Hypogonadal man with osteoporosis
The underlying cause for bone loss is not always obvious.
A 68-year-old man presented for an initial visit. He had previously seen a different endocrinologist who retired several months ago.
He had been diagnosed with idiopathic secondary hypogonadism in 2002 and was treated with testosterone injections until 2009, at which time he was diagnosed with prostate cancer. The patient received external beam radiation and was taken off testosterone supplementation at that time.
The patient had been told he had osteopenia and had a bone mineral density measurement 6 months before the visit.
At the visit, he complained of decreased libido, erectile dysfunction (SHIM score 2/25) responsive to sildenafil (Viagra, Pfizer) and weight gain during the past 2 to 3 years. He shaves once a day, entered puberty around age 13 and denied changes in body hair or gynecomastia.
He had a history of two fractures of the left foot at ages 22 and 29 years.
His medical history included obstructive sleep apnea requiring continuous positive airway pressure, chronic obstructive pulmonary disease, hypertension, hyperlipidemia, impaired fasting glucose, coronary artery disease with s/p coronary artery bypass grafting, vitamin D deficiency, hyperhomocysteinemia, umbilical hernia repair, cervical discectomy and lumbar spine laminectomy.
- Ramipril 5 mg by mouth twice a day;
- Metoprolol succinate XL 50 mg by mouth twice a day;
- Amlodipine 5 mg by mouth daily;
- Digoxin 250 mcg by mouth daily;
- Hydrochlorothiazide 12.5 mg by mouth daily;
- Budesonide/formoterol (Symbicort, AstraZeneca) 80 mcg to 4.5 mcg/actuation HFA inhaler 2 puffs by mouth twice a day;
- Atorvastatin (Lipitor, Pfizer) 20 mg by mouth daily;
- Tamsulosin (Flomax, Boehringer Ingelheim) 0.4 mg by mouth daily;
- Vitamin D2 (Drisdol, Sanofi-Synthelabo) 50,000 U by mouth once a week;
- Zolpidem tartrate (Ambien, Sanofi-Aventis) 10 mg nightly as needed;
- Fluticasone propionate (Flonase, GlaxoSmithKline) 50 mcg/actuation Nasl SpSn one spray in each nostril daily;
- Aspirin 81 mg by mouth daily;
- Omega-3 fatty acids (fish oil) 500 mg oral twice a day;
- Coenzyme Q10 10 mg by mouth twice a day;
- Calcium carbonate-vitamin D2 1,200-400 mg-unit by mouth twice a day;
- Cyanocobalamin/folic acid (folic acid plus B12 oral) daily;
- Psyllium oral daily;
- Lactobacillus rhamnosus gg (probiotic oral) daily; and
- L-glutamine daily.
The patient is married, rarely consumes alcohol and quit smoking more than 20 years ago.
Family history is remarkable for heart disease in his mother and Hodgkin’s disease in his father.
The patient’s blood pressure was 138 mm Hg/68 mm Hg; pulse: 56; height: 6 feet; weight: 95.255 kg (210 lb). His estimated BMI is 28.5 kg/m2.
There was no gynecomastia. The phallus was normal in shape and size, with normal male-pattern hair distribution and testicular size approximately 20 mL bilaterally. The patient has a sternal scar after CABG. Physical exam is otherwise unremarkable.
Recent labs drawn by his primary care provider demonstrated:
- Low testosterone level of 159 ng/dL;
- Normal comprehensive metabolic profile and CBC;
- Calcium: 10 mg/dL;
- Albumin: 4.2 g/dL;
- Phosphorous: 3.8 mg/dL;
- 25-hydroxyvitamin D: 52 ng/mL; and
- Prostate-specific antigen was 1.05 ng/mL and has been rising during the past year.
Bone density performed 6 months before the visit showed:
- Femoral neck: T-score –1.8 / z score –0.7;
- lumbar spine: T-score –0.9/ z score 0; and
- Left radius 1/3: T-score –4.3 / z score –3.1.
What is the next best step in the workup and management of this patient?
A. The results for the bone density of the radius are out of sync with the BMD at other sites and therefore represent an erroneous report. Contact the site of the DXA and insist on a repeat measurement.
B. Order a parathyroid hormone level for suspected primary hyperparathyroidism.
C. Recommend the patient double up on his calcium to address his osteoporosis.
D. Restart testosterone supplementation with testosterone cypionate IM 100 mg weekly to reverse hypogonadism-induced osteoporosis.
Despite the normal calcium and phosphorous levels, the emphasis on cortical bone loss (as seen in the radius) is highly suspicious of primary hyperparathyroidism. Indeed, this patient had a parathyroid hormone level of 105 ng/dL in the setting of normocalcemia and a parathyroid adenoma (B).
Male hypogonadism is a common cause of osteoporosis in men. In the setting of rising PSA after external-beam radiation for prostate cancer, testosterone supplementation may, however, be ill-advised (D). The quality of a bone density report should never be taken for granted — patients can be poorly positioned, and radio-dense objects or reactive changes may distort the measurement, or the wrong database may have been applied to calculate T-scores and z scores. Although scrutiny is always appropriate, there was nothing in this instance to indicate any flaw in the bone density report provided (A). Finally, increasing calcium supplementation in this setting will not address the underlying problem (C).
For more information:
- Ronald Tamler, MD, PhD, MBA, is clinical director of the Mount Sinai Diabetes Center in New York. He is also an Endocrine Today Editorial Board member.
- Dr. Tamler reports that he has received research support from Abbott.