Yearbook of Paediatric Endocrinology, 2021
DOI: 10.1530/ey.18.15.12
National Academy of Sciences, Proceedings of the National Academy of Sciences, 7(118), 2021
Full text: Download
Significance We provide a dataset of millions of hormone tests from medical records that shows seasonality with a winter−spring peak in hormones for reproduction, growth, metabolism, and stress adaptation. Together with a long history of studies on a winter−spring peak in human function and growth, the hormone seasonality indicates that, like other animals, humans may have a physiological peak season for basic biological functions. We further use the specific seasonal phases of the hormones to suggest a model for a circannual clock in humans and animals that can keep track of the seasons, similar in spirit to the circadian clock that keeps track of time of day.