Inositol for the prevention of gestational diabetes: a systematic review and meta-analysis of randomized controlled trials

Inositol supplementation for the prevention and treatment of gestational diabetes mellitus: a meta-analysis of randomized controlled trials

BACKGROUND

Inositol is a potential new therapeutic agent for gestational diabetes mellitus (GDM), but its effectiveness is still controversial. The aim of the report was to evaluate the effectiveness of inositol to preventing or reducing the severity of GDM.

METHODS

We searched PubMed, EmBase, Web of science, Cochrane library databases, Clinicaltrials.gov, and International Clinical Trials Registry Platform for randomized controlled trials (RCTs) assessing the effectiveness of inositol supplementation to prevent and treat GDM. This meta-analysis was performed using the random-effects model.

RESULTS

A total of 7 RCTs (1319 pregnant women at high risk of GDM) were included in the meta-analysis. The meta-analysis found that inositol supplementation resulted in a significantly lower incidence of GDM in the inositol versus the control group (odds ratio [OR] 0.40; 95% confidence interval [CI] 0.24-0.67; P = 0.0005). The inositol group had improved fasting glucose oral glucose tolerance test (FG OGTT; mean difference [MD] = - 3.20; 95% CI - 4.45 to - 1.95; P < 0.00001), 1-h OGTT (MD = - 7.24; 95% CI - 12.23 to - 2.25; P = 0.004), and 2-h OGTT (MD = - 7.15; 95% CI - 12.86 to - 1.44; P = 0.01) results. Inositol also reduced the risk of pregnancy-induced hypertension (OR 0.37; 95% CI 0.18-0.75; P = 0.006) and preterm birth (OR 0.35; 95% CI 0.18-0.69; P = 0.003). A meta-analysis of 4 RCTs including 320 GDM patients showed that the patients' insulin resistance (P < 0.05) and neonatal hypoglycemia risk (OR 0.10, 95% CI 0.01-0.88; P = 0.04) were lower in the inositol than in the control group.

CONCLUSIONS

Inositol supplementation during pregnancy has the potential to prevent GDM, improve glycemic control, and reduce preterm birth rates.

Effective interventions in preventing gestational diabetes mellitus: A systematic review and meta-analysis

BACKGROUND

Lifestyle choices, metformin, and dietary supplements may prevent GDM, but the effect of intervention characteristics has not been identified. This review evaluated intervention characteristics to inform the implementation of GDM prevention interventions.

METHODS

Ovid, MEDLINE/PubMed, and EMBASE databases were searched. The Template for Intervention Description and Replication (TIDieR) framework was used to examine intervention characteristics (who, what, when, where, and how). Subgroup analysis was performed by intervention characteristics.

RESULTS

116 studies involving 40,940 participants are included. Group-based physical activity interventions (RR 0.66; 95% CI 0.46, 0.95) reduce the incidence of GDM compared with individual or mixed (individual and group) delivery format (subgroup p-value = 0.04). Physical activity interventions delivered at healthcare facilities reduce the risk of GDM (RR 0.59; 95% CI 0.49, 0.72) compared with home-based interventions (subgroup p-value = 0.03). No other intervention characteristics impact the effectiveness of all other interventions.

CONCLUSIONS

Dietary, physical activity, diet plus physical activity, metformin, and myoinositol interventions reduce the incidence of GDM compared with control interventions. Group and healthcare facility-based physical activity interventions show better effectiveness in preventing GDM than individual and community-based interventions. Other intervention characteristics (e.g. utilization of e-health) don't impact the effectiveness of lifestyle interventions, and thus, interventions may require consideration of the local context.

The Effectiveness of Myo-Inositol in Women With Polycystic Ovary Syndrome: A Prospective Clinical Study

Background Polycystic ovarian syndrome (PCOS) is a multifaceted complex endocrine disorder showing an alarming rise in women worldwide. Insulin resistance is the chief driving force in the pathogenesis of PCOS. Myo-inositol is an upcoming insulin-sensitizing agent, which is a second messenger responsible for insulin-mediated intracellular glucose transport. This study aims to evaluate the efficacy of myo-inositol and its clinical, hormonal, and metabolic profile in treating women with PCOS. Methodology A prospective clinical study was conducted over 18 months in the Department of Obstetrics and Gynecology at Sree Balaji Medical College and Hospital, Chennai, after obtaining permission from the Institutional Ethical Committee. A total of 90 women diagnosed with PCOS, according to Rotterdam's criteria, were included in the study. They received tablet myo-inositol 1 g BD for six months. Before the start of the therapy, detailed history and baseline investigations were recorded and subsequently re-assessed at the end of six months. Results Around 68% of patients restored menstrual cycle regularity. There was a statistically significant decrease in luteinizing hormone (LH) (10.31 ± 7.92 to 7.42 ± 6.25; p = 0.002), LH/follicle-stimulating hormone ratio (2.34 ± 0.34 to 1.91 ± 0.32; p = 0.000), fasting serum insulin levels (16.71 ± 13.92 to 13.18 ± 9.41; p = 0.041), and homeostatic model assessment for insulin resistance (4.52 ± 1.34 to 2.74 ± 1.28; p = 0.041). Conclusions According to our study, it was observed that myo-inositol led to a statistically significant improvement in the hormonal and metabolic profile of PCOS patients. Moreover, it is safe and has good compliance. Hence, we can justify the addition of myo-inositol to the armamentarium for PCOS management.

Impact of preconception and antenatal supplementation with myo-inositol, probiotics, and micronutrients on offspring BMI and weight gain over the first 2 years

BACKGROUND

Nutritional intervention preconception and throughout pregnancy has been proposed as an approach to promoting healthy postnatal weight gain in the offspring but few randomised trials have examined this.

METHODS

Measurements of weight and length were obtained at multiple time points from birth to 2 years among 576 offspring of women randomised to receive preconception and antenatally either a supplement containing myo-inositol, probiotics, and additional micronutrients (intervention) or a standard micronutrient supplement (control). We examined the influence on age- and sex-standardised BMI at 2 years (WHO standards, adjusting for study site, sex, maternal parity, smoking and pre-pregnancy BMI, and gestational age), together with the change in weight, length, BMI from birth, and weight gain trajectories using latent class growth analysis.

RESULTS

At 2 years, there was a trend towards lower mean BMI among intervention offspring (adjusted mean difference [aMD] - 0.14 SD [95% CI 0.30, 0.02], p = 0.09), and fewer had a BMI > 95th percentile (i.e. > 1.65 SD, 9.2% vs 18.0%, adjusted risk ratio [aRR] 0.51 [95% CI 0.31, 0.82], p = 0.006). Longitudinal data revealed that intervention offspring had a 24% reduced risk of experiencing rapid weight gain > 0.67 SD in the first year of life (21.9% vs 31.1%, aRR 0.76 [95% CI 0.58, 1.00], p = 0.047). The risk was likewise decreased for sustained weight gain > 1.34 SD in the first 2 years of life (7.7% vs 17.1%, aRR 0.55 [95% CI 0.34, 0.88], p = 0.014). From five weight gain trajectories identified, there were more intervention offspring in the "normal" weight gain trajectory characterised by stable weight SDS around 0 SD from birth to 2 years (38.8% vs 30.1%, RR 1.29 [95% CI 1.03, 1.62], p = 0.029).

CONCLUSIONS

Supplementation with myo-inositol, probiotics, and additional micronutrients preconception and in pregnancy reduced the incidence of rapid weight gain and obesity at 2 years among offspring. Previous reports suggest these effects will likely translate to health benefits, but longer-term follow-up is needed to evaluate this.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02509988 (Universal Trial Number U1111-1171-8056). Registered on 16 July 2015.

Myoinositols Prevent Gestational Diabetes Mellitus and Related Complications: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Although gestational diabetes mellitus (GDM) has several short- and long-term adverse effects on the mother and the offspring, no medicine is generally prescribed to prevent GDM. The present systematic review and meta-analysis aimed to investigate the effect of inositol supplementation in preventing GDM and related outcomes. Systematic search was performed in CENTRAL, MEDLINE, and Embase until 13 September 2023. Eligible randomized controlled trials (RCTs) compared the efficacy of inositols to placebo in pregnant women at high risk for GDM. Our primary outcome was the incidence of GDM, whereas secondary outcomes were oral glucose tolerance test (OGTT) and maternal and fetal complications. (PROSPERO registration number: CRD42021284939). Eight eligible RCTs were identified, including the data of 1795 patients. The incidence of GDM was halved by inositols compared to placebo (RR = 0.42, CI: 0.26-0.67). Fasting, 1-h, and 2-h OGTT glucose levels were significantly decreased by inositols. The stereoisomer myoinositol also reduced the risk of insulin need (RR = 0.29, CI: 0.13-0.68), preeclampsia or gestational hypertension (RR = 0.38, CI: 0.2-0.71), preterm birth (RR = 0.44, CI: 0.22-0.88), and neonatal hypoglycemia (RR = 0.12, CI: 0.03-0.55). Myoinositol decrease the incidence of GDM in pregnancies high-risk for GDM. Moreover, myoinositol supplementation reduces the risk of insulin need, preeclampsia or gestational hypertension, preterm birth, and neonatal hypoglycemia. Based on the present study 2-4 g myoinositol canbe suggested from the first trimester to prevent GDM and related outcomes.

The "Asthma-Polycystic Ovary Overlap Syndrome" and the Therapeutic Role of Myo-Inositol

Asthma is a heterogeneous inflammatory disease characterized by abnormalities in immune response. Due to the inherent complexity of the disease and the presence of comorbidities, asthma control is often difficult to obtain. In asthmatic patients, an increased prevalence of irregular menstrual cycles, infertility, obesity, and insulin resistance has been reported. Given that these conditions are also common in patients with polycystic ovary syndrome (PCOS), we propose the definition of "asthma-PCOS overlap syndrome" to indicate a medical condition which shares characteristics of both diseases. The aim of this review is to analyze the links between asthma and PCOS and evaluate the therapeutic role of myo-inositol, a natural compound currently utilized in patients with PCOS, in the management of asthma patients.

Neurobiology and Applications of Inositol in Psychiatry: A Narrative Review

Inositol is a natural sugar-like compound, commonly present in many plants and foods. It is involved in several biochemical pathways, most of them controlling vital cellular mechanisms, such as cell development, signaling and nuclear processes, metabolic and endocrine modulation, cell growth, signal transduction, etc. In this narrative review, we focused on the role of inositol in human brain physiology and pathology, with the aim of providing an update on both potential applications and current limits in its use in psychiatric disorders. Overall, imaging and biomolecular studies have shown the role of inositol levels in the pathogenesis of mood disorders. However, when administered as monotherapy or in addition to conventional drugs, inositol did not seem to influence clinical outcomes in both mood and psychotic disorders. Conversely, more encouraging results have emerged for the treatment of panic disorders. We concluded that, despite its multifaceted neurobiological activities and some positive findings, to date, data on the efficacy of inositol in the treatment of psychiatric disorders are still controversial, partly due to the heterogeneity of supporting studies. Therefore, systematic use of inositol in routine clinical practice cannot be recommended yet, although further basic and translational research should be encouraged.

Antenatal dietary supplementation with myo-inositol for preventing gestational diabetes

BACKGROUND

Gestational diabetes with onset or first recognition during pregnancy is an increasing problem worldwide. Myo-inositol, an isomer of inositol, is a naturally occurring sugar commonly found in cereals, corn, legumes and meat. Myo-inositol is one of the intracellular mediators of the insulin signal and correlates with insulin sensitivity in type 2 diabetes. The potential beneficial effect of improving insulin sensitivity suggests that myo-inositol may be useful for women in preventing gestational diabetes. This is an update of a review first published in 2015.

OBJECTIVES

To assess if antenatal dietary supplementation with myo-inositol is safe and effective, for the mother and fetus, in preventing gestational diabetes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, WHO ICTRP (17 March 2022) and the reference lists of retrieved studies.

SELECTION CRITERIA

We included published and unpublished randomised controlled trials (RCTs) including cluster-RCTs and conference abstracts, assessing the effects of myo-inositol for the prevention of gestational diabetes in pregnant women. We included studies that compared any dose of myo-inositol, alone or in a combination preparation, with no treatment, placebo or another intervention. Quasi-randomised and cross-over trials were not eligible. We excluded women with pre-existing type 1 or type 2 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, assessed risk of bias and extracted the data. We checked the data for accuracy. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included seven RCTs (one conducted in Ireland, six conducted in Italy) reporting on 1319 women who were 10 weeks to 24 weeks pregnant at the start of the studies. The studies had relatively small sample sizes and the overall risk of bias was low. For the primary maternal outcomes, meta-analysis showed that myo-inositol may reduce the incidence of gestational diabetes (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.31 to 0.90; 6 studies, 1140 women) and hypertensive disorders of pregnancy (RR 0.34, 95% CI 0.19 to 0.61; 5 studies, 1052 women). However, the certainty of the evidence was low to very low. For the primary neonatal outcomes, only one study measured the risk of a large-for-gestational-age infant and found myo-inositol was associated with both appreciable benefit and harm (RR 1.40, 95% CI 0.65 to 3.02; 1 study, 234 infants; low-certainty evidence). None of the included studies reported on the other primary neonatal outcomes (perinatal mortality, mortality or morbidity composite). For the secondary maternal outcomes, we are unclear about the effect of myo-inositol on weight gain during pregnancy (mean difference (MD) -0.25 kilogram (kg), 95% CI -1.26 to 0.75 kg; 4 studies, 831 women) and perineal trauma (RR 4.0, 95% CI 0.45 to 35.25; 1 study, 234 women) because the evidence was assessed as being very low-certainty. Further, myo-inositol may result in little to no difference in caesarean section (RR 0.91, 95% CI 0.77 to 1.07; 4 studies, 829 women; low-certainty evidence). None of the included studies reported on the other secondary maternal outcomes (postnatal depression and the development of subsequent type 2 diabetes mellitus). For the secondary neonatal outcomes, meta-analysis showed no neonatal hypoglycaemia (RR 3.07, 95% CI 0.90 to 10.52; 4 studies; 671 infants; very low-certainty evidence). However, myo-inositol may be associated with a reduction in the incidence of preterm birth (RR 0.35, 95% CI 0.17 to 0.70; 4 studies; 829 infants). There were insufficient data for a number of maternal and neonatal secondary outcomes, and no data were reported for any of the long-term childhood or adulthood outcomes, or for health service utilisation outcomes.

AUTHORS' CONCLUSIONS

Evidence from seven studies shows that antenatal dietary supplementation with myo-inositol during pregnancy may reduce the incidence of gestational diabetes, hypertensive disorders of pregnancy and preterm birth. Limited data suggest that supplementation with myo-inositol may not reduce the risk of a large-for-gestational-age infant.  The current evidence is based on small studies that were not powered to detect differences in outcomes such as perinatal mortality and serious infant morbidity. Six of the included studies were conducted in Italy and one in Ireland, which raises concerns about the lack of generalisability to other settings. There is evidence of inconsistency among doses of myo-inositol, the timing of administration and study population. As a result, we downgraded the certainty of the evidence for many outcomes to low or very low certainty. Further studies for this promising antenatal intervention for preventing gestational diabetes are encouraged and should include pregnant women of different ethnicities and varying risk factors. Myo-inositol at different doses, frequency and timing of administration, should be compared with placebo, diet and exercise, and pharmacological interventions. Long-term follow-up should be considered and outcomes should include potential harms, including adverse effects.

The Role of Lifestyle Interventions in the Prevention and Treatment of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is one of the most common pregnancy-related endocrinopathies, affecting up to 25% of pregnancies globally. GDM increases the risk of perinatal and delivery complications, and the chance of developing type 2 diabetes mellitus and its complications, including cardiovascular diseases. This elevated risk is then passed on to the next generation, creating a cycle of metabolic dysfunction across generations. For many years, GDM preventive measures have had inconsistent results, but recent systematic reviews and meta-analyses have identified promising new preventative routes. This review aims to summarize the evidence investigating the efficacy of lifestyle treatments for the prevention of GDM and to summarize the effects of two lifestyle interventions, including physical activity and dietary interventions. Based on the present research, future studies should be conducted to investigate whether initiating lifestyle interventions during the preconception period is more beneficial in preventing GDM. In addition, research targeting pregnancy should be designed with a personalized approach. Therefore, studies should customize intervention approaches depending on the presence of modifiable and non-modifiable risk factors at the individual level.

Inositol Nutritional Supplementation for the Prevention of Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This study was aimed at assessing the efficacy and safety of inositol nutritional supplementation during pregnancy for the prevention of GDM. PubMed, Embase, MEDLINE, and Cochrane library were systematically searched for randomized controlled trails (RCTs) in this field until May 2022. Primary outcomes were the incidence for GDM and plasma glucose levels by oral glucose tolerance test (OGTT). Pooled results were expressed as relative risk (RR) or mean difference (MD) with a 95% confidence interval (95% CI). Seven RCTs with 1321 participants were included in this study. Compared with the control group, 4 g myo-inositol (MI) supplementation per day significantly decreased the incidence of GDM (RR = 0.30, 95% CI (0.18, 0.49), p < 0.00001). It significantly decreased the plasma glucose levels of OGTT regarding fasting-glucose OGTT (MD = −4.20, 95% CI (−5.87, −2.54), p < 0.00001), 1-h OGTT (MD = −8.75, 95% CI (−12.42, −5.08), p < 0.00001), and 2-h OGTT (MD = −8.59, 95% CI (−11.81, −5.83), p < 0.00001). It also decreased the need of insulin treatment, and reduced the incidence of preterm delivery and neonatal hypoglycemia. However, no difference was observed between 1.1 g MI per day plus 27.6 mg D-chiro-inositol (DCI) per day and the control group regarding all evaluated results. In conclusion, 4 g MI nutritional supplementation per day during early pregnancy may reduce GDM incidence and severity, therefore may be a practical and safe approach for the prevention of GDM.

Myo-inositol supplementation for prevention of gestational diabetes mellitus in overweight and obese pregnant women: a systematic review and meta-analysis

BACKGROUND

The prevalence of gestational diabetes mellitus [GDM] and of its most important predisposing factor, i.e. overweight and obesity, have increased dramatically over the past 20 years. Therefore, the aim of this study was to systematically review the articles on the effect of myo-inositol supplementation on the prevention of GDM in pregnant women with overweight and obesity.

METHODS

We conducted a systematic literature search in electronic database (MEDLINE, Cochrane Library, ClinicalTrials.gov, Embase, ProQuest, PubMed, Google scholar, Scopus, Web of science and forward and backward citations) to identify all randomized controlled trials (RCTs) published until 21 December 2021. Finally, Among the 118 identified records, four studies were eligible and were included in this systematic review. The meta-analysis results were reported in the form of odds ratio (OR) to compare the incidence of GDM and pregnancy outcomes. They were also presented in the form of mean difference (MD) to compare fasting glucose (FG), 1-h and 2-h oral glucose tolerance test (OGTT) levels between the two groups. This study was registered on PROSPERO, number CRD42021290570.

RESULTS

The results showed that the incidence of GDM was significantly lower in the myo-inositol group (OR 0.32, 95% CI 0.21 to 0.48; P < 0.001; I² = 0%; Moderate certainty evidence). Moreover, FG-OGTT (MD - 2.64 mg/dl, 95% CI - 4.12 to - 1.17; P < 0.001; I² = 0%; Moderate certainty evidence), 1-h-OGTT (MD - 7.47 mg/dl, 95% CI - 12.24 to - 2.31; P = 0.005; I² = 27%; Low certainty evidence) and 2-h-OGTT levels (MD - 10.51 mg/dl, 95% CI - 16.88 to - 4.14; P = 0.001; I² = 59%; Low certainty evidence) in the myo-inositol group were significantly lower than in the control group. Regarding the pregnancy outcomes, the incidence of gestational hypertension and preterm delivery was significantly lower in the myo-inositol group. However, no between-group difference was observed in the other outcomes.

CONCLUSIONS

Based on the results, myo-inositol has shown to be a new and safe preventive strategy in reducing the incidence of GDM and in regulating FG and 1-h and 2-h OGTT levels, and also in reducing the incidence of GDM complications such as preterm delivery and gestational hypertension in pregnant women with overweight and obesity.

Myoinositol supplementation in the treatment of gestational diabetes mellitus: effects on glycaemic control and maternal-foetal outcomes

Background

Gestational diabetes mellitus (GDM) is defined as glucose intolerance with onset during pregnancy. It is characterized by high risk of adverse outcomes for the mother and the foetus, if not adequately controlled. The aim of the study was to evaluate the effects of 4000 mg of myoinositol supplementation in women with GDM on maternal-foetal outcomes, compared to controls.

Methods

A cohort of 330 women with GDM, 150 supplemented with myoinositol and 180 controls were enrolled. Clinical and metabolic parameters and the prevalence of maternal and foetal complications were assessed.

Results

The same number of women in the two groups started insulin as additional therapy. Women treated with myoinositol more frequently had a long-acting insulin scheme of treatment than those untreated (p<0.001), while women untreated with myoinositol more frequently had a basal-bolus insulin regimen (p<0.001) compared to women on myoinositol.

Patients treated with myoinositol had significantly lower fasting plasma glucose (p=0.032), post-prandial dinner glucose (p=0.014), insulin requirement both in the 2nd and in the 3rd trimesters (p=0.001 and p<0.001, respectively), than those not treated with myoinositol.

With regard to maternal/foetal outcomes, lower birth weight (p=0.043) and frequency of hypoglycaemic events (p=0.001) were observed in women treated with myoinositol compared to controls.

Conclusions

Women with GDM treated with myoinositol showed an improved glycaemic control in the 3^rd trimester of pregnancy and a lower insulin requirement, when insulin was added to the treatment, compared to controls. In addition, they showed lower preterm birth weight and neonatal hypoglycaemia, compared to women not supplemented with myoinositol.

The efficacy of myo-inositol supplementation to reduce the incidence of gestational diabetes: a meta-analysis

INTRODUCTION

Myo-inositol supplementation is used to reduce the incidence of gestational diabetes, but its efficacy is not well established. This meta-analysis aims to explore the influence of myo-inositol supplementation on the prevention of gestational diabetes.

METHODS

This meta-analysis has been conducted up to March 2022 to identify randomized clinical trials comparing the efficacy of myo-inositol supplementation to prevent gestational diabetes. Several databases including PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systemically.

RESULTS

We have included eight RCTs in this meta-analysis. Compared with control group in pregnant women, myo-inositol supplementation was found to significantly decrease the incidence of gestational diabetes (OR = 0.40; 95% CI = 0.19 to 0.84; p = .01), 2-h glucose OGTT (SMD = -0.22; 95% CI = -0.41 to -0.02; p = .03), HOMA-IR (SMD = -0.25; 95% CI = -0.42 to -0.08; p = .004) and preterm delivery (OR = 0.41; 95% CI = 0.23 to 0.73; p = .003), but demonstrated no obvious impact on gestational age at birth (SMD = 0.12; 95% CI = -0.05 to 0.29; p = .18) or birth weight (SMD = -0.04; 95% CI = -0.20 to 0.13; p = .68).

CONCLUSIONS

Myo-inositol supplementation is effective to reduce the incidence of gestational diabetes, 2-h glucose OGTT, HOMA-IR and preterm delivery, which suggested that myo-inositol supplementation should be recommended to prevent gestational diabetes.

Overview of Neural Tube Defects: Gene–Environment Interactions, Preventative Approaches and Future Perspectives

Neural tube defects (NTDs) are the second most common congenital malformations of humans, characterized by impaired development of the central nervous system. Even though the etiology of most birth defects remains undetermined, genetic and environmental risk factors in the background of NTDs have been identified and extensively reported. On top of genetic and nutritional risks which include mutations in both coding and non-coding regions and maternal folate status, respectively, recent years have seen a rise in the identification of a variety of teratogens that could be implicated in NTD development. These include polycyclic aromatic hydrocarbons, arsenic, pesticides, maternal hyperthermia and antibiotics as well as pain and seizure medication. With an increase in understanding of teratogens leading to NTD formation, preventative and treatment approaches have witnessed great advances throughout the years. While the most common preventative approach includes folic acid food fortification as well as suggested inositol supplementation, treatment and management approaches differ greatly depending on the developmental stage and the site of the lesion and include prenatal surgery, stem cell transplantation and postnatal surgery. Because NTDs still represent a large health and financial burden for the patient and society as a whole, it is crucial to investigate potential risk factors and develop novel approaches in order to fully prevent this category of disorders.

Inositols, Probiotics, and Gestational Diabetes: Clinical and Epigenetic Aspects

There is growing interest in the potential role of different stereoisomers of inositol or their combination as well as probiotics supplementation in healthy glucose metabolism during pregnancy and in promoting offspring health. The aim of this review is to clarify the effects of several inositol and probiotics-based supplements in the prevention and treatment of gestational diabetes (GDM). Moreover, we will discuss the epigenetic aspects and their short- and long-term effects in response to probiotic intervention as well as the possible implications of these findings in guiding appropriate supplementation regimens in pregnancy.

Myo-inositol nutritional supplement for prevention of gestational diabetes (EMmY): a randomised, placebo-controlled, double-blind pilot trial with nested qualitative study

OBJECTIVES

To determine the feasibility and acceptability of conducting a randomised trial on the effects of myo-inositol in preventing gestational diabetes in high-risk pregnant women.

DESIGN

A multicentre, double-blind, placebo-controlled, pilot randomised trial with nested qualitative evaluation.

SETTING

Five inner city UK National Health Service hospitals PARTICIPANTS: Multiethnic pregnant women at 12⁺⁰ and 15⁺⁶ weeks' gestation with risk factors for gestational diabetes.

INTERVENTIONS

2 g of myo-inositol or placebo, both included 200 µg folic acid, twice daily until delivery.

PRIMARY OUTCOME MEASURES

Rates of recruitment, randomisation, adherence and follow-up.

SECONDARY OUTCOME MEASURES

Glycaemic indices (including homoeostatic model assessment-insulin resistance HOMA-IR), gestational diabetes (diagnosed using oral glucose tolerance test at 28 weeks and by delivery), maternal, perinatal outcomes, acceptability of intervention and costs.

RESULTS

Of the 1326 women screened, 58% (773/1326) were potentially eligible, and 27% (205/773) were recruited. We randomised 97% (198/205) of all recruited women (99 each in intervention and placebo arms) and ascertained outcomes in 90% of women (178/198) by delivery. The mean adherence was 52% (SD 44) at 28 weeks' and 34% (SD 41) at 36 weeks' gestation. HOMA-IR and serum insulin levels were lower in the myo-inositol vs placebo arm (mean difference -0.6, 95% CI -1.2 to 0.0 and -2.69, 95% CI -5.26 to -0.18, respectively). The study procedures were acceptable to women and healthcare professionals. Women who perceived themselves at high risk of gestational diabetes were more likely to participate and adhere to the intervention. The powder form of myo-inositol and placebo, along with nausea in pregnancy were key barriers to adherence.

CONCLUSIONS

A future trial on myo-inositol versus placebo to prevent gestational diabetes is feasible. The intervention will need to be delivered in a non-powder form to improve adherence. There is a signal for efficacy in reducing insulin resistance in pregnancy with myo-inositol.

TRIAL REGISTRATION NUMBER

ISRCTN48872100.

Gestational Diabetes Mellitus and Preeclampsia: Correlation and Influencing Factors

Gestational diabetes mellitus (GDM) and preeclampsia (PE) are common pregnancy complications with similar risk factors and pathophysiological changes. Evidence from previous studies suggests that the incidence of PE is significantly increased in women with GDM, but whether GDM is independently related to the occurrence of PE has remained controversial. GDM complicated by PE further increases perinatal adverse events with greater impact on the future maternal and offspring health. Identify factors associated with PE in women with GDM women, specifically those that are controllable, is important for improving pregnancy outcomes. This paper provides the findings of a review on the correlation between GDM and PE, factors associated with PE in women with GDM, possible mechanisms, and predictive markers. Most studies concluded that GDM is independently associated with PE in singleton pregnancy, and optimizing the treatment and management of GDM can reduce the incidence of PE, which is very helpful to improve pregnancy outcomes.

Maternal folic acid and multivitamin supplementation: International clinical evidence with considerations for the prevention of folate-sensitive birth defects

More evidence is available for maternal intake, absorption, distribution, tissue specific concentrations, and pregnancy outcomes with folic acid (fortification/supplementation) during preconception - first trimester. This Quality Improvement prevention review used expert guidelines/opinions, systematic reviews, randomized control trials/controlled clinical trials, and observational case control/case series studies, published in English, from 1990 to August 2021. Optimization for an oral maternal folic acid supplementation is difficult because it relies on folic acid dose, type of folate supplement, bio-availability of the folate from foods, timing of supplementation initiation, maternal metabolism/genetic factors, and many other factors. There is continued use of high dose pre-food fortification 'RCT evidenced-based' folic acid supplementation for NTD recurrence pregnancy prevention. Innovation requires preconception and pregnancy use of 'carbon one nutrient' supplements (folic acid, vitamin B12, B6, choline), using the appropriate evidence, need to be considered. The consideration and adoption of directed personalized approaches for maternal complex risk could use serum folate testing for supplementation dosing choice. Routine daily folic acid dosing for low-risk women should consider a multivitamin with 0.4 mg of folic acid starting 3 months prior to conception until completion of breastfeeding. Routine folic acid dosing or preconception measurement of maternal serum folate (after 4-6 weeks of folate supplementation) could be considered for maternal complex risk group with genetic/medical/surgical co-morbidities. These new approaches for folic acid oral supplementation are required to optimize benefit (decreasing folate sensitive congenital anomalies; childhood morbidity) and minimizing potential maternal and childhood risk.

D-Chiro-Inositol improves testosterone levels in older hypogonadal men with low-normal testosterone: a pilot study

BACKGROUND

Several recent journal articles report that D-chiro-inositol (DCI), primarily known as insulin second messenger, influences steroidogenesis. In particular, new evidence is arising on DCI ability to regulate aromatase expression and testosterone biosynthesis. In this regard, DCI administration could represent a good therapeutic opportunity in case of reduced levels of testosterone. Older men generally have lower testosterone concentrations than younger men, and recent randomized controlled trials have examined whether testosterone treatment might improve health outcomes in this age group. There is limited information about the safety of testosterone replacement therapy in these men, hence DCI could represent an interesting alternative for future trials. Therefore, this study aims to evaluate the effect of DCI treatment on testosterone levels in older male patient.

RESULTS

Ten older men with basal low testosterone levels were enrolled in this study. Patients took 600 mg of DCI, two-times per day, for 30 days. We evaluated hormonal and glycaemic parameters, weight, waist circumference, and Body-Mass Index at baseline (T0) and after 30 days (T1). Finally, all patients also filled in the standardized International Index of Erectile Function questionnaire and performed the Handgrip test at T0 and T1. Men receiving DCI showed increased androgen and reduced oestrogen concentrations, and improved glycaemic profiles. DCI was also associated with reduced weight, Body-Mass Index, waist circumference, and improved grip strength and self-reported sexual function. All these effects led to the improvement of sexual function and physical strength.

CONCLUSIONS

In this pilot study, DCI treatment improved the levels of testosterone and androstenedione at the expense of oestrogens in elder men with low basal levels of these hormones without adverse effects.

TRIAL REGISTRATION

Clinicaltrials.gov: D-chiroinositol Administration in Hypogonadal Males, NCT04708249.

Dietary Supplements for Female Infertility: A Critical Review of Their Composition

Infertility is the condition of about 15% of couples that cannot get a conception after one year of unprotected sexual intercourse. In females, the reduced reproductive capacity underlies the most varied causes. Dietary supplements (DS) might be used to improve the pregnancy rate and a wide range of DS are proposed today to support female fertility. Although many authors demonstrated the positive effect of some of these products, the real efficacy of this approach is still debated. In order to evaluate the potential efficacy of DS for female infertility, we analysed the products marketed in Italy, using an original approach. A review of literature was performed to evaluate the effect of nutraceuticals on various female reproductive outcomes and to detect the minimal effective daily dose (mED) able to improve at least one of these. Thereafter, we conceived a formula to classify the expected efficacy of each DS. Each DS was scored and included into three classes of expected efficacy: higher, lower, and none. Ten out of 24 supplements (41.7%) resulted in the higher and 8 (34.3%) in the lower efficacy group, the remaining 6 DS (25.0%) were expected to have no efficacy. DS marketed in Italy are usually blends of many substances that are frequently employed at a negligible dose or without any evidence of efficacy. These findings raise serious doubt about the potential effectiveness of most commercial DS for female infertility.

A reminder system for postpartum diabetes screening after gestational diabetes: a randomized clinical trial

OBJECTIVE

To evaluate if a reminder postpartum screening system, providing patients with laboratory requisition on the postpartum ward followed by a telephone reminder one week prior to their 6 weeks appointment, would increase the diabetes mellitus screening rate.

METHODS

Parallel group, open label, multicenter randomized trial. Patients were recruited between July 2015 and March 2016. All women with gestational diabetes mellitus in their index pregnancy with access to a mobile or landline phone were eligible for participation. Gestational diabetes mellitus diagnosis was made with a one-hour 50 g OGTT ≥135 mg/dl, and a subsequent 3 h OGTT with ≥2 values above fasting 95 mg/dl, 1 h 180 mg/dl, 2 h 155 mg/dl, and 3 h 140 mg/dl. Participants were assigned in a 1:1 ratio to "reminder system" (intervention group) or to "routine care (control group)." Those assigned to the reminder system were provided with two reminders. The first was a laboratory requisition slip given to them while on the postpartum ward. The second was a telephone reminder on the fifth week postpartum, consisting of a standardized script to encourage contacted participants to complete the screening test during the sixth week postpartum. The primary outcome was completion of the two-hour 75 g OGTT 6-12 weeks postpartum.

RESULTS

A total of 75 patients were included in the study. Thirty-eight patients were randomized to the reminder system, and 37 patients were randomized to routine care. A total of 22 women (29.3%) completed the test. In the "reminder" group, 31.6% completed the test, and in the "routine care" group 27% of patients completed the test. This increase in screening uptake in the reminder group was not noted to be statistically significant (p=.8). When evaluating whether perinatal or sociodemographic factors influenced the effect of reminder systems on screening uptake, only insurance type was noted to have a statistically significant influence. Screening uptake was significantly increased in patients with public insurance assigned to "reminder group" (13.5%) compared to those assigned to "routine care" (0%). Of those women who completed the test, seven patients (31.8 %) were diagnosed with prediabetes and none with diabetes.

CONCLUSIONS

Telephone reminders were not found to have a significant impact on increasing postpartum screening for diabetes. The exception was among the publicly insured population. These findings suggest a targeted role for reminder systems, particularly among those with socioeconomic disadvantage.

Melatonin and Myo-Inositol: Supporting Reproduction from the Oocyte to Birth

Human pregnancy is a sequence of events finely tuned by several molecular interactions that come with a new birth. The precise interlocking of these events affecting the reproductive system guarantees safe embryo formation and fetal development. In this scenario, melatonin and myo-inositol seem to be pivotal not only in the physiology of the reproduction process, but also in the promotion of positive gestational outcomes. Evidence demonstrates that melatonin, beyond the role of circadian rhythm management, is a key controller of human reproductive functions. Similarly, as the most representative member of the inositol’s family, myo-inositol is essential in ensuring correct advancing of reproductive cellular events. The molecular crosstalk mediated by these two species is directly regulated by their availability in the human body. To date, biological implications of unbalanced amounts of melatonin and myo-inositol in each pregnancy step are growing the idea that these molecules actively contribute to reduce negative outcomes and improve the fertilization rate. Clinical data suggest that melatonin and myo-inositol may constitute an optimal dietary supplementation to sustain safe human gestation and a new potential way to prevent pregnancy-associated pathologies.

Myo-Inositol as a Key Supporter of Fertility and Physiological Gestation

Pregnancy is a complex process, featuring several necessary changes in women’s physiology. Most women undergo healthy pregnancies; even so, several women experience reduced fertility or pathologies related to the pregnancy. In the last years, researchers investigated several molecules as promoters of fertility. Among all, myo-inositol (myo-ins) represents a safe compound that proved useful in issues related to fertility and pregnancy. In fact, myo-ins participates in several signaling processes, including the pathways of insulin and gonadotropins, and, therefore, it is likely to positively affect fertility. In particular, several clinical trials demonstrate that its administration can have therapeutic effects in infertile women, and that it can also be useful as a preventive treatment during pregnancy. Particularly, myo-ins could prevent the onset of neural tube defects and the occurrence of gestational diabetes mellitus, promoting a trouble-free gestation. Due to the safety and efficiency of myo-ins, such a treatment may also substitute several pharmaceuticals, which are contraindicated in pregnancy.

Effectiveness and acceptability of myoinositol in prevention of gestational diabetes mellitus: A protocol for systematic review and meta-analysis

Background:

The existing meta-analyses and randomized studies on myoinositol are of poor quality, with small sample sizes, and involve a homogeneous population. The general applicability of these findings to the National Health Service is unclear. We thus conduct this new high-quality systematic review and meta-analysis to assess the efficacy and safety of myoinositol in pregnant woman.

Methods:

The study protocol will be developed and executed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. All of the following inclusion criteria in the PICOS order will be met by the studies included in our meta-analysis:

The following electronic databases will be searched: PubMed, Scopus, EMBASE, and Cochrane Library databases. The Cochrane risk of bias tool will be used to evaluate the risk of bias of the included randomized trials by 2 independent reviewers.

Results:

We will perform a meta-analysis using standard techniques for the outcomes.

Conclusions:

It was hypothesized that myoinositol supplementation could increase the action of endogenous insulin and prevent GDM and its complications.

Trial registration:

10.17605/OSF.IO/9W8DV.

Dietary supplementation for gestational diabetes prevention and management: a meta-analysis of randomized controlled trials

PURPOSE

The use of supplement to prevent and ease gestational diabetes (GDM) progression has been examined in various studies, but the results were inconclusive, and studies evaluated dietary supplements separately. The present review aimed to evaluate the efficacy of various dietary supplementation on GDM risk and the surrogate markers for cardiometabolic risk of pregnant women with GDM.

METHODS

A comprehensive search on multiple databases were performed to identify randomized controlled trials. Random-effects model was used to pool the results in relative risk (RR) or mean difference.

RESULTS

Fifty-three randomized controlled studies with 9443 pregnant women were included. Vitamin D (5 studies, RR 0.64; 95% CI 0.44, 0.94) and myo-inositol (4 studies, RR 0.34, 95% CI 0.20, 0.58) supplementation significantly reduced the risk of GDM. Myo-inositol, probiotics, and vitamin D showed significant intervention effect on surrogate markers related to glycemic control, lipid profile, inflammatory, and oxidative stress. However, the majority of included studies were clustered to Iran and Italy, which might convey a generalizability bias.

CONCLUSION

Dietary supplementation including vitamin D and myoinositol supplementation has the potential in primary prevention and management of GDM, whereas probiotics demonstrated its ability in GDM management by improving the levels of surrogate markers for cardiometabolic risk. The potential for dietary supplement in preventing GDM or managing cardiometabolic risk of pregnant women should receive more attentions.

Efficacy of myoinositol in treatment of gestational diabetes mellitus in Asian Indian women: A pilot randomized clinical trial

OBJECTIVE

To compare efficacy of myoinositol as an adjuvant to dietary modification for treatment of gestational diabetes mellitus in Asian Indian women compared to controls.

STUDY DESIGN

Setting: This pilot randomized open label trial was conducted in a single antenatal clinic in India.

SUBJECTS

One hundred women with singleton pregnancy and gestational diabetes diagnosed between 14-28 weeks' gestation were included. Overt diabetes, twin pregnancy, pre-existing renal disease, heart disease and other chronic medical disorders were exclusions.

INTERVENTION

Participants were randomized in two groups (1:1 ratio) by opaque envelope method. Individualized nutrition counseling with dietary modification and routine antenatal care was provided to all. Fifty women received myoinositol 1000 mg twice daily; 50 controls did not receive myoinositol. Fasting and postprandial glucose levels were assessed after two weeks. Women not achieving glycemic targets (fasting glucose <95 and postprandial glucose <120 mg/dL) were given pharmacologic therapy. Contributory factors in women requiring additional pharmacologic therapy, maternal and fetal outcomes were noted.

STATISTICAL ANALYSIS

Between group comparisons reported relative risk and mean difference. To assess predictive factors for need for pharmacologic therapy, univariate and multivariable logistic regression analysis were used.

RESULTS

Baseline characteristics were comparable in both groups. Except one woman in the myoinositol group, all women provided glycaemia data throughout their pregnancy. Glycemic control was achieved in 44/ 49 (89.8 %) women in myoinositol group which was significantly higher than 34/50 (68 %) in the controls ((relative risk 0.31, 95 % confidence interval 0.13 to 0.80, p = 0.008). Mean duration of myoinositol treatment was 17.6 weeks (standard deviation 5.3). Additional treatment with metformin/insulin was needed in all women failing to achieve glycaemic control. The mean (range) dose of insulin was 25.3 units in myoinositol group compared to 14.27 units in controls (p = 0.058). Secondary outcomes were similar in two groups except baby weight which was higher in controls (p = 0.018).

CONCLUSIONS

Oral supplementation with myoinositol in dose of 1 gm twice-daily, when started soon after the diagnosis of GDM, is effective in achieving glycemic control and decreasing the need for additional pharmacological therapy in Asian Indian women.

The Impact of Diagnostic Criteria for Gestational Diabetes Mellitus on Adverse Maternal Outcomes: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to examine the impact of different gestational-diabetes (GDM) diagnostic-criteria on the risk of adverse-maternal-outcomes. The search process encompassed PubMed (Medline), Scopus, and Web of Science databases to retrieve original, population-based studies with the universal GDM screening approach, published in English language and with a focus on adverse-maternal-outcomes up to January 2020. According to GDM diagnostic criteria, the studies were classified into seven groups. A total of 49 population-based studies consisting of 1409018 pregnant women with GDM and 7,667,546 non-GDM counterparts were selected for data analysis and knowledge synthesis. Accordingly, the risk of adverse-maternal-outcomes including primary-cesarean, induction of labor, maternal-hemorrhage, and pregnancy-related-hypertension, overall, regardless of GDM diagnostic-criteria and in all diagnostic-criteria subgroups were significantly higher than non-GDM counterparts. However, in meta-regression, the increased risk was not influenced by the GDM diagnostic-classification and the magnitude of the risks among patients, using the IADPSG criteria-classification as the most strict-criteria, was similar to other criteria. In conclusion, a reduction in the diagnostic-threshold increased the prevalence of GDM, but the risk of adverse-maternal-outcome was not different among those women who were diagnosed through more or less intensive strategies. Our review findings can empower health-care-providers to select the most cost-effective approach for the screening of GDM among pregnant women.

A review of the role of inositols in conditions of insulin dysregulation and in uncomplicated and pathological pregnancy

Inositols, a group of 6-carbon polyols, are highly bioactive molecules derived from diet and endogenous synthesis. Inositols and their derivatives are involved in glucose and lipid metabolism and participate in insulin-signaling, with perturbations in inositol processing being associated with conditions involving insulin resistance, dysglycemia and dyslipidemia such as polycystic ovary syndrome and diabetes. Pregnancy is similarly characterized by substantial and complex changes in glycemic and lipidomic regulation as part of maternal adaptation and is also associated with physiological alterations in inositol processing. Disruptions in maternal adaptation are postulated to have a critical pathophysiological role in pregnancy complications such as gestational diabetes and pre-eclampsia. Inositol supplementation has shown promise as an intervention for the alleviation of symptoms in conditions of insulin resistance and for gestational diabetes prevention. However, the mechanisms behind these affects are not fully understood. In this review, we explore the role of inositols in conditions of insulin dysregulation and in pregnancy, and identify priority areas for research. We particularly examine the role and function of inositols within the maternal-placental-fetal axis in both uncomplicated and pathological pregnancies. We also discuss how inositols may mediate maternal-placental-fetal cross-talk, and regulate fetal growth and development, and suggest that inositols play a vital role in promoting healthy pregnancy.

An update on the use of inositols in preventing gestational diabetes mellitus (GDM) and neural tube defects (NTDs)

INTRODUCTION

Obstetric history and maternal body composition and lifestyle may be associated with serious complications both for the mother, such as gestational diabetes mellitus (GDM), and for the fetus, including congenital malformations such as neural tube defects (NTDs).

AREAS COVERED

In view of the recent knowledge, changes in nutritional and physical activity habits ameliorate glycemic control during pregnancy and in turn improve maternal and neonatal health outcomes. Recently, a series of small clinical and experimental studies indicated that supplemenation with inositols, a family of insulin sensitizers, was associated with beneficial impact for both GDM and NTDs.

EXPERT OPINION

Herein, we discuss the most significant scientific evidence supporting myo-inositol administration as a prophylaxis for the above-mentioned conditions.

Nutrition and Metabolic Adaptations in Physiological and Complicated Pregnancy: Focus on Obesity and Gestational Diabetes

Pregnancy offers a window of opportunity to program the future health of both mothers and offspring. During gestation, women experience a series of physical and metabolic modifications and adaptations, which aim to protect the fetus development and are closely related to both pre-gestational nutritional status and gestational weight gain. Moreover, pre-gestational obesity represents a challenge of treatment, and nowadays there are new evidence as regard its management, especially the adequate weight gain. Recent evidence has highlighted the determinant role of nutritional status and maternal diet on both pregnancy outcomes and long-term risk of chronic diseases, through a transgenerational flow, conceptualized by the Development Origin of Health and Diseases (Dohad) theory. In this review we will analyse the physiological and endocrine adaptation in pregnancy, and the metabolic complications, thus the focal points for nutritional and therapeutic strategies that we must early implement, virtually before conception, to safeguard the health of both mother and progeny. We will summarize the current nutritional recommendations and the use of nutraceuticals in pregnancy, with a focus on the management of pregnancy complicated by obesity and hyperglycemia, assessing the most recent evidence about the effects of ante-natal nutrition on the long-term, on either maternal health or metabolic risk of the offspring.

Inositol and Non-Alcoholic Fatty Liver Disease: A Systematic Review on Deficiencies and Supplementation

Liver lipid accumulation is a hallmark of non-alcoholic fatty liver disease (NAFLD), broadly associated with insulin resistance. Inositols (INS) are ubiquitous polyols implied in many physiological functions. They are produced endogenously, are present in many foods and in dietary supplements. Alterations in INS metabolism seems to play a role in diseases involving insulin resistance such as diabetes and polycystic ovary syndrome. Given its role in other metabolic syndromes, the hypothesis of an INS role as a supplement in NAFLD is intriguing. We performed a systematic review of the literature to find preclinical and clinical evidence of INS supplementation efficacy in NAFLD patients. We retrieved 10 studies on animal models assessing Myoinosiol or Pinitol deficiency or supplementation and one human randomized controlled trial (RCT). Overall, INS deficiency was associated with increased fatty liver in animals. Conversely, INS supplementation in animal models of fatty liver reduced hepatic triglycerides and cholesterol accumulation and maintained a normal ultrastructural liver histopathology. In the one included RCT, Pinitol supplementation obtained similar results. Pinitol significantly reduced liver fat, post-prandial triglycerides, AST levels, lipid peroxidation increasing glutathione peroxidase activity. These results, despite being limited, indicate the need for further evaluation of INS in NAFLD in larger clinical trials.

Interventions to prevent women from developing gestational diabetes mellitus: an overview of Cochrane Reviews

BACKGROUND

The prevalence of gestational diabetes mellitus (GDM) is increasing, with approximately 15% of pregnant women affected worldwide, varying by country, ethnicity and diagnostic thresholds. There are associated short- and long-term health risks for women and their babies.

OBJECTIVES

We aimed to summarise the evidence from Cochrane systematic reviews on the effects of interventions for preventing GDM.

METHODS

We searched the Cochrane Database of Systematic Reviews (6 August 2019) with key words 'gestational diabetes' OR 'GDM' to identify reviews pre-specifying GDM as an outcome. We included reviews of interventions in women who were pregnant or planning a pregnancy, irrespective of their GDM risk status. Two overview authors independently assessed eligibility, extracted data and assessed quality of evidence using ROBIS and GRADE tools. We assigned interventions to categories with graphic icons to classify the effectiveness of interventions as: clear evidence of benefit or harm (GRADE moderate- or high-quality evidence with a confidence interval (CI) that did not cross the line of no effect); clear evidence of no effect or equivalence (GRADE moderate- or high-quality evidence with a narrow CI crossing the line of no effect); possible benefit or harm (low-quality evidence with a CI that did not cross the line of no effect or GRADE moderate- or high-quality evidence with a wide CI); or unknown benefit or harm (GRADE low-quality evidence with a wide CI or very low-quality evidence).

MAIN RESULTS

We included 11 Cochrane Reviews (71 trials, 23,154 women) with data on GDM. Nine additional reviews pre-specified GDM as an outcome, but did not identify GDM data in included trials. Ten of the 11 reviews were judged to be at low risk of bias and one review at unclear risk of bias. Interventions assessed included diet, exercise, a combination of diet and exercise, dietary supplements, pharmaceuticals, and management of other health problems in pregnancy. The quality of evidence ranged from high to very low. Diet Unknown benefit or harm: there was unknown benefit or harm of dietary advice versus standard care, on the risk of GDM: risk ratio (RR) 0.60, 95% CI 0.35 to 1.04; 5 trials; 1279 women; very low-quality evidence. There was unknown benefit or harm of a low glycaemic index diet versus a moderate-high glycaemic index diet on the risk of GDM: RR 0.91, 95% CI 0.63 to 1.31; 4 trials; 912 women; low-quality evidence. Exercise Unknown benefit or harm: there was unknown benefit or harm for exercise interventions versus standard antenatal care on the risk of GDM: RR 1.10, 95% CI 0.66 to 1.84; 3 trials; 826 women; low-quality evidence. Diet and exercise combined Possible benefit: combined diet and exercise interventions during pregnancy versus standard care possibly reduced the risk of GDM: RR 0.85, 95% CI 0.71 to 1.01; 19 trials; 6633 women; moderate-quality evidence. Dietary supplements Clear evidence of no effect: omega-3 fatty acid supplementation versus none in pregnancy had no effect on the risk of GDM: RR 1.02, 95% CI 0.83 to 1.26; 12 trials; 5235 women; high-quality evidence. Possible benefit: myo-inositol supplementation during pregnancy versus control possibly reduced the risk of GDM: RR 0.43, 95% CI 0.29 to 0.64; 3 trials; 502 women; low-quality evidence. Possible benefit: vitamin D supplementation versus placebo or control in pregnancy possibly reduced the risk of GDM: RR 0.51, 95% CI 0.27 to 0.97; 4 trials; 446 women; low-quality evidence. Unknown benefit or harm: there was unknown benefit or harm of probiotic with dietary intervention versus placebo with dietary intervention (RR 0.37, 95% CI 0.15 to 0.89; 1 trial; 114 women; very low-quality evidence), or probiotic with dietary intervention versus control (RR 0.38, 95% CI 0.16 to 0.92; 1 trial; 111 women; very low-quality evidence) on the risk of GDM. There was unknown benefit or harm of vitamin D + calcium supplementation versus placebo (RR 0.33, 95% CI 0.01 to 7.84; 1 trial; 54 women; very low-quality evidence) or vitamin D + calcium + other minerals versus calcium + other minerals (RR 0.42, 95% CI 0.10 to 1.73; 1 trial; 1298 women; very low-quality evidence) on the risk of GDM. Pharmaceutical Possible benefit: metformin versus placebo given to obese pregnant women possibly reduced the risk of GDM: RR 0.85, 95% CI 0.61 to 1.19; 3 trials; 892 women; moderate-quality evidence. Unknown benefit or harm:eight small trials with low- to very low-quality evidence showed unknown benefit or harm for heparin, aspirin, leukocyte immunisation or IgG given to women with a previous stillbirth on the risk of GDM. Management of other health issues Clear evidence of no effect: universal versus risk based screening of pregnant women for thyroid dysfunction had no effect on the risk of GDM: RR 0.93, 95% CI 0.70 to 1.25; 1 trial; 4516 women; moderate-quality evidence. Unknown benefit or harm: there was unknown benefit or harm of using fractional exhaled nitrogen oxide versus a clinical algorithm to adjust asthma therapy on the risk of GDM: RR 0.74, 95% CI 0.31 to 1.77; 1 trial; 210 women; low-quality evidence. There was unknown benefit or harm of pharmacist led multidisciplinary approach to management of maternal asthma versus standard care on the risk of GDM: RR 5.00, 95% CI 0.25 to 99.82; 1 trial; 58 women; low-quality evidence.

AUTHORS' CONCLUSIONS

No interventions to prevent GDM in 11 systematic reviews were of clear benefit or harm. A combination of exercise and diet, supplementation with myo-inositol, supplementation with vitamin D and metformin were of possible benefit in reducing the risk of GDM, but further high-quality evidence is needed. Omega-3-fatty acid supplementation and universal screening for thyroid dysfunction did not alter the risk of GDM. There was insufficient high-quality evidence to establish the effect on the risk of GDM of diet or exercise alone, probiotics, vitamin D with calcium or other vitamins and minerals, interventions in pregnancy after a previous stillbirth, and different asthma management strategies in pregnancy. There is a lack of trials investigating the effect of interventions prior to or between pregnancies on risk of GDM.

Inositols in Polycystic Ovary Syndrome: An Overview on the Advances

This review details the physiologic roles of two insulin sensitizers, myo-inositol (MI) and d-chiro-inositol (DCI). In the human ovary, MI is a second messenger of follicle-stimulating hormone (FSH) and DCI is an aromatase inhibitor. These activities allow a treatment for polycystic ovary syndrome (PCOS) to be defined based on the combined administration of MI and DCI, where the best MI:DCI ratio is 40:1. Moreover, MI enhances the effect of metformin and clomiphene on the fertility of PCOS women seeking pregnancy. As impaired intestinal transport may lead to unsuccessful inositol treatment, we also discuss new data on the use of alpha-lactalbumin to boost inositol absorption. Overall, the physiological activities of MI and DCI dictate the dosages and timing of inositol supplementation in the treatment of PCOS.

Experts' opinion on inositols in treating polycystic ovary syndrome and non-insulin dependent diabetes mellitus: a further help for human reproduction and beyond

Introduction: This Experts' opinion provides an updated scientific support to gynecologists, obstetricians, endocrinologists, nutritionists, neurologists and general practitioners on the use of Inositols in the therapy of Polycystic Ovary Syndrome (PCOS) and non-insulin dependent (type 2) diabetes mellitus (NIDDM).Areas covered: This paper summarizes the physiology of Myo-Inositol (MI) and D-Chiro-Inositol (DCI), two important molecules present in human organisms, and their therapeutic role, also for treating infertility. Some deep differences between the physiological functions of MI and DCI, as well as their safety and intestinal absorption are discussed. Updates include new evidence on the efficacy exerted in PCOS by the 40:1 MI/DCI ratio, and the innovative approach based on alpha-lactalbumin to overcome the decreased therapeutic efficacy of Inositols in some patients.Expert opinion: The evidence suggests that MI, alone or with DCI in the 40:1 ratio, offers a promising treatment for PCOS and NIDDM. However, additional studies need to evaluate some still unresolved issues, such as the best MI/DCI ratio for treating NIDDM, the potential cost-effectiveness of reduced gonadotropins administration in IVF due to MI treatment, or the benefit of MI supplementation in ovulation induction with clomiphene citrate in PCOS patients.

From Prediabetes to Type 2 Diabetes Mellitus in Women with Polycystic Ovary Syndrome: Lifestyle and Pharmacological Management

AIMS

Despite the very clear association between polycystic ovary syndrome (PCOS) and dysglycemia, few studies have explored the continuum of glycemic alterations leading from minor glucose abnormalities to overt diabetes. The purpose of this review is to trace the natural history of glycemic alteration in women with PCOS.

METHODS

We performed a literature review without time limit until August 2019. Inclusion criteria were studies addressing the association between impaired glucose tolerance or impaired fasting glucose or type 2 diabetes (T2D) and PCOS with at least an English abstract. The exclusion criteria were no PCOS or impaired glucose tolerance or impaired fasting glucose or T2D as outcome. The outcomes of interest were the onset of impaired glucose tolerance, impaired fasting glucose, T2D, and the progression from impaired glucose tolerance or impaired fasting glucose to T2D.

RESULTS

Healthy diet and physical activity are the first-line therapy for PCOS. Treatment with metformin was associated with significant lower 2-hour postload glucose levels and with reduction in fasting glucose when compared to placebo. Thiazolidinediones were more effective in reducing fasting glucose levels compared to placebo. Metformin and pioglitazone treatments showed similar effects on fasting glucose levels. The sodium-glucose cotransporter-2 inhibitor empagliflozin did not show differences in metabolic parameters when compared to metformin. The combination therapy with metformin plus the glucagon-like peptide-1 receptor agonist liraglutide was associated with significant improvements in basal and postload glucose levels compared with only liraglutide. Likewise, a combination therapy with the dipeptidyl peptidase-4 inhibitor saxagliptin and metformin demonstrated superiority versus metformin in fasting glucose and oral glucose tolerance test normalization. Myo-inositol supplementation was associated with lower insulin levels, glucose levels, and insulin resistance when compared with placebo, metformin, or estrogen treatments.

CONCLUSIONS

The use of insulin-sensitizing agents, such as metformin and inositols, along with lifestyle interventions may improve the metabolic profile in PCOS women.

Inositol Supplementation in the Prevention of Gestational Diabetes Mellitus

Inositol, an emerging novel therapy for the treatment of gestational diabetes mellitus (GDM), is a cyclic polyol that has insulin-like effects and plays an important role in glucose homeostasis. The conventional treatment of GDM with insulin and oral antihyperglycemic drugs usually comes with side effects, paving the way for and shedding spotlight on clinical trials involving inositol. This review analyzed a host of recent trials that involved inositol supplementation for preventing GDM and their positive outcomes in reducing the rate of GDM among obese and overweight pregnant women, as well as women with polycystic ovarian syndrome (PCOS) or a family history of type 2 diabetes mellitus.

Nutritional Supplementation for the Prevention and/or Treatment of Gestational Diabetes Mellitus

PURPOSE OF REVIEW

Gestational diabetes mellitus (GDM) is a common pregnancy complication that has short- and long-term health implications for both the mother and child. While lifestyle modifications, insulin therapy, and oral agents such as metformin are effective, they can be difficult to adhere to, and there remain concerns over long-term effects of oral agents on the infant. Further, GDM has no proven preventive strategies, which could be more effective than treatment postdiagnosis. Nutritional supplements are an appealing, potentially safer, and better tolerated alternative to pharmaceuticals to treat and/or prevent GDM. Here, we review the existing evidence for nutritional supplementation for treatment and prevention of GDM.

RECENT FINDINGS

There is limited evidence that myo-inositol, vitamins D and B6, magnesium, selenium, zinc, fatty acids, and probiotics might be beneficial for the prevention or treatment of GDM. There are very few studies for each nutrient, and the existing studies tend to have few participants. Where multiple studies of a nutrient exist, often those studies were conducted within the same country, limiting the generalizability of the findings, or alternatively there was no consensus across findings. There is limited evidence that nutritional supplementation of myo-inositol, vitamins D and B6, magnesium, selenium, zinc, fatty acids, and probiotics could improve glycemic control or prevent GDM. Our understanding is constrained by the small number of studies, small sample sizes in most studies, and by lack of consistency across findings. Further large, high-quality, randomized controlled trials are required to determine the efficacy of nutritional supplements to treat or prevent GDM.