FGF-23: just a phosphate metabolism regulator or something else?

Endocrine communication between the bone, kidney, and the intestine is involved in maintaining appropriate serum phosphate concentrations, which is critical for the maintenance of skeletal integrity and is central to signal transduction and cell metabolism. In addition, hyperphosphatemia is statistically associated with vascular calcification, increased morbidity and mortality; because of this, phosphate regulation has become an important field of research. In this sense, fibroblast growth factor 23 (FGF-23) has been identified as a new hormone involved in phosphate regulation through feedback mechanisms involving parathyroid hormone and vitamin D. Given what the kidney is the primary site for regulation of phosphate levels and the principal target for FGF-23, its discovery has changed the understanding of disordered mineral metabolism in chronic kidney disease, especially now, since there is clinical evidence in favor of FGF-23 playing a central role for the pathogenesis of sHPT.     

SAPHO: rare or just not recognized?

OBJECTIVE: The SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome describes an association between musculoskeletal disorders, in particular hyperostosis involving the bones and joints of the anterior chest wall, and various dermatologic conditions. It has been reported in Europe and Japan, but no Australian series have been published. We describe the clinical, laboratory, and radiographic features of a group of patients with the SAPHO syndrome and compare this with the literature. METHODS: We performed a retrospective review of patients seen in our department between 1990 and 1998 who met the proposed diagnostic criteria for SAPHO. Information regarding age, sex, disease duration, skeletal site(s) of disease, presence of skin disease, previous treatment, and response to treatment was collected. Laboratory tests were reviewed, as was all available radiology and bone scintigraphy. RESULTS: Six women with a mean age of 40 years fulfilled the criteria for SAPHO. The skeletal manifestations were similar to those reported in the literature, with hyperostosis of the anterior chest wall being the central feature. Cervical spine and pubic bone were other sites of involvement, whereas sacroiliitis and peripheral joint synovitis were not seen. Skin disease was less frequent in our population than has been reported in other series. Nonsteroidal anti-inflammatory drugs were frequently prescribed as first-line treatment but had limited efficacy. Intravenous pamidronate was administered to two patients, resulting in complete resolution of pain in one patient and 50% reduction in pain in the other. CONCLUSIONS: The SAPHO syndrome may be underrecognized as the skin manifestations in our patients were mild or absent. Although optimal treatment for these patients remains unclear, it is important to make the diagnosis of SAPHO to avoid unnecessary investigations and treatment.     

The cost of diabetes: time for a different approach?

We argue that studies estimating the treatment cost of diabetes and other economic issues have progressed dramatically over recent years. This has undoubtedly improved our understanding of diabetes. However, attention needs to now shift to more detailed studies that require prospective bespoke data collection from epidemiologists as well as economists. This is not to say that investigation of costs using routine data is of no value--such work will continue to provide new data and methods to those evaluating new interventions, as well as by helping to identify important research areas. However, it may be time for a new paradigm to help in our understanding of this challenging disease. Such an approach must be capable of supporting the complex evaluation of new technologies, and subsequently, can not rely solely on routine data.