Testosterone Effects on Insulin Sensitivity in Old Men in the TEAAM Study as Measured by the Octreotide Insulin Suppression Test

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SAT 554-583-Male Reproductive Endocrinology & Case Reports
Clinical
Saturday, June 15, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SAT-567
Shabeena Shaik*1, Panayiotis Diomedes Tsitouras2, Shalender Bhasin3, Shehzad Sultan Basaria4, Frank Gucciardo5 and Sherman Mitchell Harman1
1Phoenix VA Health Care System, Phoenix, AZ, 2The Univ of Oklahoma, Oklahoma City, OK, 3Boston Univ Schl of Med, Weston, MA, 4Boston University, Chestnut Hill, MA, 5Kronos Longevity Rsrch Inst, Phoenix, AZ
Serum testosterone (T) levels and insulin sensitivity both decrease with age and T treatment has been reported to improve insulin sensitivity in men with diabetes or the metabolic syndrome. The TEAAM (Testosterone Effects on Atherosclerosis in Aging Men) study was a multicenter, prospective, RCT of transdermal testosterone in 311 healthy community dwelling men ages 60-80 years with low or low normal T levels (200-450 ng/dl). We performed analyses of baseline relationships in a subset of 174 men (mean age 66.4 ± 5.0 years) who had pretreatment octreotide insulin suppression tests (OIST) and analyses of effects of treatment on the 112 (62 T and 50 placebo treated) of these men who had repeat OIST’s at 3 and 36 months of study. In the OIST glucose and insulin are infused at constant rates proportional to body surface area while endogenous insulin secretion is inhibited by octreotide infusion. Insulin sensitivity is estimated as concentration of glucose at equilibrium (mean of 160, 170, and 180 min time points). Secondary outcomes included body mass index (BMI) and lean body mass (LBM) and percent fat mass (PFM) by DXA. Repeated measures analysis of variance showed no significant (p=0.23) effect of T treatment on OIST glucose over time. However, there was a significant (p=0.003) increase in OIST glucose in the placebo group, which was not seen in the T-treated subjects. Age did not predict the mean OIST glucose at baseline or the change in OIST glucose from 0-36 months. Lean body mass increased slightly in both groups (p=0.058). There was a significant increase in PFM (p<0.0002) in the placebo, but not in the T-treated, group. However, there was no significant difference in change of PFM over time between the two groups by repeated measures ANOVA. As expected, BMI (p<0.001) and PFM (p=0.008) were strong predictors of OIST glucose at baseline, but neither baseline BMI, LBM, PFM or changes in these variables were significantly correlated with change in OIST glucose from 0-36 months overall or in either treatment group. We conclude that transdermal testosterone treatment of healthy elderly men tends to ameliorate the age-related decrease in insulin sensitivity but that this effect does not appear to be related to changes or lack thereof in body composition.

Nothing to Disclose: SS, PDT, SB, SSB, FG, SMH

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: The Aurora Foundation