Pre-analytic considerations for the proper assessment of hormones of the hypothalamic-pituitary axis in epidemiological research.

There is growing epidemiological interest in hormones as predictors of chronic diseases. The correct handling and analysis of hormones can be cumbersome, and great care must be taken in these processes in order to gain the most information possible. Given differences in sampling, processing, and stability of the various hormonal assays, we sought to provide a comprehensive review to aid future epidemiological research. We have coupled a thorough literature search with our own analytical experience to outline common laboratory problems one must consider in analyzing the hormones of the hypothalamic-pituitary axis. In addition, we describe the benefits and limitations of using alternative media--including urine, saliva, and blood spots on filter paper--to measure endocrine hormones in epidemiological studies.