OBJECTIVES: To investigate the effect of metformin on the expression of testicular steroidogenesis-related genes, spermatogenesis, and fertility of male diabetic rats.
MATERIALS AND METHODS: Eighteen adult male Sprague Dawley rats were divided into three groups, namely normal control (NC), diabetic control (DC), and metformin-treated (300 mg/kg body weight/day) diabetic rats (D+Met). Diabetes was induced using a single intraperitoneal injection of streptozotocin (60 mg/kg b.w.), followed by oral treatment with metformin for four weeks.
RESULTS: Diabetes decreased serum and intratesticular testosterone levels and increased serum but not intratesticular levels of luteinizing hormone. Sperm count, motility, viability, and normal morphology were decreased, while sperm nuclear DNA fragmentation was increased in DC group, relative to NC group. Testicular mRNA levels of androgen receptor, luteinizing hormone receptor, cytochrome P450 enzyme (CYP11A1), steroidogenic acute regulatory (StAR) protein, 3β-hydroxysteroid dehydrogenase (HSD), and 17β-HSD, as well as the level of StAR protein and activities of CYP11A1, 3β-HSD, and 17β-HSD, were decreased in DC group. Similarly, decreased activities of epididymal antioxidant enzymes and increased lipid peroxidation were observed in DC group. Consequently, decreased litter size, fetal weight, mating and fertility indices, and increased pre- and post-implantation losses were recorded in DC group. Following intervention with metformin, we observed increases in serum and intratesticular testosterone levels, Leydig cell count, improved sperm parameters, and decreased sperm nuclear DNA fragmentation. Furthermore, mRNA levels and activities of steroidogenesis-related enzymes were increased, with improved fertility outcome.
DISCUSSION AND CONCLUSION: Diabetes mellitus is associated with dysregulation of steroidogenesis, abnormal spermatogenesis, and fertility decline. Controlling hyperglycemia is therefore crucial in preserving male reproductive function. Metformin not only regulates blood glucose level, but also preserves male fertility in diabetic state.
PATIENTS AND METHODS: A total of 120 men, aged 40-70 years, with TD (serum total testosterone [TT] ≤ 12 nmol/L) were randomised to receive either i.m. TU (1000 mg) or placebo. In all, 58 and 56 men in the placebo and treatment arm, respectively, completed the study. Participants were seen six times in the 48-week period and the following data were collected: physical examination results, haemoglobin, haematocrit, TT, lipid profile, fasting blood glucose, sex hormone-binding globulin, liver function test, prostate- specific antigen (PSA) and adverse events.
RESULTS: The mean (sd) age of the participants was 53.4 (7.6) years. A significant increase in serum TT (P < 0.001), PSA (P = 0.010), haematocrit (P < 0.001), haemoglobin (P < 0.001) and total bilirubin (P = 0.001) were seen in the treatment arm over the 48-week period. Two men in the placebo arm and one man in the treatment arm developed myocardial infarction. Common adverse events observed in the treatment arm included itching/swelling/pain at the site of injection, flushing and acne. Overall, TU injections were well tolerated.
CONCLUSIONS: TU significantly increases serum testosterone in men with TD. PSA, haemoglobin and haematocrit were significantly elevated but were within clinically safe limits. There was no significant adverse reaction that led to the cessation of treatment.
METHODS: PCOS was induced in rats except for normal control by administering LTZ at 1 mg/kg/day for 21 days. Methanolic extract of F. deltoidea leaf was then orally administered to the PCOS rats at the dose of 250, 500, or 1000 mg/kg/day, respectively for 15 consecutive days. Lipid profile was measured enzymatically in serum. The circulating concentrations of reproductive hormone and antioxidant enzymes were determined by ELISA assays. Ovarian and uterus histomorphometric changes were further observed by hematoxylin and eosin (H&E) staining.
RESULTS: The results showed that treatment with F. deltoidea at the dose of 500 and 1000 mg/kg/day reduced insulin resistance, obesity indices, total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL), malondialdehyde (MDA), testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) to near-normal levels in PCOS rats. The levels of high-density lipoprotein cholesterol (HDL), estrogen, and superoxide dismutase (SOD) are also similar to those observed in normal control rats. Histomorphometric measurements confirmed that F. deltoidea increased the corpus luteum number and the endometrial thickness.
CONCLUSIONS: F. deltoidea can reverse PCOS symptoms in female rats by improving insulin sensitivity, antioxidant activities, hormonal imbalance, and histological changes. These findings suggest the potential use of F. deltoidea as an adjuvant agent in the treatment program of PCOS.
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.
METHODS: Data from 549 subjects from the Malaysian Aging Male Study, which included Malay and Chinese men aged 20 years and older residing in the Klang Valley, were used for analysis. The subjects' calcaneal speed of sound was measured, and their blood was collected for biochemical analysis. Two sets of multiple regression models were generated for the total/bioavailable testosterone and estradiol to avoid multicollinearity.
RESULTS: The multiple regression results revealed that bioavailable testosterone and serum total calcium were significant predictors of the calcaneal speed of sound in the adjusted model. After adjustment for ethnicity and body mass index, only bioavailable testosterone remained significant; the total serum calcium was marginally insignificant. In a separate model, the total testosterone and sex hormone-binding globulin were significant predictors, whereas the total serum calcium was marginally insignificant. After adjustment for ethnicity and body mass index (BMI), the significance persisted for total testosterone and SHBG. After further adjustment for age, none of the serum biochemical determinants was a significant predictor of the calcaneal speed of sound.
CONCLUSION: There is a significant age-dependent relationship between the calcaneal speed of sound and total testosterone, bioavailable testosterone and sex hormone-binding globulin in Chinese and Malay men in Malaysia. The relationship between total serum calcium and calcaneal speed of sound is ethnicity-dependent.
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.