Microbiota and gut-brain axis dysfunction in autism spectrum disorder: Evidence for functional gastrointestinal disorders

INTRODUCTION

The high frequency of functional gastrointestinal disorders (FGIDs) in autism spectrum disorders (ASD) has drawn attention to the composition of gut microbiota as a possible factor in ASD pathogenesis. However, characterization of a distinctive ASD microbial pattern is still unclear.

OBJECTIVE

To conduct a narrative review on ASD microbial profile and diversity changes relative to NT children and FGID comorbidity and ASD pathogenesis.

METHODOLOGY

First, we searched the PubMed database in peer-reviewed journals for evidence regarding the current epidemiological evidence on FGID comorbidity. For the identification of a microbial profile in ASD children, only original studies examining gut bacterial and fungal abundances and diversity in ASD children and adolescents were included. Lastly, research on the role of microbial dysbiosis as an interface between genetic and environmental risk factors in the pathogenesis of neuropsychiatric disorders, and specifically ASD, was examined.

RESULTS

Prevalence and risk of FGIDs is significantly higher in ASD children and correlates with the severity of ASD. Bacterial and fungal diversity differ between ASD and NT children, indicating a difference in taxonomic abundance profiles, which have been reported at all bacterial phylogenetic levels. However, studies analyzing gut microbiota have a heterogeneous methodology and several limitations that could account for the variety of findings for each taxon. Also, covariate analysis reveals influence of demographics, diet, disease severity, GI comorbidity and allergies. Integration of these findings with changes in metabolome and genetic risk factors allowed for a better understanding of microbiota involvement in ASD pathogenesis for future research.

MCCB cognitive profile in Spanish first episode schizophrenia patients

The objective of the study was to examine the cognitive profile of Spanish patients with a first episode of schizophrenia (FESz) and to compare that to the profile of patients with a chronic schizophrenia (CSz) and non-psychiatric (NP) control subjects. The study included 106 FESz, 293 CSz, and 210 NP, assessed with the Spanish version of the MATRICS Consensus Cognitive Battery (MCCB). The MCCB cognitive profile in a Spanish sample of FESz was similar to the cognitive profile of CSz with some discrepancies in select domains. The scores of both patient samples were about 1-2 SD below the scores of non-psychiatric control subjects.

Clinically relevant anxiety and risk of Alzheimer's disease in an elderly community sample: 4.5 years of follow-up

OBJECTIVES

To investigate whether clinically relevant anxiety increased the risk for developing Alzheimer's disease (AD) while controlling for the presence of depression and other confounders; and to report the population attributable fraction (PAF) associated with anxiety disorder.

METHOD

We used data from the longitudinal, community-based Zaragoza Dementia and Depression (ZARADEMP) study. A random sample of 4057 dementia-free community dwellers aged ≥55 years were followed for 4.5 years. The Geriatric Mental State-Automated Geriatric Examination for Computer Assisted Taxonomy package was used for the diagnosis of clinically significant cases and subcases of anxiety; and AD was diagnosed by a panel of research psychiatrists according to DSM-IV criteria. Multivariate survival analysis with competing risk regression model was performed.

RESULTS

We observed a significant association between anxiety cases at baseline and AD risk in the univariate analysis that persisted in the fully adjusted model (SHR: 3.90; 95% CI: 1.59-9.60; p = 0.003), with a PAF for AD of 6.11% (95% CI: 1.30%-16.17%). No significant association between 'subcases' of anxiety at baseline and AD risk was found.

LIMITATIONS

Data on apolipoprotein E were not available. The hospital-based diagnosis was not completed in all cases of dementia.

CONCLUSION

Late-life, clinically significant anxiety (but not subclinical anxiety) seems to increase the risk of AD, independently of the effect of several confounders, including depression. Taking into account the high prevalence of anxiety among the elderly, future studies are warranted to determine potential risk reduction of AD.

Prevalence of anxiety disorder among older adults in Spain: A meta-analysis

BACKGROUND

Anxiety disorders are recognized as one of the most prevalent mental disorders in late-life. However, the prevalence of anxiety disorders in older Spanish people has not yet been determined. The aim was to review epidemiological studies systematically to calculate the overall prevalence of anxiety in Spanish older adults by using meta-analytic techniques.

METHODS

We searched relevant published studies in electronic databases up to January 2018 providing data on the prevalence of anxiety among people aged 65+  years in Spain. Overall anxiety prevalence estimates were calculated using random-effects models. Sources of heterogeneity were explored by means of univariate meta-regressions.

RESULTS

A total of 9 studies were included in the meta-analysis (N = 12,577). Pooled overall prevalence of anxiety was 11% (95% confidence interval (CI): 6%-18%) representing 1958,471 people aged 65+  (95%CI: 1068,257-3204,771). Point, 12-month and lifetime prevalence of anxiety disorders were 12%, 6% and 19%, respectively.

LIMITATIONS

We detected a small publication bias effect for life-time prevalence of anxiety. The use of different diagnostic methods across the studies would have required separate analyzes.

CONCLUSION

Some heterogeneity was found across studies, probably due to different methodological issues. Overall, the pooled prevalence of anxiety disorders in Spanish older adults was lower than that observed in other countries. Due to the negative consequences of anxiety disorders in older adults, detection and treatment should be a priority in this population.

Clinically significant anxiety as a risk factor for dementia in the elderly community

OBJECTIVE

To evaluate whether clinically significant anxiety is an independent risk factor for dementia, taking into account both depression among potentially confounding factors and the competing risk of death.

METHOD

During the Zaragoza Dementia and Depression (ZARADEMP) study, a random sample of community dwellers aged 55 years or older was assessed (n = 4803), and a two-wave, 4.5-year follow-up was completed. Geriatric Mental State (GMS)-AGECAT criteria were used to diagnose anxiety and DSM-IV criteria were applied to diagnose incident dementia. The multivariate Fine and Gray regression model was implemented to calculate dementia risk.

RESULTS

Compared with non-cases (GMS-AGECAT criteria), the incidence rate of dementia was significantly higher in subcases of anxiety, and particularly significant in the cases of anxiety (incidence rate ratio (IRR): 2.77; P = 0.010). Cases of anxiety, but not subcases, at baseline were significantly associated with dementia risk (adjusted subdistribution hazard ratio (SHR): 2.7; P = 0.019).

CONCLUSION

Clinically significant anxiety is associated with an almost threefold increase in the risk of dementia in the population, even when controlling for depression and considering mortality in the competing risks model.

The influence of obesity and weight gain on quality of life according to the SF-36 for individuals of the dynamic follow-up cohort of the University of Navarra

BACKGROUND

The health-related quality of life is an important element for the comprehensive assessment of overweight and obesity.

OBJECTIVE

To assess the impact of obesity and weight gain on the health-related quality of life of the dynamic cohort of the Follow-up Program of the University of Navarra.

MATERIAL AND METHODS

The analysis included 10,033 participants of the prospective dynamic cohort of the Follow-up Project of the University of Navarra, with a response rate of approximately 90%. The quality of life was measured with the Short Form 36 Health Survey (SF-36) (0, worst quality of life; 100, best quality of life). The statistical analysis was performed with generalized lineal models (mean of each SF-36 domain and 95% CI). A difference of 3 points was considered clinically relevant.

RESULTS

The SF-36 analysis showed that physical function, general health and the physical component summary were inferior in individuals with excess weight and obesity at the start of the study, compared with individuals with normal weight. The study population with unchanged excess weight or obesity after 2 years of follow-up presented lower scores on the SF-36 domains corresponding to physical function, body pain, physical component summary and general health than individuals who maintained the normal weight category according to BMI (kg/m²).

CONCLUSIONS

Obesity appears to be associated with a negative impact on health-related quality of life, affecting the physical area more significantly than the psychosocial.

Inflammation in metabolically healthy and metabolically abnormal adolescents: The HELENA study

BACKGROUND AND AIMS

Inflammation may influence the cardio-metabolic profile which relates with the risk of chronic diseases. This study aimed to assess the inflammatory status by metabolic health (MH)/body mass index (BMI) category and to assess how inflammatory markers can predict the cardio-metabolic profile in European adolescents, considering BMI.

METHODS AND RESULTS

A total of 659 adolescents (295 boys) from a cross-sectional European study were included. Adolescents were classified by metabolic health based on age- and sex-specific cut-off points for glucose, blood pressure, triglycerides, high density cholesterol and BMI. C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin (IL-6), complement factors (C3, C4) and cell adhesion molecules were assessed.

RESULTS

Metabolically abnormal (MA) adolescents had higher values of C3 (p < 0.001) and C4 (p = 0.032) compared to those metabolically healthy (MHy). C3 concentrations significantly increased with the deterioration of the metabolic health and BMI (p < 0.001). Adolescents with higher values of CRP had higher probability of being in the overweight/obese-MH group than those allocated in other categories. Finally, high C3 and C4 concentrations increased the probability of having an unfavorable metabolic/BMI status.

CONCLUSIONS

Metabolic/BMI status and inflammatory biomarkers are associated, being the CRP, C3 and C4 the most related inflammatory markers with this condition. C3 and C4 were associated with the cardio-metabolic health consistently.

Ideal cardiovascular health and inflammation in European adolescents: The HELENA study

BACKGROUND AND AIMS

Inflammation plays a key role in atherosclerosis and this process seems to appear in childhood. The ideal cardiovascular health index (ICHI) has been inversely related to atherosclerotic plaque in adults. However, evidence regarding inflammation and ICHI in adolescents is scarce. The aim is to assess the association between ICHI and inflammation in European adolescents.

METHODS AND RESULTS

As many as 543 adolescents (251 boys and 292 girls) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional multi-center study including 9 European countries, were measured. C-reactive protein (CRP), complement factors C3 and C4, leptin and white blood cell counts were used to compute an inflammatory score. Multilevel linear models and multilevel logistic regression were used to assess the association between ICHI and inflammation controlling by covariates. Higher ICHI was associated with a lower inflammatory score, as well as with several individual components, both in boys and girls (p < 0.01). In addition, adolescents with at least 4 ideal components of the ICHI had significantly lower inflammatory score and lower levels of the study biomarkers, except CRP. Finally, the multilevel logistic regression showed that for every unit increase in the ICHI, the probability of having an inflammatory profile decreased by 28.1% in girls.

CONCLUSION

Results from this study suggest that a better ICHI is associated with a lower inflammatory profile already in adolescence. Improving these health behaviors, and health factors included in the ICHI, could play an important role in CVD prevention.

Folate and vitamin B12 concentrations are associated with plasma DHA and EPA fatty acids in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study

This study aimed to examine the association between vitamin B6, folate and vitamin B12 biomarkers and plasma fatty acids in European adolescents. A subsample from the Healthy Lifestyle in Europe by Nutrition in Adolescence study with valid data on B-vitamins and fatty acid blood parameters, and all the other covariates used in the analyses such as BMI, Diet Quality Index, education of the mother and physical activity assessed by a questionnaire, was selected resulting in 674 cases (43 % males). B-vitamin biomarkers were measured by chromatography and immunoassay and fatty acids by enzymatic analyses. Linear mixed models elucidated the association between B-vitamins and fatty acid blood parameters (changes in fatty acid profiles according to change in 10 units of vitamin B biomarkers). DHA, EPA) and n-3 fatty acids showed positive associations with B-vitamin biomarkers, mainly with those corresponding to folate and vitamin B12. Contrarily, negative associations were found with n-6:n-3 ratio, trans-fatty acids and oleic:stearic ratio. With total homocysteine (tHcy), all the associations found with these parameters were opposite (for instance, an increase of 10 nmol/l in red blood cell folate or holotranscobalamin in females produces an increase of 15·85 µmol/l of EPA (P value <0·01), whereas an increase of 10 nmol/l of tHcy in males produces a decrease of 2·06 µmol/l of DHA (P value <0·05). Positive associations between B-vitamins and specific fatty acids might suggest underlying mechanisms between B-vitamins and CVD and it is worth the attention of public health policies.

Staging cognitive impairment and incidence of dementia

AIMS

In a background of interest in staging models in psychiatry, we tested the validity of a simple staging model of cognitive impairment to predict incident dementia.

METHOD

A large community sample of adults aged ≥55 years (N = 4803) was assessed in the baseline of a longitudinal, four-wave epidemiological enquiry. A two-phase assessment was implemented in each wave, and the instruments used included the Mini-Mental Status Examination (MMSE); the History and Aetiology Schedule and the Geriatric Mental State-AGECAT. For the standardised degree of cognitive impairment Perneczky et al's MMSE criteria were applied. A panel of psychiatrists diagnosed cases of dementia according to DSM-IV criteria, and cases and sub-cases of dementia were excluded for the follow-up waves. Competing risk regression models, adjusted by potential confounders, were used to test the hypothesised association between MMSE levels and dementia risk.

RESULTS

Out of the 4057 participants followed up, 607 (14.9%) were classified as 'normal' (no cognitive impairment), 2672 (65.8%) as 'questionable' cognitive impairment, 732 (18.0%) had 'mild' cognitive impairment, 38 (0.9%) had 'moderate' cognitive impairment and eight (0.2%) had 'severe' impairment. Cognitive impairment was associated with risk of dementia, the risk increasing in parallel with the level of impairment (hazard ratio: 2.72, 4.78 and 8.38 in the 'questionable', 'mild' and 'moderate' level of cognitive impairment, respectively).

CONCLUSIONS

The documented gradient of increased risk of dementia associated with the severity level of cognitive impairment supports the validity of the simple staging model based on the MMSE assessment.

Conversion to dementia in mild cognitive impairment diagnosed with DSM-5 criteria and with Petersen's criteria

OBJECTIVE

In a background of revision of criteria for states of increased risk for progression to dementia, we compare the conversion rate to dementia and Alzheimer's disease (AD) of mild cognitive impairment (MCI) as diagnosed using DSM-5 (DSM-5-MCI) and Petersen's (P-MCI) criteria.

METHOD

A population representative cohort of 4057 dementia-free individuals 55+ years of age was followed up at 2.5 and 4.5 years in Zaragoza, Spain (ZARADEMP). Using the Geriatric Mental State- AGECAT for assessment, research psychiatrists diagnosed DSM-5-MCI and P-MCI following operationalized criteria. 'Conversion rate' (CR), 'annual conversion rate' (ACR), and incidence rate (IR) were calculated along with incidence rate ratio (IRR) to compare the performance of the intermediate cognitive definitions.

RESULTS

At 4.5-year follow-up, in individuals aged 65+ years, ACRs for non-cases, P-MCI, and DSM-5-MCI were 0.8, 1.9 and 3.4, respectively, for global dementia. The IRRs were 2.9 and 5.3 for P-MCI and DSM5-MCI, respectively, being the non-cases the reference category. The corresponding values were slightly lower for AD.

CONCLUSION

Conversion rate to dementia and AD was higher using DSM-5-MCI criteria than using Petersen's criteria. However, prediction of the construct still has some way to go, as most MCI individuals did not convert at 4.5-year follow-up.

The MCCB impairment profile in a Spanish sample of patients with schizophrenia: Effects of diagnosis, age, and gender on cognitive functioning

The MATRICS Consensus Cognitive Battery (MCCB) was administered to 293 schizophrenia outpatients and 210 community residents in Spain. Our first objective was to identify the age- and gender-corrected MCCB cognitive profile of patients with schizophrenia. The profile of schizophrenia patients showed deficits when compared to controls across the seven MCCB domains. Reasoning and Problem Solving and Social Cognition were the least impaired, while Visual Learning and Verbal Learning showed the greatest deficits. Our second objective was to study the effects on cognitive functioning of age and gender, in addition to diagnosis. Diagnosis was found to have the greatest effect on cognition (Cohen's d>0.8 for all MCCB domains); age and gender also had effects on cognitive functioning, although to a lesser degree (with age usually having slightly larger effects than gender). The effects of age were apparent in all domains (with better performance in younger subjects), except for Social Cognition. Gender had effects on Attention/Vigilance, Working Memory, Reasoning and Problem Solving (better performance in males), and Social Cognition (better performance in females). No interaction effects were found between diagnosis and age, or between diagnosis and gender. This lack of interactions suggests that age and gender effects are not different in patients and controls.

Degree of cognitive impairment and mortality: a 17-year follow-up in a community study

BACKGROUND

To test the hypothesis that cognitive impairment in older adults is associated with all-cause mortality risk and the risk increases when the degree of cognitive impairment augments; and then, if this association is confirmed, to report the population-attributable fraction (PAF) of mortality due to cognitive impairment.

METHOD

A representative random community sample of individuals aged over 55 was interviewed, and 4557 subjects remaining alive at the end of the first year of follow-up were included in the analysis. Instruments used in the assessment included the Mini-Mental Status Examination (MMSE), the History and Aetiology Schedule (HAS) and the Geriatric Mental State (GMS)-AGECAT. For the standardised degree of cognitive impairment Perneczky et al's MMSE criteria were applied. Mortality information was obtained from the official population registry. Multivariate Cox proportional hazard models were used to test the association between MMSE degrees of cognitive impairment and mortality risk. We also estimated the PAF of mortality due to specific MMSE stages.

RESULTS

Cognitive impairment was associated with mortality risk, the risk increasing in parallel with the degree of cognitive impairment (Hazard ratio, HR: 1.18 in the 'mild' degree of impairment; HR: 1.29 in the 'moderate' degree; and HR: 2.08 in the 'severe' degree). The PAF of mortality due to severe cognitive impairment was 3.49%.

CONCLUSIONS

A gradient of increased mortality-risk associated with severity of cognitive impairment was observed. The results support the claim that routine assessment of cognitive function in older adults should be considered in clinical practice.

Identification of components of health complexity on internal medicine units by means of the INTERMED method

BACKGROUND

The INTERMED was developed for the early identification of biological, psychological, social and health system factors considered interacting in health complexity. This is defined as the interference with the achievement of expected or desired health and service use outcomes when patients are exposed to standard care.

OBJECTIVE

The aim of this study was to test the INTERMED's ability to identify 'case' and 'care' complexity, identifying patients that would especially benefit from integrated care.

METHODS

Observational longitudinal study of Internal medicine in patients in two National Health System hospitals in Spain using the INTERMED (patients scoring ≥ 21 were considered to be 'complex'); the Cumulative Illness Rating Scale (CIRS), a severity of illness assessment; and standard clinical variables.

RESULTS

Six hundred and fifteen consecutives were included, and the prevalence of health complexity was 27.6%. The greatest differences between patients with and without health complexity were observed in the non-biological domains. Eighty-five per cent of patients with health complexity had non-biological items considered to require timely (immediately or soon) assistance or intervention compared to 30% of those without, nearly a threefold difference. Complex patients had a significantly higher number of medical diagnoses (p = 0.002) and number of psychiatric referrals (p = 0.041), but there were no differences in CIRS scores or lengths of stay.

CONCLUSION

The INTERMED has the potential to identify a considerable subset of complex internal medicine inpatients for which timely corrective action related to non-biological risk factors not typically uncovered during standard medical evaluations would be considered beneficial.

Mild cognitive impairment diagnosed with the new DSM-5 criteria: prevalence and associations with non-cognitive psychopathology

OBJECTIVE

To contrast the prevalence of mild cognitive impairment (MCI) as diagnosed using DSM-5 criteria (DSM5-MCI) with MCI as diagnosed using Petersen's criteria (P-MCI) and to explore the association of both with non-cognitive psychopathological symptoms (NCPS).

METHOD

A two-phase epidemiological screening was implemented in a population-based sample of individuals aged 55+ (n = 4803). The Geriatric Mental State (GMS) was the main psychopathological instrument used, and AGECAT was used to make psychiatric diagnoses. Research psychiatrists diagnosed DSM5-MCI and P-MCI using operational criteria. Logistic regression models were then used to investigate the association of MCI with anxiety and depression and with NCPS.

RESULTS

Weighted prevalence of DSM5-MCI and P-MCI was, respectively, 3.72% and 7.93% for the aged 65+. NCPS were common in both MCI categories, but negative-type symptoms such as 'anergia' and 'observed slowness' were considerably more frequent among persons with DSM5-MCI. Anxiety and depression diagnostic categories were associated with both P-MCI and DSM5-MCI, but affective-type symptoms were mainly associated with P-MCI. Some negative-type symptoms were inversely associated with P-MCI, and no association was observed with DSM5-MCI.

CONCLUSION

The prevalence of DSM5-MCI was half that of P-MCI. Negative-type NCPS were more frequently and typically associated with DSM5-MCI.

Central adiposity in children born small and large for gestational age

OBJECTIVE

To evaluate body composition differences between children that were born small (SGA) or large for gestational age (LGA) compared with their counterparts born adequate for gestational age (AGA).

METHODS

Body composition was assessed in 124 healthy Caucasian children (50% girls) aged 6-10, classified according to their birth weight for gestational age as AGA, SGA and LGA. Fat mass (FM), percentage of FM, lean mass (LM), bone mineral content (BMC) and bone mineral density were measured by dual-energy X-ray absorptiometry (DXA) in the whole body and at different body regions.

RESULTS

LM (adjusted for age and sex) and total BMC (adjusted for age, sex and weight) were both significantly higher in LGA children and lower in SGA when compared with those born AGA. After adjustments for height, LM and BMC differences between groups were not significant. In SGA children, truncal (P<0.05) and abdominal fatness (P<0.01) were higher when compared with both AGA and LGA children, after adjustments for age, sex and height. There were no differences in the percentage of total and central FM between children born LGA and AGA.

CONCLUSIONS

During childhood, children born SGA had higher central adiposity regardless of their body size. Children born LGA seem to have a higher body size but with harmonic body composition and adequate body fat distribution. Small size for gestational age at birth could programme excess abdominal fat deposition in children, which is a major factor for the clustering of cardiovascular disease risk factors defining the metabolic syndrome.

Incidence and lifetime risk of dementia and Alzheimer's disease in a Southern European population

OBJECTIVE

To calculate both the incidence rates and the lifetime risk (LTR) of dementia and Alzheimer's disease (AD).

METHODS

A two-phase case-finding procedure was implemented in a cohort of 4057 cognitively intact individuals 55+ years of age living in Zaragoza, Spain, and followed-up at 2.5 and 4.5 years. Age- and sex-specific incidence rates were calculated. A mortality-adjusted, multivariate model was used to document LTRs.

RESULTS

The incidence rate of dementia continued to rise after the age of 90 years, but was slightly lower than in North and West European studies. Only a tendency for an increased LTR with age was observed. Thus, LTR was 19.7% for a 65-year-old woman and 20.4% at the age of 85 years, the corresponding figures for AD being 16.7% and 17.6%. The LTR of AD was higher in women and was about twice as high among illiterate individuals when compared with individuals with higher educational levels.

CONCLUSIONS

The incidence rate of dementia in this Southern European city was slightly lower than in previous studies in North-West Europe. LTR of dementia and AD seems to be slightly increased with age. The association of illiteracy with higher LTR of AD is intriguing.