No effect of Trp64Arg beta3-adrenoceptor polymorphism on the plasma leptin concentration in Pima Indians.
In rodents, administration of leptin promotes beta3-adrenergic stimulation of thermogenesis in brown adipose tissue. Conversely, administration of a beta3-adrenoceptor (beta3-AR) agonist decreases leptin mRNA expression and secretion, suggesting that leptin and sympathetic nervous system activity mediated through the beta3-AR comprise a negative-feedback loop. It has recently been proposed that a defect in the beta3-AR in humans may contribute to a resistance to the sympathetically mediated effects of leptin on thermogenesis and lipolysis, thus leading to obesity and type 2 diabetes mellitus. We thus hypothesized that the Trp64Arg variant in the human beta3-AR would be associated with elevated plasma leptin concentrations. We studied 101 healthy nondiabetic Pima Indians: 11 Arg64 homozygotes, 35 Trp64 homozygotes, and 55 heterozygotes. The fasting plasma leptin concentration as an absolute value or after adjustment for percent body fat and sex was not associated with the beta3-AR genotype. Thus, the data do not support an influence of the Trp64Arg variant on the plasma leptin concentration.
Snitker
S
S
Clinical Diabetes and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Phoenix, AZ 85016, USA.
Nicolson
M
M
Shuldiner
A R
AR
Silver
K
K
Ravussin
E
E
D000328:Adult; D000483:Alleles; D001823:Body Composition / Q000235:genetics; D015992:Body Mass Index; D001835:Body Weight / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D007198:Indians, North American; D007328:Insulin / Q000097:blood; D008297:Male; D009765:Obesity / Q000235:genetics; D011110:Polymorphism, Genetic / Q000235:genetics*; D011943:Receptors, Adrenergic, beta / Q000235:genetics*; D022702:Receptors, Adrenergic, beta-3; D054411:Receptors, Leptin; D012044:Regression Analysis
D007328:Insulin; C515448:LEPR protein, human; D011943:Receptors, Adrenergic, beta; D022702:Receptors, Adrenergic, beta-3; D054411:Receptors, Leptin