CHANGES IN TOTAL BODY WATER DURING ADOLESCENT GROWTH

Total body water was determined on 59 boys and 59 girls and on 40 boys and 45 girls attending junior and senior high schools, respectively. The volunteers were studied for three years. They were given D2O (99.8%) orally, and urine samples were used for determination of the ratio of heavy hydrogen to normal hydrogen by [...]

EFFECTS OF WATER TEMPERATURE AND FLAVORING ON VOLUNTARY DEHYDRATION IN MAN

Effects of water temperature and flavoring on fluid consumption and body weight losses were studied in fourteen unacclimatized men (21-33 years) during 6 hr of treadmill exercise (4.8 km.hr-1, 5% grade for 30 min.hr-1) in a hot environment. Subjects consumed each of four beverages (15 degrees C water, 40 degrees C water, 15 degrees C [...]

By |2013-01-31T18:33:42+00:00enero 31st, 2013|Scientific papers, Thirst|0 Comments

THE INFLUENCE OF AGE ON THE RENAL RESPONSE TO WATER DEPRIVATION IN MAN

Alterations in urine concentrating ability with age were examined in 98 active community-dwelling volunteers (aged 20-79 years) who were free from evidence of diseases known to adversely affect renal function. There was a significant decrease in urine osmolality reached after 12 h dehydration with advancing age, which could not be correlated with the age-related decline [...]

By |2013-01-31T18:33:42+00:00enero 31st, 2013|Age and the elderly, Scientific papers|0 Comments

VOLUNTARY HYPOHYDRATION IN 10- TO 12-YEAR-OLD BOYS

This study was performed to determine whether a) children voluntarily dehydrate while exercising in hot climate; b) such dehydration affects their well-being and thermoregulation. Eleven 10p to 12-yr old, partially acclimatized boys underwent two work-in-the-heat protocols (cycle rides, 45% aerobic capacity at 39 degrees C, 45% rh). During one session they drank only voluntarily when [...]

By |2013-01-31T18:33:42+00:00enero 31st, 2013|Children, Scientific papers|0 Comments

VALIDATION OF THE DEUTERIUM DILUTION TECHNIQUE FOR THE MEASUREMENT OF FLUID INTAKE IN INFANTS

The validity of the deuterium dilution technique as a method of measuring fluid intake was investigated by comparing values obtained with this technique and direct measurements of milk intake in 10 exclusively bottle-fed infants recovering from protein-energy malnutrition. Values for total body water were derived from body weight and length using Friis-Hansen's formula. During a [...]

By |2013-01-31T18:33:42+00:00enero 31st, 2013|Assessment methodologies, Scientific papers|0 Comments

AGE-RELATED FAILURE OF VOLUME-PRESSURE-MEDIATED VASOPRESSIN RELEASE

Osmoreceptor sensitivity, as estimated by the plasma vasopressin (AVP) response to hypertonic saline infusion, increases with age. We studied volume-pressure sensitivity, as estimated by the plasma AVP response to orthostasis, in healthy young (19-31 yr old; n = 12) and old (62-80 yr old; n = 15) subjects. After remaining recumbent overnight (minimum of 8 [...]

By |2013-01-31T18:33:42+00:00enero 31st, 2013|Age and the elderly, Scientific papers|0 Comments

ACUTE CONFUSIONAL STATES AND DEMENTIA IN THE ELDERLY: THE ROLE OF DEHYDRATION/VOLUME DEPLETION, PHYSICAL ILLNESS AND AGE

A prospective study was undertaken to investigate the incidence and aetiology of acute confusional states in physically ill old people. The subjects were 71 patients aged 70 years or over who were admitted as emergencies to a general medical unit. Mental testing revealed that: (a) one in six patients had an acute confusional state on [...]

By |2013-01-31T18:33:42+00:00enero 31st, 2013|Age and the elderly, Scientific papers|0 Comments

PROBLEM: THIRST, DRINKING BEHAVIOR, AND INVOLUNTARY DEHYDRATION

The phenomenon of involuntary dehydration, the delay in full restoration of a body water deficit by drinking, has been described extensively but relatively little is known about its physiological mechanism. It occurs primarily in humans when they are exposed to various stresses including exercise, environmental heat and cold, altitude, water immersion, dehydration, and perhaps microgravity, [...]