1.
Systematic review and meta-analysis of candidate gene association studies of benign prostate hyperplasia.
Lin, L, Li, P, Liu, X, Xie, X, Liu, L, Singh, AK, Singh, HN
Systematic reviews. 2022;11(1):60
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Benign prostatic hyperplasia (BPH) is a non-malignant enlargement of the prostate which can cause urinary dysfunction and may affect the quality of life of patients. Polymorphism in several genes has been linked to the high susceptibility of BPH. The aim of this study was to analyse genetic variations in important genes towards the susceptibility of BPH. This study is a systematic review and meta-analysis of twenty-three case-control studies (11 for CYP17 [gene], 10 for VDR - vitamin D receptor [a member of the steroid/ thyroid hormone receptor family] and 4 for ACE - angiotensin-converting enzyme [component of the renin–angiotensin system] polymorphisms). The sample size in each study ranged from 20 to 588 participants. Results show that genetic polymorphism in the ACE gene was significantly associated with the risk of BPH when compared with control subjects. Whereas there was a negative association for the polymorphism located in VDR and CYP17 genes with the risk of BPH. Authors conclude that larger studies with prospective data and larger sample sizes are required.
Abstract
BACKGROUND Benign prostate hyperplasia (BPH) is the most common urological problem in elderly males. Recent studies have reported polymorphism in various metabolic genes in BPH. However, their association with the susceptibility of BPH is still inconsistent. Here, we systematically reviewed and performed a meta-analysis of CYP17, VDR, and ACE genes to determine their precise association with the risk of BPH. METHODS A comprehensive literature search for published studies on candidate gene associations involving vitamin D receptor (VDR), angiotensin-converting enzyme (ACE), and CYP17 genes with the risk of BPH was done up to April 2020 in PubMed, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar databases. Fixed/random effects models were used to estimate the odd's ratio (OR) and 95% confidence intervals (CIs). Begg's funnel plot was used to assess the potential for publication bias. RESULTS We found a total of 23 studies containing 3461 cases and 3833 controls for these gene polymorphisms. A significant association of ACE gene polymorphism was observed under the recessive (II vs. ID + DD) model for BPH susceptibility compared to control subjects (overall OR = 1.67, 95% CI = 1.03-2.73). Similar trends were observed for ACE gene polymorphism in Caucasian (OR = 6.18, 95% CI = 1.38-27.68) and Asian (OR = 1.42, 95% CI = 0.99-2.03) populations under study. No significant association was observed in VDR and CYP17 gene polymorphisms in any dominant or recessive models. CONCLUSION Significant OR demonstrated the implication of ACE gene polymorphism in the proliferation of prostate tissue, which in turn is associated with BPH susceptibility. However, prospective studies at large scale and sample size are needed to confirm the current findings.
2.
Vitamin D and miscarriage: a systematic review and meta-analysis.
Tamblyn, JA, Pilarski, NSP, Markland, AD, Marson, EJ, Devall, A, Hewison, M, Morris, RK, Coomarasamy, A
Fertility and sterility. 2022;118(1):111-122
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Miscarriage causes significant physical and psychological harm. Vitamin D deficiency (low serum levels of 25- hydroxyvitamin D) is a major global health concern, with pregnant women and those planning pregnancy at increased risk. The aim of this study was to evaluate the association between vitamin D status and pregnancy loss, including spontaneous miscarriage and recurrent miscarriage. This study is a systematic review and meta-analysis of ten studies (6 where observational studies and 4 interventional studies). Results show that women who were vitamin D deficient were at significantly increased risk of miscarriage compared with those who were vitamin D replete. This association was maintained when women with insufficient levels were included, with a biologic gradient evident. Authors conclude that new evidence-based interventions are required for women at risk of miscarriage.
Abstract
OBJECTIVE To investigate whether a significant association between vitamin D status and the risk of miscarriage or recurrent miscarriage (RM) exists. DESIGN Systematic review and meta-analysis. SETTING Not applicable. PATIENT(S): Women with miscarriage and RM. INTERVENTION(S): We searched the Ovid MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature, and Cochrane Central Register of Controlled Trials from database inception to May 2021. Randomized and observational studies investigating the association between maternal vitamin D status and miscarriage and/or vitamin D treatment and miscarriage were included. MAIN OUTCOME MEASURE(S): The primary outcome was miscarriage or RM, with vitamin D status used as the predictor of risk. Whether vitamin D treatment reduces the risk of miscarriage and RM was also assessed. RESULT(S): Of 902 studies identified, 10 (n = 7,663 women) were included: 4 randomized controlled trials (n = 666 women) and 6 observational studies (n = 6,997 women). Women diagnosed with vitamin D deficiency (<50 nmol/L) had an increased risk of miscarriage compared with women who were vitamin D replete (>75 nmol/L) (odds ratio, 1.94; 95% confidence interval, 1.25-3.02; 4 studies; n = 3,674; I2 = 18%). Combined analysis, including women who were vitamin D insufficient (50-75 nmol/L) and deficient (<50 nmol/L) compared with women who were replete (>75 nmol/L), found an association with miscarriage (odds ratio, 1.60; 95% confidence interval, 1.11-2.30; 6 studies; n = 6,338; I2 = 35%). Although 4 randomized controlled trials assessed the effect of vitamin D treatment on miscarriage, study heterogeneity, data quality, and reporting bias precluded direct comparison and meta-analysis. The overall study quality was "low" or "very low" using the Grading of Recommendations, Assessment, Development and Evaluations approach. CONCLUSION(S): Vitamin D deficiency and insufficiency are associated with miscarriage. Whether preconception treatment of vitamin D deficiency protects against pregnancy loss in women at risk of miscarriage remains unknown. REGISTRATION NUMBER CRD42021259899.
3.
Vitamin D metabolites across the menstrual cycle: a systematic review.
Subramanian, A, Gernand, AD
BMC women's health. 2019;19(1):19
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Vitamin D deficiency is highly prevalent in women compared to men particularly at reproductive age. The Institute of Medicine defines vitamin D deficiency as having concentrations of 25-hydroxyvitamin D [25(OH)D] < 30 nmol/l and vitamin D insufficiency as 25(OH)D < 50 nmol/l. Furthermore, 25(OH)D is further metabolised in the kidneys to 1,25 dihydroxyvitamin D [1,25(OH)2D], the biologically active form of vitamin D. The aim of this study was to conduct a systematic review of studies that assessed concentrations of 25(OH)D and/or 1,25(OH)2D longitudinally to assess if these vitamin D biomarkers change across the normal menstrual cycle. This study is a systematic review of ten longitudinal studies. Results show conflicting data between studies. For example, 1,25(OH)2D concentrations increased across the menstrual cycle in a few studies but did not change in others. 25(OH)D concentrations changed across the cycle in one study but not others. This was due to the fact that only a few studies have examined vitamin D metabolites across the menstrual cycle, thus, there is limited to insufficient data to be able to understand potential changes or lack thereof. Authors conclude that future studies are needed to better understand 25(OH)D and 1,25(OH)2D in menstruating women. These studies should particularly focus on examining both metabolites (at minimum) at least two points across the menstrual cycle using the robust lab methods.
Abstract
BACKGROUND Accurate estimation of vitamin D status is important for health research and can impact prevention and treatment of deficiency in women of reproductive age. We aimed to assess if blood concentrations of 25-hydroxyvitamin D [25(OH)D] or 1,25-dihydroxyvitamin D [1,25(OH)2D] change across the menstrual cycle. METHODS We conducted a systematic search in PubMed, Web of Science, CAB and BIOSIS of literature published until December 2018 which reported concentrations of vitamin D metabolites at two or more identified points among women with regular menstrual cycles. RESULTS Ten longitudinal studies met the inclusion criteria; nine studies measured 1,25(OH)2D and five studies measured 25(OH)D. Study size ranged from 5 to 47 subjects, with an age range of 18-47 years. One study found a decrease in concentration of 25(OH)D in the periovulatory and luteal phase. Four studies found no changes in concentrations of 25(OH)D. Two studies found a rise in 1,25(OH)2D within the follicular phase, including a 128% increase from day 1 to 15 and a 56% increase from day 0 to 12. Two studies found rises in 1,25(OH)2D concentrations from the follicular to luteal phase of 13 and 26%. Five studies did not find any changes in concentrations of 1,25(OH)2D. CONCLUSIONS No conclusion can be drawn on the pattern of 1,25(OH)2D concentrations across the normal menstrual cycle due to inconsistencies in study findings. Evidence is currently insufficient to assess 25(OH)D concentrations across the cycle. Future studies should aim to measure 1,25(OH)2D and 25(OH)D longitudinally, to understand relationships with other hormones and the potential impact on estimates of vitamin D deficiency.