A systematic review and meta-analysis on the impact of oral vitamin E supplementation on apolipoproteins A1 and B100

BACKGROUND AND AIM

Cardiovascular diseases (CVDs) are the number one cause of mortality worldwide. Apolipoprotein B (ApoB), apolipoprotein A1 (ApoA1), and ApoB/ApoA1 ratio are considered as predictors of CVD alongside with lipid profile. Evidence suggest that nutrients with antioxidant properties, especially vitamin E, are essential for a healthy cardiovascular system. The aim of present meta-analysis was to determine the effect alpha-tocopherol on ApoA1 and ApoB levels.

METHODS

PubMed-Medline and SCOPUS databases and Google Scholar were searched up to July 2021. Random-effects model was employed to perform meta-analysis. In order to find heterogeneity sources, subgroup analysis was performed. Trim and fill analysis was performed in case of presence of publication bias. Quality assessment was performed using Cochrane Collaboration's tool.

RESULTS

Seven eligible studies, involving 1284 individuals were included. Mean age of participants ranged between 25.4 and 59 years. There was no significant effect of vitamin E supplementation on Apo A1 (SMD = 0.22 IU/d; 95% CI: -0.38, 0.28; P = 0.481) and Apo B levels (SMD = -0.62 IU/d; 95% CI: -1.94, 0.70; P = 0.360).

CONCLUSION

No remarkable effect of vitamin E supplementation was observed on ApoA1 and ApoB levels in adults. Additional studies investigating the influence of vitamin E on apolipoproteins as primary outcome with larger sample size are suggested.

The association between carbohydrate quality index and anthropometry, blood glucose, lipid profile and blood pressure in people with type 1 diabetes mellitus: a cross-sectional study in Iran

BACKGROUND & AIM

Both types and amounts of dietary carbohydrates have always been issues of discussion in diabetes mellitus. Therefore, this study aimed to investigate the association between carbohydrate quality index (CQI) and anthropometry, fasting blood glucose (FBG), lipid profile, systolic (SBP), and diastolic (DBP) blood pressure in adults with type 1 diabetes mellitus (T1DM).

MATERIALS & METHODS

This was a cross-sectional study conducted on 261 adults with T1DM aged 17-36 years who referred to the Iranian Diabetes Association or Diabetes Clinic of Tehran University of Medical Sciences. Dietary data were collected using a 147-item food frequency questionnaire (FFQ). The CQI was calculated from the three indices including dietary fiber, glycemic index (GI), and solid carbohydrates/total carbohydrates ratio. The weight, height, waist circumference, physical activity, HcA1c, SBP, DBP of all participants were measured. Biochemical assessment including serum lipids and FBG levels were analyzed on 81 individuals.

RESULTS

Participants with a higher CQI had a lower body weight, GI, glycemic load, energy, and macronutrient intake (p < 0.05). In addition, after adjustment for age, sex, duration of diabetes, body mass index, physical activity, and energy intake, the lowest level of glycated hemoglobin A1c (HbA1c) was observed in the third tertile of CQI (β = -0.2; SE = 0.1; p-trend = 0.04). No significant association was observed with respect to CQI with FBG, lipid profile, and blood pressure.

CONCLUSION

It was concluded that there was an inverse association between CQI and HbA1c. No significant association was found with respect to CQI with FBG, lipid profile and blood pressure.

Effect of L-Carnitine Supplementation on Inflammatory Markers and Serum Glucose in Hemodialysis Children: A Randomized, Placebo-Controlled Clinical Trial

OBJECTIVES

Chronic inflammation is present in a high proportion of the chronic kidney disease (CKD) population, which can increase the risk of cardiovascular disease. Moreover, it is known as the leading cause of death in these patients. In addition, change in glucose metabolism is another common problem among CKD population. In this regard, it was found that insulin resistance and inflammation can perpetuate each other and simultaneously cause atherosclerosis. Because some studies have previously shown the positive effects of L-carnitine on reducing inflammation and controlling blood sugar, in the present study, we examined the effects of L-carnitine supplementation on serum inflammatory markers, fasting blood sugar (FBS), free carnitine (FC), albumin levels, and quality of life score among children on hemodialysis.

METHOD

Twenty-four children on hemodialysis (aged between 6 and 18 years) were enrolled in this randomized clinical trial study. Thereafter, 12 patients received 50 mg/kg of L-carnitine and 12 patients received placebo for a 10-week period. Afterward, we determined serum FC, interleukin-6 (IL-6), high-sensitivity C-reactive protein, FBS, and albumin and Pediatrics Quality of Life scores once at the baseline and once after performing intervention for 10 weeks. Moreover, the one-way repeated measures analysis was used to evaluate the effects of L-carnitine supplementation.

RESULTS

Although oral L-carnitine supplementation led to the decreased high-sensitivity C-reactive protein, this change was not significant compared with the placebo. Also, L-carnitine supplementation has significantly reduced serum levels of IL-6 and FBS, which has also raised serum FC and Pediatrics Quality of Life scores compared with the placebo. Notably, no significant change was observed in serum albumin levels.

CONCLUSION

Given the significant reductions in IL-6 and FBS levels, L-carnitine supplementation appeared to have some positive effects on the inflammation, blood glucose control, and prevention of cardiovascular events in these patients, as well as the improvement of quality of life. In this regard, L-carnitine therapy with a longer duration is recommended to obtain more effective results.

Effects of vitamin D supplementation on apolipoprotein A1 and B100 levels in adults: Systematic review and meta-analysis of controlled clinical trials

Cardiovascular disease (CVD) is a leading cause of death around the world. According to the studies, apolipoproteins A1 and B100 play crucial role in CVD development and progression. Also, findings have indicated the positive role of vitamin D on these factors. Thus, we conducted the present meta-analysis of randomized controlled trials (RCTs) to demonstrate the impact of vitamin D supplementation on apolipoproteins A1 and B100 levels in adults. PubMed and Scopus databases and Google Scholar were searched up to 21 December 2020. Relevant articles were screened, extracted, and assessed for quality based on the Cochrane collaboration's risk of bias tool. Data analysis conducted by random-effect model and expressed by standardized mean difference (SMD). The heterogeneity between studies was assessed by I-squared (I2) test. Subgroups and sensitivity Analyses were also conducted. Seven RCTs were identified investigating the impact of vitamin D on Apo A1 levels and six on Apo B100 levels. The findings showed the insignificant effect of vitamin D supplementation on Apo A1 (SMD=0.26 mg/dL; 95% confidence interval (CI), -0.10, 0.61; P = 0.155) and Apo B100 (standardized mean difference (SMD)=-0.06 mg/dL; 95% CI, -0.24, 0.12; P = 0.530) in adults. There was a significant between-study heterogeneity in Apo A1 (I2=89.3%, P < 0.001) and Apo B100 (I2 = 57.1%, P = 0.030). However, significant increase in Apo A1 in daily dosage of vitamin D (SMD=0.56 mg/dL; 95% CI, 0.02, 1.11; P = 0.044) and ≤12 weeks of supplementation duration (SMD=0.71 mg/dL; 95% CI, 0.08, 1.34; P = 0.028) was observed. No significant effects of vitamin D on Apo A1 and Apo B100 levels after subgroup analysis by mean age, gender, study population, dosage and duration of study. Overall, daily vitamin D supplementation and ≤12 weeks of supplementation might have beneficial effects in increasing Apo A1 levels, however, future high-quality trials considering these a primary outcome are required.

Carbohydrate quality index: Its relationship to menopausal symptoms in postmenopausal women

OBJECTIVE

The aim of this study was to determine the relationship between carbohydrate quality intake and menopausal symptoms.

STUDY DESIGN

This is a cross-sectional study of 393 postmenopausal women attending municipality health houses and health centers in the south of Tehran, Iran, from September 2016 to January 2017.

MAIN OUTCOME MEASURES

The dietary intake and menopausal symptoms of the participants were assessed with a validated food frequency questionnaire and a menopause rating scale (MRS) carbohydrate quality index (CQI) was calculated using three indices: dietary fiber, glycemic index, and the ratio of solid carbohydrates to total carbohydrates. Linear and logistic regressions were used to assess the relationship between CQI and menopausal symptoms.

RESULTS

After adjustment for age, education, time passed since menopause, body mass index, physical activity and energy intake, an inverse association was found between CQI and total MRS score (TMRSS) (β -0.61; p <0.001), somatic score (SS) (β -0.27; p <0.001) and psychological score (PS) (β -0.37; p <0.001) in multivariable linear regression. In addition, logistic regression analysis revealed that compared with the lowest quartile of CQI, participants in the highest quartile of CQI had a lower TMRSS (odds ratio (OR) 0.36, 95% confidence interval (CI) 0.19-0.68). Moreover, CQI was inversely related to SS (OR 0.34; 95% CI 0.17-0.68) and PS (OR 0.32; 95% CI 0.16-0.61). However, there was no significant association between CQI and urogenital score (US).

CONCLUSIONS

Higher-quality carbohydrate intake was found to be associated with lower somatic and psychological symptoms of menopause. These findings suggest that CQI may be an important basis for developing an effective dietary modification for reducing menopausal symptoms.

The impact of general health and social support on health promoting lifestyle in the first year postpartum: the structural equation modelling

Background and aim

Postpartum is a critical period for mothers which often leads to neglect of their own health. Mothers’ new responsibilities may affect their health promoting lifestyle (HPL). The aim of this study was to determine the impact of both general health and social support on health-promoting lifestyle.

Methods

A cross-sectional survey was conducted on 310 women who gave birth over a one-year period in Zanjan (Iran), 2016. A proportionate stratified random sampling technique was used to select respondents from each stratum. Health-promoting lifestyle was assessed using the health-promoting lifestyle profile II (HPLP II) scale. A structure equation model (SEM) was used to determine the relationship between observed and latent variables. Data were analysed using SPSS version 22 and LISREL 8.5 software.

Results

The age of 42.6% of the participants was more than 30 years and 40.3% of them had an academic education. The mean score of the health-promoting lifestyle was 131.28 (15.37). The structural equation model fitted well with RMSEA =0.07, CFI=0.92, and GFI=0.94. Among the latent factors, general health, with a factor load of −0.68, had greater impact on health-promoting lifestyle than social support. Moreover, there was a significant correlation (−0.63) between general health and perceived social support in the postpartum period.

Conclusion

health-promoting lifestyle was not at appropriate levels among women in the first year after delivery. These findings suggest that strengthening general health and social support would improve a health-promoting lifestyle in Iranian postpartum women.

A dose-response meta-analysis of the impact of body mass index on stroke and all-cause mortality in stroke patients: a paradox within a paradox

The obesity paradox is often attributed to fat acting as a buffer to protect individuals in fragile metabolic states. If this was the case, one would predict that the reverse epidemiology would be apparent across all causes of mortality including that of the particular disease state. We performed a dose-response meta-analysis to assess the impact of body mass index (BMI) on all-cause and stroke-specific mortality among stroke patients. Data from relevant studies were identified by systematically searching PubMed, OVID and Scopus databases and were analysed using a random-effects dose-response model. Eight cohort studies on all-cause mortality (with 20,807 deaths of 95,651 stroke patients) and nine studies of mortality exclusively because of stroke (with 8,087 deaths of 28,6270 patients) were evaluated in the meta-analysis. Non-linear associations of BMI with all-cause mortality (P < 0.0001) and mortality by stroke (P = 0.05) were observed. Among overweight and obese stroke patients, the risk of all-cause mortality increased, while the risk of mortality by stroke declined, with an increase in BMI. Increasing BMI had opposite effects on all-cause mortality and stroke-specific mortality in stroke patients. Further investigations are needed to examine how mortality by stroke is influenced by a more accurate indicator of obesity than BMI.