Why Bone Destruction Is Accelerated with Aging

It is well known that CD38, an enzyme that takes away NAD+, increases with age. The gradual depletion of this core metabolic molecule is, as expected, linked to multiple problems, one of which is a loss in bone-building osteoblasts [1]. Instead, CD38 contributes to the formation of osteoclasts, the cells that wear away bone [2].
Why Bone Destruction Is Accelerated with Aging | Lifespan.io

This argues a different case:

https://www.nature.com/articles/s43587-021-00105-8

Maybe both contribute?

I think one is causal. The other perhaps is downstream.