ABSTRACT
The phenotypic, and possibly many of the metabolic, differences between the genders are influenced by sex hormones. The predominant sex hormones discussed in this chapter will be the “male” hormone testosterone and the “female” hormones estrogen and progesterone. “Male” and “female” are generalizations, since testosterone 16is also present in females, and estrogen and progesterone are present in males. This chapter is not meant to be a comprehensive review of the endocrinology of the sex hormones, but rather to provide a brief overview of the physiology of these hormones, particularly as they relate to substrate metabolism and the physiology of growth. An overview of some of the models to manipulate the sex hormones will be discussed as they pertain to an understanding of gender differences in metabolism. We would also like to provide some human reference values that can be used to determine the sex hormone status of a group of individuals in a given study.
