Dehydroepiandrosterone-sulfate (DHEA-S), sex, and age in zoo-housed western lowland gorillas (Gorilla gorilla gorilla)

Ashley N. Edes

Among humans, dehydroepiandrosterone-sulfate (DHEA-S) declines with age and is hypothesized to be involved in somatic maintenance and healthy aging. Men have significantly higher DHEA-S than women, contradicting longer lifespans in the latter. Declines of DHEA-S with age also are observed in chimpanzees. In both chimpanzees and bonobos, males and females show no differences in DHEA-S production. Based on human and chimpanzee data, gorillas were predicted to show declining DHEA-S with age. Similar to chimpanzees and bonobos, it also was predicted DHEA-S would not be significantly different between males and females. DHEA-S was assayed from serum banked during physical examinations of gorillas housed at three North American zoos (n = 63). Gorillas ranged from 6 to 52 years of age. Differences between males and females were examined using t tests. Linear regression was used to determine the relationship of DHEA-S with age. There was no significant difference in DHEA-S between males and females. Additionally, there was no significant relationship between DHEA-S and age. As predicted, there were no sex-based differences in DHEA-S in gorillas, which is similar to chimpanzees and bonobos but different from modern humans. Unlike chimpanzees and humans, there was no significant relationship between DHEA-S and age in gorillas. The absence of a relationship between age and DHEA-S may be due to the lack of gorillas under age 6 years in this sample as declines in chimpanzees occur prior to age 5 years, more rapid growth and development among gorillas compared with other African hominoids, or a unique pattern of DHEA-S production.