Coronary heart disease is associated with regional grey matter volume loss: implications for cognitive function and behaviour

Coronary heart disease (CHD) has been associated with impaired cognition, but the mechanisms underlying these changes remain unclear. We designed this study to determine whether adults with CHD show regional brain losses of grey matter volume relative to controls. We used statistical parametric mapping (SPM5) to determine regional changes in grey matter volume of T₁-weighted magnetic resonance images of 11 adults with prior history of myocardial infarction relative to seven healthy controls. All analyses were adjusted for total grey and white matter volume, age, sex and handedness. CHD participants showed a loss of grey matter volume in the left medial frontal lobe (including the cingulate), precentral and postcentral cortex, right temporal lobe and left middle temporal gyrus, and left precuneus and posterior cingulate. CHD is associated with loss of grey matter in various brain regions, including some that play a significant role in cognitive function and behaviour. The underlying causes of these regional brain changes remain to be determined.     

Structural magnetic resonance imaging in eating disorders: a systematic review of voxel-based morphometry studies

This systematic review summarises and critically appraises the literature on structural magnetic resonance imaging in people with a current or past eating disorder. Studies using voxel-based morphometry image analysis were included. Ten studies reported on a total of 236 people with a current or past eating disorder and 257 healthy controls. Sample heterogeneity prohibited a meta-analytic approach. The findings do not unequivocally indicate grey or white matter volume abnormalities in people with an eating disorder. Nevertheless, these preliminary data suggest that, compared with healthy controls, people with anorexia nervosa have decreased grey matter in a range of brain regions and that those with bulimia nervosa have increased grey matter volumes in frontal and ventral striatal areas. Research in the recovery phase and longitudinal studies suggest that potential brain tissue abnormalities may recover with clinical improvement. Overall, as the available data are inconclusive, further efforts in this field are warranted.     

Brain structure in healthy adults is related to serum transferrin and the H63D polymorphism in the HFE gene

Control of iron homeostasis is essential for healthy central nervous system function: iron deficiency is associated with cognitive impairment, yet iron overload is thought to promote neurodegenerative diseases. Specific genetic markers have been previously identified that influence levels of transferrin, the protein that transports iron throughout the body, in the blood and brain. Here, we discovered that transferrin levels are related to detectable differences in the macro- and microstructure of the living brain. We collected brain MRI scans from 615 healthy young adult twins and siblings, of whom 574 were also scanned with diffusion tensor imaging at 4 Tesla. Fiber integrity was assessed by using the diffusion tensor imaging-based measure of fractional anisotropy. In bivariate genetic models based on monozygotic and dizygotic twins, we discovered that partially overlapping additive genetic factors influenced transferrin levels and brain microstructure. We also examined common variants in genes associated with transferrin levels, TF and HFE, and found that a commonly carried polymorphism (H63D at rs1799945) in the hemochromatotic HFE gene was associated with white matter fiber integrity. This gene has a well documented association with iron overload. Our statistical maps reveal previously unknown influences of the same gene on brain microstructure and transferrin levels. This discovery may shed light on the neural mechanisms by which iron affects cognition, neurodevelopment, and neurodegeneration.     

Craving is associated with amygdala volumes in adolescent marijuana users during abstinence

Background: Amygdala volume abnormalities have been reported in relation to craving in substance-dependent adults, but it remains unclear if these effects are seen in adolescent marijuana (MJ) users, particularly following abstinence. Objectives: The aim of this study was to examine the relationship between amygdala volume and craving during 28 days of abstinence in adolescent MJ users. Methods: MJ-using adolescents (n?=?22) aged 16–19 were recruited as part of a larger study on brain function in teen drug users. Craving measures were collected twice per week throughout a 28-day abstinence period. High-resolution anatomical magnetic resonance imaging data were collected at the end of the 28 days of confirmed abstinence. Left and right amygdala volumes were traced by hand (ICC?>?0.86). Composite scores for self-reported craving and withdrawal symptoms throughout the 28-day abstinence period were calculated to provide four composite measures of total craving, mood, sleep, and somatic complaints. Results: Results revealed that greater craving during abstinence was significantly associated with smaller left and right amygdala volumes, after controlling for age and gender. Other measures of withdrawal, including mood, somatic complaints and sleep problems, were not related to amygdala morphometry. Conclusion: These results are consistent with previous findings in adult alcohol- and cocaine-dependent individuals, who demonstrated a relationship between reduced amygdala volumes and increased craving. Future studies are needed to determine if these brain-behavior relationships are attributable to MJ use or predate the onset of substance use.     

Neural sensitivity to social rejection is associated with inflammatory responses to social stress

Although stress-induced increases in inflammation have been implicated in several major disorders, including cardiovascular disease and depression, the neurocognitive pathways that underlie inflammatory responses to stress remain largely unknown. To examine these processes, we recruited 124 healthy young adult participants to complete a laboratory-based social stressor while markers of inflammatory activity were obtained from oral fluids. A subset of participants (n = 31) later completed an fMRI session in which their neural responses to social rejection were assessed. As predicted, exposure to the laboratory-based social stressor was associated with significant increases in two markers of inflammatory activity, namely a soluble receptor for tumor necrosis factor-α (sTNFαRII) and interleukin-6 (IL-6). In the neuroimaging subsample, greater increases in sTNFαRII (but not IL-6) were associated with greater activity in the dorsal anterior cingulate cortex and anterior insula, brain regions that have previously been associated with processing rejection-related distress and negative affect. These data thus elucidate a neurocognitive pathway that may be involved in potentiated inflammatory responses to acute social stress. As such, they have implications for understanding how social stressors may promote susceptibility to diseases with an inflammatory component.     

Alcohol consumption is inversely associated with adherence to diabetes self-care behaviours.

AIMS: Our aim was to examine the associations of alcohol consumption with six diabetes self-care behaviours. METHODS: We determined levels of alcohol consumption and examined associations between alcohol consumption and six self-care behaviours in 65 996 adults with diabetes who received care through Kaiser Permanente Northern California and who responded to a 1994-1997 survey. Adherence with recommendations for self monitoring of blood glucose, HbA1c testing, and diabetes medications were determined from electronic records; smoking and use of diet and exercise to treat diabetes were self reported. Multiple logistic regression models were used to determine the associations between alcohol consumption (average number of drinks/day in the past year) and the probability of adherence to each self-care behaviour. RESULTS: Current alcohol consumption was reported by 50.8% of adults with diabetes. In adjusted models, we observed a gradient of increasing risk for poor adherence to diabetes self-care behaviours with increasing alcohol consumption, starting with those who consume even one drink a day. Former drinkers had the greatest compliance with each self-care behaviour, except for current smoking. CONCLUSIONS: Alcohol consumption is a marker for poorer adherence to diabetes self-care behaviours. These findings highlight the importance of routine assessment of alcohol intake in people with diabetes, particularly as half of adults with diabetes consume alcohol. Given extant evidence that moderate alcohol intake may have cardiovascular benefits for patients with diabetes, examination of the trade-offs between cardiovascular benefits vs. potential risk of lower adherence with self-care behaviours deserves study.     

Alcohol consumption is associated with reduced prevalence of goitre and solitary thyroid nodules

OBJECTIVE: Goitre prevalence is dependent on iodine intake and smoking habits, but further risk factors have only been examined briefly. We examined the association between alcohol consumption and the prevalence of thyroid enlargement and nodularity. DESIGN: Cross-sectional population study with ultrasonography of the thyroid gland and assessment of alcohol intake and smoking habits from questionnaires. SUBJECTS: Four thousand six-hundred and forty-nine men and women aged 18-65 years, randomly selected from the Danish Civil Registration System. MEASUREMENTS: Thyroid volume and prevalence of thyroid enlargement, multiple nodules or a solitary nodule in the thyroid. RESULTS: Abstainers and participants with a low alcohol consumption (< 7 drinks/week) had the same prevalence of thyroid enlargement and nodularity, but participants with moderate (8-28 drinks/week for women, 8-42 for men) or high (> 28/42 drinks/week) alcohol consumption had much lower prevalence of thyroid abnormalities. Possible confounding by sex, age, iodine status and smoking was considered in all models. Odds ratios compared to abstainers for thyroid enlargement were 0.74 [95% confidence interval (CI) 0.57-0.96] for moderate- and 0.44 (95% CI 0.22-0.88) for high alcohol consumption. Odds ratios compared to abstainers for a solitary nodule were 0.64 (95% CI 0.42-0.96) for moderate- and 0.41 (95% CI 0.12-1.37) for high alcohol consumption. Mean thyroid volume was 13.5 ml among abstainers compared to 10.9 ml among participants with high alcohol consumption (P < 0.001). Both wine- and beer consumption were associated to lower prevalence of thyroid abnormalities. CONCLUSIONS: Increasing levels of alcohol consumption were associated to lower prevalence of thyroid enlargement and to lower prevalence of a solitary nodule in the thyroid, and indications of a causal relationship were found.     

Voxel-based morphometry demonstrates reduced grey matter density on brain MRI in patients with diabetic retinopathy

Aims/hypothesis In addition to nephropathy, retinopathy and peripheral neuropathy, a microvascular complication of type 1 diabetes that may be tentatively referred to as ‘diabetic encephalopathy’ has gained increasing attention. There is growing evidence that lowered cognitive performance in patients with type 1 diabetes is related to chronic hyperglycaemia rather than recurrent episodes of severe hypoglycaemia, as previously speculated. The aim of our study was to use magnetic resonance imaging (MRI) to establish whether long-term hyperglycaemia, resulting in advanced retinopathy, contributes to structural changes in the brain (reduced grey matter). Subjects, materials and methods We applied voxel-based morphometry on magnetic resonance images to compare grey matter density (GMD) between three groups of participants. GMD is used as a marker of cortical atrophy. We compared 13 type 1 diabetic patients with a microvascular complication (i.e. proliferative retinopathy) with 18 type 1 diabetic patients who did not have retinopathy in order to assess the effects of microvascular changes on GMD. Both patient groups were compared with 21 healthy control subjects to assess the effect of diabetes in itself. Results Patients with diabetic retinopathy showed reduced GMD in the right inferior frontal gyrus and right occipital lobe compared both with patients without retinopathy and with healthy controls (p<0.05). Conclusions/interpretation Our data show that patients with type 1 diabetes, who, as a consequence of chronic hyperglycaemia, had developed advanced retinopathy, also showed increased focal cortical atrophy on brain MRI.     

Functional connectivity alterations in patients with chronic hepatitis C virus infection: A multimodal MRI study

Chronic hepatitis C virus (HCV) infection is associated with fatigue and depression. Cognitive impairments are also reported in a smaller number of HCV‐positive patients. Recent studies linked HCV to low‐grade inflammation in brain. Here, we test the hypothesis that chronic HCV is associated with 3T‐neuroimaging‐derived grey matter volume (GMV) and functional connectivity alterations in a sample of chronic HCV (1b), without severe liver disease. Regional GMV and resting‐state fMRI‐derived eigenvector centrality (EC) were compared between 19 HCV‐positive patients and 23 healthy controls (all females, 50‐69 and 52‐64 years, respectively), controlling for white matter hyperintensities and age. Standard tests were used to assess fatigue, depression and cognitive performance. Also, liver fibrosis stage and viral load were quantified among patients. In comparison with controls, HCV‐positive patients had higher scores in fatigue and depression, and worse alertness scores. The groups performed similarly in other cognitive domains. We report higher EC in a cluster in the right anterior superior parietal lobule in patients, while no differences are found in GMV. Post hoc functional connectivity analysis showed increased connectivity of this cluster with primary and secondary somatosensory cortex, and temporal and occipital lobes in patients. Higher mean EC in the superior parietal cluster, adjusted for mean framewise displacement, was associated with better memory and attention performance, but not with fatigue, depression, viral load or level of liver fibrosis, among patients. These results suggest a compensatory mechanism in chronic hepatitis C and explain equivocal results in the literature about cognitive deficits in infected persons. Further studies should define the relation of these connectivity changes to the brain's inflammatory activity.     

Grey matter alterations in obesity: A meta‐analysis of whole‐brain studies

Obesity is a major problem in the modern world causing a higher risk for various cerebrovascular diseases causing a profound individual and societal burden. The neurobiological foundation bears potential to understand the complex interaction of individual differences in brain structure and function and ingestive behaviour. This systematic review was performed on the current evidence of structural abnormalities in grey matter volume (GMV) in patients with obesity based on studies published until December 2017, which were selected through search in PubMed, CENTER (Cochrane Library), PsycINFO, Web of Science, and Ovid MEDLINE. Ten studies were included; all of them included patients with obesity and provided a whole‐brain analysis of grey matter (GM) distribution. Our findings confirmed the most consistent GM reductions in patients with obesity in the left, middle, and right inferior frontal gyrus (including the insula), the left middle temporal cortex, the left precentral gyrus, and the cerebellum. On the other hand, increased GMV in patients with obesity were found in the left cuneus, left middle frontal gyrus, left inferior occipital gyrus, and corpus callosum.     

Effective alcohol policies are associated with reduced consumption among demographic groups who drink heavily

Background

Alcohol policies stand out among other noncommunicable disease-relevant policies for the lack of uptake. Composite indicators have been developed to measure the effects of alcohol control policy. We investigated whether drinking patterns among demographic groups from general population samples of drinkers from diverse countries are associated with alcohol control policy as measured by the International Alcohol Control (IAC) Policy Index.

Methods

Representative samples of adult drinkers from 10 countries (five high-income and five middle-income) were surveyed about alcohol consumption, using beverage and location-specific questions.

Measurements

The IAC Policy Index was analyzed with frequency, typical occasion quantity, and volume consumed. Analyses used mixed models that included interactions between country IAC Policy Index score and age group, gender, and education level.

Findings

Each increase in IAC policy index score (reflecting more effective alcohol policy) was associated with a 13.9% decrease in drinking frequency (p = 0.006) and a 16.5% decrease in volume (p = 0.001). With each increase in IAC Policy Index score, both genders decreased for all three measures, but men less so than women. Women decreased their typical occasion quantity by 1.2% (p = 0.006), frequency by 3.1% (p < 0.001), and total volume by 4.2% (p < 0.001) compared to men. Low and mid-education groups decreased their typical occasion quantity by 2.6% (p < 0.001) and 1.6% (p = 0.001), respectively, compared to high education, while for drinking frequency the low education group increased by 7.0% (p < 0.001). There was an overall effect of age (F = 19.27, p < 0.0001), with 18–19 and 20–24-year-olds showing the largest decreases in typical occasion quantity with increasing IAC policy index score.

Conclusions

The IAC Policy Index, reflecting four effective policies, was associated with volume and frequency of drinking across 10 diverse countries. Each increase in the IAC Policy Index was associated with lower typical quantities consumed among groups reporting heavy drinking: young adults and less well-educated. There is value in implementing such alcohol policies and a need to accelerate their uptake globally.