The objectives of this study were to determine if mutations impairing the function of MC4R or MC3R were associated with severe obesity in North American adults.
Leptin therapy reverses morbid obesity related to congenital leptin deficiency and appears to possibly treat lipodystrophy, a finding which has led to the approval of leptin for the treatment of lipodystrophy in the USA and Japan.
At the time of follow-up, AMS children exhibited 3-fold lower prevalence of severe obesity (11 vs. 35%, P = 0.004), greater insulin sensitivity (homeostasis model assessment of insulin resistance index 3.4 +/- 0.3 vs. 4.8 +/- 0.5, P = 0.02), improved lipid profile (cholesterol/high-density lipoprotein cholesterol 2.96 +/- 0.11 vs 3.40 +/- 0.18, P = 0.03; high-density lipoprotein cholesterol 1.50 +/- 0.05 vs. 1.35 +/- 0.05 mmol/liter, P = 0.04), lower C-reactive protein (0.88 +/- 0.17 vs. 2.00 +/- 0.34 microg/ml, P = 0.004), and leptin (11.5 +/- 1.5 vs.19.7 +/- 2.5 ng/ml, P = 0.005) and increased ghrelin (1.28 +/- 0.06 vs.1.03 +/- 0.06 ng/ml, P = 0.005) than BMS offspring (AMS vs. BMS, respectively, for all).
University hospital, United States METHODS: Spexin, body mass index (BMI), insulin, glucose, total and high molecular weight adiponectin, leptin, and high sensitivity C- reactive protein were measured longitudinally (baseline, 6 mo, and 12 mo) after RYGB surgery in girls with severe obesity (n = 12; age = 16.7 ± 1.5 years; BMI = 51.6 ± 2.9 kg/m<sup>2</sup>).
We have assessed the incidence of LEP and MC4R mutations and associated hormonal profiles, in a cohort of randomly selected Pakistani children with early onset of severe obesity.
In humans, mutations in leptin, leptin receptor, proopiomelanocortin (POMC), melanocortin-4 receptor (MC4R) and prohormone convertase 1 (PC1) have been described in patients with severe obesity.
The only situation in which obesity does not parallel leptin values is the rare case of morbid obesity due to leptin deficiency caused by missense mutation of the leptin gene.
We hypothesize that haploinsufficiency of SIM1, possibly acting upstream or downstream of the melanocortin 4 receptor in the PVN, is responsible for severe obesity in our subject.
To investigate the physiological role of leptin in the control of meal size and the response to satiety signals, and to identify brain areas mediating this effect, we studied Koletsky (fa(k)/fa(k)) rats, which develop severe obesity due to the genetic absence of leptin receptors.
Systematic screening of 431 obese children and adults for mutations in the coding sequence and the minimal core promoter of MC4R reveals that genetic variation in the transcriptionally essential region of the MC4R promoter is not a significant cause of severe obesity in humans.
MC4R haploinsufficiency clearly segregates with higher BMI; however, severe obesity is not fully penetrant even in MC4R LOF carriers, suggesting critical roles for environmental and lifestyle factors in MC4R monogenic obesity.
While mouse models with deficient IL-6 signaling show an ameliorated but not absent Diethylnitrosamine (DEN)-induced HCC development, the morbid obesity in mice with mutant leptin signaling complicates the dissection of hepatic leptin receptor (LEPR) and IL-6 signaling in HCC development.
Our aim was to investigate the regulation of the gene expression of leptin in subcutaneous adipose tissue biopsies in morbid obesity before and after biliopancreatic diversion (BPD).
We identified a homozygous loss-of-function mutation, NM_002303.5:c.464 T > G; p.(Tyr155*), in the LEPR in an extended consanguineous family with multiple individuals affected by early-onset severe obesity and hyperphagia.
In humans, mutations in leptin, leptin receptor, prohormone convertase 1 (PC1), pro-opiomelanocortin (POMC), melanocortin 4-receptor (MC4-R), and peroxisome proliferator-activated receptor (PPAR) gamma2 genes have been described in patients with severe obesity.