leptin and Respiratory-Tract-Diseases

Topics: Adipokines; Adiponectin; Humans; Inflammation; Leptin; Obesity; Respiratory Tract Diseases; Stress, Physiological

Leptin is a product of the obese (ob) gene and acts through its receptor Ob-R. Leptin is primarily known for its role as a hypothalamic modulator of food, especially in intake, energy balance, fat stores and body weight. Recent studies have shown that leptin may be involved in the development of respiratory diseases such as pulmonary artery hypertension, chronic obstructive pulmonary disease, lung neoplasms and asthma. Therefore, further studies are needed to elucidate the mechanisms accounting for the association between leptin and respiratory diseases, which may lead to the development of novel approaches to the prevention and treatment of these diseases. Here we give an overview of the distribution and physiological function of leptin and ob-R, and summarize the recent progress in the relationship between leptin and respiratory diseases.

Topics: Animals; Asthma; Humans; Leptin; Lung Neoplasms; Pulmonary Disease, Chronic Obstructive; Receptors, Leptin; Respiratory Tract Diseases

Obesity, especially visceral adiposity, is associated with morbidity and mortality through endocrine and mechanical processes. Clinical manifestations due to effects of obesity on the cardiovascular, respiratory, gastrointestinal, musculoskeletal, immune, and integumentary systems have been described. Further studies are needed to understand the pathologic processes underlying these clinical manifestations to improve disease prevention.

Topics: Adipocytes; Adiponectin; Adiposity; Cardiovascular Diseases; Energy Metabolism; Exercise; Gastrointestinal Diseases; Humans; Insulin Resistance; Intra-Abdominal Fat; Leptin; Musculoskeletal Diseases; Neoplasms; Obesity; Respiratory Tract Diseases

The prevalence of obesity has considerably increased during the past thirty years. Possible consequences of obesity on respiratory physiology include a restrictive disorder, changes in ventilatory mechanics and an alteration of respiratory drive. Apart from the well established relation between obesity and obstructive sleep apnea-hypopnea syndrome, obesity is associated with two other respiratory disorders. On one hand, epidemiological and animal data suggest a causal relationship between obesity and asthma. On the other hand, morbid obesity is associated, through an alteration of the respiratory drive involving leptin, with a diurnal and nocturnal alveolar hypoventilation defining the obesity-hypoventilation syndrome. These data emphasize the necessity for the medical practitioner to investigate any respiratory symptomatology in obese patients.

Topics: Animals; Asthma; Body Mass Index; Humans; Leptin; Obesity; Obesity Hypoventilation Syndrome; Prevalence; Respiratory Tract Diseases; Sleep Apnea, Obstructive; Switzerland

Topics: Animals; Chemokine CXCL2; Chemotactic Factors; Disease Models, Animal; Inflammation; Leptin; Mice; Mice, Inbred C57BL; Monokines; Oxidants, Photochemical; Ozone; Respiratory Tract Diseases

Prolonged, exhaustive exercise frequently leads to an increased incidence of upper respiratory tract illness (URTI) which is linked to transient immunodepression. We investigated potential biochemical markers of stress and fatigue, and URTI symptoms as a surrogate of immunodepression, in US Marines undergoing intensive winter training at altitude. Selected plasma amino acids and leptin (p[Lep]) were measured as possible markers of fatigue and immunodepression, together with nonesterified fatty acids (p[NEFA]) and total antioxidant capacity (p[TAC]). Changes were observed in plasma free tryptophan (p[FT]), p[Gln], p[Lep], p[NEFA], p[TAC] but not branched chain amino acids (p[BCAA]). p[FT] decreased markedly. Resting p[Gln] decreased overall after one month at altitude. p[Gln] routinely decreases 1-2 hrs after prolonged exercise. Importantly, we observed early morning decreases in p[Gln], suggesting a cumulative effect of prolonged activity, stress, and fatigue. Concomitantly, individuals with highest illness scores had the greatest p[Gln] decrease: low p[Gln] may therefore be associated with a diminished stress tolerance.

Topics: Antioxidants; Biomarkers; Chromatography, High Pressure Liquid; Environmental Exposure; Enzyme-Linked Immunosorbent Assay; Exercise Tolerance; Fatty Acids, Nonesterified; Glutamine; Humans; Immune System; Immune Tolerance; Leptin; Male; Military Personnel; Respiratory Tract Diseases; Retrospective Studies; Tryptophan

Resistin is a recently discovered signal molecule, which could help elucidation of the pathophysiology of the insulin resistance and its correlation with obesity. As little information was available about resistin determination in venous blood at the time of our study, we focused on the question whether any correlation exists between persons with type 2 diabetes mellitus, with systemic inflammation, healthy persons and resistin concentrations and laboratory markers of inflammation, peptone, BMI. Differences of resistin values in these types of volunteers were studied as well.. Persons under study were divided into 3 groups: group A - with clinical signs of inflammatory disease of respiratory tract, leukocytosis > 10000/ul and CRP concentration > 50 mg/l (n = 35); group B - with well controlled type 2 DM treated by oral antidiabetic drugs, without clinical signs of inflammation and negative case history of acute disease (n = 12); group C - without clinical signs of inflammation and negative case history of acute disease (n = 77). For all volunteers we determined BMI index and examined resistin, leptin, interleukin 6, TNF-alpha, Na, K, Cl, insulin, cholesterol, HDL-cholesterol, LDL-cholesterol, triacylglycerols, creatinine, uric acid, ALT, AST, GMT, P, Mg and albumin in serum.. Persons with clinical signs of severe inflammation had higher concentrations of Il6, CRP, resistin and a markedly lower BMI, decreased values of glucose, sodium, triacylglycerols, cholesterol, LDL-cholesterol and HDL-cholesterol compared to diabetics of type 2 (p < 0.05). Persons with clinical signs of severe inflammation showed significantly higher concentrations of TNF-alpha, Il6, CRP, resistin, glucose, leptin and considerably lower values of albumin, sodium and HDL-cholesterol than healthy individuals (p < 0.05). Persons with type 2 DM had markedly higher values of BMI, CRP, glucose, triacylglycerols, LDL-cholesterol, GMT and leptin, compared to healthy volunteers (p < 0.05). None of the three groups differed markedly in age or sex. Healthy volunteers show a significant correlation between leptin and resistin (correlation coefficient 0.82); this correlation was not found in patients with inflammation and type 2 DM. The group of volunteers with inflammations was found to have a significant positive correlation between resistin and inflammatory markers (correlation coefficient 0.3-0.5), negative correlation between resistin and cholesterol. We also found positive correlations between leptin and BMI as well as negative correlations between leptin and CRP. No significant correlations between resistin and other studied parameters were found in persons with type 2 DM.. In healthy population a correlation was found between leptin and resistin concentrations in serum. In patients with severe inflammatory disease a correlation between resistin concentration and laboratory markers of inflammation was shown, however, no correlation was found between leptin and resistin. Resistin concentration in the serum of these patients is significantly higher ( p < 0.01) compared to healthy subjects and well controlled persons with type 2 DM with signs of insulin resistance. This may be due to a direct effect of inflammatory cytokines on resistin production. In persons with type 2 DM no significant correlations were found between resistin and other individual parameters ( insulin sensitivity markers, BMI or leptin). Resistin concentrations in persons with type 2 DM do not differ from concentrations of common population.

Topics: Acute Disease; Aged; C-Reactive Protein; Diabetes Mellitus, Type 2; Female; Humans; Inflammation; Leptin; Male; Middle Aged; Resistin; Respiratory Tract Diseases