Age as a function in the development of sodium-related hypertension.

Abstract

The populations of the developed nations of the world exhibit an increase in blood pressure with age, while in primitive societies blood pressure remains relatively constant throughout adult life. Hypertension may be a complex of diseases all having the same clinical manifestations but not being caused necessarily by the same factors. A possible common denominator in the development of any chronic elevation of blood pressure is the need for the kidney to increase urine volume to promote sodium excretion and, thereby, prevent a chronically expanded extracellular fluid (ECF). Hypertension may be viewed as a maladaptation of the body in its attempt to maintain homeostasis of the ECF. Man evolved under conditions of relative scarcity of salt and even now can maintain normal body function with an intake of less than 2 g/day. The high risk person appears to have a hereditary predisposition to a rise in blood pressure in the presence of a high sodium (NaCl) intake. Actually, the degree of rise in blood pressure may be an interaction between the amount of genetic predisposition and the level of sodium and its relation to potassium intake. Recent work in two Massachusetts communities supports this interpretation and suggests that differences in blood pressure distribution may increase with age between a higher and lower sodium community.

Dietary sodium loading in normotensive healthy volunteers does not increase arterial vascular reactivity or blood pressure

“…have observed that higher baseline blood pressure values result in greater reductions in blood pressure for the same reduction in sodium intake. Of importance is the fact that all participants in this study were White and of European origin, so would be expected to be less sodium‐sensitive than cohorts that included subjects of African or Asian descent 20–23 . The amount of benefit a low‐sodium diet will have to an individual will vary within populations.…”

Estimating Sodium Intake from Food Consumption Data

“…In terest in this is growing at the moment, and in several studies food consumption data have been combined with urinary analysis [16,17,22], The data collected in nutrition surveys could be used for sodium intake analysis even without urine collections when ever data are available on the salt content of foods consumed in the area.…”

The relationship between income, education and hypertension

“…It is influenced not only by physical factors such as diet (Morgan, 1978;Hill, 1979;Swales, 1980), race (Yankauer, 1978), obesity (Sims, 1978), weight (Stamler, 1978), and age (Kilcoyne, 1978;Katz, 1980;Tuthill, 1979;Voors, 1978), but also by psychological variables such as stress (Yankauer, 1977), and personality (Smyth, 1978;Jenkins, 1979;Murphy, 1977), and other variables related to stress, e.g. occupation and geographic location (Nadium, 1978) and social status (Langford, 1968).…”