title: Hyperleptinemia is associated with parameters of low-grade systemic inflammation and metabolic dysfunction in obese human beings.
abstract: Leptin is an adipose tissue-derived hormone that has been involved in hypothalamic and systemic inflammation, altered food-intake patterns, and metabolic dysfunction in obese mice. However, it remains unclear whether leptin has a relationship with parameters of systemic inflammation and metabolic dysfunction in humans. We thus evaluated in a cross-sectional study the circulating levels of leptin in 40 non-obese and 41 obese Mexican individuals, examining their relationship with tumor necrosis factor alpha (TNF-α), interleukin (IL) 12, IL-10, central obesity, serum glucose and insulin levels, and serum triglyceride and cholesterol concentrations. Circulating levels of leptin, TNF-α, IL-12, IL-10, and insulin were measured by ELISA, while concentrations of glucose, triglyceride, and cholesterol were determined by enzymatic assays. As expected, serum levels of leptin exhibited a significant elevation in obese individuals as compared to non-obese subjects, showing a clear association with increased body mass index (r = 0.4173), central obesity (r = 0.4678), and body fat percentage (r = 0.3583). Furthermore, leptin also showed a strong relationship with serum TNF-α (r = 0.6989), IL-12 (r = 0.3093), and IL-10 (r = -0.5691). Interestingly, leptin was also significantly related with high concentrations of fasting glucose (r = 0.5227) and insulin (r = 0.2229), as well as elevated levels of insulin resistance (r = 0.3611) and circulating triglyceride (r = 0.4135). These results suggest that hyperleptinemia is strongly associated with the occurrence of low-grade systemic inflammation and metabolic alteration in obese subjects. Further clinical research is still needed to determine whether hyperleptinemia may be a potential marker for recognizing the advent of obesity-related metabolic disorders in human beings.
authors.affiliation: Departamento de Biología de la Reproducción y Clínica de Desórdenes de Sueño, Universidad Autónoma Metropolitana-Iztapalapa D.F., México.
authors.forename: Sonia
authors.initials: S
authors.lastname: Leon-Cabrera
authors.forename: Lourdes
authors.initials: L
authors.lastname: Solís-Lozano
authors.forename: Karina
authors.initials: K
authors.lastname: Suárez-Álvarez
authors.forename: Antonio
authors.initials: A
authors.lastname: González-Chávez
authors.forename: Yadira L
authors.initials: YL
authors.lastname: Béjar
authors.forename: Guillermo
authors.initials: G
authors.lastname: Robles-Díaz
authors.forename: Galileo
authors.initials: G
authors.lastname: Escobedo
keywords: human; hyperleptinemia; leptin; low-grade inflammation; metabolic disease; obesity; type 2 diabetes