Hormone physiology and sleep dynamics among BaYaka foragers of the Congo Basin: Gendered associations between nighttime activity, testosterone, and cortisol

Horm Behav. 2023 Sep 6;155:105422. doi: 10.1016/j.yhbeh.2023.105422. Online ahead of print.ABSTRACTSleep quality is an important contributor to health disparities and affects the physiological function of the immune and endocrine systems, shaping how resources are allocated to life history demands. Past work in industrial and post-industrial societies has shown that lower total sleep time (TST) or more disrupted nighttime sleep are linked to flatter diurnal slopes for cortisol and lower testosterone production. There has been little focus on these physiological links in other socio-ecological settings where routine sleep conditions and nighttime activity demands differ. We collected salivary hormone (testosterone, cortisol) and actigraphy-based sleep data from Congolese BaYaka foragers (N = 39), who have relatively short and fragmented nighttime sleep, on average, in part due to their typical social sleep conditions and nighttime activity. The hormone and sleep data collections were separated by an average of 11.23 days (testosterone) and 2.84 days (cortisol). We found gendered links between nighttime activity and adults' hormone profiles. Contrary to past findings in Euro-American contexts, BaYaka men who were more active at night, on average, had higher evening testosterone than those with lower nighttime activity, with a relatively flat slope relating nighttime activity and evening testosterone in women. Women had steeper diurnal cortisol curves with less disrupted sleep. ...
Source: Hormones and Behavior - Category: Endocrinology Authors: Source Type: research