Steve Orme

Comparison of tests of stress-released cortisol secretion in pituitary disease

OBJECTIVES We wished to compare peak and incremental rise in plasma cortisol in response to insulin induced hypoglycaemia (IIH) stress test, i.m. glucagon stimulation test (IMGST) and short Synacthen test (SST) in patients with pituitary disease, using a modern radioimmunoassay for cortisol. We compared the three stimulants using receiver operator characteristic (ROC) plots, assuming a cortisol threshold of 500 nmol/l or 580 nmol/l for the IIH stress test which we used as the standard from which to evaluate the SST and the IMGST.

Serum testosterone and bioavailable testosterone correlate with age and body size in hypogonadal men treated with testosterone undecanoate (1000 mg IM – Nebido®)

Objective  To investigate the loading regimen for intramuscular (IM) testosterone undecanoate (Nebido®) to determine whether testosterone and bioavailable testosterone levels achieved correlate with age or body size of subjects studied.

The role and efficacy of denosumab in the treatment of osteoporosis: an update.

Introduction: Bone strength determinants such as bone mineral density and bone quality parameters are determined by life-long remodeling of skeletal tissue. Denosumab is a fully human mAb receptor activator of NF-κB ligand, which selectively inhibits osteoclastogenesis, the end product of a cascade interaction among numerous systemic and local factors and osteoblasts. It has been approved for clinical use by the FDA in the US and by the European Medicines Agency in Europe since June 2010 (trade name Prolia™, Amgen, Thousand Oaks, CA, USA). Areas covered: This review establishes the concerns and provides insights in issues concerning the cost-effectiveness and safety profile of this new pharmaceutical agent. There is an effort to clarify the special characteristics and the anti-catabolic role of denosumab in the bone tissue homeostasis and more specifically its potential clinical applications and clinical results in the field of postmenopausal osteoporosis. Expert opinion: Administrated as a subcutaneous injection every 6 months, denosumab has been shown to decrease bone turnover and increase bone mineral density in postmenopausal women with low bone mass or osteoporosis and reduce vertebral, hip and nonvertebral fracture risk in postmenopausal women with osteoporosis. The rapid, sustained and reversible effect in suppressing osteoclastic bone resorption, the return of responsiveness on rechallenge, its good tolerability and ease of administration are features that distinguish it from other antiresorptive therapies.

Cardiac Functional Reserve is Diminished in Growth Hormone-Deficient Adults

Various studies have shown that patients with severe growth hormone deficiency (GHD) have diverse changes in left ventricular (LV) size or performance but so far there is no direct indication of cardiac reserve ability to maintain the circulation during peak exercise. We tested the hypothesis that patients with severe GHD have reduced cardiac reserve function compared with healthy controls. Eighteen patients with severe GHD were studied and compared with 18 age-, sex-, and body mass index (BMI)-matched healthy controls. Peak cardiac power and cardiorespiratory fitness were investigated using noninvasive hemodynamic measurements during maximal cardiopulmonary exercise testing. Compared with matched controls, the cardiac power of GHD patients during exercise to volitional exhaustion was significantly reduced by 15% (mean +/- SD: 4.4 +/- 1.0 watts (W) vs. 5.2 +/- 1.0 W, P= 0.02), despite attaining similar aerobic exercise peaks (VO(2max), GHD: 2390 +/- 822 mL/min vs. controls: 2461 +/- 872 mL/min, P= 0.80) and similar peak respiratory exchange ratios. The lower peak cardiac power could not be accounted for by peripheral alterations because both groups reached similar peak exercise systemic vascular resistances. Patients with GHD also had lower cardiac chronotropic reserve (peak heart rate: 154 +/- 21 bpm vs. 174 +/- 11 bpm, P= 0.001) and a lower cardiac pressure-generating capacity (systolic blood pressure [SBP] 160 +/- 25 mmHg vs. 200 +/- 15 mmHg, P < 0.0001). Using this robust noninvasive method of assessing functional cardiac pumping capacity we have for the first time shown that patients with severe GHD have a significantly impaired cardiac functional reserve associated with chronotropic incompetence and impaired pressure-generating capacity.

Fracture risk associated with chronic use of bisphosphonates: evidence today

Importance of the field: Bisphosphonates are the most widely used antiresorptive agents for the treatment of osteoporosis. However, the cumulative bisphoshonate exposure and its association with atypical fragility fractures, and the optimum duration of treatment remain obscure. Areas covered in this review: This review article focuses on the existing evidence relevant to the development of stress fractures following prolonged administration of bisphosphonates. Furthermore, the optimal duration of bisphosphonate treatment and the real risk of associated stress fractures are discussed. What the reader will gain: A detailed overview of the cases reported thus far in the literature. In addition, the reader will become aware that the currently available observational studies and clinical trials are not powered to detect complications of very low incidence such as atypical insufficiency fractures. Take home message: It is unknown whether the pathophysiology of these atypical insufficiency fractures is related to the mode of action of bisphosphonates, or else if they represent an unusual osteoporotic fracture manifestation. Clinicians should be aware that patients on long-term treatment may develop this side effect. The decision to maintain a patient on therapy beyond 5 years should be taken on a case-by-case approach, guided by individual overall fracture risk, and the drugs efficacy and safety profile.

Reduced cardiac functional reserve and quality of life in adults with GH deficiency.

Introduction  Patients with severe GH deficiency (GHD) suffer with a reduced quality of life in addition to diverse changes in cardiac size and performance. So far, the cardiac reserve ability to maintain the circulation during peak exercise has not been measured. We tested the hypothesis that patients with severe GHD have reduced cardiac reserve function compared with healthy controls and that this could explain, in part, their reduced quality of life.