Hormones regulating lipid metabolism and plasma lipids in childhood obesity.
OBJECTIVE
To review the mechanisms by which leptin, insulin and adiponectin influence lipid metabolism and plasma lipids in obesity, as well as to describe the associations between these hormones in prepubertal children.


METHODS
Revision of relevant papers published in the last 5 y related to the interactions of leptin, insulin and adiponectin, with special emphasis on those reporting potential mechanisms by which these hormones regulate lipid metabolism and plasma lipids. We also provide original results concerning the relationships found between plasma lipids and leptin, and insulin and adiponectin in prepubertal obese children.


RESULTS
Recent data in the literature shed new light to explain the effects of both leptin and adiponectin in the regulation of lipid metabolism in peripheral tissues. Activation of the AMP-dependent kinase pathway and subsequent increased fatty acid oxidation seems to be the main mechanism of action of these hormones in the regulation of lipid metabolism. In addition, we have found that insulin plasma levels are positively associated to leptin but negatively correlated with adiponectin in obese children. Adiponectin is negatively associated to plasma lipid markers of metabolic syndrome but positively related to HDL-cholesterol, whereas insulin and leptin show opposite patterns. These results support the effect of adiponectin in increasing insulin sensitivity and decreasing plasma triglycerides.


CONCLUSIONS
Leptin, insulin and adiponectin are associated hormones that regulate lipid metabolism in childhood. Adiponectin appears to be the missing link to explain the alterations in lipid metabolism and plasma lipids seen in obesity.
Gil-Campos
M
M
Unit of Pediatric Endocrinology, University Hospital Reina Sofia, Avda. Menendez Pidal, Cordoba, Spain.
Cañete
R
R
Gil
A
A
D052242:Adiponectin; D002648:Child; D005260:Female; D006728:Hormones / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood / Q000378:metabolism; D020738:Leptin / Q000097:blood / Q000378:metabolism; D050356:Lipid Metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D009765:Obesity / Q000097:blood / Q000378:metabolism*
D052242:Adiponectin; D006728:Hormones; D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; D020738:Leptin; D008055:Lipids