Circulating concentrations of soluble leptin receptor: influence of menstrual cycle and diet therapy.
Concentrations of the soluble leptin receptor (sOB-R) may be related to leptin resistance in obesity. We measured sOB-R concentrations in serum in 103 non-diabetic Japanese men and women. All subjects were grouped according to body mass index (BMI; in kg/m(2)). Serum sOB-R concentrations did not differ significantly between normal-weight (18.5 < or = BMI < 25.0) men and women, but were significantly higher in underweight subjects (BMI < 18.5) than in normal-weight subjects. In contrast, overweight (25 < or = BMI < 30) and obese (30 < or = BMI < 35.0, 35.0 < or = BMI < 40, and BMI > or = 40) subjects had significantly lower sOB-R concentrations than did normal-weight subjects. Serum sOB-R concentrations were inversely correlated with BMI and serum immunoreactive leptin concentrations. Very low-energy diet therapy for 4 wk significantly lowered serum immunoreactive leptin concentrations but did not significantly affect serum sOB-R concentrations. Serum sOB-R concentrations did not change significantly during the menstrual cycle. Our results showed that serum sOB-R concentrations decrease with increasing BMI and that sex hormones likely do not affect serum sOB-R concentrations in non-pregnant women. The reduction in serum sOB-R concentrations in overweight and obese persons may reflect downregulation of hypothalamic leptin receptor production as a result of an increase in circulating leptin and might be an important factor in leptin resistance.
Shimizu
Hiroyuki
H
First Department of Internal Medicine, Gunma University School of Medicine, 3-39-22 Showamachi, Maebashi, Gunma 371-8511, Japan. hshimizu@showa.sb.gunma-u.ac.jp
Shimomura
Kenju
K
Negishi
Mayumi
M
Masunaga
Miki
M
Uehara
Yutaka
Y
Sato
Noriyuki
N
Shimomura
Yohnosuke
Y
Kasai
Kikuo
K
Mori
Masatomo
M
D000328:Adult; D015992:Body Mass Index; D002352:Carrier Proteins / Q000097:blood*; D004038:Diet, Reducing; D005260:Female; D006801:Humans; D007564:Japan; D020738:Leptin / Q000097:blood; D008297:Male; D008597:Menstrual Cycle / Q000097:blood*; D009765:Obesity / Q000097:blood* / Q000178:diet therapy*; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin
D002352:Carrier Proteins; C515448:LEPR protein, human; D020738:Leptin; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin