Volume 2 Issue 6, June 2006

Prolactinomas are the most common hormone-secreting pituitary tumors. Treatment with dopamine agonists can stabilize disease and recent evidence suggests that in many cases therapy can be subsequently withdrawn without relapse. This Viewpoint discusses the safety and efficacy of dopamine agonist withdrawal and the optimal timing of this approach.

Niacin therapy has beneficial effects on lipid profiles and might afford some protection against coronary artery disease; however, prescription of niacin has been limited. In this Viewpoint, the author considers whether using niacin might pose a risk in patients presenting with insulin resistance or the metabolic syndrome in the absence of diabetes.

As detailed in this Review, leptin seems to act primarily in states of energy deficiency, and common forms of obesity are characterized by leptin resistance. Clinical trials have shown leptin to be effective in subjects with relative or complete leptin deficiency.

At the molecular level, puberty remains an enigmatic process. This article details the discovery of a novel pathway involving GPR54 and its ligand, kisspeptin-1, in control of the gonadotropin-releasing-hormone pulsatility that characterizes sexual maturation and the female estrus cycle. These findings have clear implications for treatment of reproductive disorders.

Excess free fatty acids, an imbalance of adipocytokines and mitochondrial dysfunction all contribute to abnormalities in hepatocellular lipid content in diabetes and can lead to steatosis and insulin resistance. Thus liver fat is a novel target for therapies such as fat-reduced diets and thiazolidendiones.