Nelson Vergel
Founder, ExcelMale.com
This super elegantly done study looked at the effect of testosterone and DHT on body fat and insulin sensitivity. The researchers previously did a similar study that determined that low estradiol was linked to increased fat mass. By blocking testosterone, DHT and estradiol in different arms, this study could actually see the effect of each of these hormones on fat mass and insulin sensitivity.
T gel plus DHT blocker (T only allowed to aromatize to estradiol) improved body composition but not insulin sensitivity (thus, this was due to T and E2). So, DHT may have a role in
Testosterone with dutasteride, but not anastrazole, improves insulin sensitivity in young obese men: a randomized controlled trial.
Juang PS, et al.
J Sex Med. 2014 Feb;11(2):563-73. doi: 10.1111/jsm.12368. Epub 2013 Nov 6.
Abstract
INTRODUCTION: Testosterone (T) administration to men increases T, estradiol (E2), dihydrotestosterone (DHT), and fat-free mass (FFM), and decreases fat mass (FM) but does not consistently improve insulin sensitivity (IS).
AIM: The aim of this study was to examine the effects of T administration in obese, nondiabetic men on body composition and IS, and to determine if inhibition (i) of metabolism of T to E2 with anastrazole or to DHT with dutasteride alters these effects.
METHODS: This was a 98-day randomized, double-blind, parallel group, placebo-controlled trial of 57 men, 24-51 year, free T in the lower 25% of normal range (<0.33 nmol/L), body mass index ≥ 30.0 kg/m(2). Subjects were randomized to one of four groups:
(i) placebo: gel, pills, and injection (control arm: T+DHT+E2)
(ii) T/DHT/iE2: T gel, anastrazole, and acyline (gonadotropin releasing-hormone antagonist to suppress endogenous T) (T +DHT and no E2)
(iii) T/iDHT/E2: T gel, dutasteride, and acyline (T+E2 and no DHT)
(iv) T/DHT/E2: T gel, placebo pills, and acyline. (T+DHT+E2)
MAIN OUTCOME MEASURES: Main outcome measures are insulin sensitivity as percent change (%Δ
in glucose disposal rates (GDR) from a two-step euglycemic clamp (GDR1 and 2), and %FM and %FFM by dual X-ray absorptiometry scan.
RESULTS:
Insulin Sensitivity: %Δ GDR1 differed across groups (P = 0.02, anova) and was significantly higher in the dutasteride (T/iDHT/E2) compared with the placebo and T gel (T/DHT/E2) groups.
%ΔGDR2 was higher in the dutasteride (T/iDHT/E2) compared with the anastrazole (T/DHT/iE2) group.
Body Composition: T gel alone (T/DHT/E2) or with dutasteride (T/iDHT/E2) significantly increased %FFM (P < 0.05) and decreased %FM (P < 0.05). There was no change in %FFM or %FM after placebo or anastrazole (T/DHT/iE2).
CONCLUSIONS: The combination of T plus dutasteride improved body composition and IS while T alone improved body composition but not IS, suggesting that when T is administered to men, reduction to DHT attenuates the beneficial effects of aromatization to E2 on insulin sensitivity but not body composition.
Note: DHT and estradiol are both linked to improved sex drive. Excess estradiol may increase cardiovascular risk and clotting in those predisposed to those issues. Excess DHT can cause hair loss, prostate volume increase, and acne. Blocking DHT and/or estradiol to low levels may cause sexual dysfunction.
T gel plus DHT blocker (T only allowed to aromatize to estradiol) improved body composition but not insulin sensitivity (thus, this was due to T and E2). So, DHT may have a role in
Testosterone with dutasteride, but not anastrazole, improves insulin sensitivity in young obese men: a randomized controlled trial.
Juang PS, et al.
J Sex Med. 2014 Feb;11(2):563-73. doi: 10.1111/jsm.12368. Epub 2013 Nov 6.
Abstract
INTRODUCTION: Testosterone (T) administration to men increases T, estradiol (E2), dihydrotestosterone (DHT), and fat-free mass (FFM), and decreases fat mass (FM) but does not consistently improve insulin sensitivity (IS).
AIM: The aim of this study was to examine the effects of T administration in obese, nondiabetic men on body composition and IS, and to determine if inhibition (i) of metabolism of T to E2 with anastrazole or to DHT with dutasteride alters these effects.
METHODS: This was a 98-day randomized, double-blind, parallel group, placebo-controlled trial of 57 men, 24-51 year, free T in the lower 25% of normal range (<0.33 nmol/L), body mass index ≥ 30.0 kg/m(2). Subjects were randomized to one of four groups:
(i) placebo: gel, pills, and injection (control arm: T+DHT+E2)
(ii) T/DHT/iE2: T gel, anastrazole, and acyline (gonadotropin releasing-hormone antagonist to suppress endogenous T) (T +DHT and no E2)
(iii) T/iDHT/E2: T gel, dutasteride, and acyline (T+E2 and no DHT)
(iv) T/DHT/E2: T gel, placebo pills, and acyline. (T+DHT+E2)
MAIN OUTCOME MEASURES: Main outcome measures are insulin sensitivity as percent change (%Δ
in glucose disposal rates (GDR) from a two-step euglycemic clamp (GDR1 and 2), and %FM and %FFM by dual X-ray absorptiometry scan.RESULTS:
Insulin Sensitivity: %Δ GDR1 differed across groups (P = 0.02, anova) and was significantly higher in the dutasteride (T/iDHT/E2) compared with the placebo and T gel (T/DHT/E2) groups.
%ΔGDR2 was higher in the dutasteride (T/iDHT/E2) compared with the anastrazole (T/DHT/iE2) group.
Body Composition: T gel alone (T/DHT/E2) or with dutasteride (T/iDHT/E2) significantly increased %FFM (P < 0.05) and decreased %FM (P < 0.05). There was no change in %FFM or %FM after placebo or anastrazole (T/DHT/iE2).
CONCLUSIONS: The combination of T plus dutasteride improved body composition and IS while T alone improved body composition but not IS, suggesting that when T is administered to men, reduction to DHT attenuates the beneficial effects of aromatization to E2 on insulin sensitivity but not body composition.
Note: DHT and estradiol are both linked to improved sex drive. Excess estradiol may increase cardiovascular risk and clotting in those predisposed to those issues. Excess DHT can cause hair loss, prostate volume increase, and acne. Blocking DHT and/or estradiol to low levels may cause sexual dysfunction.
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