A Comparison of the Changes in Gestational Weight, Body Mass Index, and Serum Vitamin D Level in Gestational Diabetes Mellitus Patients Complemented with Vitamin D in Contrast to Those Who Did Not Receive the Supplement: A Protocol for Systematic Review and Meta-Analysis of Randomised Controlled Trials

J Turkish German Gynecol Assoc

Saha²

2020

Self Cite

The aim of this study was to study the role of vitamin D containing supplements in the risk of cesarean section (CS), a common complication in gestational diabetes mellitus (GDM) patients. An additional objective was to assess the risk of developing pre-eclampsia, preterm delivery, macrosomia, and polyhydramnios in these participants. Various electronic databases were searched for double-blinded parallel-arm randomized controlled trials that reported the incidence of CS in adult, non-insulin treated GDM patients who received vitamin D and placebo in different treatment arms, respectively. Next, each eligible trial’s risk of bias was assessed, and the effects of the above interventions on the respective outcomes were compared meta-analytically across the trials. This review included five Iranian trials sourcing data from nearly 380 participants. The risk of bias in the trials was primarily low. In contrast to the placebo group, the risk of CS [risk ratio (RR): 0.61, p=0.002, 95% confidence interval (CI): 0.44,0.83; I 2 =0%, p-value of Cochrane’s Q: 0.373) and macrosomia (RR: 0.31, p=0.006, 95% CI: 0.13,0.72; I 2 =0%, p-value of Cochrane’s Q: 0.935] was less in the vitamin D supplemented group. The remaining outcomes did not differ between the intervention groups. The antenatal use of vitamin D containing supplements in non-insulin treated GDM patients might reduce the risk of CS and macrosomia.

“…Vitamin D is a fat-soluble hormone ( 32 ). It is available from diet and supplements in two physiologically inactive forms - D2 (ergocalciferol) and D3 (cholecalciferol) ( 33 , 34 ).…”

Section: The Interventionmentioning

confidence: 99%

A comparison of the risk of cesarean section in gestational diabetes mellitus patients supplemented antenatally with vitamin D containing supplements versus placebo: A systematic review and meta-analysis of double-blinded randomized controlled trials

J Turkish German Gynecol Assoc

Saha²

2020

Self Cite

“…Likewise, the chances of bias can be judged for continuous outcomes, for example; in systematic review articles intending to judge RCTs that tested the changes in gestational weight or body mass index in prenatal vitamin D receiving GDM patients [4]. The influence of missingness of such outcomes increases with the proportion of missing data in these trials [1].…”

Section: Dear Editormentioning

confidence: 99%

Impact of missingness on clinical trials on the effectiveness of antenatal vitamin D supplementation in gestational diabetes mellitus patients

2020

jidhealth

Self Cite

Gestational diabetes mellitus (GDM) is a vital medical complication of pregnancy in which glucose intolerance is first detected or develops during gestation. GDM is associated with adverse maternal and neonatal outcomes, and contemporarily, several clinical trials have tested their incidence in antenatal vitamin D receiving GDM patients. Considering their clinical significance, these trials' findings pertaining to the above outcomes require cautious interpretation, in terms of the risk of bias due to missingness. Any such bias in randomized controlled trials (RCT) can contaminate the results of a meta-analysis that extracts data from these RCTs.

“…Vitamin D is a fat-soluble hormone, available from diet and supplements in two inactive forms: D2 (ergocalciferol) and D3 (cholecalciferol). [22][23][24] The D3 form is additionally produced in the skin on exposure to the sun. [22,23] Upon hydroxylation of pre-vitamin D in the liver, the main circulatory form of vitamin D (bound to albumin or in a free state), 25hydroxyvitamin D (25(OH)D) is produced.…”

Section: Intervention Descriptionmentioning

confidence: 99%

“…[13,32–34] Besides, a protocol for systematic review and meta-analysis exists that intends to determine how the intervention might influence the various maternal health parameters like body mass index, gestational weight, and 25(OH)D levels. [24] However, best known to this author, the risk of attrition in these trials has not been systematically explored. Therefore, to study this poorly explored area of the GDM literature, this systematic review protocol is proposed here.…”

Section: Introductionmentioning

confidence: 99%

A systematic review and meta-analysis protocol to compare the risk of attrition among prenatal vitamin D supplemented gestational diabetes mellitus patients with its non-recipients

2020

Preprint

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Aim: Recently, several clinical trials have tested the effect of prenatal vitamin D supplementation in gestational diabetes mellitus (GDM) patients and their newborns. However, their participant attrition, an important determinant of the internal validity, remains poorly explored. Therefore, this review protocol is proposed, which aims to compare it between prenatal vitamin D supplemented and not supplemented GDM patients. Method: Randomized clinical trials studying the above will be searched mainly in different electronic databases. It will search for the English language articles irrespective of publication date. Data concerning the reviewed trials design, population, interventions, and outcome of interest will be extracted. Subsequently, their risk of bias will be assessed. Outcome data between the interventions will be juxtaposed meta-analytically to estimate the risk ratio. Next, the statistical heterogeneity (by Chi2 and I2 statistics) and publication bias (using funnel plot and Eggers test) among the trials will be evaluated. Subgroup analysis will follow if the heterogeneity is high. Finally, a sensitivity analysis will iterate the meta-analysis using an alternative model and by eliminating a trial every time. Statistical significance will be determined at p<0.05 and 95% CI. All analyses will be done in Stata. If a meta-analysis is not possible, a narrative reporting will ensue. Results: The review will follow the PRISMA reporting guideline. Any statistically significant findings evidence quality will be graded by the GRADE approach. Conclusion: The proposed review will compare the risk of loss to follow up among GDM patients complemented and not complemented with prenatal vitamin D.