Course Hero Logo

Osteoporosis (1).docx - Osteoporosis The International...

Course Hero uses AI to attempt to automatically extract content from documents to surface to you and others so you can study better, e.g., in search results, to enrich docs, and more. This preview shows page 1 - 2 out of 5 pages.

OsteoporosisThe International Osteoporosis Foundation (2022), defines osteoporosis literally as "porousbones." Porous means are full of holes. This disease is characterized by bones that becomevery weak and are more likely to break. This often develops and remains unnoticed for years,with no symptoms or discomfort until it breaks. It is estimated that the number of patients withosteoporotic hip fractures accounts for more than 200 million and 30% of women in Europe andthe United States are osteoporotic; it was also estimated that 40% postmenopausal women and30% men will experience an osteoporotic fracture in the rest of their lives. Globally, It wasestimated that around the age of 50 years old, the chance of having a hip fracture in theremaining years was 3.5% in men and 14.6% in women.PathophysiologyThis disorder is a multifactorial disease that has a complex interplay of intrinsic, genetic,lifestyle, and exogenous factors that contribute to the individual's risk of the illness. Traditionalpathophysiologic models often emphasized endocrine mechanisms as key factors forpostmenopausal osteoporosis, such as estrogen deficiency and secondary hyperparathyroidismin the elderly due to estrogen deficiency,widely prevalent vitamin D deficiency, and dietaryintake(Sözen, et al., 2017). However, the pathophysiological mechanisms go beyond these. Inadults, the daily removal of small amounts of bone mineral through the process known asresorption is balanced by an equivalent deposition of new mineral to maintain bone strength.When this balance tips towards excessive resorption, bones over time can weaken and becomebrittle, thus prone to fracture. This continual re- deposition and resorption of bone mineral, andremodeling is tied to the pathophysiology of osteoporosis. Bones have different architecture andgeometry; long bones are tubular in shape, with a strong cortical layer surrounding a spongiercore. The combination makes these bones light and strong, but are flexible enough to absorbstress- high impact exercises- without breaking. The vertebrae are similarly formed, with a thickcortical layer and surrounding sheets of trabecular bone. Each vertebra as a unit, can compresswhen temporarily loaded and return to their original size. However, bones grow, heal, andrespond to the stimuli- this is where remodeling takes its crucial role. Gradual resorption ofthese minerals on the inside of the cortical layer and in the bone cavity leads to the inevitableloss of trabecular bone and widening of the bone cavity. This is partly compensated by theincremental proliferation of extra layers of mineral to the outside of the cortical layer. Thiscontinuous remodeling and its effect on the bone's architecture significantly impact the disease'spathophysiology. Osteoclasts and osteoblasts determine the balance between bone resorptionand deposition. Osteoclasts are granted with highly active ion channels in the cell membranethat pumps protons into the extracellular space causing the pH to lower in their environment. Adrop in pH dissolves the bone mineral. In the bone's microenvironment, proteolytic enzyme suchas the cathepsin K, which dissolve bone matrix. On the other hand, osteoblasts have a poorlycharacterized mechanism but lay down new bone mineral. The balance between these activitiesgoverns whether a bone is made, maintained or lost. Hormones are the most crucial factors of

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 5 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Spring
Professor
N/A
Tags
postmenopausal osteoporosis

Newly uploaded documents

Show More

Newly uploaded documents

Show More

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture