The effect of inositol supplementation on blood pressure: A systematic review and meta-analysis of randomized-controlled trials

The Role of Diet in the Prevention of Hypertension and Management of Blood Pressure: An Umbrella Review of Meta-Analyses of Interventional and Observational Studies

High blood pressure (BP) is a major pathological risk factor for the development of several cardiovascular diseases. Diet is a key modifier of BP, but the underlying relationships are not clearly demonstrated. This is an umbrella review of published meta-analyses to critically evaluate the wide range of dietary evidence from bioactive compounds to dietary patterns on BP and risk of hypertension. PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception until October 31, 2021, for relevant meta-analyses of randomized controlled trials or meta-analyses of observational studies. A total of 175 publications reporting 341 meta-analyses of randomized controlled trials (145 publications) and 70 meta-analyses of observational studies (30 publications) were included in the review. The methodological quality of the included publications was assessed using Assessment of Multiple Systematic Reviews 2 and the evidence quality of each selected meta-analysis was assessed using NutriGrade. This umbrella review supports recommended public health guidelines for prevention and control of hypertension. Dietary patterns including the Dietary Approaches to Stop Hypertension and the Mediterranean-type diets that further restrict sodium, and moderate alcohol intake are advised. To produce high-quality evidence and substantiate strong recommendations, future research should address areas where the low quality of evidence was observed (for example, intake of dietary fiber, fish, egg, meat, dairy products, fruit juice, and nuts) and emphasize focus on dietary factors not yet conclusively investigated.

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.

Myo-inositol supplementation improves cardiometabolic factors, anthropometric measures, and liver function in obese patients with non-alcoholic fatty liver disease

Background

Non-alcoholic fatty liver disease (NAFLD) as the hepatic manifestation of metabolic syndrome is closely associated with type 2 diabetes mellitus. Myo-inositol (MI)-a 6-C sugar alcohol-with insulin-mimetic, anti-diabetic, lipid-lowering, and anti-inflammatory properties has exerted favorable effects on insulin resistance-related disorders and metabolic disease, while recent animal studies revealed its positive effects on liver function. This study aimed to investigate the effects of MI supplementation on cardiometabolic factors, anthropometric measures, and liver function in obese patients with NAFLD.

Methods

This double-blinded placebo-controlled randomized clinical trial was carried out on 48 obese patients with NAFLD who were randomly assigned to either MI (4g/day) or placebo (maltodextrin 4g/day) along with dietary recommendations for 8 weeks. Glycemic indices, lipid profile, liver enzymes anthropometric measures, and blood pressure were evaluated pre- and post-intervention. Dietary intakes were assessed using a 3-day 24 h recall and analyzed by Nutritionist IV software. Insulin resistance was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR), and beta-cell function (HOMA-B) was also estimated.

Results

Anthropometric measures decreased significantly in both groups, while the reduction in weight (p = 0.049) and systolic blood pressure (p = 0.006) in the MI group was significantly greater than in the placebo group after adjusting for baseline values and energy intake. Although energy and macronutrient intakes decreased significantly in both groups, between-group differences were not significant after adjusting for the potential confounders. MI supplementation led to a significant reduction in serum fasting insulin (p = 0.008) and HOMA-IR (p = 0.046). There were significant improvements in lipid profile, liver enzymes, and aspartate aminotransferase/alanine aminotransferase ratio as well as serum ferritin level in the MI group, compared to the placebo group at the endpoint. By MI supplementation for eight weeks, 1 in 3 patients reduced one- grade in the severity of NAFLD.

Conclusion

MI supplementation could significantly improve IR, lipid profile, and liver function in patients with NAFLD. Further clinical trials with larger sample sizes, longer duration, different MI doses, and other inositol derivatives are recommended.

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.

Antihypertensive Therapy by ACEI/ARB Is Associated With Intestinal Flora Alterations and Metabolomic Profiles in Hypertensive Patients

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ACEI/ARB) are the first-line drugs for the treatment of essential hypertension (HTN), one of the most important risk factors for cardiovascular and cerebrovascular diseases. Intestinal flora and microbial metabolites have been demonstrated to play important roles in blood pressure (BP) regulation and HTN development. However, it remains elusive that intestinal bacteria and metabolites are associated with the protective effects of ACEI/ARB anti-hypertensive drugs against HTN. In this study, we evaluated the effect of ACEI/ARB on gut microbiome and metabolites in patients suffering from HTN. We performed 16S rRNA sequencing and fecal metabolomic analysis of 36 HTN patients placed on ACEI/ARB therapy and 19 newly diagnosed HTN patients with no history of anti-hypertensive treatment. Patients under medication treatment were further classified into well-controlled (n = 24) and poor-controlled (n = 12) groups according to their BP levels. The ACEI/ARB improved the intestinal microbiome of the HTN patients by reducing potentially pathogenic bacteria such as Enterobacter and Klebsiella and increasing beneficial bacteria such as Odoribacter. Moreover, ACEI/ARB therapy was correlated with significant metabolomic changes in the HTN patients, including progressively enhanced inositol from poor-controlled to well-controlled groups. The profiles of gut bacteria were linked to the production of metabolites, and inositol was negatively correlated with Klebsiella, Enterobacter, and Proteobacteria. Our study suggests that ACEI/ARB modulates gut microbial composition and functions and alters microbial metabolites in HTN patients.

Novel Chemical and Biological Insights of Inositol Derivatives in Mediterranean Plants

Inositols (Ins) are natural compounds largely widespread in plants and animals. Bio-sinthetically they derive from sugars, possessing a molecular structure very similar to the simple sugars, and this aspect concurs to define them as primary metabolites, even though it is much more correct to place them at the boundary between primary and secondary metabolites. This dichotomy is well represented by the fact that as primary metabolites they are essential cellular components in the form of phospholipid derivatives, while as secondary metabolites they are involved in a plethora of signaling pathways playing an important role in the surviving of living organisms. myo-Inositol is the most important and widespread compound of this family, it derives directly from d-glucose, and all known inositols, including stereoisomers and derivatives, are the results of metabolic processes on this unique molecule. In this review, we report the new insights of these compounds and their derivatives concerning their occurrence in Nature with a particular emphasis on the plant of the Mediterranean area, as well as the new developments about their biological effectiveness.