Skeletal Aging

Aging represents the single greatest risk factor for chronic diseases, including osteoporosis, a skeletal fragility syndrome that increases fracture risk. Optimizing bone strength throughout life reduces fracture risk. Factors critical for bone strength include nutrition, physical activity, and vitamin D status, whereas unhealthy lifestyles, illnesses, and certain medications (eg, glucocorticoids) are detrimental. Hormonal status is another important determinant of skeletal health, with sex steroid concentrations, particularly estrogen, having major effects on bone remodeling. Aging exacerbates bone loss in both sexes and results in imbalanced bone resorption relative to formation; it is associated with increased marrow adiposity, osteoblast/osteocyte apoptosis, and accumulation of senescent cells. The mechanisms underlying skeletal aging are as diverse as the factors that determine the strength (and thus fragility) of bone. This review updates our current understanding of the epidemiology, pathophysiology, and treatment of osteoporosis and provides an overview of the underlying hallmark mechanisms that drive skeletal aging. (C) 2022 Mayo Foundation for Medical Education and Research

Automated summary

Aging is the greatest risk factor for chronic diseases, including osteoporosis. Optimizing bone strength through nutrition, physical activity, and vitamin D status reduces fracture risk. Hormonal status, particularly estrogen, plays a major role in bone remodeling. Skeletal aging exacerbates bone loss and imbalanced bone resorption relative to formation, leading to increased marrow adiposity, osteoblast/osteocyte apoptosis, and accumulation of senescent cells. The underlying mechanisms of skeletal aging are diverse and complex.