Monday, November 15, 2010

Day 29... Testosterone Has Links to Insulin

By Ed Susman, Contributing Writer, MedPage Today
November 05, 2010


MedPage Today Action Points


•Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.


•Explain to interested patients that men with lower than normal testosterone appear to have higher fasting insulin levels, but researchers cautioned against overtreatment because men with high testosterone had an adverse blood lipid profile.


Review


LOS ANGELES -- Men with lower than normal testosterone appear to have higher fasting insulin levels, but researchers cautioned against overtreatment because men with high testosterone had an adverse blood lipid profile.


Men with low testosterone had insulin measurements of about 6.3 microIU/mL compared with about 5.0 microIU/mL for men with normal testosterone (P=0.003) and about 4 microIU/mL for men with high testosterone (P=0.01), according to Margaret Groves, M.Phil, M.Ed, a researcher with ZRT Laboratories in Beaverton, Ore.



However, men with high testosterone had higher LDL cholesterol (P=0.02) and lower HDL cholesterol (P<0.05), Groves said here at a poster presentation during the World Congress on Insulin Resistance, Diabetes and Cardiovascular Disease.


"What our study showed is that low testosterone is related to insulin resistance in men," she told MedPage Today, "but we also saw that too much testosterone isn't good either."


She encouraged doctors to monitor testosterone -- especially in light of recent advertisements warning men about "low T" -- with either saliva or dried blood spot testing. "These tests can ensure testosterone levels remain in a physiological range for optimum cardiometabolic risk benefits," she said.


"Testosterone supplementation is being increasingly used to help reverse symptoms of metabolic syndrome and improve cardiovascular disease risk in men," Groves noted. "However, data is sparse regarding the direct effects of testosterone levels on cardiometabolic risk markers."


The study Groves and her colleagues conducted to help provide that data enrolled 228 men, excluding those with diagnosed diabetes.


For purposes of the study, they defined low testosterone as less than 300 ng/dl in the dried blood test or less than 4 pg/dl in the saliva test; normal testosterone was defined as in the 300 to 800 ng/dl range with the blood spot test and 40 to 140 pg/dl with the saliva tests; high testosterone was defined as greater than 800 ng/dl with the blood spot tests and greater than 140 pg/dl with the saliva test.


One of the 20 men with low testosterone reported being on testosterone therapy, 15 of the 174 men with normal testosterone reported being on therapy, and 24 of the 34 men with high testosterone were on therapy.


Besides the positive effect on insulin levels, high testosterone was also associated with lower C-reactive protein -- a marker of inflammation -- levels (P<0.05).


There were no significant differences between the group in glycosylated hemoglobin A1c levels, in triglycerides, or in total cholesterol.


"Moderation in testosterone supplementation is important," said Helen Hilts, MD, of DiabeVita Medical Center in Scottsdale, Ariz.


She told MedPage Today that doctors should be seeking a balanced view, noting that testosterone supplementation does appear to improve some parameters of a man's metabolic profile.


Groves is an employee of ZRT Laboratory, which sponsored the study.


Hilts had no relevant disclosures.


Primary source: World Congress on Insulin Resistance, Diabetes and Cardiovascular Disease


Source reference:
Kapur S "Cardiometabolic risk factors and testosterone levels in men: Implications for testosterone supplementation" WCIR 2010; Abstract 65.


Disclaimer
The information presented in this activity is that of the authors and does not necessarily represent the views of the University of Pennsylvania School of Medicine, MedPage Today, and the commercial supporter. Specific medicines discussed in this activity may not yet be approved by the FDA for the use as indicated by the writer or reviewer. Before prescribing any medication, we advise you to review the complete prescribing information, including indications, contraindications, warnings, precautions, and adverse effects. Specific patient care decisions are the responsibility of the healthcare professional caring for the patient. Please review our Terms of Use.

No comments:

Post a Comment