The loss of the sex hormones estradiol and testosterone at menopause promotes an increase in bone remodeling rates in all women regardless of genetic background. In all adults after peak bone mass bone remodeling is characterized by bone absorption being slightly greater than the tightly coupled bone formation that always follows. This process is genetically determined and highly conserved in all humans by natural selection because it bestowed upon our ancestors a distinct survival advantage.
White people whose ancestors migrated out of Africa about 50,000 years ago possessed this standard bone remodeling genetic endowment shared by all other extant humans at that time. As they migrated into the earth’s northern latitude, entering a gradually more harsh environment with less ultraviolet light and food stuffs rich in calcium and magnesium they were challenged. Adaptation to this hostile environment required loss of skin pigment to allow more ultraviolet light skin exposure and subsequent vitamin D3 production. It also led to the slow accumulation of a variety of single nucleotide polymorphisms SNPs within the genes involved in bone and mineral metabolism. These SNPs resulted in a slight increase in mineral released from the skeleton by each bone-remodeling unit BMU during their remodeling cycle. The SNPs were not triggered until estrogen became deficient, which meant menopause. Over time, the mandatory additional mineral withdrawal from the skeleton causes it to become frail and fracture resulting in the disease PMO.
Age related osteoporosis is a function of the physiologic process unaffected by the OGC so it is much slower and takes a full lifetime to occur. This is why age related hip fractures happen in the very old, usually over 80 years of age, and the death rate of these people after the fracture very high because they are extremely frail.
PMO affects much younger white women. For instance, wrist fractures peak in the mid-50s, spine facture incidence takes off in the mid-60s, and hip fractures begin in the 70s. Ironically, one of the worst things about hip fracture in white women is that because they are so much younger when they fracture they are much healthier than other people and more likely live on to suffer the indignity of dependency.