The Effect of Folic Acid Supplementation on Endothelial Function and Arterial Stiffness Markers in Adults: A Systematic Review and Meta-Analysis.

Folic acid might improve endothelial function, but the results are inconclusive. This systematic review evaluated the effect of folic acid supplementation on endothelial parameters and arterial stiffness in adults. The study protocol was registered with the PROSPERO database (CRD42021290195). The PubMed, Web of Sciences, Cochrane and Scopus databases were searched to identify English-language randomised controlled trials of the effect of folate supplementation on arterial stiffness and endothelial function markers in adults. There were significant differences between the effect of folic acid and placebo on flow-mediated dilation (random-effects model, standardized mean differences (SMD): 0.888, 95% confidence interval (CI): 0.447, 1.329, p < 0.001) and monocyte chemotactic protein 1 (random-effects model, SMD: -1.364, 95% CI: -2.164, -0.563, p < 0.001), but there was no significant difference in the central pulse wave velocity (fixed-effects model, SMD: -0.069, 95% CI: -0.264, 0.125, p = 0.485) and peripheral pulse wave velocity (fixed-effects model, SMD: -0.093, 95% CI: -0.263, 0.077, p = 0.284). In conclusion, folic acid might have a favourable effect on endothelial function but may not affect arterial stiffness. Further studies are needed to confirm these results.

The Effect of Conjugated Linoleic Acid Supplementation on Densitometric Parameters in Overweight and Obese Women-A Randomised Controlled Trial.

Background and Objectives: Conjugated linoleic acid (CLA) can improve bone health in animals, yet the effects on humans have not been consistent. Therefore, this parallel randomised controlled trial aimed to assess the effect of CLA supplementation on bone mineral density (BMD) and content (BMC) in overweight or obese women. Materials and Methods: The study population included 74 women who were divided into the CLA (n = 37) and control (n = 37) groups. The CLA group received six capsules per day containing approximately 3 g of cis-9, trans-11 and trans-10, cis-12 CLA isomers in a 50:50 ratio. The control group received the same number of placebo capsules that contained sunflower oil. BMC and BMD at total body, lumbar spine (L1-L4), and femoral neck were measured before and after a three-month intervention. Results: The comparison of BMC and BMD for the total body, lumbar spine (L1-L4), and femoral neck before and after the intervention showed no differences between the groups. However, a within-group analysis demonstrated a significant increase in BMC (p = 0.0100) and BMD (p = 0.0397) at lumbar spine (L1-L4) in the CLA group. Nevertheless, there were no significant differences between the CLA and placebo groups in changes in all analysed densitometric parameters. Conclusions: Altogether, three-month CLA supplementation in overweight and obese women did not improve bone health, although the short intervention period could have limited our findings, long-term intervention studies are needed. The study protocol was registered in the German Clinical Trials Register database (ID: DRKS00010462, date of registration: 4 May 2016).

Comparison of the Effect of Amaranth Oil vs. Rapeseed Oil on Selected Atherosclerosis Markers in Overweight and Obese Subjects: A Randomized Double-Blind Cross-Over Trial.

It is well known that rapeseed oil improves lipid profile and has antiatherosclerotic properties. Recently, amaranth oil has also become popular due to its potential health benefits. However, the effect of this oil on atherosclerosis markers in humans is not clear. Therefore, this study aimed to compare the effect of amaranth and rapeseed oils on selected atherosclerosis-related parameters in overweight and obese subjects. In this randomized cross-over study, 44 subjects were instructed to consume 20 mL of amaranth oil and rapeseed oil during two consecutive three-week intervention periods separated by a washout period of the same duration as the intervention. The outcome variables included changes in tumor necrosis factor-alpha, adiponectin, oxidized low-density lipoprotein, apolipoproteins (Apo) A1, B and E as well as glucose and insulin homeostasis markers. Compared to rapeseed oil, amaranth oil had a slight positive effect on adiponectin levels (mean (95% confidence interval): 0.55 (0.22-0.89) vs. -0.29 (-0.75-0.16), p = 0.0002) but negatively affected ApoB concentrations (0.05 (-0.01-0.11) vs. 0.03 (-0.07-0.00), p = 0.0004) and ApoB/A1 ratio (0.01 (-0.03-0.05) vs. -0.02 (-0.04-0.00), p = 0.0113). No differences between the other analyzed parameters were observed. In conclusion, amaranth oil does not have a greater beneficial effect on atherosclerosis markers than rapeseed oil. However, further studies with a longer intervention period are needed. The study was retrospectively registered with the German Clinical Trials Register within the number: DRKS00014046, date of registration: 3 May 2018.

The Effect of Sodium Butyrate Enemas Compared with Placebo on Disease Activity, Endoscopic Scores, and Histological and Inflammatory Parameters in Inflammatory Bowel Diseases: A Systematic Review of Randomised Controlled Trials.

INTRODUCTION: Administration of butyrate enemas might improve the health status of patients with inflammatory bowel disease (IBD). However, the results seem equivocal. Therefore, this systematic review aimed to assess the effect of sodium butyrate enemas on disease activity index (DAI), endoscopic scores, as well as histological and inflammatory parameters in IBD patients. METHODS: The PubMed, Scopus, Web of Science, and Cochrane databases were searched. Randomised controlled trials published in English that assessed the effect of butyrate enemas on DAI, clinical symptoms, inflammatory markers, as well as histological and endoscopic scores in patients with Crohn's disease (CD) and ulcerative colitis (UC) were included in the analysis. RESULTS: Eight studies involving 227 UC patients were included in this analysis. Only one study reported significant differences in DAI between groups. Besides, butyrate treatment groups did not differ significantly from controls concerning the effect on endoscopic and histological scores. Moreover, butyrate enemas exerted a significant effect on few inflammatory parameters measured in colonic mucosal biopsies. CONCLUSION: The current evidence is limited and does not support the application of butyrate enemas in UC. There are no reliable data regarding the efficacy of butyrate enemas in CD. The systematic review protocol was registered in the PROSPERO database (CRD42020163654).

[Vitamin D and Hashimoto's disease]. / Witamina D a choroba Hashimoto.

It is probably that vitamin D may play an important role in the pathogenesis of Hashimoto's disease. Previous studies have shown a higher incidence of vitamin D deficiencies in patients with Hashimoto's disease compared to healthy subjects. Probably the severity of Hashimoto's disease may affect serum 25-hydroxycholecalciferol (25(OH)D) concentrations. In addition, a negative correlation between serum 25(OH)D concentrations and the level of antithyroid antibodies was observed. Moreover, vitamin D supplementation seems to be effective in reducing the levels of thyroid peroxidase (TPO) antibodies both in patients with deficiency and with normal concentrations of vitamin D. However, further studies are needed to more accurately determine the effect of vitamin D supplementation on the Hashimoto's disease.

The Role of Vitamin D Oral Supplementation in Insulin Resistance in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: To evaluate the effect of vitamin D supplementation (alone or with co-supplementation) on insulin resistance in patients with polycystic ovary syndrome (PCOS). METHODS: We performed a literature search of databases (Medline, Scopus, Web of Knowledge, Cochrane Library) and identified all reports of randomized controlled trials (RCTs) published prior to April 2018. We compared the effects of supplementation with vitamin D alone (dose from 1000 IU/d to 60,000 IU/week) or with co-supplements to the administration of placebos in women diagnosed with PCOS. The systematic review and meta-analysis protocol was registered in the International Prospective Register of Systematic Reviews (Prospero) as number CRD42018090572. MAIN RESULTS: Eleven of 345 identified studies were included in the analysis; these involved 601women diagnosed with PCOS. Vitamin D as a co-supplement was found to significantly decrease fasting glucose concentrations and the HOMA-IR value. HOMA-IR also declined significantly when vitamin D was supplemented with a dose lower than 4000 IU/d. CONCLUSIONS: Evidence from RCTs suggests that the supplementation of PCOS patients with continuous low doses of vitamin D (<4000 IU/d) or supplementation with vitamin D as a co-supplement may improve insulin sensitivity in terms of the fasting glucose concentration (supplementation with vitamin D in combination with other micronutrients) and HOMA-IR (supplementation with vitamin D in continuous low daily doses or as co-supplement).

The effect of vitamin D supplementation on selected inflammatory biomarkers in obese and overweight subjects: a systematic review with meta-analysis.

PURPOSE: The objective of this systematic review was to assess the effect of vitamin D supplementation on selected inflammatory biomarkers in obese and overweight subjects. METHODS: The search process was based on the selection of publications (DB-RCT and RCT) listed in the following databases: PubMed, Web of Knowledge, Scopus, the Cochrane Library and Embase. To assess the study quality, a nine-point scoring system according to the Newcastle-Ottawa scale was used, and a high-quality study was defined by a threshold of ≥7 points. Thirteen randomized controlled trials were included. The analysed population consisted of 1955 overweight and obese subjects. The mean age ranged from 13.6 to 71.7 years. Changes in the concentration of 25-hydroxycholecalciferol (25(OH)D), C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were assessed. To combine individual study results, a meta-analysis was performed. RESULTS: The baseline levels of 25(OH)D suggested vitamin D deficiency or insufficiency in the analysed population. The vitamin D supplementation did not influence on CRP (std. mean differences -0.11; 95 % CI -0.27-0.04; p = 0.15), TNF-α (std. mean differences -0.13; 95 % CI -0.38-0.12; p = 0.31) and IL-6 concentrations (std. mean differences 0.1; 95 % CI -0.43-0.63; p = 0.71). CONCLUSIONS: This meta-analysis suggests that supplementation with vitamin D does not have a significant influence on changes in the concentration of selected inflammatory biomarkers in the obese and overweight subjects.

The effect of vitamin D supplementation on insulin and glucose metabolism in overweight and obese individuals: systematic review with meta-analysis.

The aim of this systematic review was to assess the effect of vitamin D supplementation on glucose and insulin metabolism in overweight and obese subjects. The search process was based on the selection of publications listed in the databases: PubMed, Scopus, Web of Knowledge, Embase and the Cochrane library that met the inclusion criteria. Twelve randomized controlled trials were included. The analysed population consisted of 1181 individuals with BMIs > 23 kg/m2. Changes in the concentration of 25(OH)D, fasting glucose, insulin and the HOMA-IR index were assessed. In the meta-regression analysis, a restricted maximum likelihood method was applied. To combine individual study results, a meta-analysis was performed. Vitamin D supplementation did not have an effect on glucose concentrations, insulin level and HOMA-IR values when the supplemented dose, time of supplementation and baseline of 25(OH)D concentration were taken under consideration in subgroup-analysis. This meta-analysis provides evidence that vitamin D supplementation has no significant effect on glucose and insulin metabolism in overweight and obese individuals.

Successful maintenance of body weight reduction after individualized dietary counseling in obese subjects.

The aim of this study was to describe the effectiveness of individualized dietary counseling in obese subjects based on narrative interview technique on the maintenance of body weight reduction, changes in dietary behaviors, including type of cooking and physical activity. One-hundred subjects out of four-hundred patients met the inclusion criteria. Individually, 45-minute educational program with motivation counseling was performed in 0, 6 and 12 weeks of the study. Patients were advised to follow individually well-balanced diet for 12 weeks. The individuals were asked about the changes in their dietary habits (Food Frequency Questionnaire). The mean percentage of body weight changes from the baseline were as follows: in 6th week- 5.9%, in 12th week - 10.9% and in 52th week - 9.7% (P < 0.0001), however there were no statistically significant changes while comparing body weight in 12th and 52th week. The maintenance of body weight reduction was connected with the dietary habits changes, mainly the type of cooking and increased consumption of vegetable oils. In conclusion, individualized dietary counseling, based on narrative interview technique is an effective intervention for obesity treatment that may help maintain body weight reduction and adapt the pro-healthy changes in type of cooking and sources of dietary fat.