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Laboratory diagnosis of late-onset male hypogonadism andropause
Ruth Clapauch1, Aline Machado Carmo, Lizanka Marinheiro
1Hospital da Lagoa, Instituto Fernandes Figueira, Fiocruz, Rio de Janeiro, RJ, Brazil.
Objectives:
To evaluate which factors influence the laboratorial diagnosis of late-onset male hypogonadism (LOH).
Methods:
Total testosterone (TT), SHBG and albumin were measured in 216 men aged 52-84 years. The laboratorial definition of LOH was two values of calculated free testosterone (cFT) <6.5 ng/dl, according to Vermeulen's formula.
Results:
At the first blood test, cFT was <6.5 ng/dl in 27% of the men. Laboratorial LOH (confirmed by two tests) was present in 19%, but TT levels were low in only 4.1%. Age influenced TT (p=0.0051) as well as BMI; 23.5% of patients > 70 years and 38.9% of the obese men who had TT within the reference range were, in fact, hypogonadal.
Conclusion:
Especially in obese men and in those > 70 years old, SHBG dosage is important to calculate FT levels and diagnose hypogonadism.
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