BackgroundThe increase in childhood obesity is a serious public health concern. Several studies have indicated that breastfed children have a lower risk of childhood obesity than those who were not breastfed, while other studies have provided conflicting evidence. The objective of this meta-analysis was to investigate the association between breastfeeding and the risk of childhood obesity.MethodsThe PubMed, EMBASE and CINAHL Plus with Full Text databases were systematically searched from start date to 1st August 2014. Based on the meta-analysis, pooled adjusted odds ratio (AOR) and 95% confidence interval (CI) were calculated. I2 statistic was used to evaluate the between-study heterogeneity. Funnel plots and Fail-safe N were used to assess publication bias and reliability of results, and results from both Egger test and Begg test were reported.ResultsTwenty-five studies with a total of 226,508 participants were included in this meta-analysis. The studies’ publication dates ranged from 1997 to 2014, and they examined the population of 12 countries. Results showed that breastfeeding was associated with a significantly reduced risk of obesity in children (AOR = 0.78; 95% CI: 0.74, 0.81). Categorical analysis of 17 studies revealed a dose-response effect between breastfeeding duration and reduced risk of childhood obesity.ConclusionResults of our meta-analysis suggest that breastfeeding is a significant protective factor against obesity in children.

BackgroundElevated plasma homocysteine (Hcy) levels have been indicated as a strong and modifiable risk factor of ischemic stroke; the previous studies have shown that exposure to Hcy activates cultured microglia. However, whether neurotoxicity of Hcy involves microglia activation following brain ischemia and the underlying mechanisms remains incompletely understood.MethodsThe cerebral damage was evaluated by staining with 2,3,5-triphenyltetrazolium chloride, hematoxylin-eosin, and Fluoro Jade B. The activation state of microglia was assessed via immunoreaction using the microglial markers Iba1 and OX-42. Then, the inflammatory factors such as tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and phosphorylated signal transducer and activator of transcription 3 (pSTAT3) were examined by Western blot analysis and fluorescence immunohistochemistry.ResultsElevated Hcy level augmented brain damage and neural cell toxicity in the brain cortex and the dentate gyrus region of the hippocampus after cerebral ischemia/reperfusion. Meanwhile, Hcy activated microglia and induced the expression of the inflammatory factors such as TNF-α and IL-6. Moreover, Hcy caused an increase in pSTAT3 expression which occurs in microglial cells. AG490, a JAK2-STAT3 inhibitor, effectively inhibited the phosphorylation of STAT3, microglial cell activation and the secretion of IL-6, TNF-α raised by Hcy treatment.ConclusionsSTAT3 signaling pathway located in microglia plays a critical role in mediating Hcy-induced activation of microglia and neuroinflammation in rat MCAO model. This suggests the feasibility of targeting the JAK2/STAT3 pathway as an effective therapeutic strategy to alleviate the progression of Hcy-associated ischemia stroke.Electronic supplementary materialThe online version of this article (10.1186/s12974-017-0963-x) contains supplementary material, which is available to authorized users.

BackgroundLack of physical activity is a growing problem in China, due to the fast economic development and changing living environment over the past two decades. The aim of this review is to summarize the factors related to physical activity in Chinese children and adolescents during this distinct period of development.MethodsA systematic search was finished on Jan 10th, 2017, and identified 2200 hits through PubMed and Web of Science. English-language published studies were included if they reported statistical associations between factors and physical activity. Adapted criteria from the Strengthening The Reporting of OBservational studies in Epidemiology (STROBE) statement and evaluation of the quality of prognosis studies in systematic reviews (QUIPS) were used to assess the risk of bias of the included studies. Related factors that were reported in at least three studies were summarized separately for children and adolescents using a semi-quantitative method.ResultsForty two papers (published 2002–2016) were included. Most designs were cross-sectional (79%), and most studies used questionnaires to assess physical activity. Sample size was above 1000 in 18 papers (43%). Thirty seven studies (88%) showed acceptable quality by methodological quality assessment. Most studies reported a low level of physical activity. Boys were consistently more active than girls, the parental physical activity was positively associated with children and adolescents’ physical activity, children in suburban/rural regions showed less activity than in urban regions, and, specifically in adolescents, self-efficacy was positively associated with physical activity. Family socioeconomic status and parental education were not associated with physical activity in children and adolescents.ConclusionsThe studies included in this review were large but mostly of low quality in terms of study design (cross-sectional) and methods (questionnaires). Parental physical activity and self-efficacy are promising targets for future physical activity promotion programmes. The low level of physical activity raises concern, especially in suburban/rural regions. Future research is required to enhance our understanding of other influences, such as the physical environment, especially in early childhood.Electronic supplementary materialThe online version of this article (doi:10.1186/s12966-017-0486-y) contains supplementary material, which is available to authorized users.

Folic acid supplementation appears to improve cognitive function and reduce blood levels of Aβ-related biomarkers in MCI. Larger-scale double-blind placebo-controlled randomized trials of longer duration are needed.

This study demonstrated that decreased FT3, FT3/FT4 ratios, and increased FT4 levels are independently related to a higher prevalence of T2DM in both males and females, and TSH is inversely related to T2DM in males only.

Background: Folate and vitamin B12 are well-known as essential nutrients that play key roles in the normal functions of the brain. Inflammatory processes play at least some role in the pathology of AD. Effective nutritional intervention approaches for improving cognitive deficits that reduce the peripheral inflammatory cytokine levels have garnered special attention. Objective: The present study aimed to determine whether supplementation with folic acid and vitamin B12, alone and in combination improves cognitive performance via reducing levels of peripheral inflammatory cytokines. Methods: 240 participants with MCI were randomly assigned in equal proportion to four treatment groups: folic acid alone, vitamin B12 alone, folic acid plus vitamin B12 or control without treatment daily for 6 months. Cognition was measured with WAIS-RC. The levels of inflammatory cytokines were measured using ELISA. Changes in cognitive function or blood biomarkers were analyzed by repeatedmeasure analysis of variance or mixed-effects models. This trial has been registered with trial number ChiCTR-ROC-16008305. Results: Compared with control group, the folic acid plus vitamin B12 group had significantly greater improvements in serum folate, homocysteine, vitamin B12 and IL-6, TNF-α, MCP-1. The folic acid plus vitamin B12 supplementation significantly changed the Full Scale IQ (effect size d = 0.169; P = 0.024), verbal IQ (effect size d = 0.146; P = 0.033), Information (d = 0.172; P = 0.019) and Digit Span (d = 0.187; P = 0.009) scores. Post hoc Turkey tests found that folic acid and vitamin B12 supplementation was significantly more effective than folic acid alone for all endpoints. Conclusions: The combination of oral folic acid plus vitamin B12 in MCI elderly for six months can significantly improve cognitive performance and reduce the levels of inflammatory cytokines in human peripheral blood. The combination of folic acid and vitamin B12 was significantly superior to either folic acid or vitamin B12 alone.

Type 2 diabetes mellitus (T2DM) is associated with dementia. Mild cognitive impairment (MCI) is a key determinant in this association. It is not clear whether T2DM increases the risk of conversion from MCI to dementia. We plan to explore the relationship between T2DM-MCI and dementia and identify its potential risk factors. A prospective community-based cohort study was conducted from March 2010 to March 2014, including 634 participants with T2DM-MCI, 261 T2DM participants who were cognitively intact, and 585 MCI participants without diabetes. All cohort members received detailed annual evaluations to detect dementia onset during the 5 years of follow-up. The three cohorts were compared to assess differences in dementia onset. Furthermore, Cox proportional hazards regression was used to identify risk factors for dementia onset in the T2DM-MCI cohort. During follow-up, 152 and 49 subjects developed dementia in the MCI and cognitively-intact cohorts, amounting to an adjusted hazard ratio (HR) of 1.66 (95% CI 1.07-2.26). In a survival analysis of the cohorts, MCI accelerated the median progression to dementia by 2.74 years. In a multivariable analysis of the T2DM-MCI cohort, major risk factors for dementia were age >75 years and longer durations of diabetes, while significantly reduced risks of dementia were associated with oral hypoglycemic agents and HMG-CoA reductase inhibitors. Insulin was not associated with significantly changed risk. T2DM-MCI may aggravate the clinical picture as a concomitant factor. To minimize progression to dementia, it may be worthwhile to target several modifiable diabetes-specific features, such as the duration of disease, glycemic control, and antidiabetic agents.

Homocysteine (Hcy) is a risk factor for brain atrophy, cognitive impairment, and dementia. Vitamin B12 and folate are cofactors necessary for the methylation of Hcy. However, there is some debate regarding the differing levels of plasma Hcy and serum folate and vitamin B12 among healthy controls, patients with mild cognitive impairment (MCI), and patients with Alzheimer’s disease (AD). This study aimed to evaluate how the levels of plasma Hcy and its biological determinants, folate and vitamin B12, are related to MCI and AD in older Chinese adults. This is a case-control study including 112 subjects with MCI, 89 AD patients and 115 healthy controls. Diagnosis of AD was made according to the NINCDS-ADRDA and MCI with modified Petersen’s criteria. Serum folate and vitamin B12 concentrations were analyzed by radioimmunoassay, and plasma Hcy was assessed by a high-performance liquid chromatography-fluorescence method. Multivariate analysis of regression was used to examine the odds ratio (OR) of MCI or AD with Hcy or vitamin levels. Results have shown that serum folate and vitamin B12 levels were significantly lower, but the plasma Hcy level was higher, in patients with MCI and AD than in healthy controls. Multivariate regression analyses showed that subjects in the lowest folate tertile had significantly higher adjusted ORs for MCI (OR: 3.07; 95% confidence interval [CI]: 1.12, 8.07) and AD (3.42; 95% CI: 1.15, 8.34) compared to subjects in the highest tertile. The highest Hcy tertile was significantly associated with MCI (adjusted OR: 2.81; 95% CI: 1.15, 4.73) and AD (adjusted OR: 3.64; 95% CI: 1.13, 9.04) compared to the lowest tertile. No association existed between low vitamin B12 levels and AD or MCI (p > 0.05). Low blood levels of folate and vitamin B12 and elevated Hcy levels were associated with MCI and AD in older Chinese adults, and the association was stronger for AD.