Hydration status of community-dwelling seniors.

BACKGROUND AND AIMS Dehydration is the most common fluid or electrolyte disorder among older persons. This study was designed to examine the hydration status of community-dwelling seniors. METHODS Blood and urine samples were collected from 67 independently living volunteers (65-93 yrs) who had functional limitations but no condition that contraindicated 10 min of moderate exercise. Forty-six subjects who were not diabetic, had fasted for 12 hours, and had blood glucose levels < or = 115 mg/dL were thus included. Urine and serum samples were analyzed for osmolality (mosm/kg), Na+ (mmol/L) and K+ (mmol/L). Whole blood was analyzed for hemoglobin (Hb, g/dL) and hematocrit (Hct, %) and urine for specific gravity (USG). Means and standard deviations for the current data were compared with normal values. RESULTS All values were within normal ranges except urine osmolality. CONCLUSIONS While changes associated with aging may predispose an individual to dehydration, functionally limited, independently living older individuals demonstrate normal hydration status following a 12-hr fast. This suggests that dehydration is not solely a function of the aging process, but may be more related to concomitant medical conditions or dependent living.