Nutrition and health

Objectives:
Does a low-carbohydrate diet (LCD) causally increase adiponectin concentration in adults?

Study design:
This review article included 11 RCTs with 534 participants in low-carbohydrate diet group and 513 participants in control group (group without a low-carbohydrate diet).
Proportion of carbohydrate from calorie was from 4 to 34% (4-34 En%).
Time of the follow-up varied between studies and ranged from 6 to 152 weeks.
Meta-regression analysis revealed that age [β = 0.04, p = 0.15], baseline BMI [β= -0.15, p = 0.15], time of follow-up [β = 0.01, p = 0.17], energy percentage of carbohydrates [β = 0.004, p = 0.90], energy percentage of protein [β = -0.12, p = 0.08], energy percentage of fat [β = 0.20, p = 0.61] and baseline adiponectin [β = 0.001, p = 0.97] are not sources of heterogeneity

Results and conclusions:
The investigators found low-carbohydrate diet significantly increased adiponectin concentration [0.02 µg/mL, 95% CI = 0.01 to 0.03, p 0.001].

The investigators found dose-response analysis indicated a nonlinear association between the percentage of carbohydrate and change in adiponectin level from baseline [p = 0.04].

The investigators found in subgroup analysis based on the proportion of carbohydrate from calorie, there was a significant increase in adiponectin concentration in studies that prescribed 30% of calorie from carbohydrates [0.12 µg/mL, 95% CI = 0.07 to 0.18].
In contrast, diets which consisted ≥30% of carbohydrates had no significant effect on adiponectin [0.50 µg/mL, 95% CI = -0.46 to 1.48].

The investigators concluded that a diet with 30% of calorie from carbohydrates (diet with 30 En% carbohydrates) causally increases adiponectin concentration in adults.

Original title:
Effect of low-carbohydrate diet on adiponectin level in adults: a systematic review and dose-response meta-analysis of randomized controlled trials by Shemirani F, Golzarand M, […], Mahmoudi M.

Link:
https://pubmed.ncbi.nlm.nih.gov/33455438/

Additional information of El Mondo:
Find more information/studies on carbohydrate consumption, diabetes and cardiovascular diseases right here.

The most easy way to follow a diet with maximum 30% of calorie from carbohydrates (diet with 30 En% carbohydrates) is to choose only meals/products with maximum 30 En% carbohydrates. Check here which products contain maximum 30 En% carbohydrates. However, the most practical way to follow a diet with maximum 30 En% carbohydrates is, all meals/products that you eat on a daily basis should on average contain maximum 30 En% carbohydrates.
30 En% carbohydrates means that the total amounts of carbohydrates make up for a 30% of the total kcal of the diet.

Adiponectin is a protein hormone produced and secreted exclusively by adipocytes (fat cells) that regulates the metabolism of lipids and glucose. Adiponectin influences the body's response to insulin. Adiponectin also has antiinflammatory effects on the cells lining the walls of blood vessels.
 

Objectives:
To compare the immunogenicity and safety of the influenza vaccine at reduced or full intradermal doses with full intramuscular doses to inform policy design in the event of vaccine shortages.

Study design:
This review article included a total of 29 RCTs with 13,759 participants and 1 cohort study with 164,021 participants.
Approximately half of the studies (14 studies) involved only participants aged 60 years or older or reported data for participants aged 60 years or older.

Results and conclusions:
The investigators found there was no statistically significant difference in seroconversion rates between the 3-µg, 6-µg, 7.5-µg and 9-µg intradermal vaccine doses and the 15-µg intramuscular vaccine dose for each of the H1N1, H3N2 and B strains.
However, the rates were significantly higher with the 15-µg intradermal dose compared with the 15-µg intramuscular dose for the H1N1 strain [rate ratio (RR) = 1.10, 95% CI = 1.01 to 1.20] and B strain [rate ratio = 1.40, 95% CI = 1.13 to 1.73].

The investigators found the seroprotection rates for the 9-µg and 15-µg intradermal doses did not vary significantly compared with the 15-µg intramuscular dose for all the 3 strains, except for the 15-µg intradermal dose for the H1N1 strain, for which rates were significantly higher [rate ratio = 1.05, 95% CI = 1.01 to 1.09].

The investigators found local adverse events were significantly higher with intradermal doses than with the 15-µg intramuscular dose, particularly erythema [3-µg dose: RR = 9.62, 95% CI = 1.07 to 86.56; 6-µg dose: RR = 23.79, 95% CI = 14.42 to 39.23; 9-µg dose: RR = 4.56, 95% CI = 3.05 to 6.82; 15-µg dose: RR = 3.68, 95% CI = 3.19 to 4.25] and swelling [3-µg dose: RR = 20.16, 95% CI = 4.68 to 86.82; 9-µg dose: RR = 5.23, 95% CI = 3.58 to 7.62; 15-µg dose: RR = 3.47, 95% CI = 2.21 to 5.45].

The investigators found fever and chills were significantly more common with the 9-µg intradermal dose than the 15-µg intramuscular dose [fever: RR = 1.36, 95% CI = 1.03 to 1.80; chills: RR = 1.24, 95% CI = 1.03 to 1.50] while all other systemic adverse events were not statistically significant for all other doses.

The investigators concluded that immunogenicity resulting from 3-µg, 6-µg, 7.5-µg and 9-µg influenza intradermal vaccination doses is not significantly different from full-dose 15-µg intramuscular vaccination for most viral strains, irrespective of patient age.
However, the 15-µg intradermal vaccine shows significantly better immunogenicity for some of the outcomes and strains, suggesting that the immunological response may be dose-related.

Original title:
Immunogenicity and Safety of Reduced-Dose Intradermal vs Intramuscular Influenza Vaccines: A Systematic Review and Meta-analysis by Egunsola O, Clement F, […], Noseworthy T.

Link:
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2776045

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Intradermal injection is a shallow or superficial injection of a substance into the dermis. The dermis or corium is a layer of skin between the epidermis and subcutaneous tissues,

Objectives:
Vitamin D deficiency during pregnancy or infancy is associated with adverse growth in children. No systematic review has been conducted to summarize available evidence on the effect of vitamin D supplementation in pregnancy and infancy on growth and body composition in children. Therefore, this review article has been conducted.

Does vitamin D supplementation during pregnancy or infancy increase adiposity (severe or morbid overweight) risk in childhood?

Study design:
This review article included 12 RCTs with a total of 4,583 participants.
The doses of vitamin D in the intervention group (group with vitamin D supplements) were 60,000 IU/4 weeks (1,500 mcg/4 weeks) or 60,000 IU/8 weeks and in the control group (group without vitamin D supplements) was 400 IU/day.

Results and conclusions:
The investigators found vitamin D supplementation during pregnancy was associated with higher triceps skinfold thickness (mm) [MD = 0.33, 95% CI = 0.12 to 0.54, I2 = 34%] in neonates.

The investigators found vitamin D supplementation during pregnancy or infancy was associated with significantly increased length for age z-score in infants at 1 year of age [MD = 0.29, 95% CI = 0.03 to 0.54, I2 = 0%].

The investigators found vitamin D supplementation during pregnancy or infancy was associated with lower body mass index (BMI) (kg/m²) [MD = -0.19, 95% CI = -0.34 to -0.04, I2 = 0%] and body mass index z-score (BMIZ) [MD = -0.12, 95% CI = -0.21 to -0.04, I2 = 0%] in offspring at 3-6 years of age.

The investigators found vitamin D supplementation during early life was not observed to be associated with children’s bone, lean or fat mass.

The investigators concluded vitamin D supplementation during pregnancy or infancy is associated with reduced adiposity (severe or morbid overweight) in childhood. Future large well-designed double blinded RCTs are needed to assess the effectiveness of vitamin D supplementation in early life on children’s bone health, lean mass and adiposity.

Original title:
Effect of Vitamin D Supplementation in Early Life on Children's Growth and Body Composition: A Systematic Review and Meta-Analysis of Randomized Controlled Trials by Ma K, Wei SQ, [...], Wen SW.

Link:
https://www.mdpi.com/2072-6643/13/2/524/htm

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Objectives:
Fish oil has been shown to reduce the risk of metabolic disorders. However, the effects of fish oil intervention on glucose metabolism and insulin sensitivity are still controversial, especially in children. Therefore, this review article has been conducted.

Do fish oil supplements (EPA + DHA) improve insulin sensitivity in children?

Study design:
This review article included 13 RCTs with 567 children in placebo group (group without fish oil supplements) and 565 in fish oil group (intervention group).

No heterogeneity was found for the pooled and subgroup analyses.

Results and conclusions:
The investigators found compared with the placebo group, fish oil intervention had beneficial effects on insulin sensitivity in the pooled analysis [WMD = -0.219, 95% CI = -0.392 to -0.046, p = 0.013].

These beneficial effects were also found in subgroup analyses, when the fish oil intervention period was short-term (≤6 months) low dose (eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) dose 1.5 g/day) and high ratio (eicosapentaenoic acid to docosahexaenoic acid ≥1).

The investigators concluded fish oil supplements, especially 1.5 g/day EPA + DHA during 6 months, improve insulin sensitivity in children.

Original title:
Effect of Fish Oil on Insulin Sensitivity in Children: A Systematic Review and Meta-Analysis of Randomized, Controlled Trials by Hou M, Zhou W, [...], Lv H.

Link:
https://pubmed.ncbi.nlm.nih.gov/33388274/

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Find more information/studies on EPA + DHA and diabetes right here.
 

Objectives:
Increasing macular pigment optical density (MPOD) as a result of increased macular concentration of lutein and zeaxanthin may reduce the risk of age-related macular degeneration (AMD). Therefore, this review article has been conducted.

Have daily egg consumption beneficial effects on macular pigment optical density and serum lutein levels?

Study design:
This review article included 5 RCTs with a total of 296 participants.
There was no heterogeneity between studies.

Results and conclusions:
The investigators found that egg consumption significantly increased macular pigment optical density [WMD = +0.037, 95% CI = 0.004 to 0.069, p = 0.027] and serum lutein levels [WMD = +0.150 μmol/L, 95% CI = 0.037 to 0.263, p = 0.009].

The investigators found subgroup analyses showed that egg consumption had a larger effect on macular pigment optical density in studies with a parallel design and increased serum lutein levels to a greater extent in a healthy population.

The investigators concluded daily egg consumption have beneficial effects on macular pigment optical density and serum lutein level is inversely associated with reduced age-related macular degeneration progression. Further clinical trials are required to confirm the results of this review article.

Original title:
A positive effect of egg consumption on macular pigment and healthy vision: a systematic review and meta-analysis of clinical trials by Sikaroudi MK, Saraf-Bank S, […], Soltani S.

Link:
https://pubmed.ncbi.nlm.nih.gov/33491232/

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Objectives:
Data on efficacy of hepatitis-B vaccine (HBV) in patients with inflammatory bowel disease (IBD) is limited. Therefore, this review article has been conducted.

What is the efficacy of hepatitis-B vaccine (HBV) in patients with inflammatory bowel disease (IBD)?

Study design:
This review article included 14 studies with 2,375 patients.
4 data sets were available from 2 studies that compared HBV response in patients with IBD against healthy controls.

Results and conclusions:
The investigators found the pooled odds ratio of HBV response in IBD patients was 0.13 [95% CI = 0.05 to 0.33, p = 0.001].

The investigators found the pooled proportion of adequate immune response (AIR) was 64% [95% CI = 55 to 72.1, p = 0.003] from 13 data sets and effective immune response (EIR) was 39.7% [95% CI = 30.7 to 49.5, p = 0.04] from 10 data sets.

The investigators concluded that patients with inflammatory bowel disease (IBD) on immunosuppression demonstrate significantly reduced HBV response as compared with general population.

Original title:
Hepatitis-B Vaccine Response in Inflammatory Bowel Disease Patients: A Systematic Review and Meta-analysis by Kochhar GS, Mohan BP, […], Farraye F.

Link:
https://pubmed.ncbi.nlm.nih.gov/33393585/

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Objectives:
Does a low selenium level in human tissues increase the risk of breast cancer?

Study design:
This review article included 18 case-control studies with 3,374 women diagnosed with breast cancer (case group) and 3,582 healthy controls (women without breast cancer).

Results and conclusions:
The investigators found selenium level of the case group (group with women diagnosed with breast cancer) was significantly lower than the control group (group with women without breast cancer) [-0.53 μg/L, 95% CI = -0.72 to -0.34, p 0.001].

The investigators found in subgroup analysis that serum selenium level of the case group was significantly lower than the control group [-1.14 μg/L, 95% CI = -1.70 to -0.58, p 0.001].

The investigators found in subgroup analysis that plasma selenium level of the case group was significantly lower than the control group [-0.21 μg/L, 95% CI = -0.37 to -0.04, p 0.014].

The investigators found in subgroup analysis that selenium level of toenail of the case group was significantly lower than the control group [-0.21 μg/L, 95% CI = -0.38 to -0.03, p 0.021].

The investigators concluded that a low selenium level in human tissues increases the risk of breast cancer, which may improve the understanding of the effects of selenium on human health.

Original title:
Relationship Between Selenium in Human Tissues and Breast Cancer: a Meta-analysis Based on Case-Control Studies by Zhu X, Pan D, […], Sun G.

Link:
https://pubmed.ncbi.nlm.nih.gov/33420696/

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Objectives:
Chronic kidney disease (CKD) is a major health problem worldwide. Evidence supporting the use of probiotic, prebiotic and synbiotic supplementation in the management of CKD is mixed, although some studies suggest they may be useful. Therefore, this review article has been conducted.

Do probiotic, prebiotic and synbiotic supplementation improve cardiometabolic and oxidative stress parameters in patients with chronic kidney disease?  

Study design:
This review article included 14 RCTs.

Results and conclusions:
The investigators found in patients with chronic kidney disease, probiotic, prebiotic and synbiotic supplementation significantly reduced:
-total cholesterol [SMD = -0.25, 95% CI = -0.46 to -0.04, I2 = 00.0%];
-fasting blood glucose [SMD = -0.41, 95% CI = -0.65 to -0.17, I2 = 00.0%];
-homeostatic model assessment of insulin resistance [SMD = -0.63, 95% CI = -0.95 to -0.30, I2 = 43.3%];
-insulin levels [SMD = -0.49, 95% CI = -0.90 to -0.08, I2 = 65.2%];
-high-sensitivity C-reactive protein levels [SMD = -0.52, 95% CI = -0.81 to -0.22, I2 = 52.7%] and;
-malondialdehyde levels [SMD = -0.79, 95% CI = -1.22 to -0.37, I2 = 69.8%] compared with control interventions.

The investigators found in patients with chronic kidney disease, probiotic, prebiotic and synbiotic supplementation significantly increased:
-the quantitative insulin sensitivity check index [SMD = 0.78, 95% CI = 0.51 to 1.05, I2 = 00.0%];
-total antioxidant capacity [SMD = 0.42, 95% CI = 0.18 to 0.66, I2 = 00.0%] and;
-glutathione levels [SMD = 0.52, 95% CI = 0.19 to 0.86, I2 = 37.0%].

The investigators concluded probiotic, prebiotic and synbiotic supplementation improve cardiometabolic and oxidative stress parameters in patients with chronic kidney disease.

Original title:
Effect of Probiotic, Prebiotic, and Synbiotic Supplementation on Cardiometabolic and Oxidative Stress Parameters in Patients with Chronic Kidney Disease: a Systematic Review and Meta-analysis by Bakhtiary M, Morvaridzadeh M, […], Heshmati J.

Link:
https://pubmed.ncbi.nlm.nih.gov/33526314/

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Find here more information/studies about review article/significant, probitocis, kidney disease, diabetics and chronic diseases.

Levels of malondialdehyde can be also considered (as a marker of lipid peroxidation) to assess the membrane damage in spermatozoa; this is crucial because oxidative stress affects sperm function by altering membrane fluidity, permeability and impairing sperm functional competence.
Lipid peroxidation is a well-established mechanism of cellular injury and is used as an indicator of oxidative stress in cells and tissues.

Glutathione is one of the body's most important and potent antioxidants. As an antioxidant, glutathione helps neutralize free radicals and reduce oxidative stress that can damage the body’s cells.

Homeostasis model assessment (HOMA) and quantitative insulin sensitivity check index (QUICKI) have been used to quantify degrees of insulin resistance and β-cell secretory capacity.
 

Objectives:
Some studies have reported the association between maternal serum zinc (Zn) levels and pre-eclampsia. However, many studies have reported controversial results. Therefore, this review article has been conducted.

Does a low maternal serum zinc level increase risk of pre-eclampsia in African women?

Study design:
This review article included 12 observational studies.

Results and conclusions:
The investigators found the mean values of serum zinc level were significantly lower in pre-eclamptic women as compared with normotensive pregnant women [zinc = 59.40 ± 22.80 μg/dL and 80.24 ± 16.04 μg/dL], respectively.

The investigators found the pooled SMD of zinc was significantly reduced in pre-eclamptic women as compared with normotensive pregnant women with the SMD of -1.45 [95% CI -2.26 to -0.65].

The investigators concluded that the maternal serum zinc level is lower in pre-eclamptic women than normotensive pregnant women. This suggests that zinc could be involved in the etio-pathogenesis of pre-eclampsia. However, the specific functions of zinc in pre-eclampsia pathogenesis should be proved in large-scale clinical trial studies.

Original title:
Maternal Serum Zinc Level and Pre-eclampsia Risk in African Women: a Systematic Review and Meta-analysis by Tesfa E, Nibret E and Munshea A.

Link:
https://pubmed.ncbi.nlm.nih.gov/33527339/

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Find more information/studies on zinc and food fortification/malnutrition right here.

Pre-eclampsia is a disorder of pregnancy characterized by the onset of high blood pressure and often a significant amount of protein in the urine.

Objectives:
Does a high dietary intake of β-cryptoxanthin reduce the risk of osteoporosis and hip fracture?

Study design:
This review article included 7 cohort studies, 4 case-control studies and 4 cross-sectional studies with a total of 100,496 individuals.
The methodological qualities of all studies were rated as “fair” to “good”.
The number of populations in each study ranged from 59 to 25,566.

Results and conclusions:
The investigators found that a high dietary intake of β-cryptoxanthin significantly reduced risk of osteoporosis with 24% [OR = 0.76, 95% CI = 0.66 to 0.88, p = 0.0002, I2 = 36%, p = 0.11].

The investigators found in subgroup analysis that a high dietary intake of β-cryptoxanthin significantly reduced risk of osteoporosis with 28% [OR = 0.72, 95% CI = 0.58 to 0.91, p = 0.005, I2 = 59%] among women.

The investigators found in subgroup analysis that a high dietary intake of β-cryptoxanthin significantly reduced risk of osteoporosis with 20% [OR = 0.80, 95% CI = 0.65 to 1.00, p = 0.005, I2 = 11%] among men.

The investigators found that a high dietary intake of β-cryptoxanthin significantly reduced risk of hip fracture with 28% [OR = 0.72, 95% CI = 0.60 to 0.87, p = 0.0008, I2 = 55%].

The investigators found in subgroup analysis that a high dietary intake of β-cryptoxanthin significantly reduced risk of hip fracture with 29% [OR = 0.71, 95% CI = 0.54 to 0.94, p = 0.02, I2 = 71%] among women. 

The investigators concluded that a high dietary intake of β-cryptoxanthin reduces the risk of osteoporosis and hip fracture. Further longitudinal studies are needed to validate the causality of current findings.

Original title:
Effects of β-Cryptoxanthin on Improvement in Osteoporosis Risk: A Systematic Review and Meta-Analysis of Observational Studies by Kim SJ, Anh NH, […], Kwon SW.

Link:
https://www.mdpi.com/2304-8158/10/2/296/htm

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Objectives:
Is there a causal relationship between ginger intake and improvements of major oxidative stress (OS) parameters, such as glutathione peroxidase activity, total antioxidant capacity, alondialdehyde (MDA) levels and CAT activity?   

Study design:
This review article included 12 RCTs.

Results and conclusions:
The investigators found ginger intake significantly increased glutathione peroxidase (GPx) activity [SMD = 1.64, 95% CI = 0.43 to 2.85, I2 = 86.8%] compared to control group (group without ginger intake). 

The investigators found ginger intake significantly increased total antioxidant capacity (TAC) [SMD = 0.40, 95% CI = 0.06 to 0.73, I2 = 42.8%] compared to control group. 

The investigators found ginger intake significantly decreased alondialdehyde (MDA) levels [SMD = -0.69, 95% CI = -1.26 to -0.12, I2 = 85.8%] compared to control group.

The investigators found ginger supplementation non-significantly increased CAT activity [SMD = 1.09, 95% CI = -0.07 to 2.25, I2 = 87.6%].

The investigators concluded this meta-analysis (review article) presents convincing evidence supporting the efficacy of ginger supplementation on improving oxidative stress (OS) levels.

Original title:
Effect of ginger (Zingiber officinale) supplementation on oxidative stress parameters: A systematic review and meta-analysis by Morvaridzadeh M, Sadeghi E, […], Heshmati J.

Link:
https://pubmed.ncbi.nlm.nih.gov/33458848/

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Oxidative stress is an imbalance between free radicals and antioxidants in your body.
 

Objectives:
Does a high dietary cholesterol intake increase risk of gestational diabetes mellitus?

Study design:
This review article included 3 cohort studies, 4 cross-sectional studies and 2 case-control studies involving 30,123 participants and 3,237 women with gestational diabetes mellitus (diabetes mellitus in pregnancy).

Results and conclusions:
The investigators found comparing highest versus lowest category of dietary cholesterol intake, that the highest dietary cholesterol intake significantly increased risk of gestational diabetes mellitus with 49% [pooled RR = 1.49, 95% CI = 1.18 to 1.88].

The investigators found in dose-response analysis that the risk of gestational diabetes mellitus significantly increased by 32% [RR = 1.32, 95% CI = 1.20 to 1.45] for every increase of 100 mg per day in dietary cholesterol intake.

The investigators concluded a high dietary cholesterol intake (at least 100 mg per day) increases risk of gestational diabetes mellitus.

Original title:
Dietary Cholesterol Intake and Risk of Gestational Diabetes Mellitus: A Meta-Analysis of Observational Studies by Gao F and Cui CY.

Link:
https://pubmed.ncbi.nlm.nih.gov/33416437/

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Objectives:
Are serum albumin concentrations lower in patients with stable COPD compared to non-COPD controls?  

Study design:
This review article included 26 studies with a total of 2,554 COPD patients (74% males) and 2,055 non-COPD controls (63% males).
Overall, the mean age of participants across all studies was 61.7 years in COPD patients and 64.6 years in controls (patients without COPD).
Almost all (24 out of 26) were prospective cohort studies.

The Begg’s [p = 0.04] and Egger’s tests [p = 0.01] showed a significant publication bias; however, the trim-and-fill analysis found that no study was missing or should be added.

Results and conclusions:
The investigators found pooled results showed that serum albumin concentrations were significantly lower in COPD patients [SMD = -0.50, 95% CI = -0.67 to -0.32, p 0.001, I2 = 85.7%, p 0.001] .
Sensitivity analysis showed that the effect size was not modified when any single study was in turn removed [effect size ranged between -0.44 and -0.52].

The investigators found no significant differences in SMD of serum albumin concentrations between COPD patients with forced expiratory volume in the 1st second (FEV1) 50% and those with FEV1 > 50%.

The investigators concluded that serum albumin concentrations are lower in patients with stable COPD compared to non-COPD controls. This supports the presence of a deficit in systemic anti-inflammatory and antioxidant defense mechanisms in COPD.

Original title:
Serum Albumin Concentrations in Stable Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis by Zinellu E, Fois AG, […], Pirina P.

Link:
https://www.mdpi.com/2077-0383/10/2/269/htm

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Objectives:
Evidence suggests that vitamin C supplementation could be a potential therapy in type 2 diabetes. However, its effectiveness and evidence quality require further evaluation. Therefore, this review article has been conducted.

Does oral vitamin C supplementation improve glycemic control, cardiovascular risk factors and oxidative stress in people with type 2 diabetes?

Study design:
This review article included 28 RCTs with in totaal 1,574 participants.
RCTs were predominantly short term (6 months) with a small number of participants (n 100).

Results and conclusions:
The investigators found that oral vitamin C supplementation significantly reduced systolic blood pressure [mean difference = -6.27, 95% CI = -9.60 to -2.96 mmHg, p = 0.0002, with moderate evidence certainty].

The investigators found that oral vitamin C supplementation significantly reduced HbA1c levels [mean difference = -0.54%, 95% CI = -0.90 to -0.17, p = 0.004, with very low evidence certainty].

The investigators found that oral vitamin C supplementation significantly reduced diastolic blood pressure [mean difference = -3.77, 95% CI = -6.13 to -1.42 mmHg, p = 0.002, with very low evidence certainty].

The investigators concluded evidence from short-term RCTs suggests that oral vitamin C supplementation may improve glycemic control and blood pressure in people with type 2 diabetes. However, vitamin C supplementation cannot currently be recommended as a therapy until larger, long-term and high-quality trials confirm these findings.

Original title:
Effects of Vitamin C Supplementation on Glycemic Control and Cardiovascular Risk Factors in People With Type 2 Diabetes: A GRADE-Assessed Systematic Review and Meta-analysis of Randomized Controlled Trials by Mason SA, Keske MA and Wadley GD.

Link:
https://pubmed.ncbi.nlm.nih.gov/33472962/

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Objectives:
Does type 1 diabetes mellitus (T1DM) decrease bone mineral density (BMD) in children and adolescents?

Study design:
This review article included 9 cross-sectional studies with a total of 1,522 children and adolescents.

Funnel plot and the Egger test did not reveal significant publication bias.

Results and conclusions:
The investigators found a significant decrease in bone mineral density Z-score in the whole body [pooled WMD = -0.47, 95% CI = -0.92 to -0.02, I2 = 80.2%] and lumbar spine [pooled WMD = -0.41, 95% CI = -0.69 to -0.12, I2 = 80.3%] in children and adolescents with type 1 diabetes mellitus, which was consistent in published studies from Asia and South America, but inconsistent in the North America and Europe.
Sensitivity analyses did not modify these findings.

The investigators found, importantly, the differences in bone mineral density Z-scores were independent of age, level of glucose control (HbA1c) and prepubertal stage.

The investigators concluded type 1 diabetes mellitus (T1DM) decreases bone mineral density (BMD) Z-scores in the whole body and lumbar spine in children and adolescents.

Original title:
Association between type 1 diabetes mellitus and reduced bone mineral density in children: a meta-analysis by Zhu Q, J Xu J, […], Shi J.

Link:
https://pubmed.ncbi.nlm.nih.gov/33404757/  

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Objectives:
Is fish or omega-3 fatty acids consumption associated with a lower risk of venous thromboembolism (VTE)?

Study design:
This review article included 8 prospective cohort studies.
The follow-up duration ranged from 0.5 to 19 years.
The sample size ranged from 595 to 80,263.
The fish and omega-3 fatty acids consumption was assessed by food-frequency questionnaire (FFQ) in all studies.
The diagnosis of venous thromboembolism was obtained in registered medical record (imaging or autopsy) and food was considered as the source of omega-3 fatty acids in all included studies.
Begg's rank-correlation test showed no evidence of publication bias.

Results and conclusions:
The investigators found the overall multi-variable adjusted RR showed no significant relationship between fish consumption and the risk of venous thromboembolism [RR = 1.02, 95% CI = 0.93 to 1.11, p = 0.709, I2 = 33%, p = 0.176].
The sensitivity analysis showed only minimal changes in magnitude of the pooled RR when any study was excluded from the meta-analysis, suggesting that no individual study had excessive influence on these robust aggregate results.

The investigators found the overall multi-variable adjusted RR showed that omega-3 fatty acids consumption was associated with a lower risk of 11% for venous thromboembolism [RR = 0.89, 95% CI = 0.80 to 0.98, p = 0.024, I2 = 0%, p = 0.469].
The sensitivity analysis showed only minimal changes in magnitude of the pooled RR when any study was excluded from the meta-analysis, suggesting that no individual study had excessive influence on these robust aggregate results.

The investigators found the overall multi-variable adjusted RR showed that omega-3 fatty acids consumption was associated with a lower risk of 55% for recurrent venous thromboembolism [RR = 0.45, 95% CI = 0.25 to 0.81, p = 0.008, I2 = 26.4%, p = 0.244].
Significant because RR of 1 was not found in the 95% CI of 0.25 to 0.81. RR of 1 means no risk/association.

The investigators concluded omega-3 fatty acids consumption is associated with a lower risk of both venous thromboembolism and recurrent venous thromboembolism.

Original title:
Associations of Fish and Omega-3 Fatty Acids Consumption With the Risk of Venous Thromboembolism. A Meta-Analysis of Prospective Cohort Studies by Zhang Y, Ding J, [...],Li Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7793732/

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Find more information/studies on omega-3 and fish consumption and cardiovascular diseases right here.

Venous thromboembolism (VTE) is a condition in which a blood clot forms most often in the deep veins of the leg, groin or arm (known as deep vein thrombosis, DVT) and travels in the circulation, lodging in the lungs (known as pulmonary embolism, PE).

Objectives:
Do melatonin supplements improve sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI) in adults with various diseases?

Study design:
This review article included a total of 23 RCTs.

Results and conclusions:
The investigators found that melatonin supplements had significant effects on sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI) [WMD = -1.24, 95% CI = -1.77 to -0.71, p = 0.000, I2 = 80.7%, p = 0.000].

The investigators found subgroup analysis based on health status revealed melatonin supplements in subjects with respiratory diseases [WMD = -2.20, 95% CI = -2.97 to -1.44, p = 0.000], metabolic disorders [WMD = -2.74, 95% CI = -3.48 to -2.00, p = 0.000] and sleep disorders [WMD = -0.67, 95% CI = -0.98 to -0.37, p = 0.000] had significant effects on sleep quality.

The investigators concluded the treatment with exogenous melatonin (melatonin supplements) has positive effects on sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI) in adults, particularly with respiratory diseases, metabolic disorders, primary sleep disorders; however, not with mental disorders, neurodegenerative diseases and other diseases.

Original title:
Effect of melatonin supplementation on sleep quality: a systematic review and meta-analysis of randomized controlled trials by Fatemeh G, Sajjad M, […], Khadijeh M.

Link:
https://pubmed.ncbi.nlm.nih.gov/33417003/

Additional information of El Mondo:
Find here more information/studies about RCTs/significant and chronic diseases.

Objectives:
Undernutrition is one of the most common problems among people living with Human Immunodeficiency Virus (HIV), contributing to premature death and the development of comorbidities within this population. In Sub-Saharan Africa (SSA), the impacts of these often inter-related conditions appear in a series of fragmented and inconclusive studies. Therefore, this review article has been conducted.

Does undernutrition increase the risk of mortality and morbidity among adults living with HIV in Sub-Saharan Africa (SSA)?

Study design:
This review article included 53 studies (cohort and cross-sectional studies) with a total of 367,680 adults living with HIV (76.2% females).
Publication year of the included studies ranged from 2006 to 2019.
The sample size of the included studies ranged from 71 in Kenya to 68,378 in Tanzania. Most were cohort studies (n = 47, 88.7%). About 63.8% of the included cohort studies had a follow-up period of less than 5 years for mortality and/or less than 2 years for morbidities.
NOS quality scores ranged from 5 to 9 for cohort studies and 8 to 10 for cross-sectional studies.
The mean quality score of the included studies was 7.34 [SD = 0.14].
There was no publication bias.

Results and conclusions:
The investigators found a meta-analysis of 23 cohort studies (involving 125,790 individuals) indicated that undernutrition significantly [AHR = 2.1, 95% CI = 1.8 to 2.4, I2 = 66.4%, p  0.001] increased the risk of mortality among adults living with HIV, while severely undernourished adults living with HIV were at higher risk of death [AHR = 2.3, 95% CI = 1.9 to 2.8) as compared to mildly undernourished adults living with HIV.

The investigators found, furthermore, the pooled estimates of 10 cohort studies (involving 104,387 adults living with HIV) revealed that undernutrition significantly increased the risk of developing tuberculosis [AHR = 2.1, 95% CI = 1.6 to 2.7, I2 = 75.2%, p  0.001] among adults living with HIV.

The investigators concluded that undernutrition has significant effects on mortality and morbidity among adults living with HIV. As the degree of undernutrition became more severe, mortality rate also increased. Therefore, these findings may be used to update the nutritional guidelines used for the management of people living with HIV (PLHIV), by different stakeholders, especially in limited-resource settings.

Original title:
Effects of undernutrition on mortality and morbidity among adults living with HIV in sub-Saharan Africa: a systematic review and meta-analysis by Alebel A, Demant D, […], Sibbritt D.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7780691/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition right here.

Objectives:
Although several epidemiological studies have investigated associations between poultry and fish consumption and pancreatic cancer (PC) risk, these findings have been inconsistent. Therefore, this review article has been conducted.

Do high dietary poultry or fish intakes increase risk of pancreatic cancer?

Study design:
This review article included 25 studies (cohort studies and case-control studies).

Results and conclusions:
The investigators found for the highest vs. lowest poultry intake category a significantly increased risk of 14% for pancreatic cancer [pooled RR = 1.14, 95% CI = 1.02 to 1.26] in cohort studies.
Significant because RR of 1 was not found in the 95% CI of 1.02 to 1.26. RR of 1 means no risk/association.

The investigators found there was no association between fish intake and pancreatic cancer risk [RR = 1.00, 95% CI = 0.93 to 1.07].
No association because RR of 1 was found in the 95% CI of 0.93 to 1.07. RR of 1 means no risk/association.

The investigators concluded that large amount of poultry intake increases pancreatic cancer risk, while fish intake is unlikely to be linked to pancreatic cancer risk. These findings require further investigation, particularly between poultry and pancreatic cancer.

Original title:
Poultry and Fish Intake and Pancreatic Cancer Risk: A Systematic Review and Meta-Analysis by Gao Y, Ma Y, […], Wang X.

Link:
https://pubmed.ncbi.nlm.nih.gov/33432844/

Additional information of El Mondo:
Find more information/studies on poultry and fish consumption and cancer right here.

Objectives:
Does dietary acrylamide intake increase risk of breast, endometrial and ovarian cancer?

Study design:
This review article included 14 prospective cohort studies.

Results and conclusions:
The investigators found no significant association between dietary acrylamide intake and the risk of breast [RR = 0.95, 95% CI = 0.90 to 1.01], endometrial [RR = 1.03, 95% CI = 0.89 to 1.19] and ovarian cancers [RR = 1.02, 95% CI = 0.84 to 1.24].
In addition, no significant association between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers in different subgroup analyses by smoking status, menopausal status, BMI status and different types of breast cancer.

The investigators concluded there is no significant association between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers.

Original title:
Dietary acrylamide intake and risk of women's cancers: a systematic review and meta-analysis of prospective cohort studies by Benisi-Kohansal S, Salari-Moghaddam A, […], Esmaillzadeh A.

Link:
https://pubmed.ncbi.nlm.nih.gov/33413725/

Additional information of El Mondo:
Find more information/studies on breast cancer right here.

Acrylamide is a chemical that naturally forms in starchy food products during high-temperature cooking processes, such as frying, roasting and baking. Acrylamide in food forms from sugars and an amino acid that are naturally present in food.