Effect of the melanocortin-3 receptor C17A and G241A variants on weight loss in childhood obesity.

Abstract

BACKGROUND:

The central melanocortin system is critical for the long-term regulation of energy homeostasis. Melanocortin-3 receptor (MC3R) knock-out mice, despite being hypophagic, have increased fat mass and higher feed efficiency than do their wild-type littermates.

OBJECTIVE:

The aim was to evaluate whether, in childhood obesity, MC3R variants are associated with changes in fatness reduction as a consequence of a weight-reduction program.

DESIGN:

Molecular screening of the MC3R coding region in 184 obese children, 77 girls and 107 boys [x (+/-SEM) body mass index (BMI; in kg/m(2)) z score: 3.3 +/- 2.3; age 9.2 +/- 2 y], was performed. BMI was evaluated at baseline and after 6 and 12 mo of the weight loss program.

RESULTS:

No new mutations were found. Two previously described polymorphisms, C17A (Thr6Lys) and G241A (Val81Ile), were observed in 20 patients in almost complete linkage disequilibrium. No significant differences in BMI z scores were observed at baseline of the weight-loss program between the genotypes; however, at follow-up, heterozygotes showed a significantly higher BMI z score (P = 0.03). When the patients were divided according to the amount of weight lost, a higher prevalence of heterozygotes was observed among subjects who lowered their BMI z score <1.5 (P = 0.03).

CONCLUSION:

These results suggest a gene-diet interaction between the MC3R C17A and G241A variants and a weight loss program for the ability to lose weight in childhood obesity.

• Authors: Nicola Santoro, Laura Perrone, Grazia Cirillo, Paolo Raimondo, Alessandra Amato, Carmine Brienza, Emanuele Miraglia Del Giudice
• Journal: The American journal of clinical nutrition (Am J Clin Nutr) Vol. 85 Issue 4 Pg. 950-3 (Apr 2007) ISSN: 0002-9165 [Print] United States
• PMID: 17413091 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Receptor, Melanocortin, Type 3

Topics

• Adipose Tissue (metabolism)
• Body Composition (genetics, physiology)
• Child
• Diet, Reducing
• Female
• Genetic Testing
• Genetic Variation
• Humans
• Linkage Disequilibrium
• Male
• Obesity (genetics, metabolism)
• Polymorphism, Genetic
• Receptor, Melanocortin, Type 3 (genetics)
• Weight Loss (genetics, physiology)