This cross-sectional analysis was part of theRotterdam Study, a populationbased
cohort study aimed at assessing the occurrence of, and risk factors
for, chronic diseases in the elderly (11). The study started in 1990
among 7,983 persons aged greater than or equal to 55 years, and all
participants are invited every 3–4 years to the research center for
follow-up examinations, including spirometry and carotid ultrasonography.
The medical ethics committee of the Erasmus Medical Centre,
Rotterdam, and the review board of The Netherlands Ministry of
Health, Welfare and Sports approved the study. Participants gave written
informed consent