Reviews & Analysis

The gut hormone ghrelin is a putative signal of energy balance. In addition, ghrelin might act as a pleotrophic modulator of reproductive function. The experimental and clinical data that support a role for ghrelin in the hypothalamic–pituitary–gonadal axis are summarized by the author of this Review.

As genetic and imaging techniques advance, more is becoming known about the nature of various fetal disorders. Some of these disorders may be treated, with varying degrees of success, through the mother. This Review presents information particularly on fetal adrenal and thyroid disorders and discusses the various management approaches and their related risks and outcomes.

The prevalence of central hypothyroidism is unknown, but might be greater than reported. This disorder may arise from a variety of causes, from tumor-related hormonal disturbances, to mechanical problems related to traumatic brain injury, to being induced by drug therapy. This Review presents an overview of etiologies, diagnosis and management.

Aquaporin subtypes 7 and 9 have vital roles in the control of glycerol channels in adipocytes and hepatocytes, and thereby the balance between glycerol release and uptake by adipocytes and the liver, respectively. This Review discusses the pathophysiological importance of these channels in obesity and related disorders.

Macrophages have important roles in the complex relationship between obesity, inflammation and insulin resistance that are determined by whether they are classically or alternatively activated by T-helper-1 or T-helper-2 cytokines, respectively. The former leads to insulin resistance and the latter to protection against this condition. This Review discusses this crosstalk between the immune and metabolic systems.

The prevalence of atherogenic forms of apolipoprotein B dyslipoproteinemias is high, but effective treatments are available. Quick, accurate diagnosis is, therefore, essential to providing the best care. In this Review an algorithm is proposed to help distinguish between disease subtypes, based on simple parameters that may be measured by low-cost tests widely available in clinical laboratories.

A history of gestational diabetes mellitus predisposes women to the future development of type 2 diabetes mellitus. This Review discusses current guidelines for postpartum screening and how they might be implemented. In addition, the authors describe measures to prevent type 2 diabetes mellitus, focusing on lifestyle modifications, such as breast-feeding.

The global obesity epidemic is clearly driven by environmental factors; however, inherited factors can also influence human adiposity. In this Review, the authors focus on the genes implicated in monogenic obesity syndromes. These genes encode components of the leptin–melanocortin pathway, which is critical for regulation of food intake and body weight.

Although osteoporosis can be effectively treated with inhibitors of bone turnover or with bone forming agents, few data are available about an optimum approach. Here, Papapoulos and Makras discuss whether choices can be made based on the available evidence, addressing issues such as selection of patients for treatment, efficacy in lowering fracture risk and monotherapy versus combined therapy.

Cushing disease is an uncommon disorder frequently caused by microadenoma. Although treatment has been greatly improved by the evolution of radiotherapy, radiosurgery and medications, in a substantial proportion of cases the disease is refractory or recurrent. This Review presents and discusses the various management options for such patients.

Thiazolidinediones are antihyperglycemic drugs used to treat diabetes that increase insulin sensitivity in adipose tissue, muscles and the liver to increase glucose use and decrease its production. They are known, however, to also affect bone. This Review examines the available data to assess the effect of these drugs on skeletal health.

Alterations in the hypothalamic–pituitary–adrenal axis play an important part in survival of critically ill patients. The usefulness of currently available therapeutic interventions designed to correct these alterations is, however, unclear. This Review explains the response to stress in critically ill patients and discusses issues surrounding terminology and the role of glucocorticoids in therapy.

Autoimmune thyroiditis, which manifests as Hashimoto thyroiditis and Graves disease among other forms, is an inflammatory disorder of the thyroid gland. Various environmental factors interact with susceptibility genes and seem to be associated with disease initiation and to influence duration and severity. This Review summarizes the currently available information and highlights the areas that urgently require further study.

Between 20% and 40% of patients with diabetes ultimately develop nephropathy. The bank of data on the multiple and complex mechanisms, disease markers and disease progression continues to grow. This article provides an overview of the current status of findings relating to underlying mechanisms and genetic susceptibility.

Thyroid stimulation in Graves disease is caused by antibodies to the TSH receptor that have thyroid-stimulating or thyroid-blocking activity. Antibody detection can aid diagnosis and prediction of outcomes of the disease, as well as prediction of the course of associated ophthalmology. In this Review, Ajjan and Weetman describe the different measurement techniques available and their clinical applications.

Various endocrine abnormalities arise in anorexia nervosa. Most are related to the body's adaptation to starvation, but some might relate to susceptibility to recurrence, as they persist after recovery. Lawson and Klibanski summarize the main endocrine alterations in girls and women, concentrating particularly on bone loss.

The thyroid gland and thyroid hormones have important roles in fertility and throughout pregnancy. In fertile and infertile women with thyroid disorders, such as hypothyroidism or thyroid autoimmunity, therapy might enable conception, but a host of problems can arise. Poppe et al. present an overview of the interactions between thyroid disorders and spontaneous and assisted pregnancies.

Prediabetic states that involve impairments of insulin secretion and action can be identified. Medical therapy and lifestyle modifications can be used in people with these disorders to delay or prevent the onset of type 2 diabetes. In this Review, the data on development and evaluation of diabetes-prevention strategies are discussed and some recommendations for practice are provided.

Cushing's syndrome is no longer considered rare, but making a diagnosis remains challenging. Traditional tests yield variable results. Measurement of late-night serum cortisol levels can deliver excellent sensitivity and specificity but blood samples must be taken during a hospital stay. Here, Carroll et al. put forward the case for late-night salivary cortisol measurement as a simple alternative test.

Type 1 diabetes mellitus is a chronic process of many years, during which insulin production slowly decreases. This key feature makes the disease a potential candidate for treatment but also for prevention against symptoms becoming clinically overt. This Review discusses issues of diagnosis and risk stratification, and the development of prevention strategies.