PDA

View Full Version : Massive abuse of anabolic steroids decreases IGFBP-3



Euclides
Tuesday, April 27th, 2004, 06:03 PM
Growth hormone induced increase in serum IGFBP-3 level is reversed by anabolic steroids in substance abusing power athletes
Tuomo Karila, Hannu Koistinen, Markku Seppälä, Riitta Koistinen & Timo Seppälä
OBJECTIVE

Body builders may use growth hormone (GH) and anabolic steroids to increase fitness and muscle mass. GH increases serum concentrations of IGF-I and IGFBP-3. The combined effects of GH and anabolic androgenic steroids on IGFBP-3 and IGF-I levels are not known under authentic substance-abusing conditions. The aim of this study was to investigate this in substance-abusing power athletes.

DESIGN AND PATIENTS

Nine healthy, non-obese and non-competing male power athletes, all aggressive substance abusers, used GH and/or anabolic steroids independently of this study. Blood samples were taken both during and between the drug intake. Sixteen substance non-abusing wrestlers served as controls.

MEASUREMENTS

Serum IGF-I concentration was measured by radioimmunoassay and the IGFBP-3 concentration was measured by two immunofluorometric assays, one detecting proteolytic fragments of IGFBP-3. The capacity of serum to proteolytically cleave IGFBP-3 was studied by the proteolysis assay.

RESULTS

While growth hormone increased the IGFBP-3 and IGF-I concentrations, anabolic steroids decreased the same. Concomitant use of growth hormone and anabolic steroids decreased the IGFBP-3 concentration in five out of six abuse periods in spite of the fact that the IGF-I concentration remained elevated in four of them. However, in two men who were on low calorie diet both the IGF-I and IGFBP-3 concentrations decreased during combined GH/anabolic steroid abuse. No proteolytic fragmentation of IGFBP-3 was observed.

CONCLUSION

Massive abuse of anabolic steroids decreases both the basal and GH-stimulated IGFBP-3 concentrations, whereas its effects on serum IGF-I concentration are variable and affected by low calorie diet. This study demonstrates that detection of GH doping by measuring the IGF-I and/or IGFBP-3 levels has notable confounding factors.

Tommy Vercetti
Tuesday, April 27th, 2004, 06:17 PM
Growth hormone induced increase in serum IGFBP-3 level is reversed by anabolic steroids in substance abusing power athletes
Tuomo Karila, Hannu Koistinen, Markku Seppälä, Riitta Koistinen & Timo Seppälä
OBJECTIVE

Body builders may use growth hormone (GH) and anabolic steroids to increase fitness and muscle mass. GH increases serum concentrations of IGF-I and IGFBP-3. The combined effects of GH and anabolic androgenic steroids on IGFBP-3 and IGF-I levels are not known under authentic substance-abusing conditions. The aim of this study was to investigate this in substance-abusing power athletes.

DESIGN AND PATIENTS

Nine healthy, non-obese and non-competing male power athletes, all aggressive substance abusers, used GH and/or anabolic steroids independently of this study. Blood samples were taken both during and between the drug intake. Sixteen substance non-abusing wrestlers served as controls.

MEASUREMENTS

Serum IGF-I concentration was measured by radioimmunoassay and the IGFBP-3 concentration was measured by two immunofluorometric assays, one detecting proteolytic fragments of IGFBP-3. The capacity of serum to proteolytically cleave IGFBP-3 was studied by the proteolysis assay.

RESULTS

While growth hormone increased the IGFBP-3 and IGF-I concentrations, anabolic steroids decreased the same. Concomitant use of growth hormone and anabolic steroids decreased the IGFBP-3 concentration in five out of six abuse periods in spite of the fact that the IGF-I concentration remained elevated in four of them. However, in two men who were on low calorie diet both the IGF-I and IGFBP-3 concentrations decreased during combined GH/anabolic steroid abuse. No proteolytic fragmentation of IGFBP-3 was observed.

CONCLUSION

Massive abuse of anabolic steroids decreases both the basal and GH-stimulated IGFBP-3 concentrations, whereas its effects on serum IGF-I concentration are variable and affected by low calorie diet. This study demonstrates that detection of GH doping by measuring the IGF-I and/or IGFBP-3 levels has notable confounding factors.

Are you user of stuff?

Euclides
Tuesday, April 27th, 2004, 06:35 PM
Are you user of stuff?


No.