Prevalence of hypovitaminosis D, and its association with hypoadiponectinemia and hyperfollistatinemia, in Saudi women with naïve polycystic ovary syndrome

A systematic review and meta-analysis of the association between vitamin D and ovarian reserve

It is hypothesized that vitamin D deficiency could be related to ovarian reserve. This systematic review and meta-analysis was undertaken to analyze the possible association between vitamin D and ovarian reserve among adolescent and adult women. All eligible studies identified through the ISI Web of Science, PubMed, and Scopus were included up to May 2021. A random-effects meta-analysis model was implemented and a weighted mean difference (WMD) and 95% confidence interval (CI) were calculated. A total of 38 papers covering 8608 individuals were enrolled in this systematic review and meta-analysis. Antral follicle count (AFC) was significantly lower among Asians (WMD - 0.65; 95% CI - 1.28 to - 0.01; P = 0.04; I2 = 0.0%) and luteinizing hormone (LH) levels were higher in non-Asians (WMD 2.16 IU/L; 95% CI 0.20 to 4.12; P = 0.031; I2 = 9.3%) with vitamin D insufficiency/deficiency. Also, there was a negative correlation between vitamin D and LH/FSH ratio in women with normal body mass index (BMI) (Fisher's Z: - 0.18; 95% CI - 0.37 to - 0.008; P = 0.041; I2 = 51.5%). Although there were no significant associations between serum vitamin D levels and any of the intended ovarian reserve markers, subgroup analyses have found significant findings regarding AFC, LH, and LH/FSH ratio. In order to understand the underlying mechanisms of vitamin D in female reproduction, further attempts are needed.

Low Vitamin D Level in Saudi Women With Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age. In this study, serum 25-hydroxyvitamin D levels were compared between women with and without PCOS and with regard to anthropometric indices and lipid and glucose biomarkers. Thirty-one women with PCOS and 75 controls answered a questionnaire on vitamin D, in addition to general health and lifestyle. The patients with PCOS had lower vitamin D levels (p < 0.05), a significantly higher rate of obesity (p < 0.05), and significantly higher serum triglyceride levels than did controls. The number of patients with PCOS consumed milk and dairy products (p < 0.05) and exposed to sun (p < 0.006) were lower compared to controls. Triglyceride levels were significantly correlated with body mass index (BMI); vitamin D level was not significantly correlated with anthropometrical or biochemical variables. These results affirm that vitamin D levels are lower in women with PCOS; however, despite the significantly higher proportion of obesity among patients with PCOS, hypovitaminosis was not associated with BMI. The relationship between body composition and vitamin D in PCOS and the effect of vitamin D correction on metabolic and hormonal parameters associated with PCOS must be assessed in future trials.

Circulating resistin and follistatin levels in obese and non-obese women with polycystic ovary syndrome: A systematic review and meta-analysis

This meta-analysis was performed to resolve the inconsistencies regarding resistin and follistatin levels in women with polycystic ovary syndrome (PCOS) by pooling the available evidence. A systematic literature search using PubMed and Scopus was carried out through November 2020 to obtain all pertinent studies. Weighted mean differences (WMDs) with corresponding 95% confidence intervals (CIs) were calculated to evaluate the strength of the association between the levels of resistin and follistatin with PCOS in the overall and stratified analysis by obesity status. A total of 47 publications, 38 for resistin (2424 cases; 1906 controls) and 9 studies for follistatin (815 cases; 328 controls), were included in the meta-analysis. Resistin levels were significantly higher in PCOS women compared with non-PCOS controls (WMD = 1.96 ng/ml; 95%CI = 1.25–2.67, P≤0.001) as well as in obese PCOS women vs. obese controls, and in non-obese PCOS women compared with non-obese controls, but not in obese PCOS vs. non-obese PCOS patients,. A significantly increased circulating follistatin was found in PCOS patients compared with the controls (WMD = 0.44 ng/ml; 95%CI = 0.30–0.58, P≤0.001) and in non-obese PCOS women compared with non-obese controls and in obese PCOS women vs. obese controls, but, no significant difference in follistatin level was observed in obese PCOS compared with non-obese PCOS women. Significant heterogeneity and publication bias was evident for some analyses. Circulating levels of resistin and follistatin, independent of obesity status, are higher in women with PCOS compared with controls, showing that these adipokines may contribute to the pathology of PCOS.

Adverse Effects of Selected Markers on the Metabolic and Endocrine Profiles of Obese Women With and Without PCOS

The aim of the present study, is to investigate the influence of obesity, with and without polycystic ovarian syndrome (PCOS), on the levels of kisspeptin, vitamin D (Vit D), and vascular endothelial growth factor (VEGF) and to explore the relationship between these parameters and endocrine and metabolic variables. The study group included 126 obese Saudi females. Of these 63 were suffering from PCOS while the rest were normo-ovulatory obese women (non-PCOS obese). In the obese PCOS, VEGF was almost four times as high as in the non-PCOS obese, while kisspeptin and Vit D did not differ. A highly significant elevation was recorded in the waist/hip (WHR), cholesterol, LDL-C, fasting glucose, LH, LH/FSH ratio, estradiol (E2), and testosterone, while hip circumference, leptin, progesterone, and sex hormone binding globulin (SHBG) were lower in the obese PCOS subjects. BMI, HDL-C, ghrelin, insulin, and FSH levels did not differ significantly between the two groups. The obese PCOS had the same level of insulin resistance as the non-PCOS group, as judged by QUICK Index. Correlation studies showed a significant negative correlation between kisspeptin and glucose and LH levels, and a positive correlation with LH/FSH ratio in obese PCOS while in the non-PCOS obese, the kisspeptin correlated positively with glucose, and there was no correlation with LH or LH/FSH. VEGF negatively correlated with FSH and positively with LH/FSH ratio in the non-PCOS obese but this was lost in the obese PCOS. PCOS had no effect on the correlation between Vit D and all studied parameters. Multiple regression analysis showed triglyceride as predictor variable for kisspeptin as a dependent variable, while, leptin is a predictor variable for VEGF as a dependent variable. ROC studies showed the highest sensitivity and specificity for VEGF (AOC=1.00), followed by LH/FSH ratio (AOC=0.979). In conclusion, our study shows that PCOS results in significant elevation of VEGF in obese females, while kisspeptin and Vit D levels are not affected. It also leads to elevation in several of the lipid and hormonal abnormalities in the obese females. In addition, PCOS influences relationship between Kisspeptin and VEGF and some parameters such as glucose, LH or FSH and LH/FSH ratio in obese females, but does not affect Vit D relationship with other parameter.