury and Eggleston and it is an idiopathic disease in which there is a selective degeneration at the level of the vegetative system, with preservation of all other neurological functions. In 1960,

At the genetic level, it is worth mentioning the results of a study carried out by Schwartz 19 in which it was evidenced that primary neurogenic HO could be linked to a mutation in the mitochondrial genome located on the long arm of chromosome 18 (18q).

If we focus on the secondary ones, the HO produced by diabetes mellitus deserves special attention as it is a frequent cause of vegetative dysfunction in adults. The incidence of diabetics with clinical symptoms of vegetative dysfunction is 40% in patients with 10 or more years of evolution, being the parasympathetic alteration the earliest in these cases.

Non-neurogenic (Tables II and III )

The most common mechanism of non-neurogenic HO production is intravascular volume reduction 17,20. In addition to the causes listed in Tables II and III, there are certain somatic alterations that can interfere with the homeostatic mechanisms of BP. It has been described that certain patients with an asthenic habit and poor muscular development present HO, probably due to the decrease in venous return due to an inadequate muscle pumping action. A similar mechanism may be the cause of the HO seen in states of significant malnutrition. A special form of HO is that of pregnancy.