The tubular handling of sodium in two groups of healthy old people, under the action of indomethacin and aldosterone was studied. Urinary aldosterone elimination was measured. From the results obtained, it is deduced that the elderly lose sodium through incompetence of the distal nephron. The possibility is put forward of a Na-K-ATPase deficit and/or interstitial [...]

We examined osmotic control of thirst and free water clearance in healthy older (65+, n = 10) and younger (Y, n = 6) subjects during a 3-h rehydration period after an approximately 2.4% decrease in body weight. Plasma volume (PV), plasma osmolality (Posm), renal function, and thirst were measured before and after dehydration and during [...]

BACKGROUND. There is little information for age differences in body composition in elderly people > 65 years of age, especially for those > 80 years. As the proportion of people older than 65 years is expected to nearly double during the next few decades, this information is needed. METHODS. Age differences in body composition and [...]

Dehydration is a common clinical syndrome associated with many illnesses and treatments in the elderly. Prior studies have shown diminished sensation of thirst during water deprivation. It is currently unclear whether age-related decreases in thirst perception impair the defense against a hyperosmolar challenge. To examine the impact of water ingestion during hyperosmolality, young and old [...]

OBJECTIVES: To assess early clinical signs and their prognostic value in elderly patients with hypernatremia. DESIGN: Prospective, case control study of 150 patients with hypernatremia matched to 300 controls. SETTING: Multicenter study including seven short- and long-term geriatric care facilities. MEASUREMENTS: Clinical assessment of hydration status at bedside, such as abnormal skin turgor or dry [...]

The renal and vasopressin (AVP) response to a standard oral water load (20 ml/kg) was examined in a group of water-replete healthy elderly men (n = 6). Two groups, respectively, of water-replete and water-deprived young healthy volunteers acted as controls. After 2 h, the old group had excreted 41 +/- 2.4% (mean +/- SEM) of [...]

The mechanisms of renal tubular dysfunction in old age have been examined in twenty-eight clinically healthy elderly subjects without infection, and in fourteen subjects of similar age with laboratory evidence of intrarenal infection. The data were compared with those from thirteen clinically healthy young subjects. Studied were: proximal tubular (Tm(PAH)) and distal tubular (CH2O) activity, [...]

No abstract available.

The effect of age on the hypothalamic-hypophyseal-renal axis in normal man was determined by assaying plasma arginine vasopressin (AVP) responses to inhibitory and to secretory stimuli. Nine young (21-49 years) and 13 old (54-92 years) subjects received IV ethanol (375 mg/m2 per min). AVP levels fell progressively during the infusion in the young group, but [...]

The causes, therapy for, and consequences of hypernatremia in elderly patients are not well understood. We found that in 15,187 consecutive hospital admissions, 162 (1.1%) patients who were at least 60 years of age had serum sodium levels that measured greater than 148 meq/L. Of that 162, 57% had become hypernatremic in the hospital; the [...]