Diuretic action of weak and strong alcoholic beverages in elderly men

Alcohol consumption is known to increase urine output, which could interfere
with normal hydration. The underlying mechanism of this effect is possibly due
to the inhibition of the release of antidiuretic hormone, vasopressin. So far,
no consistent theory exists on the extent of diuresis by alcohol consumption.
For health communication purposes, specifically towards elderly who have an
increased risk of dehydration, it is important to know the exact extent of the
diuretic effect of different alcoholic beverages. To the best of our knowledge,
no studies have examined the diuretic effect of commercial available weak and
strong alcoholic beverages in normal life settings.

To assess the diuretic effect of three standard glasses of beer, red wine and
spirits in euhydrated elderly men

The study has a diet-controlled randomized cross-over design (within subject
design) in which participants consume 3 standard glasses of beer,
non-alcoholic beer, red wine, non-alcoholic red wine, spirits or water at 6
different test sessions. The order in which participants are exposed to the
test beverages is randomized and counterbalanced.

Subjects will participate in six experimental trials, each separated by a
period of at least seven days. Beverage types vary between the six trials.
Subjects are randomly exposed to: beer (lager), non-alcoholic beer, red wine,
non-alcoholic red wine, spirits (jenever) or water.
During the test sessions, they will collect urine starting after the first
morning urine and the total diet will be provided (same standard diet and lunch
on each test day). The diet will have different levels of energy intake per
day, depending on the body weight of the subjects. During each trial day
subjects are not allowed to eat or drink anything but the foods supplied and
they should maintain their habitual physical activity pattern. Subjects will
consume all foods and drinks at home except for a warm meal in the afternoon
that is provided at the research facility. Subjects will consume 3 standard
glasses of one of the 6 test beverages within 30 minutes after the meal has
started. They will stay for 4 hours after the meal during which they will have
to give multiple urine samples (after 1, 2, 3, 4 hours). Also, they have to
collect urine from the moment they leave the research facilities until the next
morning at home. Before each breakfast, lunch and dinner subjects will have to
take one PABA tablet (3 times per day).

There is no direct (health-related) benefit for the participant. Three of the 6
test beverages contain alcohol and when consumed these subjects not allowed to
leave the research area until their breath alcohol concentration is within the
accepted range. Except for the blood sampling for screening (plasma
concentrations of creatinine and urea) all functional measurements during the
trial (urine volume, urine osmolality, urine sodium, potassium and PABA, body
weight and breath alcohol concentrations) are non-invasive and risks are
therefore minimal.
During the test sessions, the total diet will be provided (same standard diet
and lunch on each test day).
The time investment requested from the participants excluding travel time is in
total approximately 30 hours for 18 visits and screening