The effect of a very low calorie diet on insulin sensitivity, beta cell function, insulin clearance, incretin hormone secretion, androgen levels and body composition in obese young women.
OBJECTIVE
Evaluation of the effect of an 8-week very low calorie diet (VLCD, 500-600 kcal daily) on weight, body fat distribution, glucose, insulin and lipid metabolism, androgen levels and incretin secretion in obese women.


METHODS
Seventeen overweight women (BMI > 28) were recruited to the study. Glucose, insulin and lipid metabolism were evaluated by euglycemic clamp technique, indirect calorimetry and an oral glucose tolerance test (OGTT). Insulin sensitivity was calculated as glucose disposal rate (GDR) and insulin sensitivity index (ISI), and also by HOMA-IR. Insulin secretion rate (ISR) was calculated from plasma C-peptide measurements. Secretion of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) was measured during an oral glucose tolerance test. Abdominal fat distribution was assessed by dual x-ray absorptiometry scan and computed tomography.


RESULTS
Ten women completed the intervention. The subjects lost an average 11% of their baseline weight. There was a significant loss of subcutaneous abdominal fatty tissue (p < 0.01) and intra-abdominal fatty tissue (p =0.05). Whole body (HOMA-IR) (p < 0.05) insulin sensitivity increased significantly, but peripheral (ISI) insulin sensitivity was unaltered after weight loss. GIP increased (p < 0.05) and GLP-1 was unaltered after the dietary intervention. Insulin responses did not differ before and after dietary intervention, however, a significant increase in insulin clearance (p < 0.05) was observed. The weight loss resulted in a significant decrease in free testosterone.


CONCLUSIONS
A VLCD is an effective weight loss treatment, which results in an immediate improvement in several metabolic parameters.
Department of Obstetrics and Gynaecology,Copenhagen University Hospital at Hvidovre, Hvidovre, Denmark. pernillefsvendsen@hotmail.com
Pernille F
PF
Svendsen
Frank K
FK
Jensen
Jens J
JJ
Holst
Steen B
SB
Haugaard
Lisbeth
L
Nilas
Sten
S
Madsbad
D000328:Adult; D000728:Androgens / Q000097:blood*; D001823:Body Composition; D001835:Body Weight; D031204:Caloric Restriction; D013196:Dihydrotestosterone / Q000097:blood; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D005951:Glucose Tolerance Test; D006801:Humans; D054795:Incretins / Q000097:blood / Q000378:metabolism*; D007328:Insulin / Q000097:blood* / Q000378:metabolism; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000502:physiology*; D050152:Intra-Abdominal Fat / Q000473:pathology; D008053:Lipid Mobilization; D009765:Obesity / Q000097:blood / Q000178:diet therapy*; D013739:Testosterone / Q000097:blood; D016896:Treatment Outcome; D055815:Young Adult
D000728:Androgens; D054795:Incretins; D007328:Insulin; D013196:Dihydrotestosterone; D013739:Testosterone; D052216:Glucagon-Like Peptide 1