OBJECTIVES: To compare age-associated 8-year changes in total testosterone, calculated bioavailable testosterone and sex hormone binding globulin (SHBG) across five groups of men stratified according to change in body mass index (BMI) (i.e., BMI stable (+/-0.69 kg/m(2)), decreased (-0.7 kg/m(2)), increased minimally (0.7-1.74 kg/m(2)), increased moderately (1.75-3.19 kg/m(2)) and increased most (> or =3.20 kg/m(2))). DESIGN: Eight-year longitudinal cohort study. SUBJECTS: Four hundred and seventy-four black and 695 white men, aged 24-31 years at the time of the first hormone measurement. MEASUREMENTS: Aging-related changes in serum SHBG, total testosterone and bioavailable testosterone. RESULTS: SHBG significantly increased with age for men whose BMI decreased, and there were progressively smaller increases for men whose BMI was stable, or whose BMI increased minimally or moderately (range 1.1-0.3 nM per year, P< or =0.03, respectively). There was no age relationship with SHBG among men whose BMI increased most. Total testosterone did not change with age for men whose BMI decreased, was stable or increased minimally, but for men whose BMI increased moderately and most there was a graded decrease in total testosterone with age (beta=-0.2 and -0.4 nM per year, respectively, P< or =0.005). However, bioavailable testosterone decreased with age to a similar extent across all groups. CONCLUSIONS: These results suggest that changes in BMI during young adulthood modulate age-related changes in SHBG and total testosterone, but not bioavailable testosterone.
OBJECTIVES: To compare age-associated 8-year changes in total testosterone, calculated bioavailable testosterone and sex hormone binding globulin (SHBG) across five groups of men stratified according to change in body mass index (BMI) (i.e., BMI stable (+/-0.69 kg/m(2)), decreased (-0.7 kg/m(2)), increased minimally (0.7-1.74 kg/m(2)), increased moderately (1.75-3.19 kg/m(2)) and increased most (> or =3.20 kg/m(2))). DESIGN: Eight-year longitudinal cohort study. SUBJECTS: Four hundred and seventy-four black and 695 white men, aged 24-31 years at the time of the first hormone measurement. MEASUREMENTS: Aging-related changes in serum SHBG, total testosterone and bioavailable testosterone. RESULTS:SHBG significantly increased with age for men whose BMI decreased, and there were progressively smaller increases for men whose BMI was stable, or whose BMI increased minimally or moderately (range 1.1-0.3 nM per year, P< or =0.03, respectively). There was no age relationship with SHBG among men whose BMI increased most. Total testosterone did not change with age for men whose BMI decreased, was stable or increased minimally, but for men whose BMI increased moderately and most there was a graded decrease in total testosterone with age (beta=-0.2 and -0.4 nM per year, respectively, P< or =0.005). However, bioavailable testosterone decreased with age to a similar extent across all groups. CONCLUSIONS: These results suggest that changes in BMI during young adulthood modulate age-related changes in SHBG and total testosterone, but not bioavailable testosterone.
Authors: Sabine Rohrmann; Elizabeth A Platz; Elizabeth Selvin; Meredith S Shiels; Corinne E Joshu; Andy Menke; Manning Feinleib; Shehzad Basaria; Nader Rifai; Adrian S Dobs; Norma Kanarek; William G Nelson Journal: Clin Endocrinol (Oxf) Date: 2011-08 Impact factor: 3.478
Authors: Miguel Angel Mollar Puchades; Rosa Cámara Gómez; Maria Isabel del Olmo García; José Luis Ponce Marco; Raquel Segovia Portolés; Pablo Abellán Galiana; Francisco Piñón Sellés Journal: Obes Surg Date: 2007-08 Impact factor: 4.129
Authors: Louise A Brinton; Michael B Cook; Valerie McCormack; Kenneth C Johnson; Håkan Olsson; John T Casagrande; Rosie Cooke; Roni T Falk; Susan M Gapstur; Mia M Gaudet; J Michael Gaziano; Georgios Gkiokas; Pascal Guénel; Brian E Henderson; Albert Hollenbeck; Ann W Hsing; Laurence N Kolonel; Claudine Isaacs; Jay H Lubin; Karin B Michels; Eva Negri; Dominick Parisi; Eleni Th Petridou; Malcolm C Pike; Elio Riboli; Howard D Sesso; Kirk Snyder; Anthony J Swerdlow; Dimitrios Trichopoulos; Giske Ursin; Piet A van den Brandt; Stephen K Van Den Eeden; Elisabete Weiderpass; Walter C Willett; Marianne Ewertz; David B Thomas Journal: J Natl Cancer Inst Date: 2014-02-19 Impact factor: 13.506