Effect of weight loss and regional fat distribution on plasma leptin concentration in obese women.
OBJECTIVE
To investigate how circulating leptin concentrations are related to regional fat distribution and whether moderate weight loss alters these relationships.


METHODS
A 6 month, clinical weight reduction trial with measurements before and after weight loss.


METHODS
38 healthy, obese women (age: 44.3+/-9.9 y, BMI: 34.0+/-4.0 kg/m2).


METHODS
The following measurements were made. 1. indices of obesity and fat distribution: weight, body mass index (BMI), hip circumference (peripheral fat), waist circumference, total body fat (bioelectrical impedance), abdominal fat distribution: visceral fat and abdominal subcutaneous fat (ultrasonography); and 2. Biochemical measurements: plasma leptin and serum insulin.


RESULTS
Baseline plasma leptin concentrations were three-fold higher in obese women than in normal weight controls. After weight loss averaging 8.4 kg (9.0%), plasma leptin decreased by a mean of 22.3% (P < 0.001), corresponding to body fat decrease of 16.6% (P < 0.001), abdominal subcutaneous fat decrease of 17.4% (P < 0.001) and visceral fat decrease of 18.7% (P < 0.001). The total amount of body fat correlated with plasma (serum) leptin before (r = 0.64, P < 0.001) and after (r = 0.75, P < 0.001) weight loss. Plasma leptin concentrations expressed per kg of body fat did not change significantly during weight loss. After controlling for body fat, baseline leptin concentrations were significantly associated with hip circumference (r = 0.57, P < 0.001) but not with any indices of abdominal fat distribution. After weight loss the associations became significant for hip and waist circumference as well as for visceral and abdominal subcutaneous fat. Changes in leptin correlated with changes in all indices of obesity except visceral fat.


CONCLUSIONS
Plasma leptin concentrations reflect not only total fat mass but also adipose tissue distribution, especially peripheral fat. Plasma leptin values per kilogram of fat mass do not change significantly with modest weight loss.
Rissanen
P
P
Department of Clinical Nutrition, University of Kuopio and Obesity Research Group, Helsinki, Finland. paivi.rissanen@huch.fi
Mäkimattila
S
S
Vehmas
T
T
Taavitsainen
M
M
Rissanen
A
A
D000005:Abdomen; D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000378:metabolism*; D000328:Adult; D001824:Body Constitution; D017097:Electric Impedance; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000000981:diagnostic imaging / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D014463:Ultrasonography; D014781:Viscera; D015431:Weight Loss
D007328:Insulin; D020738:Leptin; D011506:Proteins