leptin and Respiration-Disorders

Since its cloning in 1994, leptin has emerged in the literature as a pleiotropic hormone whose actions extend from immune system homeostasis to reproduction and angiogenesis. Recent investigations have identified the lung as a leptin responsive and producing organ, while extensive research has been published concerning the role of leptin in the respiratory system. Animal studies have provided evidence indicating that leptin is a stimulant of ventilation, whereas researchers have proposed an important role for leptin in lung maturation and development. Studies further suggest a significant impact of leptin on specific respiratory diseases, including obstructive sleep apnoea-hypopnoea syndrome, asthma, COPD and lung cancer. However, as new investigations are under way, the picture is becoming more complex. The scope of this review is to decode the existing data concerning the actions of leptin in the lung and provide a detailed description of leptin's involvement in the most common disorders of the respiratory system.

Topics: Animals; Humans; Leptin; Lung; Lung Diseases; Pulmonary Gas Exchange; Respiration Disorders; Respiratory Mechanics

Leptin is best known as a regulator of energy homeostasis, but it also interacts with sleep and breathing. Leptin secretion increases at night and decreases during the day. The circadian secretory profile of leptin is determined both by the hypothalamic circadian pacemaker and sleep-wake cycle. Leptin is also a powerful respiratory stimulant. Serum leptin levels are higher in obstructive sleep apnoea syndrome but lower during extended sleep deprivation in healthy subjects or in narcolepsy. Abnormalities in serum leptin concentrations have recently been linked with deleterious effects on weight control, cardiovascular health and glucose regulation. Since sleep curtailment and sleep-disordered breathing are epidemics of the modern society, better understanding of leptin pathophysiology could open new perspectives to pathophysiology of major public diseases, including obesity and metabolic syndrome.

Topics: Humans; Leptin; Receptors, Leptin; Receptors, Serotonin; Respiration; Respiration Disorders; Sleep; Sleep Wake Disorders