Associations of vitamin D status and vitamin D-related polymorphisms with sex hormones in older men

J Steroid Biochem Mol Biol. 2016 Nov:164:11-17. doi: 10.1016/j.jsbmb.2015.11.013. Epub 2015 Nov 21.

Abstract

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 >75nmol/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 <8.0nmol/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 50-75nmol/L (n=240) had lower total testosterone levels compared to men with serum 25(OH)D higher than 75nmol/L (n=148) (β (95% confidence interval): -2.1 (-3.7 to -0.4nmol/L), -0.8 (-1.9 to 0.4nmol/L) and -1.4 (-2.4 to -0.3nmol/L), respectively). For bioavailable testosterone the association was significant only for men with serum 25(OH)D less than 25nmol/L (-0.8 (-1.4 to -0.1nmol/L)) compared to men with serum 25(OH)D >75nmol/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.

Keywords: Gonadotropins; Polymorphisms; Sex hormones; Vitamin D; Vitamin D receptor.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Body Mass Index
  • Cohort Studies
  • Estradiol / blood
  • Follicle Stimulating Hormone / blood
  • Genotype
  • Gonadal Steroid Hormones / blood*
  • Humans
  • Hypogonadism / blood
  • Longitudinal Studies
  • Luteinizing Hormone / blood
  • Male
  • Middle Aged
  • Netherlands
  • Polymorphism, Genetic*
  • Polymorphism, Single Nucleotide
  • Prospective Studies
  • Receptors, Calcitriol / blood*
  • Receptors, Calcitriol / genetics*
  • Reproducibility of Results
  • Sex Hormone-Binding Globulin / metabolism
  • Testosterone / blood
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D / genetics
  • Young Adult

Substances

  • Gonadal Steroid Hormones
  • Receptors, Calcitriol
  • Sex Hormone-Binding Globulin
  • VDR protein, human
  • Vitamin D
  • Testosterone
  • Estradiol
  • Luteinizing Hormone
  • Follicle Stimulating Hormone
  • 25-hydroxyvitamin D