Nelson Vergel
Founder, ExcelMale.com
Free Estradiol, Percent
Reference Ranges (%)
Age Range
Adult Males 1.7 - 5.4
Adult Females 1.6 - 3.6
Free Estradiol, Serum
Reference Ranges (pg/mL)
Age Range
Adult Males 0.2 - 1.5
Adult Females 0.6 - 7.1
"Free estradiol is a negative, whereas free testosterone is a positive, predictor of cortical bone size in young men at the age of peak bone mass. These findings support the notion that estrogens reduce, whereas androgens increase, cortical bone size, resulting in the well-known sexual dimorphism of cortical bone geometry.
Until recently, not much attention has been paid to the role of estrogens in elderly men. The studies that have been reported so far show no change of total estradiol levels with age in men or a decrease of estradiol levels at old age . The earlier studies also reported a decrease of bioavailable estradiol. In women, estrogen deficiency is the major cause of early postmenopausal, and perhaps also the subsequent phase of late post- menopausal physical changes. This leads to a conceptual problem in defining the cause of age- related physical changes in men because serum levels of total estradiol and testosterone decline only minimally with age. Moreover, previous epidemiological studies have found either no association or even a negative association between serum total testosterone levels and physiological changes in aging men. The latter study did note a positive association between serum estradiol levels and bone mineral density in elderly men, but it was difficult to attribute bone mineral density loss with aging in men to estrogen deficiency as serum total estradiol levels remain relatively constant over the lifespan in men as shown in the present study. Our data for each fraction of bioavailable estradiol and testosterone levels may help to resolve these issues. In the present study, the free, albumin-bound and bioavailable (free and albumin-bound) estradiol concentrations decreased with age to an even greater extent than total estradiol. Together with the results of the present study, it is possible that age-related bone loss in men seems to be attributed to the decrease in bioavailable estradiol. By directly measuring free and bioavailable estradiol and testosterone levels, we are able to demonstrate that elderly men have age-related decrease in both free, albumin- bound and bioavailable (free þ albumin-bound) estradiol levels as well as testosterone levels. Taken together, our data are consistent with the hypothesis that age-related decrease in estradiol bioavailability could at least in part account for physical changes in elderly men.
Moreover, our results suggest that the decrease of bioavailable estradiol and testosterone is mainly due to the age-related decrease of albumin-bound ones. Earlier study suggested that albumin-bound sex steroid is available for uptake by most tissues, whereas SHBG-bound sex steroid is not. Considering the fact that bioavailable sex steroid as well as the albumin-bound fraction are strongly related to the physical characteristics of aging, it is possible that the albumin-bound fraction of sex steroid is available for uptake by tissues and can exert biological effects. In the present study, albumin- bound estradiol and testosterone levels as well as bioavailable estradiol and testosterone levels have stronger relations to ages than total estradiol and testosterone levels, and also have slightly stronger relations than free estradiol and testosterone levels. Previous study showed that bioavailable sex steroid seems to be the best parameter for serum levels of bioactive sex steroid, which seems to play a direct role in the various changes that occur during aging. Therefore, the decrease of albumin-bound estradiol and testosterone with age seems to be the best parameter for the decrease of circulating bioactive sex steroid levels. Moreover, serum albumin concentration has an important role for main- taining serum levels of bioactive sex steroids and SHBG levels is also one of the important determinants of bioavailable sex steroids particularly when serum albumin concentration is low.
In addition, it is noteworthy that the relationships of the albumin-bound and bioavailable sex steroid levels with serum albumin level are strongest in males in their seventies followed by sixties, and that the tendency of inverse correlation between albumin- bound and bioavailable sex steroid levels with serum SHBG level is strongest in males in their sixties, while their relationships with serum SHBG levels are not statistically significant in all ages. These results give rise to the possibility that albumin level is a much more important factor than SHBG level to influence bioavailable sex steroid levels in males in their sixties and seventies.
In conclusion, the age-related changes in circulating free, albumin-bound and bioavailable (free þ albumin-bound) estradiol levels were estab- lished as well as each fraction of testosterone levels. Our results raise the possibility that the decrease of albumin-bound fraction in combination with the increase of SHBG-bound fraction is the important determinant of the decrease of bioavailable estradiol as well as testosterone, and that albumin levels affect albumin-bound sex steroid levels especially in males in their sixties and seventies and SHBG levels affect bioavailable sex steroid levels particularly when serum albumin level is low. Therefore, the decreases of serum albumin levels, which are caused by undernourished state, illness or aging, might induce symptoms of sex hormone deficiencies in sixties and seventies regardless of total estradiol and/or testosterone levels. We need to reevaluate the traditional belief in the effects of sex steroids on the human male physiology age by age in relation to the albumin- bound estradiol and testosterone levels"
http://onlinelibrary.wiley.com/doi/10.1359/JBMR.050404/epdf
Reference Ranges (%)
Age Range
Adult Males 1.7 - 5.4
Adult Females 1.6 - 3.6
Free Estradiol, Serum
Reference Ranges (pg/mL)
Age Range
Adult Males 0.2 - 1.5
Adult Females 0.6 - 7.1
"Free estradiol is a negative, whereas free testosterone is a positive, predictor of cortical bone size in young men at the age of peak bone mass. These findings support the notion that estrogens reduce, whereas androgens increase, cortical bone size, resulting in the well-known sexual dimorphism of cortical bone geometry.
Until recently, not much attention has been paid to the role of estrogens in elderly men. The studies that have been reported so far show no change of total estradiol levels with age in men or a decrease of estradiol levels at old age . The earlier studies also reported a decrease of bioavailable estradiol. In women, estrogen deficiency is the major cause of early postmenopausal, and perhaps also the subsequent phase of late post- menopausal physical changes. This leads to a conceptual problem in defining the cause of age- related physical changes in men because serum levels of total estradiol and testosterone decline only minimally with age. Moreover, previous epidemiological studies have found either no association or even a negative association between serum total testosterone levels and physiological changes in aging men. The latter study did note a positive association between serum estradiol levels and bone mineral density in elderly men, but it was difficult to attribute bone mineral density loss with aging in men to estrogen deficiency as serum total estradiol levels remain relatively constant over the lifespan in men as shown in the present study. Our data for each fraction of bioavailable estradiol and testosterone levels may help to resolve these issues. In the present study, the free, albumin-bound and bioavailable (free and albumin-bound) estradiol concentrations decreased with age to an even greater extent than total estradiol. Together with the results of the present study, it is possible that age-related bone loss in men seems to be attributed to the decrease in bioavailable estradiol. By directly measuring free and bioavailable estradiol and testosterone levels, we are able to demonstrate that elderly men have age-related decrease in both free, albumin- bound and bioavailable (free þ albumin-bound) estradiol levels as well as testosterone levels. Taken together, our data are consistent with the hypothesis that age-related decrease in estradiol bioavailability could at least in part account for physical changes in elderly men.
Moreover, our results suggest that the decrease of bioavailable estradiol and testosterone is mainly due to the age-related decrease of albumin-bound ones. Earlier study suggested that albumin-bound sex steroid is available for uptake by most tissues, whereas SHBG-bound sex steroid is not. Considering the fact that bioavailable sex steroid as well as the albumin-bound fraction are strongly related to the physical characteristics of aging, it is possible that the albumin-bound fraction of sex steroid is available for uptake by tissues and can exert biological effects. In the present study, albumin- bound estradiol and testosterone levels as well as bioavailable estradiol and testosterone levels have stronger relations to ages than total estradiol and testosterone levels, and also have slightly stronger relations than free estradiol and testosterone levels. Previous study showed that bioavailable sex steroid seems to be the best parameter for serum levels of bioactive sex steroid, which seems to play a direct role in the various changes that occur during aging. Therefore, the decrease of albumin-bound estradiol and testosterone with age seems to be the best parameter for the decrease of circulating bioactive sex steroid levels. Moreover, serum albumin concentration has an important role for main- taining serum levels of bioactive sex steroids and SHBG levels is also one of the important determinants of bioavailable sex steroids particularly when serum albumin concentration is low.
In addition, it is noteworthy that the relationships of the albumin-bound and bioavailable sex steroid levels with serum albumin level are strongest in males in their seventies followed by sixties, and that the tendency of inverse correlation between albumin- bound and bioavailable sex steroid levels with serum SHBG level is strongest in males in their sixties, while their relationships with serum SHBG levels are not statistically significant in all ages. These results give rise to the possibility that albumin level is a much more important factor than SHBG level to influence bioavailable sex steroid levels in males in their sixties and seventies.
In conclusion, the age-related changes in circulating free, albumin-bound and bioavailable (free þ albumin-bound) estradiol levels were estab- lished as well as each fraction of testosterone levels. Our results raise the possibility that the decrease of albumin-bound fraction in combination with the increase of SHBG-bound fraction is the important determinant of the decrease of bioavailable estradiol as well as testosterone, and that albumin levels affect albumin-bound sex steroid levels especially in males in their sixties and seventies and SHBG levels affect bioavailable sex steroid levels particularly when serum albumin level is low. Therefore, the decreases of serum albumin levels, which are caused by undernourished state, illness or aging, might induce symptoms of sex hormone deficiencies in sixties and seventies regardless of total estradiol and/or testosterone levels. We need to reevaluate the traditional belief in the effects of sex steroids on the human male physiology age by age in relation to the albumin- bound estradiol and testosterone levels"
http://onlinelibrary.wiley.com/doi/10.1359/JBMR.050404/epdf
