Comparison of testosterone fractions between Framingham Heart Study participants and Japanese participants

Abstract

Abbreviations & Acronyms aFT = analog-based free testosterone AMS = Aging Questionnaire ASA = American Society of Andrology cFT = calculated free testosterone CI = confidence interval CV = coefficient of variation Objectives: To determine testosterone fractions in Japanese men and to compare these values with those of Framingham Heart Study participants. Methods: We enrolled 498 healthy Japanese men. Total testosterone was assayed by liquid chromatography tandem mass spectrometry, sex hormone-binding globulin was assayed by immunoassay and free testosterone was calculated by a laboratory at the Boston Medical Center. Analog-based free testosterone and immunoassay-based total testosterone were determined by immunoassay. We compared mass spectrometry assay-based total testosterone and calculated free testosterone values in the Japanese participants with values in the American Framingham Heart Study third generation cohort. Results: The mean serum mass spectrometry assay-based total testosterone, sex hormone-binding globulin, and calculated free testosterone values were 439.4 ± 167 ng/dL, 65.34 ± 30.61 nmol/L, and 58.75 ± 20.0 pg/mL, respectively. The correlation coefficients with age for mass spectrometry assay-based total testosterone, sex hormone-binding globulin, and calculated free testosterone were 0.0010, 0.5041, and −0.496, respectively. There were no age-related changes in mass spectrometry assay-based total testosterone values in healthy men (P = 0.981), whereas sex hormone-binding globulin and calculated free testosterone levels showed similar age-related changes (P < 0.0001). Serum analog-based free testosterone levels (8.24 ± 2.9 pg/mL) showed age-related changes (P < 0.0001) regardless of immunoassay-based total testosterone levels (P = 0.828). Serum immunoassay-based total testosterone values (486.1 ± 162.5 ng/dL) correlated with serum mass spectrometry assay-based total testosterone values (r = 0.740, 95% confidence interval 0.6965-0.7781, P < 0.0001). Similarly, analog-based free testosterone and calculated free testosterone values showed a highly significant correlation (r = 0.706, 95% confidence interval 0.6587-0.7473, P < 0.0001). The analog-based free testosterone values were approximately 10% of the calculated free testosterone values. Conclusions: In contrast to the Framingham Heart Study cohort, total testosterone values in Japanese men are not associated with advancing age; thus, they cannot be used to diagnose late-onset hypogonadism in Japan. The analog-based free testosterone value can be considered instead as a suitable biochemical determinant for diagnosing late-onset hypogonadism syndrome.

Total testosterone is the most valuable indicator of metabolic syndrome among various testosterone values in middle-aged Japanese men

“…Furthermore, multivariate analysis revealed that lowered TT, tentatively defined as <4 ng/mL, was the only detection marker for MetS. It is controversial whether serum TT levels decrease with aging or not [25][26][27][28][29]. As an example, a slight decrease of TT with aging was observed in the Framingham Heart Study [25].…”

“…As an example, a slight decrease of TT with aging was observed in the Framingham Heart Study [25]. However, recent large scale investigations targeting healthy Chinese men [26] and healthy Japanese men [27][28][29] have repeatedly concluded that the serum levels of TT were unchanged by aging. According to one report, the differences that have been observed may be owing to racial differences but not to a difference in the assay method [29].…”

“…However, recent large scale investigations targeting healthy Chinese men [26] and healthy Japanese men [27][28][29] have repeatedly concluded that the serum levels of TT were unchanged by aging. According to one report, the differences that have been observed may be owing to racial differences but not to a difference in the assay method [29]. Specifically, even though they examined the TT levels of 498 Japanese men using the same method (liquid chromatography tandem mass spectrometry) in the same laboratory as performed in the Framingham Heart Study [25], the TT levels of Japanese men remained unchanged by aging [29].…”

“…According to one report, the differences that have been observed may be owing to racial differences but not to a difference in the assay method [29]. Specifically, even though they examined the TT levels of 498 Japanese men using the same method (liquid chromatography tandem mass spectrometry) in the same laboratory as performed in the Framingham Heart Study [25], the TT levels of Japanese men remained unchanged by aging [29]. These facts indicate that serum TT levels in Japanese men are age-independently stable and are References an indicator of MetS, at least in middle-age.…”

Androgen replacement therapy for cancer-related symptoms in male advanced cancer patients: study protocol for a randomised prospective trial (ARTFORM study)

“…Among male advanced cancer patients with cachexia, up to 70% of patients reportedly have hypogonadism defined as low serum testosterone levels which could induce many cancer -related symptoms including cachexia itself (1,2,6). Testosterone functions to keep males healthy and decreases gradually with age (7,8). Testosterone increases bone mineral density and muscle mass (9,10), improves mental function and cognitive impairment (11,12), decrease lower urinary tract symptoms and nocturia (13,14), and maintains cardiovascular health (15).…”