Vitamin D deficiency in pregnancy is not associated with diabetes mellitus development in pregnant women at low risk for gestational diabetes

Impact of Vitamin D Deficiency on Gestational Diabetes and Pregnancy Outcomes Across Diverse Ethnic Groups: A Retrospective Cohort Study

Background: Vitamin D deficiency is linked to adverse pregnancy outcomes like gestational diabetes mellitus (GDM), but its effects across ethnic groups are unclear. This study examines the relationship among vitamin D levels, glucose tolerance, GDM prevalence, and neonatal outcomes in a multi-ethnic cohort of pregnant women. Methods: We conducted a retrospective analysis of 252 pregnant women from antenatal clinics between 2018 and 2022. Participants were divided into four groups based on serum vitamin D levels: severely deficient (<25 nmol/L), deficient (25-50 nmol/L), insufficient (51-75 nmol/L), and sufficient (>75 nmol/L). The analysis included multivariate linear regression models adjusted for age, ethnicity, BMI, gestational diabetes status, and seasonality. An area under the receiver operating characteristic (AUROC) analysis identified the vitamin D threshold linked to an increased GDM risk. Results: Women classified as severely deficient had higher fasting glucose levels (5.73 ± 1.24 mmol/L) than those in other groups (p = 0.003, adjusted). The AUROC analysis identified a vitamin D threshold of 45 nmol/L associated with an elevated GDM risk (AUROC = 0.78, CI: 0.70-0.85). South Asian women had lower vitamin D levels (41.17 ± 18.03 nmol/L vs. 45.15 ± 16.75 nmol/L) and higher glucose tolerance test (GTT) levels than Caucasian women, despite having lower BMIs. Moreover, vitamin D levels positively correlated with neonatal birth weight (p = 0.02). Conclusions: There is a strong link between vitamin D deficiency and increased GDM risk, especially among South Asian women. These findings underscore the need for targeted interventions to improve vitamin D levels in high-risk ethnic groups.

Insulin resistance unraveled: Hormonal correlations in gestational diabetes

Background

To investigate the correlation between the variations of cortisol and insulin-like growth factor 1 (IGF1) and sex hormone binding globulin (SHBG) levels with insulin resistance and glucolipid metabolism in gestational glucose diabetics.

Methods

The study included 110 pregnant women diagnosed with gestational diabetes mellitus in the GDM group, and 130 healthy pregnant women in the control group. Data collection, examination of relevant indexes, and comparison of differences in indexes between groups were conducted. Pearson correlation analysis was utilized to identify risk variables associated with GDM development, while binary logistic regression was employed to determine risk factors for GDM development.

Results

The GDM group showed significantly greater levels of FPG, HbA1c, FINS, TG, FFA, Lp-PLA2, HOMA-IR, Cortisol, and IGF-1 compared to the control group (P<0.05), but considerably lower levels of SHBG, and HOMA-β. HOMA-IR was found to be positively correlated with FPG, HbA1c, FINS, TG, FFA, Lp-PLA2, Cortisol and IGF-1, whereas, negatively correlated with SHBG. FINS and SHBG were found to be independent protective factors for GDM (OR=0.463, 0.801, P<0.05), whereas, HbA1c, TG, FFA, and gestational BMI were found to be independent risk factors for GDM (OR=1.992, 4.234, 1.990, 1.629, P<0.05).

Conclusions

SHBG, IGF-1, and Cortisol are all linked to glucose-lipid metabolism indices, and aberrant serum hormone expression is a major contributor to insulin resistance.

Vitamin D Deficiency During the First Trimester of Pregnancy and the Risk of Developing Gestational Diabetes Mellitus

OBJECTIVE

To investigate the relationships among various factors that affect serum vitamin D levels and vitamin D in the first trimester and the risk of developing gestational diabetes mellitus (GDM).

DESIGN

A prospective cohort design.

SETTING

The family health center of Ankara, Turkey.

PARTICIPANTS

Out of 889 pregnant women who participated in the study in the first trimester (6-13 weeks gestation), 814 participated in GDM screening in the second trimester (24-28 weeks gestation).

METHODS

We determined serum vitamin D levels, demographic data, various biochemical and anthropometric parameters, and factors that affect vitamin D synthesis of participants in the first trimester and used logistic regression analysis to analyze the effects of the associations among vitamin D deficiency and the other variables on the occurrence of GDM.

RESULTS

Vitamin D deficiency in the first trimester was present in 425 (82.5%) participants. In the second trimester, 198 participants (24.3%) were diagnosed with GDM through oral glucose tolerance test screening. We detected GDM in the second trimester in 5.7% of participants who had vitamin D deficiency in the first trimester. Even after adjustment for vitamin D intake, clothing style, and duration of exposure to the sun, the risk of GDM was significantly greater in participants who were vitamin D deficient than those who were not deficient. The risk of GDM among women with vitamin D deficiency was sustained or increased significantly after we adjusted for age, parity, prepregnancy body mass index, history of diabetes, triglyceride levels, vitamin D intake, clothing style, and length of sun exposure, OR = 10.60, p < .001, 95% confidence interval [2.82, 39.76].

CONCLUSIONS

Our results suggest that vitamin D deficiency in the first trimester may significantly increase the risk of developing GDM.

Sufficience serum vitamin D before 20 weeks of pregnancy reduces the risk of gestational diabetes mellitus

Objective

Our aim was to evaluate the relationship between serum vitamin D levels before 20 weeks of pregnancy and the risk of gestational diabetes mellitus.

Methods

This study is a retrospective study. We analyzed the relationship between serum 25 (OH) D level before 20 weeks of pregnancy (first antenatal examination) and the risk of gestational diabetes mellitus. Age, parity and pre-pregnancy body mass index were used as confounding factors. 8468 pregnant women were enrolled in this study between January 2018 and March 2020 at the Obstetrics and Gynecology Hospital of Fudan University. Adjusted smoothing splinespline plots, subgroup analysis and multivariate logistic regression analysis was conducted to estimate the relative risk between 25(OH)D and gestational diabetes mellitus.

Results

After fully adjusting the confounding factors, serum vitamin D is a protective factor in gestational diabetes mellitus (OR = 0.90). Compared with vitamin D deficiency, vitamin D insufficiency (OR = 0.78), sufficience (OR = 0.82) are a protective factor for gestational diabetes mellitus.

Conclusion

Sufficience vitamin D before 20 weeks of pregnancy is a protective factor for gestational diabetes mellitus. Vitamin D > 20 ng/mL can reduce the risk of GDM, which is not much different from the effect of > 30 ng/mL. The protective effect of vitamin D is more significant in obese pregnant women.

Evaluation of the efficacy of two doses of vitamin D supplementation on glycemic, lipidemic and oxidative stress biomarkers during pregnancy: a randomized clinical trial

BACKGROUND

Vitamin D deficiency during pregnancy is common and is likely to be associated with metabolic complications in the mother. The aim of this study was to assess the efficacy of two doses of vitamin D supplementation during pregnancy on maternal and cord blood vitamin D status and metabolic and oxidative stress biomarkers.

METHODS

The eligible pregnant women (n = 84) invited to participate in the study and randomly allocated to one of the two supplementation groups (1000 IU/d vitamin D and 2000 IU/d). Biochemical assessments of mothers including serum concentrations of 25(OH)D, calcium, phosphate, iPTH, fasting serum sugar (FBS), insulin, triglyceride, total cholesterol, LDL-C, HDL-C, malondialdehyde (MDA) and total antioxidant capacity (TAC) were done at the beginning and 34 weeks of gestation. Cord blood serum concentrations of 25(OH)D, iPTH, MDA and TAC were assessed at delivery as well. To determine the effects of vitamin D supplementation on metabolic markers 1-factor repeated-measures analysis of variance (ANOVA) was used. Between groups comparisons was done by using Independent-samples Student's t-test or Mann-Whitney test. P < 0.05 was considered as significant.

RESULTS

Supplementation with 1000 IU/d and 2000 IU/d vitamin D resulted in significant changes in vitamin D status over pregnancy (24.01 ± 21.7, P < 0.001 in 1000 IU/d group and 46.7 ± 30.6 nmol/L, P < 0.001 in 2000 IU/d group). Daily intake of 2000 compared with 1000 IU/d tended to increase the serum concentration of HDL-C (10 ± 8.37, P < 0.001 in 1000 IU/d group and 9.52 ± 11.39 mg/dL, P < 0.001 in 2000 IU/d group). A significant decrement in serum concentration of iPTH observed in both groups (- 4.18 ± 7.5, P = 0.002 in 1000 IU/d group and - 8.36 ± 14.17, P = 0.002 in 2000 IU/d group).

CONCLUSIONS

Supplementation with 2000 IU/d vitamin D as compared with 1000 IU/d, is more effective in promoting vitamin D status and HDL-C serum concentration and in decreasing iPTH over pregnancy.

TRIAL REGISTRATION

This trial is registered at clinicaltrials.gov ( NCT03308487 ). Registered 12 October 2017 'retrospectively registered'.

Relationship between vitamin D status in the first trimester of pregnancy and gestational diabetes mellitus - A nested case-control study

BACKGROUND & AIMS

Gestational diabetes mellitus (GDM) is one of the most frequent medical complications during pregnancy. It has been associated with many adverse pregnancy, fetal and neonatal outcomes, as well as with an increased risk for mothers and children in the long term. There is a growing interest in vitamin D and its potential role in the development of metabolic disorders. However, the medical literature is not consensual. The aim of this study was to assess the risk of GDM according to vitamin D status during the first trimester.

METHODS

This study is a nested case-control study performed from a multicenter prospective observational cohort of pregnant women assessed for 25-hydroxyvitamin D levels (25OHD). Three hundred ninety-three patients were included in the initial cohort. After applying exclusion criteria, a total of 1191 pregnant women were included. Two hundred fifty women with GDM (cases) were matched to 941 women without GDM (controls) for parity, age, body mass index before pregnancy, the season of conception, and phototype. This study was funded by a grant from the "Programme Hospitalier de Recherche Publique 2010".

RESULTS

The GDM risk was significantly greater for patients with 25OHD levels <20 ng/mL (OR = 1∙42, 95% CI 1∙06-1∙91; p = 0∙021). However, there was no significant relationship with other thresholds. The study of 25OHD levels with the more precise cutting of 5 units intervals showed a variable relationship with GDM risk, as the risk was low for very low 25OHD levels, increased for moderated levels, decreased for normal levels, and finally increased for higher levels.

CONCLUSION

According to our study, there seems to be no linear relationship between GDM and 25OHD levels in the first trimester of pregnancy since GDM risk does not continuously decrease as 25OHD concentrations increase. Our results most probably highlight the absence of an association between 25OHD levels and GDM risk.

Vitamin D status during pregnancy and the risk of gestational diabetes mellitus: A longitudinal study in a multiracial cohort

AIM

To prospectively and longitudinally investigate vitamin D status during early to mid-pregnancy in relation to gestational diabetes mellitus (GDM) risk.

METHODS

In a nested case-control study of 107 GDM cases and 214 controls within the Fetal Growth Studies-Singleton Cohort, plasma levels of 25-hydroxyvitamin D2 and D3 (25(OH)D) and vitamin D binding protein were measured at gestational weeks 10 to 14, 15 to 26, 23 to 31, and 33 to 39; we further calculated total, free, and bioavailable 25(OH)D. Conditional logistic regression models and linear mixed-effects models were used.

RESULTS

We observed a threshold effect for the relation of vitamin D biomarkers with GDM risk. Vitamin D deficiency (<50 nmol/L) at 10 to 14 gestational weeks was associated with a 2.82-fold increased risk for GDM [odds ratio (OR) = 2.82, 95% confidence interval (CI): 1.15-6.93]. Women with persistent vitamin D deficiency at 10 to 14 and 15 to 26 weeks of gestation had a 4.46-fold elevated risk for GDM compared with women persistently non-deficient (OR = 4.46, 95% CI: 1.15-17.3).

CONCLUSIONS

Maternal vitamin D deficiency as early as the first trimester of pregnancy was associated with an elevated risk of GDM. The association was stronger for women who were persistently deficient through the second trimester. Assessment of vitamin D status in early pregnancy may be clinically important and valuable for improving risk stratification and developing effective interventions for the primary prevention of GDM.

The prevalence and risk factors of gestational diabetes mellitus in Turkey: a systematic review and meta-analysis

OBJECTIVE

To identify the prevalence and related risk factors of gestational diabetes mellitus (GDM) based on studies on the condition conducted in Turkey.

METHODS

The study is a systematic review and meta-analysis and was conducted over the period November-December 2017 by performing a search of the Turkish and English literature. The international databases were accessed using the keywords "gestational diabetes" and "Turkey" and the national databases were scanned using the word groups, "gestational diabetes", "diabetes in pregnancy", "pregnancy and diabetes," and "pregnancy diabetes". Forty-one complete articles on research carried out in Turkey over the period 2004-2016 and published in 2006-2018 on the prevalence of GDM and/or a reported risk factor were included in the study. Combined percentage calculations were employed to determine GDM prevalence.

RESULTS

It was found in this systematic review and meta-analysis of the studies examined that out of the total of 50,767 pregnant women included in the studies, 3891 had GDM. Based on these data, combined GDM prevalence was calculated as 7.7% (range: 1.9-27.9%). It was observed that the highest combined GDM prevalence was 17.6% in the black Sea Region and the lowest was 5.1% in the Central Anatolian Region. Fourteen risk factors had been reported as statistically significant in the studies included in the systematic review. The most commonly reported of these was advanced maternal age, being overweight prior to pregnancy, gaining weight in pregnancy, diabetes in the family, a history of GDM or giving birth to a large baby.

CONCLUSIONS

It was observed in this meta-analysis that the prevalence of GDM in Turkey is notably high and risk factors are similar to what has been reported in current international literature. The continuation of routine screening tests to detect GDM may contribute to controlling the condition while ensuring that risk groups take special preventive measures and mother-child health is protected.

IMPLICATIONS FOR PRACTICE

Results of this study might be used in the organization of prenatal care, especially high-risk pregnant women for GDM. Nursing researchers and health care managers should consider this situation in the implementing of prenatal care serving.