Scientific Concept of the National Cohort (status ... - Nationale Kohorte

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A.3 Study design
200,000 Americans visit their physicians each year with smell disorders. Similarly, a recent
survey from Switzerland, Austria, and Germany indicates that this figure is at approximately
70,000 in the three German-speaking countries 635, 636 . Causes of smell dysfunction are manifold,
the most important ones being aging, sinunasal disease, head trauma, or infections
of the upper respiratory tract. Loss of olfactory function is also related to neurodegenerative
disease, as it has been shown to be an early sign of Parkinson’s disease 197, 637 and
Alzheimer’s disease 198, 638 .
Procedure of measurement:
The test of olfactory function will be performed using the “Sniffin’ Sticks” (Burghart, Medizintechnik
Wedel; Germany). This test is an odor-dispensing system based on felt-tip pens;
it has previously been validated against large smell test batteries and used in a populationbased
study in Germany 639 . Twelve common odors are administered. For odor presentation
the pen’s cap is removed, and the pen is placed in front of both nostrils for approximately 3
s. Using a multiple forced-choice task, odors must be identified from a list of four descriptors
for each odor. Following recommended cut-off scores, hyposmic subjects will be defined
as subjects identifying less than 10 but more than 6 out of 12 odors correctly. “Functionally
anosmic” subjects identify 8 or less odors out of 12 correctly.
A.3.3.9 Anthropometry
Body height, body weight, and obesity
Height is of scientific interest as a predictor of morbidity and mortality for CVD and respiratory
diseases, metabolic diseases, cancer, and other diseases 640-643 . Gaining an understanding
of the proposed associations and identifying further factors (e.g., environmental factors)
that may explain these associations represent a challenge for future research. Furthermore,
height is an important confounder or explanatory variable as it is independently associated
with blood pressure and blood lipids 644, 645 .
Differences in weight can mostly be accounted for by height and body fatness. Body weight
in relation to body height is a simple and widely used indicator of body fatness.
BMI is a simple measure of relative body weight and is often used in health-related analyses of
anthropometric cohort data. Although BMI does not directly measure the amount of body fat,
it was found to be an appropriate indicator for obesity as it is highly correlated with body fat 646 .
Procedure of measurement:
Specifically trained and certified personnel will measure anthropometric parameters according
to a standardized protocol. Body height will be measured with an accuracy of 0.1
cm using an electronic device (e.g., Seca 242) . The device has to be correctly set up and the
participant should stand unsupported and upright with the back towards the pole. The measurement
will take 1–2 min and requires only little staff training.
Body weight will be measured with an accuracy of 0.1 kg using, for example, the SECA 635
device. The participant should wear light clothes only (no shoes) and will stand in the center
of the device, without leaning or holding onto anything. The measurement will take 1–2 min
and requires only little staff training.
waist and hip circumference
Measures taking fat distribution and location of body fat into account are important in relation
to health outcomes. A genetic basis for waist measurements that is independent of the
A.3