Total and high molecular weight adiponectin are elevated in patients with Laron syndrome despite marked obesity.
OBJECTIVE
Patients with Laron syndrome (LS; primary GH insensitivity) caused by molecular defects of the GH receptor gene, are characterized by dwarfism, profound obesity, and hyperlipidemia. The aim of the current study was to evaluate adiponectin levels in LS, as obesity is known to be associated with low adiponectin.


METHODS
We studied nine untreated LS adult patients (5 males, 4 females) and six girls with LS receiving once-daily treatment by IGF1. Total and high molecular weight (HMW) adiponectin levels, adiponectin multimers distribution, and metabolic indices were analyzed in serum samples obtained during several years of follow-up.


RESULTS
Adiponectin levels in the severely obese adult LS patients (percent body fat; females 61.0+/-2.5%, males 40.6+/-8.1%) were two- to three-fold higher than those reported for subjects of corresponding age, gender and degree of adiposity. Total adiponectin was significantly higher in females compared with males (21.4+/-3.5 vs 10.2+/-4.6 microg/ml, P<0.001). The elevated adiponectin in LS subjects was associated with an increased abundance of the HMW isoform, and positively correlated with body fat percentage (r=0.65, P=0.017) and leptin (r=0.65, P=0.012). There was no correlation between adiponectin levels (total and HMW) and the degree of insulin resistance in LS subjects or their blood lipids levels. Adiponectin was also high in young girls with LS (22.9+/-7.4 microg/ml) and did not change during long-term IGF1 replacement therapy.


CONCLUSIONS
Adiponectin hypersecretion in LS, despite profound obesity, suggests that GH activity may negatively impact adiponectin secretion from adipocytes.
Kanety
Hannah
H
Institute of Endocrinology, Chaim Sheba Medical Center, Tel-Hashomer 52621, Israel. hkanety@sheba.health.gov.il
Hemi
Rina
R
Ginsberg
Shira
S
Pariente
Clara
C
Yissachar
Eleanor
E
Barhod
Ehud
E
Funahashi
Tohru
T
Laron
Zvi
Z
D052242:Adiponectin / Q000097:blood*; D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000627:therapeutic use; D046150:Laron Syndrome / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009765:Obesity / Q000097:blood; D055503:Protein Multimerization
D052242:Adiponectin; D007334:Insulin-Like Growth Factor I