Diagnosing adrenal insufficiency: which test is best--the 1-microg or the 250-microg cosyntropin stimulation test?

OBJECTIVE: To review the available literature on the low-dose cosyntropin stimulation test (CST) for the diagnosis of primary and secondary adrenal insufficiency in both nonstressed and acutely ill patients. METHODS: We performed a MEDLINE search of all English-language literature, published between 1965 and 2007, in which the 1-microg and the 250-microg CSTs were compared in patients with primary and secondary adrenal insufficiency. RESULTS: The majority of published evidence suggests that the 1-microg CST is more sensitive than the 250-microg CST for the diagnosis of secondary adrenal insufficiency in nonstressed patients. In patients with primary adrenal insufficiency, the low-dose CST is unlikely to add any diagnostic sensitivity to the high-dose CST. In critically ill patients, the 1-microg test is also likely to be more sensitive than the 250-microg test when an appropriate cutoff value is used (25 microg/dL). CONCLUSION: The 1-microg CST with a cortisol level determined at 30 minutes after stimulation, with use of a cutoff level of 18 to 20 microg/dL in nonstressed patients and less than 25 microg/dL or an increment of less than 9 microg/dL from baseline in critically ill patients, is the best test that is currently available for establishing the diagnosis of secondary adrenal insufficiency.

Male hypogonadism: The unrecognized cardiovascular risk factor.

Normal levels of male sex hormones are essential to men's health. Many studies demonstrate that hypogonadal men are at higher risk for developing a host of metabolic derangements, including dyslipidemia, type 2 diabetes mellitus, obesity, and hypertension. We examined the most recent studies supporting this notion of hypogonadism as a cardiac risk factor by reviewing all relevant PubMed data. Most studies showed an increase in metabolic disorders and cardiac events in hypogonadal men compared to their eugonadal counterparts. Mechanisms explaining this increased risk include adverse cytokine profiles produced by excess adipose tissue, abnormal lipid metabolism by understimulated hormone-sensitive lipase, and abnormal cellular respiration leading to insulin resistance. In contrast, some studies have not demonstrated such an increased cardiac risk. Conflicting data between studies is expected, given the complexity of testosterone and its metabolic effects. Additionally, the interaction of testosterone with the androgen receptor differs based on an individual genome. Hypogonadism will affect individual men differently because of this genomic variance. The literature points toward true hypogonadism as a major cardiac risk factor. Men at risk of being hypogonadal should be screened and brought back to eugonadism with hormone replacement.

Bisphosphonates induce inflammation and rupture of atherosclerotic plaques in apolipoprotein-E null mice.

The apolipoprotein E knockout (Apo-E-/-) mouse is a well-known model of atherosclerosis. Bisphosphonates, through their affinity to hydroxyapatite, are known to reduce arterial calcification in several animal models. Thus, we examined the effect of two therapeutically used oral bisphosphonates, alendronate and risedronate, on plaque formation in the Apo-E-/- mouse. The drugs were administered by gavage to 16-week-old Apo-E-/- mice for 8 weeks. At 8 weeks, there was no difference in bone mineral density (BMD) of the alendronate- and risedronate-treated mice at any site. A time-dependent increase in BMD was demonstrated in Apo-E-/- mice with risedronate (p<0.01). Histological evaluation revealed that both bisphosphonates caused atherosclerotic plaque rupture. Five of 17 mice had severe inflammation with or without plaque rupture, while seven mice showed inflammation, but without plaque rupture. Neither caspase 3 nor metalloproteinases 2 and 9 were increased in ruptured plaques on immunocytochemistry. Quantitative measurements of arterial caliber remained unaffected. Our finding of plaque inflammation and rupture in bisphosphonate-treated Apo-E-/- mice may provide the first animal model for studies aimed at characterizing mechanisms of plaque rupture in animal models.

Experiences with three different fiber supplements in weight reduction.

BACKGROUND: Fiber supplements added to a caloric diet have additional effects on weight reduction in overweight subjects. The aim of this study was to compare the effect of various commercial fiber supplements (glucomannan, guar gum and alginate) on weight reduction in healthy overweight subjects. MATERIAL/METHODS: One hundred and seventy six men and women were included to receive either active fiber substance or placebo in randomized placebo-controlled studies. The fiber supplements consisted of the viscous fibers glucomannan (Chrombalance), glucomannan and guar gum (Appe-Trim) and glucomannan, guar gum and alginat (Glucosahl). RESULTS: All fiber supplements plus a balanced 1200 kcal diet induced significantly weight reduction more than placebo and diet alone, during a five week observation period. However, there were no significant differences between the different fibers in their ability to induce weight reduction, which was approximately 0.8 kg/week (3.8 +/- 0.9, 4.4 +/- 2.0, 4.1 +/- 0.6 in the Chrombalance, Appe-Trim and Glucosahl group, respectively). CONCLUSIONS: Glucomannan induced body weight reduction in healthy overweight subjects, whereas the addition of guar gum and alginate did not seem to cause additional loss of weight.

Fibrous pleural tumor with hypoglycemia: case study.

Many neoplastic tumors exhibit paraneoplastic syndromes manifested by endocrinopathy. This is particularly true of intrathoracic tumors such as lung cancers, thymomas, carcinoid tumors and mediastinal germ cell neoplasm. Fibrous tumors of the pleura are rare intrathoracic tumors, which are usually benign and often grow to huge size. A subset of these neoplasms present with the syndrome of hypoglycemia. Although first reported more than 70 years ago, the diagnosis is rarely considered when a patient presents with syncope and hypoglycemia. This article reports a patient who presented with a large pleural mass and a hypoglycemic syndrome. (The disease was surgically cured.) The probable mechanism of hypoglycemia is discussed.