Osteoporosis Low bone mass and osteoporosis affect an estimated 30 million US women, or approximately 55% of women older than age 50 years (32). Because therapy is most likely to benefit those at highest risk, it is important to review a woman’s risk factors for osteoporosis when making treatment decisions. Bone mineral density screening should be considered for high-risk women (Table 34.3). Nonmodifiable risk factors include age, family history, Asian or Caucasian race, history of a prior fracture, small body frame, early menopause, and prior oophorectomy. Modifiable risk factors include smoking, decreased intake of calcium and vitamin D, and a sedentary lifestyle. Medical conditions associated with an increased risk of
Table 34.3 Risk Factors for Osteoporosis
Age  Race (white, Asian)  Small body frame
Family history of osteoporosis
Inadequate intake of calcium and vitamin D  Smoking osteoporosis include anovulation during the reproductive years (e.g., secondary to excess exercise or an eating disorder), chronic renal disease, hyperparathyroidism, hyperthyroidism, and diseases requiring systemic corticosteroid use.
Table 34.4 Options for Osteoporosis Prevention and Treatment
Additional potential benefits: none
Potential risks: esophageal ulcers, osteonecrosis of jaw (rare), atypical femoral fractures (rare) Zoledronic acid: hypocalcemia, atrial fibrillation, renal impairment
Side effects: gastrointestinal distress, arthralgias/myalgias
Additional potential benefits: treatment of vasomotor symptoms and urogenital atrophy  Potential risks: breast cancer, gallbladder disease, venous thromboembolic events, coronary heart disease, stroke
Side effects: vaginal bleeding, breast tenderness
Additional potential benefits: reduced risk of breast cancer
Potential risks: venous thromboembolic events
Side effects: vasomotor symptoms, leg cramps
Additional potential benefits: none  Potential risks: none  Side effects: rhinitis, back pain
Additional potential benefits: none  Potential risks: osteosarcoma (after long-term use in rodents), hypercalcemia  Side effects: musculoskeletal pain
Additional potential benefits: none
Potential risks: rash, serious infection, hypocalcemia
Side effects: musculoskeletal pain osteoporosis-related fractures by approximately 50% (39). The Women’s Health Initiative (WHI) trial confirmed a significant (34%) reduction in hip fractures in healthy women randomized to hormone therapy (conjugated estrogen 0.625 mg per day) after a mean follow-up of 5.6 years (40). Combined with calcium and vitamin D, even very low-dose estrogen therapy (conjugated estrogen 0.3 mg per day; transdermal estradiol 0.014 mg per day) produces significant increases in bone mineral density compared with placebo (41).
Bisphosphonates, including alendronate (Fosamax, 35 or 70 mg orally weekly), risedronate (Actonel, 35 mg weekly or 150 mg orally monthly), ibandronate (Boniva, 150 mg orally monthly or 3 mg every 3 months intravenous), and zoledronic acid (Zometa, 5 mg intravenous yearly) specifically inhibit bone resorption and are very effective for both the prevention and treatment of osteoporosis (42–44). Patients should take oral bisphosphonates on an empty stomach with a large glass of water and remain upright for at least 30 minutes. The major side effect is gastrointestinal distress; esophageal ulceration, osteonecrosis of the jaw, and atypical femoral fractures are very rare occurrences.