Nelson Vergel
Founder, ExcelMale.com
Associations of vitamin D status and vitamin D-related polymorphisms with sex hormones in older men.
Highlights
· Vitamin D might influence sex hormone and gonadotropin levels.
· We studied relationships between 25(OH)D, gene polymorphisms and sex hormone levels.
· Lower Vitamin D status is associated with lower testosterone levels.
· There was no association between gene polymorphisms and sex hormone levels.
Rafiq R, van Schoor NM, Sohl E, et al. J Steroid Biochem Mol Biol. http://www.sciencedirect.com/science/article/pii/S0960076015301394
OBJECTIVE: Evidence regarding relationships of serum 25-hydroxyvitamin D (25(OH)D) with sex hormones and gonadotropin concentrations remains inconsistent. Polymorphisms in vitamin D-related genes may underly these relationships. Our aim was to examine the relationship of vitamin D status and polymorphisms in vitamin D-related genes with sex hormone and gonadotropin levels.
DESIGN AND MEASUREMENTS: We analysed data from the Longitudinal Aging Study Amsterdam, an ongoing population-based cohort study of older Dutch individuals (65-89 years).
We included data of men with measurements of serum 25-hydroxyvitamin D (25(OH)D) (n=643) and determination of vitamin D-related gene polymorphisms (n=459). 25(OH)D concentrations were classified into four categories: <25, 25-50, 50-75 and >75 nmol/L.
Outcome measures were total testosterone, calculated bioavailable and free fraction testosterone, SHBG, estradiol, LH and FSH concentrations. Hypogonadism was defined as a total testosterone level <8.0 nmol/L.
RESULTS: Serum 25(OH)D was positively associated with total and bioavailable testosterone levels.
After adjustments for confounders, men with serum 25(OH)D less than 25 (n=56), 25-50 (n=199) and 50-75 nmol/L (n=240) had lower total testosterone levels compared to men with serum 25(OH)D higher than 75 nmol/L (n=148) (Beta(95% confidence interval): -2.1(-3.7 to -0.4 nmol/L), -0.8(-1.9 to 0.4 nmol/L) and -1.4 (-2.4 to -0.3 nmol/L), respectively).
For bioavailable testosterone the association was significant only for men with serum 25(OH)D less than 25 nmol/L (-0.8 (-1.4 to -0.1 nmol/L)) compared to men with serum 25(OH)D >75 nmol/L.
Serum 25(OH)D was not related to SHBG, estradiol or gonadotropin levels.
Hypogonadism (n=29) was not associated with lower serum 25(OH)D.
No significant differences were found in hormone levels between the different genotypes of the vitamin D-related gene polymorphisms. Also, the polymorphisms did not modify the relationships of serum 25(OH)D with sex hormones or gonadotropins.
CONCLUSION: Vitamin D status is positively associated with testosterone levels. No association was found between vitamin D-related gene polymorphisms and hormone levels.
Highlights
· Vitamin D might influence sex hormone and gonadotropin levels.
· We studied relationships between 25(OH)D, gene polymorphisms and sex hormone levels.
· Lower Vitamin D status is associated with lower testosterone levels.
· There was no association between gene polymorphisms and sex hormone levels.
Rafiq R, van Schoor NM, Sohl E, et al. J Steroid Biochem Mol Biol. http://www.sciencedirect.com/science/article/pii/S0960076015301394
OBJECTIVE: Evidence regarding relationships of serum 25-hydroxyvitamin D (25(OH)D) with sex hormones and gonadotropin concentrations remains inconsistent. Polymorphisms in vitamin D-related genes may underly these relationships. Our aim was to examine the relationship of vitamin D status and polymorphisms in vitamin D-related genes with sex hormone and gonadotropin levels.
DESIGN AND MEASUREMENTS: We analysed data from the Longitudinal Aging Study Amsterdam, an ongoing population-based cohort study of older Dutch individuals (65-89 years).
We included data of men with measurements of serum 25-hydroxyvitamin D (25(OH)D) (n=643) and determination of vitamin D-related gene polymorphisms (n=459). 25(OH)D concentrations were classified into four categories: <25, 25-50, 50-75 and >75 nmol/L.
Outcome measures were total testosterone, calculated bioavailable and free fraction testosterone, SHBG, estradiol, LH and FSH concentrations. Hypogonadism was defined as a total testosterone level <8.0 nmol/L.
RESULTS: Serum 25(OH)D was positively associated with total and bioavailable testosterone levels.
After adjustments for confounders, men with serum 25(OH)D less than 25 (n=56), 25-50 (n=199) and 50-75 nmol/L (n=240) had lower total testosterone levels compared to men with serum 25(OH)D higher than 75 nmol/L (n=148) (Beta(95% confidence interval): -2.1(-3.7 to -0.4 nmol/L), -0.8(-1.9 to 0.4 nmol/L) and -1.4 (-2.4 to -0.3 nmol/L), respectively).
For bioavailable testosterone the association was significant only for men with serum 25(OH)D less than 25 nmol/L (-0.8 (-1.4 to -0.1 nmol/L)) compared to men with serum 25(OH)D >75 nmol/L.
Serum 25(OH)D was not related to SHBG, estradiol or gonadotropin levels.
Hypogonadism (n=29) was not associated with lower serum 25(OH)D.
No significant differences were found in hormone levels between the different genotypes of the vitamin D-related gene polymorphisms. Also, the polymorphisms did not modify the relationships of serum 25(OH)D with sex hormones or gonadotropins.
CONCLUSION: Vitamin D status is positively associated with testosterone levels. No association was found between vitamin D-related gene polymorphisms and hormone levels.
