Hyperhomocysteinemia, insulin resistance and body mass index in Iranian young women with polycystic ovary syndrome

Homocysteine, vitamin B12, and folate circulating levels in women with and without polycystic ovary syndrome: A systematic review and meta-analysis

BACKGROUND

Some studies have reported that homocysteine, vitamin B12, and folic acid levels are associated with polycystic ovary syndrome (PCOS), whereas other studies yielded controversial results.

OBJECTIVES

This study aimed to systematize the available evidence of homocysteine, vitamin B12, and folate levels in women with and without PCOS.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES AND METHODS

A systematic search without language restrictions was performed on PubMed, Ovid/Medline, Scopus, Embase, and Web of Science. In addition, the reference lists of the selected studies were reviewed. The Newcastle-Ottawa Scale was employed to evaluate the quality of studies. The means and standard deviations of the outcomes were pooled as standardized mean differences (SMDs) with 95% confidence intervals (CI). Furthermore, the DerSimonian and Laird method was employed for the quantitative synthesis.

RESULTS

A total of 75 studies met the eligibility criteria for at least one outcome. Patients with PCOS had higher circulating homocysteine levels than those without (SMD: 0.82; 95% CI: 0.62-1.02, n = 70 studies, p < 0.001). This trend remained in the sensitivity and subgroup analyses by world regions of studies, assay methods, and insulin resistance. No significant differences were observed in circulating vitamin B12 (SMD: -0.11; 95% CI: -0.25 to 0.03; n = 17 studies, p = 0.13) and folate levels (SMD: -0.2; 95% CI: -0.68 to 0.27; n = 17 studies, p = 0.41) between patients with and without PCOS.

CONCLUSIONS

(i) Patients with PCOS exhibited significantly higher homocysteine levels than those without, and (ii) no significant differences were observed in both vitamin B12 and folate levels in women with and without PCOS.

REGISTRATION

PROSPERO ID (CRD42023432883).

B vitamins, polycystic ovary syndrome, and fertility

PURPOSE OF REVIEW

This review provides a general overview of the literature on B vitamins and fertility, as well as summarizes the evidence concerning B vitamin supplementation and fertility among polycystic ovary syndrome (PCOS) women.

RECENT FINDINGS

Studies among women conceiving with and without medical assistance provide strong evidence for a beneficial effect of B vitamins, particularly folate and vitamin B12, on fecundability and fertility. Moreover, recent work suggests that effects may be even more pronounced among women with menstrual cycle dysfunction (a common symptom of PCOS). Among PCOS women, intervention studies have demonstrated that folic acid supplementation may reduce homocysteine levels, potentially improve women's metabolic profiles, and possibly ameliorate some hallmark features of PCOS. Although none of these intervention studies have included fertility endpoints, it is possible that by reducing homocysteine levels (or other clinical/biochemical features) in PCOS women, there may be a downstream improvement in fertility outcomes.

SUMMARY

There is growing evidence folate (and possibly vitamin B12) supplementation may be beneficial to fertility in women. Although most studies have not exclusively focused on women with PCOS, there is biological plausibility and some evidence that B vitamin supplementation may be even more important for improving reproductive health outcomes in PCOS women.

Correlation of serum homocysteine levels and hyperinsulinaemia with body mass index in polycystic ovarian syndrome

Background:

Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies affecting women in reproductive age group. The interrelationship of serum homocysteine, homoeostatic assessment of insulin resistance (HOMA-IR) and body mass index amongst overweight, obese and non-obese PCOS patients is not fully established.

Aims:

We aimed to study the correlation of serum homocysteine levels and hyperinsulinaemia with body mass index (BMI) in PCOS patients.

Study Setting and Design:

This was a case–control study in which 35 women with PCOS and 35 non-PCOS women acting as controls were enrolled.

Materials and Methods:

Cases were identified by Rotterdam's criteria. (IR) indices, HOMA determination and serum homocysteine levels were determined and their correlation with BMI was studied.

Statistical Analysis Used:

Student's t-test and analysis of variance test were used for statistical analysis. The Pearson correlation coefficient was then used to estimate the correlation.

Results:

On overall evaluation, a significant positive correlation of fasting insulin, HOMA-IR and serum homocysteine) was observed (P < 0.05), however, on evaluating the correlation of these markers independently in cases and controls, only fasting insulin and HOMA-IR showed a significant correlation. In a multivariate model where PCOS was considered a dependent variable with age, fasting glucose, HOMA-IR, serum homocysteine and body mass index as the independent variables, only serum homocysteine levels were found to be significantly associated with the dependent variable (odds ratio = 1.172; 95% confidence interval = 1.032–1.330).

Conclusion:

PCOS women had significantly higher mean fasting glucose, fasting insulin, HOMA-IR and homocysteine levels as compared to non-PCOS controls. Mean HOMA-IR, homocysteine and fasting insulin levels showed a significant incremental trend with increasing BMI category in overall evaluation as well as in cases and controls independently.

Association between homocysteine and obesity: A meta-analysis

According to previous studies of obesity, we found that the association between homocysteine concentrations and obesity was reported controversially. Thus, we carried out this meta-analysis to investigate this association. We searched PubMed, The Cochrane library, and EMBASE database for studies that evaluate the relationship between homocysteine concentrations and obesity from inception to March, 2019. The quality of all included studies was assessed by the Newcastle Ottawa Scale (NOS) and the Agency for Healthcare Research Quality (AHRQ). The RevMan5.3 software and Stata12.0 software were used for conducting all data analyses. Standardized mean differences (SMD) with the corresponding 95% confidence intervals (95% CIs) were used as a measure of effect size to assess the relationship between homocysteine concentrations and obesity through a meta-analysis. The level of significance was set at P < .05. A total of 14 studies were ultimately included in our meta-analysis. Meta-analysis of the 14 studies found remarkable lower homocysteine concentrations in controls than in obese patients (SMD = 0.76, 95% CI = 0.25-1.27, P < .01; I²  = 94% and P < .01 for heterogeneity), regardless of nutritional status, dietary habit, insulin resistance (IR) status, special disease history, history of medicine taken, genetic background, and so on. Homocysteine concentrations in nonobese patients with polycystic ovarian syndrome (PCOS) were lower than obese patients with PCOS (SMD = 0.48, 95% CI = 0.20-0.77, P < .01; I²  = 39% and P = .18 for heterogeneity). The result of our meta-analysis showed that homocysteine concentrations were significantly elevated among obese patients.

Vitamin D3 prevents cardiovascular diseases by lowering serum total homocysteine concentrations in overweight reproductive women: A randomized, placebo-controlled clinical trial

Obesity and overweight are associated with vitamin D deficiency and hyperhomocysteinemia, all of which are contributing factors for developing cardiovascular disease (CVD). Therefore, we hypothesized that improving serum 25-hydroxyvitamin D [25(OH)D] levels may decrease the body weight and total homocysteine concentrations among overweight reproductive women. To test our hypothesis, a randomized, double-blind placebo-controlled clinical trial, registered under ClinicalTrials.gov Identifier No. NCT03310307, was conducted on 100 overweight reproductive women that were allocated into two groups, namely, the treatment group (n = 50), which received 50 000 IU vitamin D₃ per week, and the placebo group (n = 50), and followed for 2 months. Participants' 25(OH)D, homocysteine, parathyroid hormone, calcium, phosphorus, body weight and body mass index (BMI) were measured and compared before and after treatment. The results showed that there was a significant decrease in homocysteine levels after the first and second months of vitamin D₃ intervention in the treatment group, and no significant changes were seen in the placebo group throughout the period of follow up. Statistically significant (P ≤ .05) reductions in homocysteine concentration, body weight, BMI, and parathyroid hormone levels were noticed in the treatment group compared to the placebo. Meanwhile, 25(OH)D, calcium and phosphorus levels were statistically significantly (P ≤ .05) increased in the treatment group. In conclusion, vitamin D₃ intervention with a treatment dose of 50 000 IU per week for at least 2 months can help decrease BMI and homocysteine levels, which in turn will help prevent or minimize the risk of CVD among overweight women of reproductive age.