Types of Primary Osteoporosis

Primary osteoporosis can be divided into type I (postmenopausal) osteoporosis and type II (senile) osteoporosis.

Type I osteoporosis results from loss of estrogen and predominantly affects trabecular/cancellous bone. Type I osteoporosis is most frequently associated with vertebral and wrist fractures in postmenopausal women.

Type II osteoporosis, on the other hand, results from diminished absorption of calcium and reduced serum levels of vitamin D, leading predominantly to resorption of cortical bone. Type II osteoporosis is associated with hip fractures in men and women older than 70 or so.

References

Duque G, Troen BR. Understanding the mechanisms of senile osteoporosis: new facts for a major geriatric syndrome. J Am Geriatr Soc. 2008 May;56(5):935-41.