Molecular analysis of the 17alpha-hydroxylase gene and its potential role in hyperandrogenism

The steroid 17α-hydroxylase (CYP17) enzyme plays a pivotal role in the synthesis of the glucocorticoids and the sex steroid hormones. The identification of naturally occurring mutations and polymorphisms is therefore of considerable importance to our understanding of the structure and function of the enzyme and its possible role in the development of hyperandrogenic states. This project had two aims: firstly to identify mutations in patients with CYP17 deficiency and secondly to explore the hypothesis that polymorphic variants in the CYP17 promoter and/or coding regions exist. Such variants may modify expression of the gene leading to interindividual variation in androgen production. The technique of single strand conformation polymorphism (SSCP) analysis was used to screen variants in genomic DNA samples from 4 patients with CYP17 deficiency and hyperandrogenic individuals. Two different detection systems, namely silver staining and 32P-labelling were compared for sensitivity. Cloning and sequencing were subsequently performed to identify the sequence variations. The two detection techniques gave similar results, with silver staining showing slightly greater sensitivity. Variant SSCP patterns were found in all four patients but in only two were pathological mutations identified. Two of these were single base pair substitutions causing the missense mutations arg96trp (exon 1) and thrl31ser (exon 2) and the third, a 5 bp deletion in exon 7 leading to a premature termination codon at codon 387. Seven polymorphisms were identified of which three have not previously been described. The prevalence of a polymorphism in the 5' promoter region of CYP17, with a possible influence on the transcription of CYP17, was determined in two groups of hyperandrogenic patients, namely those with polycystic ovary syndrome (PCO) and those with congenital adrenal hyperplasia compared to a reference population. No significant difference in the prevalence of this polymorphism was found between the populations, nor was there any relationship between the prevalence of a particular allele and androgen levels in patients with PCO implying that this polymorphism is not an important cause of dysregulation of this gene

The expression of COX-2 in VEGF-treated endothelial cells is mediated through protein tyrosine kinase.

Cyclooxygenase (COX), existing as the COX-1 and COX-2 isoforms, converts arachidonic acid to prostaglandin H2, which is then further metabolized to various prostaglandins. Vascular endothelial growth factor (VEGF) has been shown to play important roles in inflammation and is upregulated by the prostaglandin E series through COX-2 in several cell types. Here, we have investigated the effects of VEGF on the COX isoform expressed in human umbilical vein endothelial cells (HUVEC). The signalling mechanism of the COX isoform expressed in endothelial cells activated with VEGF will be also investigated using the tyrosine kinase inhibitor, genistein, and protein kinase C inhibitor, staurosporine. The activity of COX-2 was assessed by measuring the production of 6-keto-prostaglandin F1alpha in the presence of exogenous arachidonic acids (10 microM, 10 min) by enzyme immunoassay. The expression of COX isoform protein was detected by immunoblot using specific antibodies. Untreated HUVEC contained no COX-2 protein. In HUVEC treated with VEGF (0.01-50 ng/ml), COX-2 protein, but not COX-1, and COX activity were increased in a dose-dependent manner. Interestingly, the increased COX-2 protein and activity in response to VEGF (10 ng/ml) was inhibited by the tyrosine kinase inhibitor, genistein (0.05-5 microg/ml), but not by the protein kinase C inhibitor, staurosporine (0.1-10 ng/ml). Thus, the induction of COX-2 by VEGF in endothelial cells was mediated through protein tyrosine kinase, and the uses of specific COX-2 inhibitors in these conditions, in which VEGF was involved, might have a role

Cardiaovascular Disease Risk Factors in Thai Natural Menopause with First-Time Diagnosis of Low Bone Mass Density

Objective: To evaluate the prevalence of initial cardiovascular disease (CVD) risk factors in naturally postmenopausal Thai women with first-time diagnosis of low bone mass density (BMD), and compare with those reported among general Thai women of the same age range during the same studied time. Methods: A retrospective cross-sectional study of initial CVD risk factors of 473 naturally postmenopausal Thai women (45-60 years) with the first-time diagnosis of osteopenia or osteoporosis without previous treatment for CVD risk factors, except for hypertension(HT) and diabetes mellitus(DM), was performed. Only subjects with all available initial CVD risk factors were recruited. Data included age, weight, height, waist circumference(WC), and underlying diseases. Extracted initial CVD risk factors were: HT, DM, body mass index(BMI), cholesterol level, triglyceride, high density lipoprotein , and family history of CVD. The main outcome was prevalence of initial CVD risk factors with 95%CI. Results were compared with data of previous Thai reports in women of the same age during the same time period. Results: All subjects (86.3% osteopenic, 13.7% osteoporotic) had on average 3.6 years since menopause. Prevalence of women with initial CVD risk factors was 73.8%. The three most common risk factors were high BMI (48.6%), high WC (37.8%) and high cholesterol (22.2%). Only high BMI was more prevalent than previously reported. In contrast, the other factors were lower than previously published data. Conclusion: With the exception of high BMI, initial CVD risk factors in this study were comparable to or lower than those reported in general Thai women of the same age during the same time period

Association Between Body Mass Index and Moderate-to-Severe Vasomotor Symptoms in Thai Postmenopausal Women

Objective:  Body mass index (BMI) has been controversially reported to be positively, inversely, or not associated with vasomotor symptoms (VMS) in postmenopausal women. This study analysed the association between BMI and moderate-to-severe VMS in Thai population. Methods: A cross-sectional study was conducted among 178 Thai postmenopausal women aged 30-60 years. They were categorized into two groups by BMI. The two groups (normal BMI <25.0 kg/m2 and high BMI ≥25.0 kg/m2) were compared. Modified menopausal rating scale (MRS) was used to assess the severity of VMS. The association between BMI, types and duration of menopause, and VMS were analyzed by chi-square test and t-test analysis. Multiple logistic regression analysis was used to evaluate the associations between BMI, other variables, and severity of VMS. Results: Each group comprised 89 consecutive postmenopausal women. The percentage of women with moderate-to-severe VMS was significantly higher in the normal BMI group than in the high BMI group (60.9% vs 39.1%, respectively; p= 0.007). The association between normal BMI and moderate-to-severe VMS was statistically significant after adjustment for other confounding variables that included age, medical illness, duration or type of menopause and current medications (adjusted odd ratios [OR]: 2.378; 95% confidence interval [CI]: 1.273, 4.447). Conclusion: Interestingly, Thai postmenopausal women with a normal BMI experience a higher rate of moderate-to-severe VMS than those with a high BMI. The finding indicates that BMI is a risk factor for VMS among Thai postmenopausal women. Healthcare providers should focus on normal BMI Thai postmenopausal women when assessing for and treating VMS

Cardiaovascular Disease Risk Factors in Thai Natural Menopause with First-Time Diagnosis of Low Bone Mass Density

Objective: To evaluate the prevalence of initial cardiovascular disease (CVD) risk factors in naturally postmenopausal Thai women with first-time diagnosis of low bone mass density (BMD), and compare with those reported among general Thai women of the same age range during the same studied time. Methods: A retrospective cross-sectional study of initial CVD risk factors of 473 naturally postmenopausal Thai women (45-60 years) with the first-time diagnosis of osteopenia or osteoporosis without previous treatment for CVD risk factors, except for hypertension(HT) and diabetes mellitus(DM), was performed. Only subjects with all available initial CVD risk factors were recruited. Data included age, weight, height, waist circumference(WC), and underlying diseases. Extracted initial CVD risk factors were: HT, DM, body mass index(BMI), cholesterol level, triglyceride, high density lipoprotein, and family history of CVD. The main outcome was prevalence of initial CVD risk factors with 95%CI. Results were compared with data of previous Thai reports in women of the same age during the same time period. Results: All subjects (86.3% osteopenic, 13.7% osteoporotic) had on average 3.6 years since menopause. Prevalence of women with initial CVD risk factors was 73.8%. The three most common risk factors were high BMI (48.6%), high WC (37.8%) and high cholesterol (22.2%). Only high BMI was more prevalent than previously reported. In contrast, the other factors were lower than previously published data. Conclusion: With the exception of high BMI, initial CVD risk factors in this study were comparable to or lower than those reported in general Thai women of the same age during the same time period

Prevalence and Clinical Predictors of Insulin Resistance in Reproductive-Aged Thai Women with Polycystic Ovary Syndrome

Objectives. To determine the prevalence of insulin resistance (IR) and its predictors in reproductive-aged Thai women with polycystic ovary syndrome (PCOS). Methods. A cross-sectional study was conducted from May 2007 to January 2009. Participants were 250 Thai women with PCOS. Information regarding medical history and physical examination and results of 75 gram OGTT were recorded. Results. The overall prevalence of IR was 20.0%, comprising the prevalence of impaired fasting glucose, impaired glucose tolerance, and diabetic mellitus of 3.2%, 13.6%, and 5.6%, respectively. Multiple logistic regression analysis showed that the independent predictors for IR were age of ≥30 years old, waist circumference (WC) of ≥80 cm, presence of acanthosis nigricans (AN), and dyslipidemia with odds ratios (95% confidence interval) of 2.14 (1.01–4.52), 3.53 (1.28–9.75), 2.63 (1.17–5.88), and 3.07 (1.16–8.11), respectively. Conclusion. The overall prevalence of IR in reproductive-aged Thai women with PCOS is 20.0%. Age ≥30 years old, WC ≥80 cm, the presence of AN, and dyslipidemia are the significant clinical predictors

Association between Glucose Metabolism and Oral Combined Contraceptive Pills or Cyclic Progestin in Thai Women with Polycystic Ovary Syndrome: A 3-year Observational Study

Objective: To measure the difference in fasting blood glucose (FBG) among Thai women with polycystic ovary syndrome (PCOS), having received either oral combined contraceptive pills (OCP) or cyclic progestin, during 3 years of treatment.  Materials and Methods: The data were collected by a retrospective chart review of women with PCOS, who had been treated at Siriraj Hospital before June 2019, backward to the year 2000. The patients were divided into two groups, according to their different treatments, namely: an OCP group and a cyclic progestin group. There were 44 cases in each group, and both groups had received complete hormonal treatment over 3 years.  Results: The patients’ baseline characteristics showed a significantly lower body mass index (BMI) and waist circumference (WC) in the OCP group than in the cyclic progestin treatment group. After the 3-year period of treatment, the FBG differences in the OCP group and cyclic progestin treatment group were 3.4±8.4 and 3.6±8.5 mg/dL, respectively; which revealed no statistical significance. Additionally, the difference in the WC and metabolic profile between the studied groups after 3 years of treatment also revealed no significance. However, BMI presented a significant difference between the two hormonal regimens after 3 years of treatment (p-value=0.007), with higher differences in the OCP treatment group.  Conclusion: There was no statistically significant difference in FBG between the beginning and at the third year of treatment found in both regimens of hormonal treatment in Thai PCOS women

Functional genetic polymorphisms and female reproductive disorders: Part I: polycystic ovary syndrome and ovarian response

BACKGROUNDThe identification of polymorphisms associated with a disease can help to elucidate its pathogenesis, and this knowledge can be used to improve prognosis for women with a particular disorder, such as polycystic ovary syndrome (PCOS). Since an altered response to ovarian stimulation is also a characteristic of the disease, further knowledge about its aetiology could help in defining the parameters that determine the response of an individual to ovarian stimulation.METHODSPubMed and EMBASE databases were systematically searched for gene association studies published until the end of August 2007, using search criteria relevant to PCOS and ovarian response to stimulation. Data from additional papers identified through hand searches were also included; 139 publications were reviewed.RESULTSSeveral genes involved in ovarian function and metabolism are associated with increased susceptibility to PCOS, but none is strong enough to correlate alone with susceptibility to the disease, or response to therapy. A single-nucleotide polymorphism in exon 10 of the FSH receptor (FSHR) gene, FSHR p.N680S, was consistently identified as having a significant association with ovarian response to FSH.CONCLUSIONSNo consistent association between gene polymorphism and PCOS could be identified. The FSHR gene may play a significant role in the success of ovarian stimulation, and can be used as a marker to predict differences in FSHR function and ovarian response to FSH. Genotyping the FSHR p.N680S polymorphism may provide a means of identifying a population of poor responders before in vitro fertilization procedures are initiated