Pubertal upregulation of erythropoiesis in boys is determined primarily by androgen

Testosterone action on erythropoiesis does not require its aromatization to estrogen: Insights from the testosterone and estrogen treatment of two aromatase-deficient men

Androgens act on erythropoiesis, but the relative role of testosterone (T) and estradiol (E(2)) on erythropoietic parameters in men is a poorly investigated issue. In order to evaluate separately the effects on erythropoiesis of high-dose T administration alone and of physiological dose of E(2) administration alone two adult men with aromatase deficiency were assessed before and during each treatment. Blood cell count, hemoglobin (Hb), hematocrit (Hct), erythrocyte mean cell volume (MCV), erythrocyte mean corpuscular hemoglobin (MCH), erythrocyte mean corpuscular hemoglobin concentration (MCHC), serum ferritin, iron and total iron-binding capacity (TIBC), serum erythropoietin, serum total testosterone and estradiol were evaluated. Hb, Hct and red cell count rose during testosterone treatment, consistently with the increase in circulating testosterone, but failed to increase during estradiol treatment. A decrease in Hb, Hct and red cell count was recorded in one of the two subjects during estradiol treatment, with a concomitant decrease in serum testosterone. Circulating T alone is capable of and sufficient to influence erythropoiesis, especially at supraphysiological dosage, while circulating E(2) have not the same effect on erythropoietic parameters, suggesting the hypothesis that the erythropoietic changes induced by androgens are not mediated via its aromatization to estrogens.

Longitudinal changes in haemoglobin mass and VO(2max) in adolescents

This study assessed the relationship between haemoglobin mass (Hb(mass)) and maximum oxygen consumption (VO(2max)) in adolescents over 1 year. Twenty-three subjects (11-15 years) participated; 12 undertook ~12 months of cycle training (cyclists) and 11 were sedentary (controls). Hb(mass) and VO(2max) were measured approximately every 3 months. At baseline there was a high correlation (r = 0.82, P < 0.0001) between relative VO(2max) (ml kg(-1) min(-1)) and relative Hb(mass) (g kg(-1)). During 12 months there was a significant increase in relative VO(2max) of the cyclists but not the controls; however, there was no corresponding increase in relative Hb(mass) of either group. The correlation between percent changes in relative VO(2max) and relative Hb(mass) was not significant for cyclists (r = 0.31, P = 0.33) or controls (r = 0.42, P = 0.19). Training does not increase relative Hb(mass) in adolescents consistent with a strong hereditary role for Hb(mass) and VO(2max). Hb(mass) may be used to identify adolescents who have a high VO(2max).

Regulation of global gene expression in the bone marrow microenvironment by androgen: androgen ablation increases insulin-like growth factor binding protein-5 expression

BACKGROUND

Prostate cancer frequently metastasizes to bone. Androgen suppression treatment is initially highly effective, but eventually results in resistant cancer cells. This study evaluates the effects of androgen suppression on the bone and bone marrow (BM). In particular we questioned whether the androgen therapy could adversely facilitate prostate cancer progression through an increase growth factor secretion by the bone microenvironment.

METHODS

Global gene expression is analyzed on mPEDB DNA microarrays. Insulin-like growth factor binding protein-5 (IGFBP5) is detected by immunohistochemistry in mouse tissues and its regulation measured by qPCR and Western blotting in human BM stromal cells. Effects of extracellular matrix-associated IGFBP5 on human prostate epithelial cells are tested in an MTS cell-growth assay.

RESULTS

Castration increases expression of 159 genes (including 4 secreted cytokines) and suppresses expression of 84 genes. IGFBP5 is most consistently increased and the increase in expression is reversed by testosterone administration. IGFBP5 protein is detected in vivo in osteoblasts, BM stromal cells, and endothelial cells. Primary human stromal cell cultures secrete IGFBP5. In vitro, treatment of immortalized human marrow stromal cells with charcoal-stripped serum increases IGFBP5 mRNA expression, which is reversed by androgen supplementation. IGFBP5 is incorporated into the extracellular matrix. Further, IGFBP5 immobilized on extracellular matrices of stromal cells enhances the growth of immortalized prostate epithelial cells.

CONCLUSIONS

Androgen suppressive therapy increases IGFBP5 in the BM microenvironment and thereby may facilitate the progression of prostate cancer.

[Biochemical measures in the German Health Interview and Examination Survey for Children and Adolescents (KiGGS)]

In the framework of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) a variety of biochemical parameters was determined in order to provide objective information on health status and particular health risks, in addition to parent interview data and anthropometric measurements. Overall 43 parameters covered three areas of particular public health interest: micronutrient deficiency, seroepidemiology of infectious diseases and immunization status, and risk indicators or risk factors for chronic non-communicable diseases. A review of available evidence regarding valid reference or cutoff values as well as the standardization of laboratory methods led to the categorization of these parameters into five classification categories. Here, we discuss the present first descriptive results on selected parameters representing the various categories. In order to determine the public health impact of measurement results, and perhaps even derive normative reference data relevant to health care, more detailed analyses will be required. In the first step, these will focus on cross-sectional analyses of the association between biochemical parameters and other health-related anthropometric and sociodemographic variables. Intermediate and long-term objectives will include the construction of multidimensional reference values taking into account several laborato ry data and other clinical information at the same time, and the prognostic validation of reference or cut-off values based on a follow- up of the study participants for clinical outcomes.

Higher serum concentrations of DHEAS predict improved nutritional status in helminth-infected children, adolescents, and young adults in Leyte, the Philippines

Pubertal development and associated downmodulation of proinflammatory cytokines may predict improved nutritional status, independent of chronic parasite infections, in developing countries. We enrolled 731 individuals, aged 7-30 y, from Leyte, the Philippines, where helminth infections and nutritional morbidity are highly prevalent. The following data were collected: venous blood hemoglobin and serum concentrations of ferritin, dehydroepiandrosterone sulfate (DHEAS), C-reactive protein and proinflammatory cytokines (IL-1, IL-6, TNF-alpha, and soluble TNF receptor I); anthropometric measurements to calculate upper arm muscle area Z-score and sum of triceps and subscapular skinfolds Z-score; stool samples to determine Schistosoma japonicum and geohelminth egg counts; and responses to questionnaires assessing socio-economic status. In cross-sectional multilevel linear and logistic regression analyses adjusted for confounders, relations were assessed between 1) DHEAS and nutritional status, 2) DHEAS and proinflammatory cytokines, and 3) nutritional status and proinflammatory cytokines. Independent of age, socio-economic status, and helminth infections, increased levels of DHEAS were associated with improved nutritional status and decreased prevalence of non-iron deficiency anemia in both males and females. DHEAS showed dose-dependent inverse associations with C-reactive protein (P=0.08) and the production of IL-6 (P<0.0001). These inflammatory markers, in turn, were consistently associated with undernutrition and anemia. The results suggest that the puberty-associated rise in DHEAS downmodulates proinflammatory immune responses and thereby reduces undernutrition and anemia in a population experiencing a high burden of chronic helminth infections. This novel regulatory mechanism of inflammation-related nutritional morbidity emphasizes the importance of treating prepubescent children for helminth infections.

Low testosterone levels and the risk of anemia in older men and women

BACKGROUND

Anemia is a frequent feature of male hypogonadism and anti-androgenic treatment. We hypothesized that the presence of low testosterone levels in older persons is a risk factor for anemia.

METHODS

Testosterone and hemoglobin levels were measured in a representative sample of 905 persons 65 years or older without cancer, renal insufficiency, or anti-androgenic treatments. Hemoglobin levels were reassessed after 3 years.

RESULTS

At baseline, 31 men and 57 women had anemia. Adjusting for confounders, we found that total and bioavailable testosterone levels were associated with hemoglobin levels in women (P = .001 and P = .02, respectively) and in men (P<.001 and P = .03, respectively). Men and women in the lowest quartile of total and bioavailable testosterone were more likely than those in the highest to have anemia (men, 14/99 vs 3/100; odds ratio [OR], 5.4; 95% confidence interval [CI], 1.4-21.8 for total and 16/99 vs 1/99; OR, 13.1; 95% CI, 1.5-116.9 for bioavailable testosterone; women, 21/129 vs 12/127; OR, 2.1; 95% CI, 0.9-5.0 for total and 24/127 vs 6/127; OR, 3.4; 95% CI, 1.2-9.4 for bioavailable testosterone). Among nonanemic participants and independent of confounders, men and women with low vs normal total and bioavailable testosterone levels had a significantly higher risk of developing anemia at 3-year follow-up (21/167 vs 28/444; relative risk, 2.1; 95% CI, 1.1-4.1 for total and 26/143 vs 23/468; relative risk, 3.9; 95% CI, 1.9-7.8 for bioavailable testosterone).

CONCLUSION

Older men and women with low testosterone levels have a higher risk of anemia.

Nutritional status improves after treatment of schistosoma japonicum-infected children and adolescents

Studies addressing the relation between chronic schistosomiasis japonica and nutritional status are limited. We conducted a longitudinal treatment-reinfection study in Leyte, the Philippines, among 477 Schistosoma japonicum-infected subjects aged 7-20 y, to evaluate changes in nutritional status after treatment with praziquantel. Stool, Tanner stage, anthropometric indices, and hemoglobin (Hb) were evaluated at baseline, 4 wk post-treatment, and every 3 mo for 18 mo. Height-for-age Z-score (HAZ) and BMI Z-score (BMIZ) were calculated. Change scores relative to baseline were created for all outcome measures. Multilevel repeated-measures analyses were used to adjust for socioeconomic status, sex, either pubertal status or age, and household-level clustering. Z-scores improved modestly but significantly over time. BMIZ in children wasted at baseline improved the most [0.41 (0.26-0.56) Z-score unit] and HAZ improved only in children stunted at baseline [0.17 (0.l2-0.21) Z-score unit]. Hb improvement peaked at 15 mo and occurred only in subjects that were anemic at baseline [peak improvement: 8.3 (6.0-10.6) g/L] and in males [peak improvement 4.7 (2.9-6.6) g/L]. Reinfection, evaluated as egg count over time and egg count 3 mo earlier to assess a delay in effect, was inversely associated with improvement in Hb (P = 0.06 and 0.004, respectively). High-intensity reinfection at 18 mo was associated with significantly less absolute growth from baseline compared with lower-intensity and no reinfection. Based on the peak Hb improvement at 15 mo post-treatment, annual treatment intervals are recommended to reduce schistosomiasis-associated nutritional morbidity.