The metabolic effects of preferential reduction of visceral adipose tissue in abdominally obese men.
METHODS
This study was performed on free living subjects attending the body composition laboratory on a monthly basis for a total of six months.


METHODS
Thirty-one abdominally obese men (30 <body mass index (BMI) <40, waist-to-hip ratio (WHR)>0.95) were enrolled in a placebo-controlled randomized double-blind study, using either dexfenfluramine (d-fen) or placebo, whilst also receiving food and fitness counselling. After a two week run-in period they were randomized to either d-fen or placebo for three months. This was followed by a further three months without medication, although food and fitness counselling continued.


METHODS
Body composition assessment included anthropometry (weight, height and abdominal circumferences), dual-energy X-ray absorptiometry (DEXA) for total body fat, and intra-abdominal fat measured via magnetic resonance imaging (MRI) at the L3/L4 level. Biochemistry included serum lipids, insulin and glucose. All measurements including blood pressure were performed at baseline, three months and six months.


METHODS
The change within each group in the three months on medication (d-fen or placebo) was assessed by paired t-tests, whilst the difference between the groups at baseline and at three months (measured by percentage change from baseline) was assessed by unpaired t-tests. An analysis of variance was performed over the six months for the d-fen group and the placebo group separately, to determine the overall effect of three months treatment with either d-fen or placebo, three months after medication had ceased. OUTCOMES AT THREE MONTHS: At three months, BMI decreased by -5.8+/-0.8% in the group on d-fen and by -2.7+/-0.8% in the placebo group (P<0.01 d-fen vs placebo). There was also a significant difference in the reduction of the visceral fat area between the groups (-21.0+/-4.0% in the d- fen group vs -6.7+/-2.2% in the placebo group, P<0.01) although there was no significant difference between groups with regard to reduction in subcutaneous fat area. The visceral:subcutaneous fat ratio (V/S ratio) was significantly reduced between groups at three months (-13.3+/-4.9% in the d-fen group vs -0.7+/-3.0% in the placebo group, P=0.03). At three months, the only metabolic parameters to show significant difference between the two groups were total cholesterol and LDL cholesterol. Total cholesterol reduced by -12.4+/-2.0% in the d-fen group compared with -2.3+/-2.1% in the placebo group (P<0.01). LDL cholesterol reduced by -15.6+/-2.6% in the d-fen group compared with -1.2+/-2.8% in the placebo group (P<0.01). OUTCOMES AT SIX MONTHS: In the d-fen group, the reductions in BMI, abdominal circumference and % total body fat (DEXA) were sustained after three months on no medication, whereas all changes in body composition seen in the group on placebo at three months, had reverted at the three month follow-up. Both groups sustained a reduction in the insulin to glucose (I/G) ratio and systolic and diastolic blood pressure for three months after medication was ceased, while those on d-fen initially also maintained a reduction in total and LDL cholesterol.
Clinical Nutrition and Metabolism Unit, Monash Medical Centre, Melbourne, Victoria, Australia.
S J
SJ
Marks
S
S
Chin
B J
BJ
Strauss
D000273:Adipose Tissue; D000328:Adult; D001794:Blood Pressure; D001823:Body Composition; D001824:Body Constitution; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D020372:Dexfenfluramine / Q000627:therapeutic use*; D004311:Double-Blind Method; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000188:drug therapy* / Q000503:physiopathology; D010919:Placebos; D014781:Viscera
D008078:Cholesterol, LDL; D010919:Placebos; D002784:Cholesterol; D020372:Dexfenfluramine