A 73-Year-Old Woman With Osteoporosis

DR DALEY: MRS Z IS A 73-YEAR-OLD MARRIED GRANDmother who lives in a suburb of Boston, Mass, with her husband. She works 4 days per week in her daughter’s retail business. Her gynecologist recently referred her for evaluation of “thin bones.” Mrs Z has medical insurance through Medicare and supplemental insurance. Mrs Z underwent menarche at age 11 years and had normal menstrual periods until menopause at age 50 years. She had 2 uncomplicated pregnancies and took oral contraceptives for many years. After menopause, she took hormone replacement therapy (HRT) for only 3 years, then stopped because of fear of developing breast cancer. She smoked for 1 year in her teens and quit; she does not drink alcohol. She has never taken glucocorticoids, anticonvulsants, or thyroid medication. Her mother fractured her hip twice. There is no family history of breast cancer. The patient’s daily dietary calcium intake is low, about 300 mg/d, but she has taken supplemental calcium tablets of about 1200 mg/d for the past several years. She has never had a kidney stone. Mrs Z is physically active, walking almost every day. She has had multiple fractures, including a left hip fracture in 1990, a right wrist fracture when she was in her 60s, and a right elbow fracture approximately 10 years ago. She also noted that she has lost about 2 to 3 inches in height during the past several years. Her gynecologist recently obtained a bone density study of her femoral neck and total hip, the results of which were 4.69 and 5.02 SDs below young adult peak bone mass (FIGURE 1). Mrs Z has other significant conditions, including hypertension, hyperlipidemia, and coronary artery disease leading to acute myocardial infarction in 1990. She underwent coronary artery bypass grafting in 1990 and again in February 1998; with recurrent ischemic chest pain in May 1998, she had several coronary artery stents placed. In August 1998, Mrs Z underwent a right radical nephrectomy for renal cell carcinoma. She has moderate renal insufficiency, with a stable creatinine level of 203 μmol/L (2.3 mg/dL) after nephrectomy. Mrs Z’s current medications include metoprolol tartrate, atorvastatin chloride, folic acid, pyridoxine hydrochloride (vitamin B6), cyanocobalamin (vitamin B12), aspirin, vitamin E, a multivitamin supplement, and calcium carbonate. Physical examination revealed that Mrs Z was a thin woman, with a blood pressure of 140/80 mm Hg, heart rate of 80/min, weight of 43 kg (96 lb), and height of 146 cm (57.5 in); she reported an early-adulthood height of 152 cm (60 in). Her thyroid examination showed normal findings. Examination of the back showed both kyphosis and scoliosis and a recent right nephrectomy scar. Cardiac examination showed a well-healed sternotomy scar. Laboratory results, including serum albumin, calcium, parathyroidhormone(PTH), thyroid-stimulatinghormone, free thyroxine, protein electrophoresis, and immunoelectrophoresis, were normal. Alkaline phosphatase level was elevated, at 187 U/L (reference range, 40-120 U/L). 25-Hydroxyvitamin D levels were slightly elevated, at 147 nmol/L (reference range, 25-137 nmol/L). Collagen cross-linked N-telopeptide was 89 nmol of bone collagen equivalent per millimole of creatinine(premenopausal reference range,14-74nmol), avalueconsistent with the patient’s postmenopausal state. Evaluation in the osteoporosis center of Beth Israel Deaconess Medical Center, Boston, confirmed the diagnosis of postmenopausal osteoporosis (Figure 1 and FIGURE 2). Recommendations included changing Mrs Z’s calcium supplement to Caltrate Plus D (an over-the-counter preparation of calcium and vitamin D), 600 mg 2 times per day; cholecalciferol, 400 to 800 IU/d (400 IU from her multivitamin supplement and the balance from Caltrate Plus D); daily exercise (walking); alendronate sodium, 10 mg/d; and repeat bone densitometry in 1 to 2 years.