Sex Differences in Spinal Osteoarthritis in Humans and Rhesus Monkeys (Macaca mulatta)

Abstract

Study Design Retrospective study of male and female spinal osteoarthritis, characterized by lateral spine thoracolumbar radiographs, in humans and nonhuman primates Objective To characterize differences in prevalence and vertebral distribution of spinal osteoarthritis between men and women, between male and female macaques, and between the two phylogenetically related genera. Summary of Background Data Naturally occurring spinal osteoarthritis manifests similarly in humans and rhesus macaques. Other types of osteoarthritis particularly of the knee and hip have revealed gender differences in humans. In regard to spinal osteoarthritis, gender differences have been noted but without consistent results. Sex differences in macaques have not been examined. Methods Radiographic evidence of disc space narrowing and osteophytosis was assessed using an atlas scoring method. Prevalence was determined according to sex, age, body mass (for macaques only) and spinal location (human T4-L5; macaque T8-L7). Results Average scores in macaques differed between the sexes, but they did not differ between men and women. The pattern of involvement along the spine was the same in male and female monkeys but differed between men and women: women had more thoracic involvement and men had more lumbar involvement. Overall, monkeys had a significantly higher prevalence of osteoarthritis than humans. Conclusion The appearance of sex differences in the prevalence of osteoarthritis is most likely a proxy measure for the affect of body mass. Sex differences were apparent in monkeys due to the fact that males are significantly heavier than females. No gender difference in prevalence was apparent in humans and there is substantial overlap in body mass between men and women. Differences in the location of osteoarthritic involvement along the spine between men and women were obscured when only average scores were examined.

Osteoarthritis in two marine mammals and 22 land mammals: learning from skeletal remains

“…Another study of 13 lions (Panthera leo), 16 tigers (Panthera tigris), four leopards (Panthera pardus), one snow leopard (Panthera uncia) and three jaguars (Panthera onca) found that eight individuals (lions = 3, tigers = 4, leopard = 1) had degenerative spinal disease (Kolmstetter et al 2000). Because they are primates, monkeys, like humans, are susceptible to OA (Duncan et al 2012); for this reason they have been used as a model for studying OA in humans (Carlson et al 1994;Little & Smith, 2008). In fact, a recent study found that monkeys had a higher rate of OA than humans; on the other hand, chimpanzees (Pan troglodytes schweinfurthii; Pan troglodytes troglodytes), lowland gorillas (Gorilla gorilla gorilla) and bonobos (Pan paniscus) exhibited a comparatively lower prevalence of OA (Duncan et al 2012).…”

“…Because they are primates, monkeys, like humans, are susceptible to OA (Duncan et al 2012); for this reason they have been used as a model for studying OA in humans (Carlson et al 1994;Little & Smith, 2008). In fact, a recent study found that monkeys had a higher rate of OA than humans; on the other hand, chimpanzees (Pan troglodytes schweinfurthii; Pan troglodytes troglodytes), lowland gorillas (Gorilla gorilla gorilla) and bonobos (Pan paniscus) exhibited a comparatively lower prevalence of OA (Duncan et al 2012). Differences in the obtained results of these reports may be due to the variety of monkey species and joints studied.…”

Comparison of vertebral and intervertebral disc lesions in aging humans and rhesus monkeys

“…Interestingly, the rhesus monkey naturally develops polyarticular OA with age 13,14 (Figure 1). The aging spines of rhesus monkeys are afflicted with disc degeneration, osteophytosis, and kyphosis.. As in humans, these degenerative changes are most severe in the thoracolumbar and lumbosacral zones 2,15,16 . Although this suggests that rhesus monkeys exhibit similar anatomic patterns of disc degeneration as humans, it remains unclear whether rhesus monkeys exhibit similar histologic features of disc degeneration as well.…”

Peer Review #1 of "Heritability estimation of osteoarthritis in the pig-tailed macaque (Macaca nemestrina) with a look toward future data collection (v0.1)"

“…In particular, the extent to which genetics plays a role in DDD development has not yet been uncovered. Since there are safety concerns posed by radiography, the macaque monkey is often used as an animal model for humans in the study of bone diseases, due to its close genetic relatedness to humans (Duncan et al, 2011(Duncan et al, , 2012. One may question its appropriateness for DDD as macaque monkeys are not bipedal, but this concern was addressed by Kramer et al (2002), who explored DDD specifically in the macaque species known as pig-tailed macaques (Macaca nemestrina), and concluded that they are indeed an appropriate animal model for DDD in humans.…”