Interrelation between genotypes of the vitamin D receptor gene and serum sex hormone concentrations in the Polish elderly population: the PolSenior study.

AIM: Vitamin D co-regulates the synthesis of sex hormones. Therefore, the aim of this study was to determine whether the presence of certain genotypes of the vitamin D receptor gene (VDR) is associated with the serum levels of sex hormones in the elderly Polish population. MATERIALS AND METHODS: The rs10735810, rs1544410, rs7975232, and rs731236 polymorphisms of VDR, the serum levels of testosterone and estradiol, as well as free estrogen index (FEI) and free androgen index (FAI) were evaluated in 360 women and 400 men aged 65-90years selected from 5695 respondents of the PolSenior survey. RESULTS: Only the rs1544410 VDR polymorphism was associated with the serum levels of sex hormones. The prevalence of rs1544410 genotypes was 38% BB, 46% Bb, and 16% bb in women and 41% BB, 44% Bb, and 15% bb in men. In women the frequency of the B allele was p=0.61 and b allele q=0.39, while in men it was p=0.63 and q=0.37, respectively. We found significant differences in the serum testosterone level (p<0.0004) and FAI (p<0.0015) between the rs1544410 genotypes in women but not in men. Higher mean testosterone level and higher mean FAI were observed in women with a rare bb genotype in comparison to a common BB genotype. CONCLUSION: We hypothesize that in women the increase in VDR expression associated with a rare genotype of the rs1544410 polymorphism of this gene may be associated with an increase in testosterone and FAI levels.

The reference values of sex hormones and SHBG serum levels in subjects over 65 years old - The PolSenior Study.

INTRODUCTION: Over the last decade, average life expectancy has continuously increased. There has been no data on normal sex hormone (SH) levels in a Polish elderly population. In this study, we assessed SH in the PolSenior cohort to determine normal reference ranges in relation to gender, age, and cardiovascular disease risk factors (CVDRFs). MATERIAL AND METHODS: The study was performed with 4,352 participants (2,168 men and 2,088 women), aged from 55 to over 90 years, stratified in five-year age groups. Pre-elderly subjects (55-59 years of age) served as the reference group. We assessed total testosterone (TT), estradiol (TE2) and DHEA-S (by RIA) SHBG and FSH (by IRMA) and calculated free androgen and free estrogen indices (FAI and FEI). Percentage body fat (%BF) was measured by bioelectric impedance analysis. The CVDRFs assessment included blood pressure and biochemical (blood glucose, high-density lipoproteins, triglycerides) and anthropometric (waist circumference) components of the metabolic syndrome. RESULTS: TT was low in 19.9%, normal in 78.2%, and high in 1.8% of men. TE2 was low in 94.6% of women. Age and CVDRFs significantly influenced values of SHBG, FSH, TT, FAI, FEI, and DHEA-S in men, while in women values of FSH, TT and TE2 did not change. BMI and %BF affected SH regardless of the age groups and CVDRFs. CONCLUSIONS: Our findings suggest that the reference ranges stratified by the five-year age bands seem more accurate than those given for the overall population over 60 years of age. The clinical relevance of these reference ranges increases when they are considered in relation to CVDRFs, BMI and %BF.

Thyroid dysfunction and thyroid autoimmunity in a large unselected population of elderly subjects in Poland - the 'PolSenior' multicentre crossover study.

INTRODUCTION: Data on the thyroid function of a randomly chosen elderly population was collected during a multicentre study performed in Poland (PolSenior) in 2007-2010. MATERIAL AND METHODS: The population of 4,190 participants under study was divided into six age subgroups of > 65 to > 90 years of age and a younger group aged between 55 and 59 years. Assessment of thyroid function was based on hormonal measurements. RESULTS: Concentrations of both TSH and fT(4) were significantly higher in females than in males. No differences in TSH and fT(4) concentrations between different age groups were found. Thyroid dysfunction was revealed in more than 10% of participants, hypothyroidism in 7.95%, and hyperthyroidism in 2.95%. Both types of dysfunction were more prevalent in women, and in more than 80% both dysfunctions were subclinical. In 1,542 participants, concentrations of TPOAb were measured. Increased TPOAb was revealed in 19% of the cohort and the prevalence of thyroid autoimmunity was higher in women and also more often found in participants with hypothyroidism. CONCLUSIONS: Cross sectional survey revealed thyroid dysfunctions in over 10% of non selected elderly population. No age related differences were found in TSH concentrations, TPOAb positivity and prevalence of thyroid dysfunctions.