Displaying publications 21 - 40 of 56 in total

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  1. Chin KY, Ima-Nirwana S
    Aging Male, 2015 Mar;18(1):60-6.
    PMID: 25166624 DOI: 10.3109/13685538.2014.954995
    This study aimed to determine the effects of orchidectomy and supraphysiological testosterone replacement on trabecular structure and gene expression in the bone.
    Matched MeSH terms: Testosterone/blood
  2. Leong CT, D'Souza UJ, Iqbal M, Mustapha ZA
    Redox Rep., 2013;18(4):155-64.
    PMID: 23849340 DOI: 10.1179/1351000213Y.0000000054
    The rapid emergence of various pesticides in the market is inevitable due to the demands from agriculture industries and domestic needs to control nuisance pests and to sustain green resources worldwide. However, long-term exposure to pesticide has led to adverse effects on male fertility. Organophosphate diazinon (O,O-diethyl-O-[2-isopropyl-6-methyl-4-pyrimidinyl] phosphorothiote) is an often abusively used pesticide, as it is effective and economical. This study is to determine the adverse effects of low-dose diazinon exposure on the male reproductive system. In this study, 72 Sprague-Dawley rats were segregated into 1, 2, and 8 weeks of exposure groups and further sub-grouped (n = 6) to receive 0, 10, 15, and 30 mg/kg body weight diazinon treatment. Rats were gavaged orally with diazinon and sacrificed under anaesthesia the day after the last exposure. Our results showed that consistent diazinon exposure decreased glutathione and catalase, and increased lipid peroxidation which together lead to diazinon-mediated oxidative stress. Additionally, diazinon increased serum lactate dehydrogenase and decreased serum testosterone, which may have caused sperm and histopathological anomalies. In conclusion, exposure to diazinon caused changes in lipid peroxidation and sperm, and these two effects might be causally linked.
    Matched MeSH terms: Testosterone/blood
  3. Ellis L, Das S
    Int J Offender Ther Comp Criminol, 2013 Aug;57(8):966-84.
    PMID: 22514238 DOI: 10.1177/0306624X12440564
    There is little doubt that family factors can influence involvement in delinquency, although the full nature and extent of their influences remain unclear. In recent decades, testosterone has been increasingly implicated as a contributor to adolescent offending. The present study sought to determine whether two important types of familial factors--parental socioeconomic status and amicable parent-child relationships--are interacting with testosterone (and possibly other androgens) to affect delinquency. A large sample of North American college students self-reported their involvement in eight categories of delinquency along with self-ratings of various androgen-promoted traits (e.g., muscularity and low-deep voice), parental social status, and the quality of the relationships they had with parents. In both sexes, parent-child relationships and androgens were significantly associated with delinquency but parental social status was not. Factor analysis revealed that the authors' measures of all four categories of variables exhibited strong loadings onto their respective factors. Androgens and amicable parent-child relationships were associated with delinquency but parental social status was not. About one third of the influence of parent-child relationships on delinquency appeared to be attributable to androgens. Findings are discussed from the perspective of the evolutionary neuroandrogenic theory of delinquent and criminal behavior.
    Matched MeSH terms: Testosterone/blood*
  4. Adebiyi FA, Siraj SS, Harmin SA, Christianus A
    Fish Physiol Biochem, 2013 Jun;39(3):547-57.
    PMID: 23010937 DOI: 10.1007/s10695-012-9718-x
    Plasma sex steroid hormonal profile and gonad histology were correlated to study the annual reproductive cycle of Hemibagrus nemurus. Hormones were measured by Enzyme Linked Immunosorbent Assay. Gonad tissues were observed by using light microscopy. The highest testosterone (T) value for male was observed in November and that of female was in October. 11-ketotestosterone (11-KT) and 17β-estradiol (E2) levels were highest in June and November, respectively. Hormonal profiles of T, 11-KT and E2 showed several peaks which indicated a non-seasonal pattern. There were significant differences (p 
    Matched MeSH terms: Testosterone/blood
  5. Ikonomopoulou MP, Olszowy H, Hodge M, Bradley AJ
    PMID: 19247670 DOI: 10.1007/s00360-009-0347-3
    In this study on green turtles, Chelonia mydas, from Peninsular Malaysia, the effect of selected environmental toxicants was examined in vitro. Emphasis was placed on purported hormone-mimicking chemicals such as dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene, dieldrin, lead, zinc and copper. Five concentrations were used: high (1 mg/L), medium (10(-1) mg/L), low (10(-2) mg/L), very low (10(-6) mg/L) and control (diluted carrier solvent but no toxicants). The results suggest that environmental pesticides and heavy metals may significantly alter the binding of steroids [i.e. testosterone (T) and oestradiol] to the plasma proteins in vitro. Competition studies showed that only Cu competed for binding sites with testosterone in the plasma collected from nesting C. mydas. Dieldrin and all heavy metals competed with oestradiol for binding sites. Furthermore, testosterone binding affinity was affected at various DDT concentrations and was hypothesised that DDT in vivo may act to inhibit steroid-protein interactions in nesting C. mydas. Although the precise molecular mechanism is yet to be described, DDT could have an effect upon the protein conformation thus affecting T binding (e.g. the T binding site on the steroid hormone binding protein molecule).
    Matched MeSH terms: Testosterone/blood
  6. Nwe KH, Morat PB, Hamid A, Fadzilah S, Khalid BA
    Exp. Clin. Endocrinol. Diabetes, 1999;107(5):288-94.
    PMID: 10482040
    The 11beta-hydroxysteroid dehydrogenase (11beta-HSD) protects the testis from the inhibitory effects of corticosterone on testosterone (T) production. The objectives of the present studies were to determine the effects of deoxycorticosterone (DOC) and its mechanism of actions on testicular 11beta-HSD activity and plasma T levels after 7 days of treatment. The results revealed that at the end of 7 days treatment, DOC significantly increased testicular 11beta-HSD activity and plasma T levels in normal rats. However, the time course showed that high plasma T levels lowered 11beta-HSD activity on day 14 and by 21 days both the levels normalized. In adrenalectomized (ADX) rats, only the enzyme activity increased significantly but not plasma T levels. Spironolactone, a competitive inhibitor of mineralocorticoid receptor (MR), did not change testicular 11beta-HSD activity in both normal and DOC treated rats suggesting that DOC did not act through MR in increasing 11beta-HSD activity. On the other hand, spironolactone significantly decreased plasma T levels in DOC treated rats. Progesterone (P), a competitive inhibitor of glucocorticoid receptors (GR) or corticosterone significantly suppressed testicular enzyme activity and plasma T levels in DOC treated normal rats. Carbenoxolone which is an inhibitor of 11beta-HSD activity significantly depressed testicular 11beta-HSD activity and plasma T levels in DOC treated normal rats. This paper suggests that DOC increased testicular 11beta-HSD activity through GR; whilst increase in plasma T levels required functioning adrenal glands. The testicular 11beta-HSD is one of the regulators of T levels and vice versa.
    Matched MeSH terms: Testosterone/blood*
  7. Nwe KH, Norhazlina AW, Hamid A, Morat PB, Khalid BA
    Exp. Clin. Endocrinol. Diabetes, 2000;108(5):369-77.
    PMID: 10989957
    The effects of stress and corticosterone on testicular 11beta-hydroxysteroid dehydrogenase (11beta-HSD) oxidative activity have been controversial, whilst that of adrenocorticotrophic hormone (ACTH) have not been investigated before. Hence, the aim of the present study was to determine the in vivo effects of stress due to injection and sham operation, ACTH and corticosterone on testicular and hepatic 11beta-HSD oxidative activity and plasma testosterone levels in normal and adrenalectomized (ADX) rats and their possible mechanism of actions. Adrenalectomy reduced both testicular 11beta-HSD oxidative activity and plasma testosterone levels. The effects of injection and sham operation significantly increased plasma corticosterone levels with decreased testicular 11beta-HSD oxidative activity and plasma testosterone levels in normal but not in ADX rats. Likewise. ACTH or corticosterone treatment for 7 days decreased both testicular 11beta-HSD oxidative activity in a dose dependent manner and plasma testosterone levels in normal rats; but the values in ADX rats remained unchanged. However, none of the above values were significantly lower than that of the ADX levels. Corticosterone seems to maintain testicular 11beta-HSD oxidative activity within the range between normal and ADX rats. These changes are not attributable to diurnal rhythms, as the time of sacrifice has been fixed between 8:30 and 10:30 am. In the liver, no significant change in 11beta-HSD oxidative activity was observed with sham operation, ACTH or corticosterone treatment; but adrenalectomy significantly decreased it. In conclusion, in the intact normal rats, stress, ACTH or corticosterone modulates testicular (but not hepatic) 11beta-HSD oxidative activity indirectly through the adrenal glands and the physiological level of corticosterone is ideal for normal reproductive functions.
    Matched MeSH terms: Testosterone/blood
  8. Faeza NMN, Jesse FFA, Hambali IU, Odhah MN, Umer M, Wessam MMS, et al.
    Trop Anim Health Prod, 2019 Sep;51(7):1855-1866.
    PMID: 30945156 DOI: 10.1007/s11250-019-01878-2
    Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis, a debilitating chronic disease of sheep and goats. Little is known about the buck's reproductive pathophysiology with respect to inoculation with Corynebacterium pseudotuberculois and its immunogen mycolic acid extract. Therefore, this present study was designed to determine the concentration of testosterone hormone, pro-inflammatory cytokines, and semen quality of the experimental animals. A total of 12 bucks, divided into groups 1, 2, and 3 (Negative control group, Positive control group and Mycolic acid group respectively), were enrolled in this study. Following inoculation, all goats were observed for clinical responses and monitored for 60 days post-challenge and were then sacrificed. Blood samples were collected via the jugular once before inoculation and on a weekly basis post-challenge. Semen samples were collected 2 weeks post-challenge and prior to the sacrifice of the experimental animals. During the post inoculation period of 60 days, the concentration of testosterone hormone for group 2 was increased significantly (p  0.05) but increased significantly (p  0.05) as compared to group 1. The concentration of interferon-γ (IFNγ) significantly increased (p  0.05) compared to group 1. Both group 2 and group 3 showed a reduction in semen qualities as compared to group 1, but the severity was more intense in group 2 if compared to group 3. In conclusion, therefore, the present study concluded that the mycolic acid group revealed significant responses of testosterone hormone concentration, semen quality, and its related pro-inflammatory cytokines in bucks following infection but the severity lesser compared to Corynebacterium pseudotuberculosis group.
    Matched MeSH terms: Testosterone/blood*
  9. Albishtue AA, Yimer N, Zakaria MZA, Haron AW, Babji AS, Abubakar AA, et al.
    Theriogenology, 2019 Mar 01;126:310-319.
    PMID: 30605790 DOI: 10.1016/j.theriogenology.2018.12.026
    This study was conducted to determine the effect of edible bird's nest (EBN) supplement on uterine function and embryo-implantation rate. A total of 24 adult female rats, divided equally into four groups, were treated with different doses of EBN for 8 weeks. In the last week of treatment, intact fertile male rats were introduced into each group (three per group) for overnight for mating. On day 7 post-mating (post-implantation), blood samples were collected from the hearts of anaesthetised rats that were later sacrificed. The uteri were removed for assessment of embryo implantation rate, histological and electron microscopic examination, and immunohistochemical analyses. Results showed that as the concentration of EBN supplemented increased, the pregnancy and embryo implantation rates were also increased in the treated groups; significantly at G3 and G4. Although histological evaluation did not show much difference among the groups, scanning electron microscopic examination showed enhanced development of elongated microvilli and pinopods in G4. Results also revealed up-regulated expressions of epidermal growth factor (EGF), EGF receptor (EGFR), vascular endothelial growth factor (VEGF), proliferating cell nulear antigen (PCNA), and progesterone and estrogen receptors (P4R, E2R) in the uteri of treated groups. Moreover, plasma E2, P4, growth hormone (GH) and prolactin (P) levels were higher (p 
    Matched MeSH terms: Testosterone/blood
  10. Loh SY, Salleh N
    Physiol Int, 2017 Mar 01;104(1):25-34.
    PMID: 28361574 DOI: 10.1556/2060.104.2017.1.3
    Introduction Testosterone plays an important role in the blood pressure regulation. However, information with regard to the effect of this hormone on blood pressure in normotensive and hypertensive conditions is limited. Therefore, in this study, the relationship between plasma testosterone level and mean arterial pressure (MAP) was investigated under these conditions. Methods Normotensive Wistar-Kyoto (WKY) and hypertensive Spontaneous Hypertensive (SHR) male and female rats were gonadectomized with female rats treated with testosterone. Estrous cycle stages of intact female rats of both strains were identified by vaginal smear. Pressure in the carotid artery of anesthetized rats was measured via direct cannulation technique. The blood was withdrawn for plasma testosterone level measurement by enzyme-linked immunosorbent assay. Results Treatment of ovariectomized female WKY and SHR rats with testosterone for 6-week duration has resulted in MAP to increase (P blood pressure to increase.
    Matched MeSH terms: Testosterone/blood
  11. Mohamad NV, Wong SK, Wan Hasan WN, Jolly JJ, Nur-Farhana MF, Ima-Nirwana S, et al.
    Aging Male, 2019 Jun;22(2):129-140.
    PMID: 29925283 DOI: 10.1080/13685538.2018.1482487
    Testosterone is the predominant gonadal androgen in men. Low testosterone levels are found to be associated with an increased in metabolic risk and systematic inflammation. Since adipose tissue is a source of inflammatory cytokines, testosterone may regulate inflammation by acting on adipose tissue. This review aimed to explore the role of testosterone in inflammation and its mechanism of action. Both animal studies and human studies showed that (1) testosterone deficiency was associated with an increase in pro-inflammatory cytokines; (2) testosterone substitution reduced pro-inflammatory cytokines. The suppression of inflammation by testosterone were observed in patients with coronary artery disease, prostate cancer and diabetes mellitus through the increase in anti-inflammatory cytokines (IL-10) and the decrease in pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α). Despite these, some studies also reported a non-significant relationship. In conclusion, testosterone may possess anti-inflammatory properties but its magnitude is debatable. More evidence is needed to validate the use of testosterone as a marker and in the management of chronic inflammatory diseases.
    Matched MeSH terms: Testosterone/blood*
  12. Abd Aziz NAA, Chatterjee A, Chatterjee R, Durairajanayagam D
    Andrologia, 2019 Apr;51(3):e13199.
    PMID: 30461035 DOI: 10.1111/and.13199
    This study examined whether tocotrienol supplementation to corticosterone-treated male rats could prevent foetal loss in females upon their mating. Epididymides of adult male Sprague-Dawley (SD) rats with proven fertility were surgically separated at the testis-caput junction. Twenty-four hours post-surgery, these animals received for 7 days either: tocopherol-stripped corn oil (Control), corticosterone 25 mg/kg s.c. (CORT), CORT 25 mg/kg s.c. and tocotrienol-rich fraction (TRF) 100 mg/kg orally (CORT + TRF) or TRF 100 mg/kg orally (TRF). On day 8, males were cohabited with proestrus females. A spermatozoa-positive vaginal smear indicated pregnancy. Males were euthanised for analysis of testosterone and antioxidant activities. Reproductive organs were weighed. On day 8 of pregnancy, females were laparotomised to count the number of implantation sites. Pregnancy was continued until term. Number of pups delivered and their weights were determined. Data were analysed using ANOVA. Malondialdehyde levels were significantly lower in CORT + TRF group compared with CORT group. Enzymatic antioxidant activities, testosterone level and reproductive organ weights were significantly higher in CORT + TRF group compared with CORT group. Number of implantation sites and live pups delivered, and their birth weights from females mated with CORT + TRF males were significantly higher compared to CORT group. Therefore, TRF prevents foetal loss in females mated with CORT + TRF-treated males.
    Matched MeSH terms: Testosterone/blood
  13. Yee A, Loh HS, Danaee M, Riahi S, Ng CG, Sulaiman AH
    J Sex Med, 2018 02;15(2):159-166.
    PMID: 29275046 DOI: 10.1016/j.jsxm.2017.12.004
    BACKGROUND: Methadone has been recognized as an effective maintenance treatment for opioid dependence. However, its use is associated with several complications, including sexual dysfunction in men.

    AIM: To assess plasma testosterone and sexual function in Southeast Asian men on methadone maintenance treatment (MMT) or buprenorphine maintenance treatment (BMT).

    METHODS: 76 sexually active men on MMT (mean age = 43.30 ± 10.32 years) and 31 men on BMT (mean age = 41.87 ± 9.76 years) from a Southeast Asian community were evaluated using plasma total testosterone (TT) and prolactin levels, body mass index, social demographics, substance use measures, and depression severity scale.

    OUTCOMES: Prevalence and associated factors of TT level lower than the reference range in men on MMT or BMT.

    RESULTS: More than 1 third of men (40.8%, n = 31) on MMT had TT levels lower than the reference range, whereas 1 fourth of men (22.6%, n = 7) on BMT did. At univariate analysis, MMT vs BMT (β = 0.298, adjusted R2 = 0.08, P = .02) and body mass index (β = -0.23, adjusted R2 = 0.12, P = .02) were associated with changes in TT after stepwise regression. There were no significant associations with age; Opiate Treatment Index Q scores for alcohol, heroin, stimulant, tobacco, or cannabis use and social functioning domain; education levels; hepatitis C status; and severity of depression. Prolactin level did not differ between the MMT and BMT groups.

    CLINICAL IMPLICATIONS: The sex hormonal assay should be used regularly to check men on MMT.

    STRENGTHS AND LIMITATIONS: This is the first study conducted in the Southeast Asian community. Our study was limited by the lack of a healthy group as the reference for serum levels of testosterone and prolactin.

    CONCLUSIONS: The findings showed that plasma testosterone levels are lower in MMT than in BMT users. Hence, men who are receiving MMT should be screened for hypogonadism routinely in the clinical setting. Yee A, Loh HS, Danaee M, et al. Plasma Testosterone and Sexual Function in Southeast Asian Men Receiving Methadone and Buprenorphine Maintenance Treatment. J Sex Med 2018;15:159-166.

    Matched MeSH terms: Testosterone/blood*
  14. Ho CC, Rohaizak M, Zulkifli SZ, Siti-Aishah MA, Nor-Aini U, Sharifah-Noor-Akmal SH
    Singapore Med J, 2009 May;50(5):513-8.
    PMID: 19495523
    This study was conducted to determine the association between serum sex hormone levels and breast cancer.
    Matched MeSH terms: Testosterone/blood*
  15. Jayusman PA, Mohamed IN, Alias E, Mohamed N, Shuid AN
    Nutrients, 2018 Jun 21;10(7).
    PMID: 29933617 DOI: 10.3390/nu10070799
    Male osteoporosis is associated with higher rates of disability and mortality. Hence the search for suitable intervention and treatment to prevent the degeneration of skeletal health in men is necessary. Eurycoma longifolia (EL), a traditional plant with aphrodisiac potential may be used to treat and prevent male osteoporosis. The skeletal protective effect of quassinoid-rich EL extract, which has a high content of eurycomanone, has not been studied. This study aimed to determine whether EL could prevent skeletal deteriorations in gonadal hormone-deficient male rats. Ninety-six male Sprague⁻Dawley rats were randomly assigned to baseline, sham-operated (Sham), orchidectomised or chemically castrated groups. Chemical castration was achieved via subcutaneous injection of degarelix at 2 mg/kg. The orchidectomised and degarelix-castrated rats were then divided into negative control groups (ORX, DGX), testosterone-treated groups (intramuscular injection at 7 mg/kg weekly) (ORX + TES, DGX + TES), and EL-supplemented groups receiving daily oral gavages at doses of 25 mg/kg (ORX + EL25, DGX + EL25), 50 mg/kg (ORX + EL50, DGX + EL50), and 100 mg/kg (ORX + EL100, DGX + EL100). Following 10 weeks of treatment, the rats were euthanized and their blood and femora were collected. Bone biochemical markers, serum testosterone, osteoprotegerin (OPG), and receptor activator of nuclear factor kappa β-ligand (RANKL) levels and histomorphometric indices were evaluated. Quassinoid-rich EL supplementation was found to reduce degenerative changes of trabecular structure by improving bone volume, trabecular number, and separation. A reduction in the percentage of osteoclast and increase in percentage of osteoblast on bone surface were also seen with EL supplementation. Dynamic histomorphometric analysis showed that the single-labeled surface was significantly decreased while the double-labeled surface was significantly increased with EL supplementations. There was a marginal but significant increase in serum testosterone levels in the ORX + EL25, DGX + EL50, and DGX + EL100 groups compared to their negative control groups. Quassinoid-rich EL extract was effective in reducing skeletal deteriorations in the androgen-deficient osteoporosis rat model.
    Matched MeSH terms: Testosterone/blood
  16. Chin KY, Soelaiman IN, Mohamed IN, Ahmad F, Ramli ES, Aminuddin A, et al.
    Clinics (Sao Paulo), 2013;68(2):159-66.
    PMID: 23525310
    OBJECTIVES: Variations in the prevalence of sex-hormone-related diseases have been observed between Asian ethnic groups living in the same country; however, available data concerning their sex hormone levels are limited. The present study aimed to determine the influence of ethnicity and age on the sex hormone levels of Malay and Chinese men in Malaysia.

    METHODS: A total of 547 males of Malay and Chinese ethnicity residing in the Klang Valley Malaysia underwent a detailed screening, and their blood was collected for sex hormones analyses.

    RESULTS: Testosterone levels were normally distributed in the men (total, free and non-sex hormone-binding globulin (SHBG) bound fractions), and significant ethnic differences were observed (p<0.05); however, the effect size was small. In general, testosterone levels in males began to decline significantly after age 50. Significant ethnic differences in total, free and non-SHBG bound fraction estradiol levels were observed in the 20-29 and 50-59 age groups (p<0.05). The estradiol levels of Malay men decreased as they aged, but they increased for Chinese men starting at age 40.

    CONCLUSIONS: Small but significant differences in testosterone levels existed between Malay and Chinese males. Significant age and race differences existed in estradiol levels. These differences might contribute to the ethnic group differences in diseases related to sex hormones, which other studies have found in Malaysia.

    Matched MeSH terms: Testosterone/blood*
  17. Watts EL, Appleby PN, Perez-Cornago A, Bueno-de-Mesquita HB, Chan JM, Chen C, et al.
    Eur Urol, 2018 Nov;74(5):585-594.
    PMID: 30077399 DOI: 10.1016/j.eururo.2018.07.024
    BACKGROUND: Experimental and clinical evidence implicates testosterone in the aetiology of prostate cancer. Variation across the normal range of circulating free testosterone concentrations may not lead to changes in prostate biology, unless circulating concentrations are low. This may also apply to prostate cancer risk, but this has not been investigated in an epidemiological setting.

    OBJECTIVE: To examine whether men with low concentrations of circulating free testosterone have a reduced risk of prostate cancer.

    DESIGN, SETTING, AND PARTICIPANTS: Analysis of individual participant data from 20 prospective studies including 6933 prostate cancer cases, diagnosed on average 6.8 yr after blood collection, and 12 088 controls in the Endogenous Hormones, Nutritional Biomarkers and Prostate Cancer Collaborative Group.

    OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Odds ratios (ORs) of incident overall prostate cancer and subtypes by stage and grade, using conditional logistic regression, based on study-specific tenths of calculated free testosterone concentration.

    RESULTS AND LIMITATIONS: Men in the lowest tenth of free testosterone concentration had a lower risk of overall prostate cancer (OR=0.77, 95% confidence interval [CI] 0.69-0.86; p<0.001) compared with men with higher concentrations (2nd-10th tenths of the distribution). Heterogeneity was present by tumour grade (phet=0.01), with a lower risk of low-grade disease (OR=0.76, 95% CI 0.67-0.88) and a nonsignificantly higher risk of high-grade disease (OR=1.56, 95% CI 0.95-2.57). There was no evidence of heterogeneity by tumour stage. The observational design is a limitation.

    CONCLUSIONS: Men with low circulating free testosterone may have a lower risk of overall prostate cancer; this may be due to a direct biological effect, or detection bias. Further research is needed to explore the apparent differential association by tumour grade.

    PATIENT SUMMARY: In this study, we looked at circulating testosterone levels and risk of developing prostate cancer, finding that men with low testosterone had a lower risk of prostate cancer.

    Matched MeSH terms: Testosterone/blood
  18. Assi N, Rinaldi S, Viallon V, Dashti SG, Dossus L, Fournier A, et al.
    Int J Cancer, 2020 Feb 01;146(3):759-768.
    PMID: 30968961 DOI: 10.1002/ijc.32324
    Alcohol consumption is associated with higher risk of breast cancer (BC); however, the biological mechanisms underlying this association are not fully elucidated, particularly the extent to which this relationship is mediated by sex hormone levels. Circulating concentrations of estradiol, testosterone, their free fractions and sex-hormone binding globulin (SHBG), were examined in 430 incident BC cases and 645 matched controls among alcohol-consuming postmenopausal women nested within the European Prospective Investigation into Cancer and Nutrition. Mediation analysis was applied to assess whether individual hormone levels mediated the relationship between alcohol intake and BC risk. An alcohol-related hormonal signature, obtained by partial least square (PLS) regression, was evaluated as a potential mediator. Total (TE), natural direct and natural indirect effects (NIE) were estimated. Alcohol intake was positively associated with overall BC risk and specifically with estrogen receptor-positive tumors with respectively TE = 1.17(95%CI: 1.01,1.35) and 1.36(1.08,1.70) for a 1-standard deviation (1-SD) increase of intake. There was no evidence of mediation by sex steroids or SHBG separately except for a weak indirect effect through free estradiol where NIE = 1.03(1.00,1.06). However, an alcohol-related hormonal signature negatively associated with SHBG and positively with estradiol and testosterone was associated with BC risk (odds ratio [OR] = 1.25 [1.07,1.47]) for a 1-SD higher PLS score, and had a statistically significant NIE accounting for a mediated proportion of 24%. There was limited evidence of mediation of the alcohol-BC association by individual sex hormones. However, a hormonal signature, reflecting lower levels of SHBG and higher levels of sex steroids, mediated a substantial proportion of the association.
    Matched MeSH terms: Testosterone/blood
  19. Chin KY, Abdul-Majeed S, Fozi NF, Ima-Nirwana S
    Nutrients, 2014 Nov;6(11):4974-83.
    PMID: 25389899 DOI: 10.3390/nu6114974
    This study aimed to evaluate the effects of annatto tocotrienol on indices of bone static histomorphometry in orchidectomized rats. Forty male rats were randomized into baseline (BL), sham (SH), orchidectomized (ORX), annatto tocotrienol-treated (AnTT) and testosterone enanthate-treated (TE) groups. The BL group was sacrificed upon receipt. All rats except the SH group underwent bilateral orchidectomy. Annatto tocotrienol at 60 mg/kg body weight was administered orally daily to the AnTT group for eight weeks. Testosterone enanthate at 7 mg/kg body weight was administered intramuscularly once weekly for eight weeks to the TE group. The rat femurs were collected for static histomorphometric analysis upon necropsy. The results indicated that the ORX group had significantly higher osteoclast surface and eroded surface, and significantly lower osteoblast surface, osteoid surface and osteoid volume compared to the SH group (p < 0.05). Annatto tocotrienol and testosterone enanthate intervention prevented all these changes (p < 0.05). The efficacy of annatto tocotrienol was on par with testosterone enanthate. In conclusion, annatto tocotrienol at 60 mg/kg can prevent the imbalance in bone remodeling caused by increased osteoclast and bone resorption, and decreased osteoblast and bone formation. This serves as a basis for the application of annatto tocotrienol in hypogonadal men as an antiosteoporotic agent.
    Matched MeSH terms: Testosterone/blood
  20. Singh GK, Turner L, Desai R, Jimenez M, Handelsman DJ
    J Clin Endocrinol Metab, 2014 Jul;99(7):2592-8.
    PMID: 24684468 DOI: 10.1210/jc.2014-1243
    Testosterone (T) and nandrolone (N) esters require deep im injections by medical personnel but these often deposit injectate into sc fat so that more convenient sc self-administration may be feasible.
    Matched MeSH terms: Testosterone/blood
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