A-Rod, Lance Armstrong, Jose Canseco, Rashard Lewis, Shawne Merriman. The list of superstar athletes accused of -- or admitting to -- taking performance-enhancing drugs is almost as impressive as the number of sports in which they compete. It's not just weightlifting, baseball and cycling. It's football, track and field, swimming, soccer and basketball . And it's not restricted to males -- or to professionals. Just ask former Olympic track star Marion Jones. Or the nine high school athletes in Texas caught using performance-enhancing drugs during the 2011-2012 academic year.
Polycythemia (elevated red blood cell count) is a rare blood disease in which the body produces too many red blood cells. Causes of polycythemia are either primary (acquired or genetic mutations) or secondary (diseases, conditions, high altitude). Examples of primary polycythemia include:
Serum estradiol associates with blood hemoglobin in elderly men; The MrOS Sweden Study. The Journal of Clinical Endocrinology & Metabolism. http:///doi/abs//-4111
Context: Blood hemoglobin (Hb) declines with age in healthy elderly men, in whom decreasing testosterone has been regarded as part of normal ageing. However, the association between Hb and serum estradiol is incompletely known.
Objective: To determine whether estradiol is associated with anemia/Hb and established determinants of Hb in elderly men without prostate cancer.
Design, Setting and Participants: The MrOS (Osteoporotic Fractures in Men) is a population-based study (n=918, median age years, range 70–81 years).
Main Outcome Measures: We evaluated total estradiol in relation to Hb and adjusted for potential confounders (. age, body mass index (BMI), erythropoietin (EPO), total testosterone, cystatin C, iron- and B-vitamin status).
Results: Estradiol correlated negatively with age (r=-, p<). Hb correlated (age adjusted) positively with estradiol (r=, p<) and testosterone (r=, p<). Independent predictors for Hb in multivariate analyses were estradiol, EPO, BMI, transferrin saturation, cystatin C and free T4 but not testosterone.
After exclusion of subjects with Hb <130g/L and/or testosterone <8 nmol/L (n=99), the correlation between Hb and testosterone was no longer significant, whereas the associations between Hb and estradiol remained. After adjusting for age, BMI and EPO, men with lower estradiol levels were more likely to have Hb in the lowest quartile of values [OR per SD decrease in estradiol = (95% CI –)]. Anemic subjects (Hb <130 g/L) had lower mean estradiol than non-anemic ( vs pmol/L, p<).
Conclusions: Estradiol correlated, positively and independently, with Hb. Decreased estradiol might partly explain the age-related Hb decline observed in healthy elderly men.