Higher Leg and Trunk Muscle Activation during Balance Control in Copers versus People with Chronic Ankle Instability and Healthy Female Athletes

Highlights

Abstract

More than 70% of people with ankle sprain experience chronic ankle instability. However, some people are well adapted to this damage (copers) and do not suffer from chronic ankle instability (CAI). This cross-sectional study involved 34 female athletes, who were classified into three groups (athletes with CAI, copers, and healthy athletes) and tested on a Biodex Balance System. Surface electromyography (EMG) and balance scores were monitored. The coper and healthy group exhibited higher medial gastrocnemius (MG) EMG activity during unstable balance conditions. The rectus abdominus (RA) in the coper group and rectus femoris (RF) in the healthy group showed greater EMG activity compared to CAI during unstable conditions. During stable conditions, the coper group showed greater RA EMG activity compared to CAI, as well as higher tibialis anterior (TA) EMG activity compared to the healthy group. Additionally, balance error scores were higher in the CAI group than those in the healthy group under unstable conditions. In conclusion, decreased EMG activity of the MG, RF, and RA in CAI athletes may contribute to impaired balance in these individuals. The increased EMG activity of the MG, TA, and RA in copers might result in more trunk and ankle stability.

The effect of β-caryophyllene on food addiction and its related behaviors: A randomized, double-blind, placebo-controlled trial

Food addiction (FA) is a psychological construct that may be involved in the etiology of obesity. The cannabinoid system is involved in the addictive-like food preferences by acting on the dopaminergic pathway of the brain. β-caryophyllene is a dietary cannabinoid that is a cannabinoid type 2 (CB2) receptor agonist. This study explored the impacts of β-caryophyllene supplementation on eating behavior, appetite, mental health, anthropometric parameters, body composition, and some hormones related to appetite in women with obesity diagnosed with FA. Women with obesity and FA, diagnosed by the Yale Food Addiction Scale Score (YFAS-S) ≥3, were randomly allocated to receive a β-caryophyllene softgel (n = 26) (100 mg/daily with meal) or placebo (n = 26) for 8 weeks. Anthropometric measurements, body composition, eating behavior, biochemical markers, dietary intake, appetite, stress, anxiety, and depression were evaluated during the study period. β-caryophyllene administration significantly reduced YFAS-S compared to the placebo group (changes in FA score: 1.5 ± 0.9 vs. - 0.7 ± 1.4; corrected P = 0.05). Serum levels of orexin-A significantly decreased in the β-caryophyllene group (p = 0.02); however, no significant difference was observed compared to the placebo group (corrected P = 0.09). β-caryophyllene supplementation had no significant effect on body composition, anthropometric indices, appetite, eating behavior, dietary intake, physical activity level, mental health, and levels of oxytocin and neuropeptide Y (NPY), compared to the placebo. β-caryophyllene supplementation may have beneficial effects on improving YFAS-S in women with obesity diagnosed with FA. TRIAL REGISTRATION: Iranian Registry of Clinical Trials identifier: IRCT20200914048712N1.

Lack of Evidence for Crossover Fatigue with Plantar Flexor Muscles

The occurrence and mechanisms underlying non-local or crossover muscle fatigue is an ongoing issue. This study aimed to investigate crossover fatigue of the plantar flexor muscles. Sixteen recreationally active males (n = 6) and females (n = 10) visited the laboratory for four sessions and performed a single 5-s pre-test maximal voluntary isometric contraction (MVIC) with each plantar flexors muscle. Thereafter, the fatigue intervention involved two 100-s MVICs (60-s recovery) with their dominant plantar flexors or rested for 260-s (control). Subsequently, in two separate sessions, Hoffman reflexes (H-reflex) were evoked in the non-dominant, non-exercised, leg before and following the dominant leg fatigue or control intervention (Fatigue-Reflex and Control-Reflex conditions). MVIC forces and volitional (V)-waves were monitored in the non-dominant leg in the other two sessions (Fatigue-MVIC and Control-MVIC) before and after the intervention (fatigue or control) as well as during 12 repeated MVICs and immediately thereafter. Despite the force reduction in the dominant leg (42.4%, p = 0.002), no crossover force deficit with single (F_(1,9) = 0.02, p = 0.88, pƞ² = 0.003) or repeated (F_(1,9) = 0.006, p = 0.93, pƞ² = 0.001) MVIC testing were observed. The H-reflex did not change after the fatigue (F_(1,7) = 0.51; p = 0.49; pƞ² = 0.06) or repeated MVICs (F_(1,8) = 0.27; p = 0.61; pƞ² = 0.03). There were also no crossover effects of fatigue on the V-wave with single (F_(1,8) = 3.71, p = 0.09, pƞ² = 0.31) or repeated MVICs (F_(1,6) = 1.45, p = 0.27, pƞ² = 0.19). Crossover fatigue was not evident with the plantar flexors nor any significant changes in H-reflex and V-waves in the soleus muscle. This finding suggests that crossover fatigue may not necessarily occur in slow-twitch predominant muscle groups.

Interaction of MC4R rs17782313 variants and dietary carbohydrate quantity and quality on basal metabolic rate and general and central obesity in overweight/obese women: a cross-sectional study

BACKGROUND

Recent studies have shown that dietary carbohydrate quantity and quality as well as genetic variants may contribute to determining the metabolic rate and general and central obesity. This study aimed to examine interactions between melanocortin 4 receptor gene (MC4R) rs17782313 and dietary carbohydrate intake, glycemic index (GI), and glycemic load (GL) on body mass index (BMI), waist circumferences (WC), basal metabolic rate (BMR), and BMR/kg in overweight/obese women.

METHODS

A total of 282 Iranian women (BMI ≥ 25) aged 18-56 years were enrolled in this cross-sectional study. All participants were assessed for blood parameters, body composition, BMR, and dietary intake. Dietary carbohydrate intake, GI, and GL were determined using a valid, reliable 147-item food frequency questionnaire. MC4R rs17782313 was genotyped by the restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

After adjustment for age and energy intake, significant interactions were observed between carbohydrate intake and MC4R rs17782313 in terms of BMI (P Interaction = 0.007), WC (P Interaction = 0.02), and BMR/kg (P Interaction = 0.003) in this way that higher carbohydrate intake, compared with lower intake, was associated with an increase in BMI and WC for individuals with C allele carriers (TC + CC genotypes), while related to an increase in BMR/kg for those carrying the TT genotype. No significant interaction was found between MC4R rs17782313 and GI and GL on BMI, WC, BMR/kg, and BMR.

CONCLUSIONS

Interactions between the MC4R rs17782313 and carbohydrate intake probably can have an effect on BMI, WC, and BMR/kg in overweight/obese women.

The effect of Brassica vegetables on blood glucose levels and lipid profiles in adults. A systematic review and meta-analysis

Previous studies on the effect of Brassica vegetables on blood glucose and lipid profile have reported inconclusive findings. Due to the high prevalence of glucose and lipid metabolism disorders and their importance as predictors of chronic diseases, the present meta-analysis was performed to clarify the effect of Brassica vegetables on blood glucose and lipid profile. A systematic search of the databases of PubMed, Scopus, and Cochran Library was performed up to October 2020. All randomized controlled trials (RCTs) that examined the effect of Brassica vegetables on blood glucose and lipid profile were included in the study. The search results were limited to English-language publications. Finally, nine RCTs, including 548 participants, were selected for the present study. Pooled analysis indicated a significant reduction in total cholesterol (TC) (SMD = -0.28, 95%CI: 0.48 to 0.08; p = 0.005) following Brassica vegetables consumption. Overall, Brassica vegetables had no significant impact on serum levels of triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting blood sugar, and glycated hemoglobin. Consumption of Brassica vegetables had a statistically significant effect on TC concentration. However, further high-quality studies are needed to firmly establish the clinical efficacy of these plants.

The negative impact of obesity on the occurrence and prognosis of the 2019 novel coronavirus (COVID-19) disease: a systematic review and meta-analysis

PURPOSE

The 2019 novel coronavirus (COVID-19) is an emerging pandemic, with a disease course varying from asymptomatic infection to critical disease resulting to death. Recognition of prognostic factors is essential because of its growing prevalence and high clinical costs. This meta-analysis aimed to evaluate the global prevalence of obesity in COVID-19 patients and to investigate whether obesity is a risk factor for the COVID-19, COVID-19 severity, and its poor clinical outcomes including hospitalization, intensive care unit (ICU) admission, need for mechanical ventilation, and mortality.

METHODS

The study protocol was registered in PROSPERO (CRD42020203386). A systematic search of Scopus, Medline, and Web of Sciences was conducted from 31 December 2019 to 1 June 2020 to find pertinent studies. After selection, 54 studies from 10 different countries were included in the quantitative analyses. Pooled odds ratios (OR) with 95% confidence intervals (CIs) were calculated to assess the associations.

RESULTS

The prevalence of obesity was 33% (95% CI 30.0%-35.0%) among patients with COVID-19. Obesity was significantly associated with susceptibility to COVID-19 (OR = 2.42, 95% CI 1.58-3.70; moderate certainty) and COVID-19 severity (OR = 1.62, 95% CI 1.48-1.76; low certainty). Furthermore, obesity was a significant risk factor for hospitalization (OR = 1.75, 95% CI 1.47-2.09; very low certainty), mechanical ventilation (OR = 2.24, 95% CI 1.70-2.94; low certainty), intensive care unit (ICU) admission (OR = 1.75, 95% CI 1.38-2.22; low certainty), and death (OR = 1.23, 95% CI 1.06-1.41; low certainty) in COVID-19 patients. In the subgroup analyses, these associations were supported by the majority of subgroups.

CONCLUSION

Obesity is associated with COVID-19, need for hospitalization, mechanical ventilation, ICU admission, and death due to COVID-19.

LEVEL OF EVIDENCE

Level I, systematic reviews and meta-analyses.

Core Muscle Activation With Foam Rolling and Static Planks

The objective of this study was to compare the activation of the core (trunk) musculature during quadriceps and hamstrings foam rolling (FR) vs. prone and supine/reverse static planks to determine if FR is a viable means of training the core musculature. Using a randomized allocation, nine recreationally trained, young adults (18-26 years) performed two sets each of quadriceps and hamstrings FR as well as supine/reverse and prone static planks for 30-s each with 1-min rest between sets and 5-min rest between exercises. Electromyographic (EMG) activity of the lower abdominals (LA), external obliques (EO), lumbosacral erector spinae (LSES), upper lumbar erector spinae (ULES) muscle groups were normalized to a maximum voluntary contraction and analyzed. Quadriceps FR exhibited a very large magnitude greater LA activity compared to reverse plank (p = 0.033, d = 4.42) and hamstrings FR (p = 0.020, d = 3.49), respectively. The prone plank demonstrated very large magnitude higher EO EMG activity compared to reverse plank (p = 0.001, d = 9.17), hamstrings FR (p = 0.002, d = 8.14), and quadriceps FR (p = 0.011, d = 5.97). Reverse plank (p = 0.003, d = 12.06), and quadriceps FR (p = 0.002, d = 7.84) induced greater ULES activity compared to the prone plank and hamstrings FR, respectively. Reverse plank also exhibited very large magnitude higher LSES activity compared to the prone plank (p < 0.001, d = 7.68), hamstrings FR (p = 0.002, d = 4.11), and quadriceps FR (p = 0.005, d = 2.34), respectively. In conclusion, whereas reverse plank was the most effective activator of dorsal core muscles, quadriceps FR may also be a time efficient alternative exercise to activate back (ventral core) muscles. The prone plank is effective for ventral core muscles activation.

Metabolic phenotypes and risk of colorectal cancer: a systematic review and meta-analysis of cohort studies

BACKGROUND

The association of obesity with colorectal cancer (CRC) may vary depending on metabolic status.

OBJECTIVE

This meta-analysis aimed to investigate the combined impacts of obesity and metabolic status on CRC risk.

METHODS

The Scopus, PubMed, and web of sciences databases were systematically searched up to Jun 2021 to find all eligible publications examining CRC risk in individuals with metabolically unhealthy normal-weight (MUHNW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUHO) phenotypes.

RESULTS

A total of 7 cohort studies with a total of 759,066 participants were included in this meta-analysis. Compared with healthy normal-weight people, MUHNW, MHO, and MUHO individuals indicated an increased risk for CRC with a pooled odds ratio of 1.19 (95% CI = 1.09-1.31) in MUHNW, 1.14 (95% CI = 1.06-1.22) in MHO, and 1.24 (95% CI = 1.19-1.29) in MUHO subjects. When analyses were stratified based on gender, associations remained significant for males. However, the elevated risk of CRC associated with MHO and MUHO was not significant in female participants.

CONCLUSIONS

The individuals with metabolic abnormality, although at a normal weight, have an increased risk for CRC. Moreover, obesity is associated with CRC irrespective of metabolic status.

Mercury Exposure and Risk of Type 2 Diabetes: A Systematic Review and Meta-Analysis

METHODS

Scopus and PubMed databases were systematically searched from their inception to November 2021 to obtain pertinent studies. Standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) were calculated to evaluate the difference in Hg levels between people with and without T2DM. The association of the Hg exposure with T2DM was assessed using a random-effects model by pooling the odds ratios (ORs) and 95% CIs.

RESULTS

A total of 17 studies, with 42,917 participants, aged ≥18 years, were analyzed. Overall, Hg levels were significantly higher in T2DM patients compared with non-T2DM controls (SMD = 1.07; 95%CI = 0.59 to 1.55, P ≤ 0.001), with significant heterogeneity across studies (I² = 96.1%; P=≤0.001). No significant association was found between Hg exposure and risk of T2DM in the overall analysis and subgroup analysis based on the source of sample and study design. However, higher exposure to Hg was related to reduced risk of T2DM in men (OR = 0.71; 95%CI = 0.57 to 0.88), but not in women. No significant evidence for publication bias was detected.

CONCLUSIONS

Although the Hg level in T2DM is significantly higher than that of nondiabetics, there was no association between Hg exposure and the overall risk of T2DM. Nevertheless, our study shows that higher exposure to Hg might reduce the risk of T2DM in men.

Factors Affecting the Life Satisfaction of the older adult: The Role of Place attachment

This study examined the association between life satisfaction and place attachment in the older adult. A total of 200 subjects of Kerman city, Iran, responded to questionnaires on life satisfaction and place attachment. The data were analyzed using chi-square, analysis of variance, correlation, and hierarchical multiple regression analysis by the SPSS software version 18. Approximately 51,4% of the subjects had intermediate life satisfaction. The Life satisfaction mean was significantly lower in subjects over 80 of the male gender, single marital status, with more than 3 chronic diseases and bad self-rated health. The majority of respondents had intermediate levels of place attachment (56,6%). There was a significant correlation between life satisfaction and place attachment. Independent variables accounted for 34,2% of the variance in life satisfaction. Individuals with higher attachment had higher levels of life satisfaction than those with lower place attachment. Place attachment is an appropriate strategy to increase life satisfaction in aging.

Effects of Pre/Probiotic Supplementation on Breast Milk Levels of TGF-b1, TGF-b2, and IgA: A Systematic Review and Meta-Analysis of Randomized-Controlled Trial

Background: Previous studies have proposed that the maternal intake of pre/probiotics may affect the immune composition of breast milk. Nevertheless, the available findings are contradictory. This meta-analysis aimed to examine the impact of maternal supplementation with pre/probiotics on the levels of total immunoglobulin A (IgA), secretory IgA (SIgA), transforming growth factor beta 1 (TGF-β1), and TGF-2 in breast milk. Methods: PubMed and Scopus were systematically searched using a comprehensive search strategy for eligible randomized-controlled trials published up to February 2021. A random-effects model was applied to pool weighted mean difference and 95% confidence interval (CI) as effect size. Cochran's Q statistic and the I2 statistic were used to measure the between-study variance. Egger's regression test was used to assess publication bias. Results: A total of 12 different studies, with a total sample size of 1722 individuals (probiotic group: 858, placebo group: 864), were included in this meta-analysis. In the overall analysis, compared with placebo, maternal supplementation with pre/probiotics had no significant effect on concentrations of total IgA, SIgA, TGF-β1, and TGF-β2 in the breast milk. In the subgroup analysis, pre/probiotics did not affect total IgA, TGF-β1, and TGF-β2 in both colostrum/transitional and mature milk. However, a significant increase in SIgA was found in colostrum/transitional milk following pre/probiotic administration (WMD = 19.33, 95% CI: 0.83-37.83; p = 0.04), without evidence for remarkable heterogeneity (I² = 0.0, p = 0.57). Conclusions: Maternal supplementation with pre/probiotics may increase SIgA in colostrum/transitional milk, without any effect on total IgA, TGF-β1, and TGF-β2.

Dietary Inflammatory Index in relation to Type 2 Diabetes: A Meta-Analysis

BACKGROUND AND AIMS

Epidemiologic studies show a strong association between chronic inflammation and type 2 diabetes (T2D). Diet may also affect the risk of T2D by modulating inflammation. This meta-analysis aimed to assess the relation of dietary inflammatory index (DII) and risk of T2D.

METHODS

PubMed and Scopus were systematically searched from their inception to September 2020 to identify relevant studies. Relative risks, hazard ratios, or odds ratios (OR), with their corresponding 95% confidence intervals (95% CI), were calculated and pooled using a random-effects model.

RESULTS

A total of 48 different studies, with a total sample size of 1,687,424 participants, were eligible to be included in this meta-analysis. In the overall analysis, no significant association was observed between DII and risk of T2D (OR = 1.03, 95% CI: 0.91 to 1.15), with significant evidence for heterogeneity (I ²  = 96.5%, P < 0.001); however, higher DII was identified as being significantly related to increased risk of T2D in high quality studies (OR = 1.58, 95% CI: 1.15 to 2.17). In the stratified analysis by the dietary assessment tool, background disease, and sex of participants, DII showed no significant association with T2D.

CONCLUSIONS

Higher DII might be associated with an increased risk of T2D. Additional well-designed studies are required to confirm this finding.

Hamstring and ACL injuries impacts on hamstring-to-quadriceps ratio of the elite soccer players: A retrospective study

This study aimed to compare the angle-specific (AS) and non-angle-specific (NAS) hamstring to quadriceps conventional and functional ratios between healthy, hamstring- and ACL-injured elite soccer players. One hundred and eleven players (27.42 ± 8.01 years, 182.11 ± 6.79 cm, 75.93 ± 7.25 kg) completed a series of concentric knee flexor and extensor strength in addition to eccentric knee flexor strength was measured at an angular velocity of 60°.s^-1. Normalized and raw peak torque values, and the torque-angle profiles were extracted for analysis. Conventional and functional NAS (peak values) and AS (waveform ratios) hamstring to quadriceps ratios were calculated and compared between the groups. Healthy players produced greater functional and conventional ratios compared to players with either ACL or hamstring injury. Players with hamstring injury produced a lower AS functional ratios between 46° and 54° of knee flexion. Players suffering from ACL injury depicted a lower value for the AS functional ratio between 33° and 56° of knee flexion. Although NAS can identify soccer players with previous hamstring or ACL injury, the range where there is a strength deficiency is eluded. With the use of AS the range where the deficiency is present can be identified, and clinicians can benefit from this analysis to design robust rehabilitation protocols.

Effect of infant formula supplemented with prebiotics and probiotics on incidence of respiratory tract infections: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Previous investigations have proposed that the consumption of infant formula supplemented with prebiotics, probiotics and synbiotics (PRO-formula) may have protective impacts on respiratory tract infections (RTIs). Nevertheless, the findings of studies are contradictory. This meta-analysis aimed to explore the influence of PRO-formula on RTIs in infants by pooling randomized controlled trials (RCTs).

METHODS

To obtain eligible RCTs, Scopus and PubMed databases were systematically searched from their inception to November 2020. A random-effects model was applied to pool the relative risks (RR) and corresponding 95% confidence intervals (CI) for RTIs following consumption of PRO-formula.

RESULTS

A total of 15 RCTs, with a total sample size of 3805 participants (1957 for intervention and 1848 for placebo), were included in the present meta-analysis. In the overall analysis, in comparison to placebo, consumption of PRO-formula had a significant protective impact against RTIs (RR = 0.89, 95%CI: 0.82-0.97) in infants, with a remarkable evidence of heterogeneity across studies (I2 = 61.4%, P < 0.001). In the meta-regression analysis, the effect of PRO-formula on RTIs was not modified by the follow-up duration. No evidence for publication bias was detected.

CONCLUSIONS

Administration of PRO-formula may be a potential approach for the prevention of respiratory tract infections in infants.

Evaluation of the Functional Movement Screen (FMS) in Identifying Active Females Who are Prone to Injury. A Systematic Review

Background

The validity of the Functional Movement Screen (FMS) in identifying active females who are predisposed to injury has not been specifically reviewed. This study aims to synthesize the literature on the ability of the FMS to identify at-risk active females.

Methods

Six online databases, including PubMed, Medline, Web of Science, Science Direct, SPORTDiscus and Google Scholar, were searched for the period of April 2006 to September 2021. Out of the 61 potential references, 17 were reviewed in detail with respect to the inclusion criteria; ten were ultimately included. The risk of bias, applicability and level of the studies were then identified using the QUADAS-2 and a checklist for assessing methodological quality. The following data were obtained from the included studies: year of publication, title, study type, participants’ demographic, sample size, FMS cutoff point, injury definition, statistical analyses used, FMS results and study level.

Results

Generally, the quality of eight studies was poor to moderate due to both small sample sizes and short follow-up periods. Except for a study on military members, all studies were carried out on team sports players. The overall bias of the studies was low, but there was an unclear amount of bias for participant selection. Two studies reported no predictive validity for the FMS, while three defended its predictive validity; the rest partially supported the FMS as a valid diagnostic tool. The reliability of the recommended cutoff point was confirmed, though cutoffs higher than 14 were significantly associated with the predictive ability of the FMS.

Conclusion

Although the FMS is reliable for clinical practice, and the current literature shows promise regarding the predictive ability of the FMS among active females, concerns remain regarding its validity in identifying at-risk females. Given the lack of clarity in the literature on the use of the FMS in females, further well-organized studies with larger sample sizes and longer monitoring periods are highly recommended. The sensitivity and specificity of the recommended cutoff of ≤ 14 has considerably decreased , and higher cutoff values should be applied to increase the FMS predictive ability.

Level of evidence The level of evidence was determined to be 2b.

The association between psoriasis and psoriatic arthritis with the risk of osteoporosis, osteopenia and bone fractures: A systematic review and meta-analysis

BACKGROUND AND AIMS

The possible association between psoriatic/psoriatic arthritis (PsA) and bone loss has been observed; however, studies have yielded inconclusive results. This meta-analysis aimed to assess whether there is an increase in the risk of osteoporosis, osteopenia and fractures in patients with psoriasis/PsA, compared with healthy individuals.

METHODS

PubMed and Scopus were systematically searched from their inception to September 2020 to identify relevant studies. Relative risk, hazard ratio or odds ratio (OR), with their corresponding 95% confidence intervals (95% CI) were calculated and pooled using a random-effects model.

RESULTS

A total of 12 different studies, with a total of 199 389 296 participants, were included. Overall, no significant relationship was observed between psoriasis/PsA and the risk of osteoporosis (psoriasis: OR = 1.28, 95%CI = 0.86-1.90; PsA: OR = 1.32, 95%CI = 0.79-2.19) and osteopenia (psoriasis: OR = 1.50, 95%CI = 0.75-3.02; PsA: OR = 1.61, 95%CI = 0.67-3.85). However, in the subgroup analysis, psoriasis was significantly associated with an increased risk of osteoporosis in men (OR = 1.27, 95%CI = 1.02-1.59) and studies with cohort design (OR = 1.04, 95%CI = 1.003-1.09). Psoriasis was also related to the risk of osteopenia in studies on a combination of both genders (OR = 2.86, 95%CI = 2.70-3.02). The pooled analysis demonstrated a significantly higher risk of fractures among patients with psoriasis (OR = 1.29, 95%CI = 1.02-1.63) and PsA (OR = 2.88, 95%CI = 1.51-5.48), compared with participants without psoriasis/PsA.

CONCLUSIONS

Patients with psoriasis/PsA have an increased risk of fractures. There is little evidence supporting the relation of psoriasis to osteoporosis/osteopenia.

Glycemic index, but not glycemic load, is associated with an increased risk of metabolic syndrome: Meta-analysis of observational studies

BACKGROUND

Diets with high glycemic index (GI) or high glycemic load (GL) have been linked to important risk factors associated with the development of metabolic syndrome (MetS), such as dyslipidemia, higher blood glucose, and insulin concentrations. However, the role of GI and GL in relation to Mets is still understudied and controversial. This review, therefore, assessed whether high GI or GL contribute to development of Mets.

METHODS

A systematic search of four bibliographic databases was conducted (MEDLINE/PubMed, EMBASE, Web of Sciences, and Scopus) from inception to January 2020 for observational studies assessing GI/GL in relation to MetS. Risk estimates were pooled using random-effect models for the highest versus lowest intake categories, and assessed for heterogeneity using subgroup analysis. The dose-response nature of the relationship was also investigated. Sensitivity analysis and Egger test were used to check the robustness of findings and the possibility of publication bias, respectively.

RESULTS

Data from 12 publications (one cohort study and eleven cross-sectional studies) with a total sample size of 36,295 subjects are included. The pooled effect sizes from the nine studies indicated high versus low dietary GI was associated with increased risk of MetS (OR = 1.05, 95% CI: 1.01 to 1.09) (I²  = 58.1, P = .004). This finding was supported by all subgroup analyses except where studies used 24-h recalls for dietary assessment. Additionally, a linear dose-response investigation revealed that each 5-point increment in GI was associated with 2% increase in the risk of MetS (OR = 1.02, 95% CI: 1.01 to 1.02); non-linear pattern was insignificant, however (p-nonlinearity = 0.63). Moreover, pooled effect sizes from ten studies suggested that no association was found between the GL and MetS with results remaining consistent in all subgroup analyses.

CONCLUSION

A diet with lower GI may protect against MetS. Nutrition policy and clinical practices should encourage a diet with low GI. Future studies should include both GI and GL and different criteria of MetS to provide a better comparison.

Effect of curcumin on C-reactive protein as a biomarker of systemic inflammation: An updated meta-analysis of randomized controlled trials

It has been suggested that curcumin is a potential agent for lowering the levels of C-reactive protein (CRP) and high-sensitivity CRP (hs-CRP), as markers of inflammation. In the current meta-analysis, we attempted to clarify the efficacy of curcumin supplementation in lowering the concentrations of CRP and hs-CRP in patients with autoinflammatory conditions. Nine studies were found evaluating the effect of curcumin on CRP levels, while 23 studies were identified for hs-CRP. CRP concentration was decreased significantly compared to the placebo (WMD = -3.67 mg/L, 95% CI = -6.96 to -0.38, p = 0.02). There was a significant effect of curcumin at dose ≤1,000 mg/day on the CRP concentration. CRP concentration significantly decreased after >10-week intervention compared with placebo.hs-CRP concentration in the intervention group was significantly lower than that of placebo group. A significant effect of curcumin consumption was detected on the serum level of hs-CRP in studies with prescribing ≤1,000 mg/day, and those with ≤10-week duration of intervention. Curcumin consumption resulted in a reduction of hs-CRP in a non-linear fashion with stronger effects with less than 2000 mg curcumin per day. Curcumin seems to be beneficial in decreasing the hs-CRP and CRP levels in proinflammatory settings.

Does infant formula containing synbiotics support adequate growth in infants? A meta-analysis and systematic review of randomized controlled trials

In recent years, several studies have shown that formulas that contain synbiotics, i.e. composed prebiotics and probiotics have been proposed to have a beneficial effect on anthropometric indices. However, the results are inconsistent thus this meta-analysis was performed to assess this effect. PubMed/MEDLINE, Web of Science, SCOPUS, and Embase were systematically searched up to May-2020. Weight gain, length gain, head circumstance gain, weight-for-age z scores, and length-for-age z scores were considered as the outcomes. Weighted mean differences (WMD) with the 95% CI were applied for estimating the combined effect size. Subgroup analysis was performed to specify the source of heterogeneity among studies. Consumption of formulas containing synbiotics did not affect growth significantly in healthy infants (weight gain (WMD = 2.06, 95% CI: - 4.08 to 8.21; p = 0.51), length gain (WMD = - 0.05, 95% CI: - 0.70 to 0.60; p = 0.88), head circumstance (WMD = - 0.28, 95% CI: - 0.66 to 0.11; p = 0.15), on weight-for-age z-scores (WMD = - 0.05, 95% CI: - 0.23 to 0.13; p = 0.57) and length-for-age z-scores (WMD = - 0.16, 95% CI: - 0.50 to 0.19; p = 0.37)). The main results indicate a non-significant increase in infant's growth following synbiotics supplementation of infant formula. Further large-scale studies are warranted to confirm present findings.

Effect of probiotic fermented dairy products on incidence of respiratory tract infections: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Previous studies have suggested that the consumption of probiotic fermented dairy products (PFDP) may have a protective effect on respiratory tract infections (RTIs). However, the results of studies are inconclusive. We aimed to systematically investigate the effect of PFDP on RTIs by performing a meta-analysis of randomized controlled trials (RCTs).

METHODS

PubMed and Scopus databases were systematically searched up to October 2020 to identify eligible RCTs. Meta-analysis outcomes were risk of incidence of upper (URTIs ) and lower (LRTIs ) respiratory tract infections. A random-effects model was used to pool the relative risks (RR) and corresponding 95 % confidence intervals (CI) for outcomes following conception of PFDP.

RESULTS

A total of 22 RCTs, with a total sample size of 10,190 participants, were included in this meta-analysis. Compared with placebo, consumption of PFDP had a significant protective effect against RTIs in the overall analysis (RR = 0.81, 95 %CI: 0.74 to 0.89) and in children (RR = 0.82, 95 %CI: 0.73 to 0.93), adults (RR = 0.81, 95 %CI: 0.66 to 1.00), and elderly population (RR = 0.78, 95 %CI: 0.61 to 0.98). The significant decreased risk of RTIs was also observed for URTIs (RR = 0.83, 95 %CI: 0.73 to 0.93), while, this effect was marginal for LRTIs (RR = 0.78, 95 %CI: 0.60 to 1.01, P = 0.06). The disease-specific analysis showed that PFDP have a protective effect on pneumonia (RR = 0.76, 95 %CI: 0.61 to 0.95) and common cold (RR = 0.68, 95 %CI: 0.49 to 0.96).

CONCLUSIONS

Consumption of PFDP is a potential dietary approach for the prevention of RTIs.

Effect of an inverted seated position with upper arm blood flow restriction on measures of elbow flexors neuromuscular performance

Purpose

The objective of the investigation was to determine the concomitant effects of upper arm blood flow restriction (BFR) and inversion on elbow flexors neuromuscular responses.

Methods

Randomly allocated, 13 volunteers performed four conditions in a within-subject design: rest (control, 1-min upright position without BFR), control (1-min upright with BFR), 1-min inverted (without BFR), and 1-min inverted with BFR. Evoked and voluntary contractile properties, before, during and after a 30-s maximum voluntary contraction (MVC) exercise intervention were examined as well as pain scale.

Results

Inversion induced significant pre-exercise intervention decreases in elbow flexors MVC (21.1%, ηp2 = 0.48, p = 0.02) and resting evoked twitch forces (29.4%, ηp2 = 0.34, p = 0.03). The 30-s MVC induced significantly greater pre- to post-test decreases in potentiated twitch force (ηp2 = 0.61, p = 0.0009) during inversion (↓75%) than upright (↓65.3%) conditions. Overall, BFR decreased MVC force 4.8% (ηp2 = 0.37, p = 0.05). For upright position, BFR induced 21.0% reductions in M-wave amplitude (ηp2 = 0.44, p = 0.04). There were no significant differences for electromyographic activity or voluntary activation as measured with the interpolated twitch technique. For all conditions, there was a significant increase in pain scale between the 40–60 s intervals and post-30-s MVC (upright<inversion, and without BFR<BFR).

Conclusion

The concomitant application of inversion with elbow flexors BFR only amplified neuromuscular performance impairments to a small degree. Individuals who execute forceful contractions when inverted or with BFR should be cognizant that force output may be impaired.

Effect of bariatric surgery on endogenous sex hormones and sex hormone-binding globulin levels: a systematic review and meta-analysis

BACKGROUND

Most studies have shown beneficial effect of bariatric surgery (BS) on serum levels of sex hormones.

OBJECTIVE

A systematic review and meta-analysis was conducted to examine the magnitude of possible changes in levels of sex hormones following BS.

SETTINGS

Electronic databases were searched, including PubMed, Scopus, Web of Science, and Embase, for relevant studies.

METHODS

The heterogeneity of the studies was examined by χ² tests and the degree of heterogeneity was estimated using I² statistic.

RESULTS

The results of pooled analyses revealed that BS caused a significant increase in luteinizing hormone (LH), follicular stimulating hormone (FSH), total testosterone (TT), and sex hormone binding globulin (SHBG) levels and conversely, decreased dehydroepiandrosterone (DHEA) and estradiol (E2) levels in males. For females, BS significantly increased LH, FSH, and SHBG levels and conversely, decreased androstenedione (AE), E2 and TT levels. Additionally, the level of progesterone (P), prolactin (PRL), free testosterone (FT) and dehydroepiandrosterone sulfate (DHEA-S) showed no significant changes in patients who had undergone BS.

CONCLUSION

BS changed most sex hormones levels including LH, FSH, TT, SHBG, AE, DHEA, and E2. It seems that BS is able to exert substantial impacts on sex hormones levels and as well as sexual function, however, larger, and more precise trials are required to specifically focus on these claims.

Non-local Muscle Fatigue Effects on Muscle Strength, Power, and Endurance in Healthy Individuals: A Systematic Review with Meta-analysis

BACKGROUND

The fatigue of a muscle or muscle group can produce global responses to a variety of systems (i.e., cardiovascular, endocrine, and others). There are also reported strength and endurance impairments of non-exercised muscles following the fatigue of another muscle; however, the literature is inconsistent.

OBJECTIVE

To examine whether non-local muscle fatigue (NLMF) occurs following the performance of a fatiguing bout of exercise of a different muscle(s).

DESIGN

Systematic review and meta-analysis.

SEARCH AND INCLUSION

A systematic literature search using a Boolean search strategy was conducted with PubMed, SPORTDiscus, Web of Science, and Google Scholar in April 2020, and was supplemented with additional 'snowballing' searches up to September 2020. To be included in our analysis, studies had to include at least one intentional performance measure (i.e., strength, endurance, or power), which if reduced could be considered evidence of muscle fatigue, and also had to include the implementation of a fatiguing protocol to a location (i.e., limb or limbs) that differed to those for which performance was measured. We excluded studies that measured only mechanistic variables such as electromyographic activity, or spinal/supraspinal excitability. After search and screening, 52 studies were eligible for inclusion including 57 groups of participants (median sample = 11) and a total of 303 participants.

RESULTS

The main multilevel meta-analysis model including all effects sizes (278 across 50 clusters [median = 4, range = 1 to 18 effects per cluster) revealed a trivial point estimate with high precision for the interval estimate [- 0.02 (95% CIs = - 0.14 to 0.09)], yet with substantial heterogeneity (Q₍₂₇₇₎ = 642.3, p < 0.01), I² = 67.4%). Subgroup and meta-regression analyses showed that NLMF effects were not moderated by study design (between vs. within-participant), homologous vs. heterologous effects, upper or lower body effects, participant training status, sex, age, the time of post-fatigue protocol measurement, or the severity of the fatigue protocol. However, there did appear to be an effect of type of outcome measure where both strength [0.11 (95% CIs = 0.01-0.21)] and power outcomes had trivial effects [- 0.01 (95% CIs = - 0.24 to 0.22)], whereas endurance outcomes showed moderate albeit imprecise effects [- 0.54 (95% CIs = - 0.95 to - 0.14)].

CONCLUSIONS

Overall, the findings do not support the existence of a general NLMF effect; however, when examining specific types of performance outcomes, there may be an effect specifically upon endurance-based outcomes (i.e., time to task failure). However, there are relatively fewer studies that have examined endurance effects or mechanisms explaining this possible effect, in addition to fewer studies including women or younger and older participants, and considering causal effects of prior training history through the use of longitudinal intervention study designs. Thus, it seems pertinent that future research on NLMF effects should be redirected towards these still relatively unexplored areas.