Reviews & Analysis

Studies of common genetic variants have yielded new insights into the actions of thyroid hormones and highlighted the importance of local regulation of thyroid hormones in tissues. The authors describe genetic polymorphisms that are related to the thyroid hormone pathway and discuss the influence of these polymorphisms on various biological systems.

The discovery of human embryonic stem cells raised hopes that cell-based therapies would soon become widely available. However, ethical concerns have limited their clinical use. An alternative approach is to reprogram adult somatic cells to a pluripotent state. The pros and cons of generating pluripotent stem cells for clinical applications are discussed.

The rapid obesity surge in industrialized countries is attributed to genetic susceptibility and environmental factors; however, the primary defects that lead to obesity are still largely unknown. This Review summarizes our current knowledge about the neuronal populations and intracellular signaling molecules that are involved in maintaining normal body weight.

Diabetic dyslipidemia, characterized by low HDL cholesterol level and high levels of triglyceride and small dense, LDL cholesterol, greatly increases the risk of cardiovascular disease. Given the complexity of the dyslipidemic profile, multiple agents are often required to achieve therapeutic goals. This Review discusses the use of various pharmacological agents as well as lifestyle changes for the treatment of dyslipidemia in diabetes mellitus.

Abnormalities in hypothalamic–pituitary axis function frequently occur in cancer survivors following prophylactic or therapeutic cranial irradiation. Growth hormone deficiency is particularly prevalent, even after low radiation doses. The author of this Review provides an overview of the epidemiology and pathophysiology of radiation-induced hypopituitarism and describes strategies for effective diagnosis and patient care.

Hyperinsulinemic hypoglycemia is a consequence of inappropriate and unregulated secretion of insulin by pancreatic β-cells. This Review provides an overview of the known genetic and nonhereditary causes and various clinical presentations of this condition, and discusses how advances in imaging and laparoscopic surgery have transformed its clinical management.

From middle-age onwards, men experience a characteristic decline in circulating total and free testosterone levels. These hormonal changes are associated with negative health outcomes, although the direction of causation is still uncertain. This Review discusses risk factors associated with age-related androgen deficiency, therapeutic approaches and possible preventive measures.

The passage of thyroid hormones from the maternal circulation to the fetal circulation is important for normal fetal development. This Review discusses the changes in maternal and fetal thyroid hormone levels during pregnancy and the factors modulating transplacental thyroid hormone supply to the fetus, as well as pathological situations in which the placenta cannot optimize fetal thyroid hormone levels.

Calcitonin is produced by the parafollicular C cells and represents the classical clinical marker for medullary thyroid carcinoma. Here, the authors describe how measurement of basal and stimulated serum calcitonin levels can be used for screening, differential diagnosis, prognostic assessment, and follow-up monitoring in patients with medullary thyroid carcinoma.

In addition to well-characterized hepatic effects, a large body of evidence now suggests that chronic infection with hepatitis C virus (HCV) can lead to endocrine dysfunction. The authors of this Review evaluate the data supporting a link between hepatitis C virus infection and the endocrine system, and discuss potential pathophysiological mechanisms.