Fluid intake of community-living, independent elderly in Germany--a nationwide, representative study

Age-related changes in kidney function and thirst sensation increase the susceptibility for dehydration in the elderly. Adequate fluid intake is the most important prerequisite for fluid homeostasis. Reliable data on fluid intake of older subjects in Germany are lacking.

To assess fluid intake from beverages and total fluid intake of independent, community-living elderly people in Germany.

From a random sample of 4020 non-institutionalized German elderly, stratified into three age-groups (65-74 y., 75-84 y., 85+ y.), 1372 subjects filled in a prospective, standardised 3-day dietary record (cross-sectional study). Fluid intake by beverages and food was calculated on the basis of the German nutrient data base BLS II.2.

Daily median beverage consumption (5. / 95. percentiles) amounted to 1567 (700 / 2967) ml in men and 1400 (600 / 2467) ml in women and thus met the actual recommendation (1310 ml per day). With increasing age beverage intake decreased in both sexes. Consequently, the proportion not meeting the reference value increased with age (33 % vs. 44 % vs. 51 %; p < 0.001). Median total water intake (2387 ml in men, 2224 ml in women) also was higher than the reference value (1990 ml per day) and showed similar differences between sex and age groups as fluid intake by beverages. In one third (28 % of the younger elderly and 41 % of the oldest old) total fluid intake was below the recommendation.

The majority of independently living elderly without major health problems ingests sufficient amounts of fluid to compensate for fluid losses and to be adequately hydrated. Very old elderly, however, require special attention with respect to adequate supply of fluid.