A rare cause of atraumatic fractures: case series of four patients with tumor-induced osteomalacia.

BACKGROUND: Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome that presents with hypophosphatemia, bone pain, muscle weakness and fractures. We report a case series of four patients with TIO that resulted in significant muscle weakness and multiple atraumatic fractures. CASE PRESENTATION: Four patients were referred to an endocrinology clinic for the evaluation of multiple atraumatic fractures, muscle weakness, generalized muscle and joint pain. Laboratory evaluation was notable for persistent hypophosphatemia due to urinary phosphate wasting, low to low-normal 1,25-dihydroxyvitamin D, elevated alkaline phosphatase and elevated fibroblast growth factor 23 (FGF23). Tumor localization was successful, and all four patients underwent resection of phosphaturic mesenchymal tumors. Post-operatively, patients exhibited normalization of serum phosphorus, in addition to significant improvement in their ambulatory function. CONCLUSION: Hypophosphatemia with elevated FGF23 and low 1,25-dihydroxyvitamin D level in the setting of multiple atraumatic fractures necessitates careful evaluation for biochemical evidence of tumor-induced osteomalacia.

Relation of baseline serum potassium levels to angiographic findings in patients with known or suspected coronary artery disease.

BACKGROUND: In experimental animal studies, potassium has been demonstrated to protect against the development of atherosclerosis through a variety of mechanisms. Data regarding the role of potassium in the development of human atherosclerosis are sparse. The objective of this study was to determine the association between plasma potassium levels and angiographically defined coronary artery disease (CAD). METHODS: In a cohort of 389 male patients undergoing coronary angiography for a variety of clinical indications, the association between baseline serum potassium levels and the extent of angiographically defined atherosclerosis was analyzed. Adjustments were made for clinical and laboratory variables (including inflammatory markers) known to be associated with atherosclerosis. RESULTS: By multivariate logistic regression analysis, baseline serum potassium levels were an independent predictor of the presence of multivessel disease (odds ratio (OR) 1.31, 95% confidence interval (CI) 1.01-1.69; P < 0.05). In addition, in the non-myocardial infarction subpopulation of patients, serum potassium was also an independent predictor of the presence of multivessel disease by multivariate logistic regression analysis (OR 1.34, 95% CI, 1.02-1.76; P < 0.05). In the myocardial infarction (MI) subpopulation, serum potassium was not a predictor of multivessel disease, possibly due to the confounding effect of hypokalemia known to be present during MI. CONCLUSIONS: These data demonstrate that a simple baseline serum potassium level is independently associated with the presence of multivessel disease, even in the context of clinical CAD risk factors and other established inflammatory markers.

Beyond lipid lowering: the anti-hypertensive role of statins.

INTRODUCTION: The management of the hypercholesterolemic patient has evolved tremendously with the introduction of the HMG-CoA Reductase inhibitors, a class of drugs better known as the statins. Statins modify cholesterol metabolism by inhibiting the rate-limiting enzyme of cholesterol biosynthesis, producing greater decreases in plasma cholesterol levels than previously realized with hypolipidemic therapy. With the advent of the classic statin-megatrials such as the Scandinavian Simvastatin Survival Study (4S), WOSCOPS, CARE, and the more recent Heart Protection Study (HPS), the role of statins in both the primary and secondary prevention and ultimate risk reduction of patients with coronary disease has been firmly established. DISCUSSION: With an increase in use and popularity, a number of beneficial actions of the statins unrelated to their cholesterol-lowering ability have been reported. These effects have generated greater interest in the possible additional roles and indications for the use of these drugs. Of central focus in this paper is the cholesterol-independent benefit of this group of agents on the cardiovascular system, particularly on the lowering of systemic blood pressure. A number of hypotheses have been proposed for this action and these shall be reviewed within this paper. CONCLUSION: We explore recent data that suggests that statins may provide substantial reduction of blood pressure in the hypertensive, hypercholesterolemic patient independent of their lipid-lowering effect. In addition, we review several notable publications that postulate unique mechanisms for this action and benefit. We also present plausible explanations as to why some of the larger statin trials did not report similar such findings.