BACKGROUND/AIMS: Origin of sex difference in urinary osmolality. METHODS: In 495 healthy children aged 4.0-14.9 years participating in the DONALD (Dortmund Nutritional and Anthropometric Longitudinally Designed) study (247 boys, 248 girls), the water intake recorded in 24-hour weighed dietary records along with urinary volume, osmolality and free water reserve in 24-hour urine samples from the same day as the dietary record were determined. RESULTS: Boys showed [...]

Abstract not available

To investigate the impact of fluid composition on rehydration effectiveness, 30 subjects (15 men and 15 women) were studied during 2 h of rehydration after a 2.5% body weight loss. In a randomized crossover design, subjects rehydrated with water (H2O), chicken broth (CB: 109.5 mmol/l Na, 25.3 mmol/l K), a carbohydrate-electrolyte drink (CE: 16.0 mmol/l [...]

These experiments examined relationships between initial osmolality and carbohydrate (CHO) composition of an infused solution and osmolality and water and CHO absorption in a test segment. A triple-lumen tube with a 10-cm mixing segment and a 40-cm test segment was passed into the duodenojejunum. The infusion port was approximately 10 cm beyond the pyloric sphincter. [...]

Sodium and water loss during, and replacement after, exercise-induced volume depletion was investigated in six volunteers volume depleted by 1.89 +/- 0.17% (SD) of body mass by intermittent exercise in a warm, humid environment. Subjects exercised in a large, open plastic bag, allowing collection of all sweat secreted during exercise. For over 60 min beginning [...]

PURPOSE: This study was conducted to determine whether preexercise ingestion of a highly concentrated sodium beverage would increase plasma volume (PV) and reduce the physiological strain of moderately trained males running in the heat. METHODS: Eight endurance-trained (.VO2max: 58 mL.kg(-1).min(-1) (SD 5); 36 yr (SD 11)) runners completed this double-blind, crossover experiment. Runners ingested a [...]

We studied the relationship between plasma osmolality, arginine vasopressin (AVP), and fluid input in patients during the acute phase of a first stroke. Fifteen consecutive patients were studied (median age 79) and their blood sampled on days 0, 1, 2, 3, 7 and 14. Plasma osmolality was related to fluid input over days 0-3 (p = 0.0013) and AVP over 14 days (p less [...]

OBJECTIVE: To investigate the reliability and validity of refractometry, hydrometry, and reagent strips in assessing  urine specific gravity in collegiate wrestlers. DESIGN AND SETTING: We assessed the reliability of refractometry, hydrometry, and reagent strips between 2 trials and among 4 testers. The validity of hydrometry and reagent strips was assessed by comparison with refractometry, the [...]

1. The present study examined whether reductions in muscle blood flow with exercise-induced dehydration would reduce substrate delivery and metabolite and heat removal to and from active skeletal muscles during prolonged exercise in the heat. A second aim was to examine the effects of dehydration on fuel utilisation across the exercising leg and identify factors related to fatigue. 2. Seven cyclists performed two [...]

BACKGROUND & AIMS: Hydration disorders are frequent in clinical practice and can be a life threatening issue in frail patients. Mild dehydration (1-2% loss of body weight) appears to impair cognitive and muscular performance. There is, however, no infallible indicator of correct hydration, and of hydration disorders. This study aim at describing total body water [...]