Biochemical reference intervals for sex hormones with a new AutoDelfia method in aged men.

BACKGROUND: Our aim was to establish sex hormone reference intervals measured with a new AutoDelfia immunoassay method for aged men free of medication and/or conditions known to influence sex hormone levels. METHODS: The reference population consisted of 466 individuals between 64 and 97 years (mean 72 years) and a mean body mass index (BMI) of 26.9 kg/m(2). RESULTS AND CONCLUSIONS: Because age correlated significantly with most sex hormones studied, we calculated reference intervals for three age groups (64-69, 70-74 and > or =75 years). In clinical practice, single ranges can be used for men aged 64 years or over for testosterone, estradiol and follicle-stimulating hormone (FSH) with the AutoDelfia method. For free testosterone and luteinizing hormone (LH), separate reference intervals should be used for men aged 64-74 years and those aged 75 years or over. For sex hormone-binding globulin, two separate reference intervals by age (64-69 and > or =70 years) are also needed for aged men. LH and FSH reference ranges should be judged with caution, because they may be too high due to cases of subclinical hypogonadism included in the reference population.