The role of the family in health promotion: a scoping review of models and mechanisms.

The family is an important contributor to the cultural conditions that support health. Current challenges in family health promotion interventions include programme design that is not always guided by theory and change mechanisms. Multifaceted programmes also make it hard to examine what works for whom, given different family roles and the range of lifestyle behaviour and mechanisms examined within diverse conceptual frameworks and cultures. We performed a scoping review on the heterogeneous literature to map and categorize the models and mechanisms by which a family may promote health behaviours among its members. We searched five electronic databases and grey literature up to 2020. Publications were included if they examined health-promoting behaviours, influences at the family level, and outlined the behavioural mechanisms involved. Two hundred and forty studies were identified. Ecological systems theory, social cognitive theory, family systems theory and the theory of planned behaviour were the frameworks most widely used in explaining either study context and/or mechanism. The most frequently studied family mechanisms involved aspects of family support, supervision and modelling, while some studies also included individual-level mechanisms. Majority of the studies investigated parental influence on the child, while few studies assessed the elderly family member as a recipient or actor of the influences. Studies on African, Asian and Middle Eastern populations were also in the minority, highlighting room for further research. Improving the understanding of context and behavioural mechanisms for family health promotion will aid the development of public health policy and chronic disease prevention programmes, complementing efforts targeted at individuals.

The validation of culturally appropriate scales to assess the family health climate in a multi-ethnic Asian population.

Background: The Family Health Climate (FHC) is a family environment attribute postulated to influence the health behaviors of family members. It can be measured by domain scales for physical activity (FHC-PA) and nutrition (FHC-NU), which have been validated and used to identify health climate patterns in families in Western populations. To extend the use of the scales to Asian settings, this study aimed to adapt and validate the instruments for use in the multi-ethnic population of Singapore, accounting for language and cultural differences. Methods: In Part A (n = 40) to adapt the scales for the Singapore population, we performed cognitive interviews, face validity testing and pre-testing of the instruments (n = 40). Besides English, the scales were translated into Chinese and Malay. In Part B (n = 400), we performed exploratory and confirmatory factor analyses respectively on two random samples. We also tested for item discriminant validity, internal consistency reliability, construct validity, and measurement invariance. Results: The findings from the cognitive interviews in Part A led to scale adaptations to accommodate cultural and linguistic factors. In Part B, EFA on Sample I resulted in a three-factor model for the PA scale (accounting for 71.2% variance) and a four-factor model for the NU scale (accounting for 72.8% variance). CFA on Sample II indicated acceptable model fits: FHC-PA: χ2 = 192.29, df = 101, p < 0.001, χ2/df = 1.90; SRMR = 0.049; RMSEA = 0.067; CFI = 0.969; TLI = 0.963; FHC-NU: χ2 = 170.46, df = 98, p < 0.001, χ2/df = 1.74; SRMR = 0.036; RMSEA = 0.061; CFI = 0.967; TLI = 0.960. The scores of family members demonstrated significant agreement on the FHC-PA (Sg) [ICC(2, 2) = 0.77] and FHC-NU (Sg) [ICC(2, 2) = 0.75] scales. Findings suggest good evidence for item discriminant validity, internal consistency reliability, construct validity, and measurement invariance. Short versions of the scales were also developed. Conclusion: We adapted, translated and validated the scales for assessing the health climate of families in Singapore, including the development of short versions. The results showed good psychometric properties and the constructs had significant relationships with health behaviors and routines. Improving our understanding of family influences on individual health behavior will be important in developing multi-level strategies for health promotion and chronic disease prevention.

Family Resilience and Psychological Responses to COVID-19: A Study of Concordance and Dyadic Effects in Singapore Households.

The impacts of COVID-19 may be magnified in a shared environment like the household, especially with people spending extended time at home during the pandemic. Family resilience is the ability of a family to adapt to crisis and can be a protective factor against stress and negative affect. While there have been calls to address family resilience during the pandemic, there is a lack of empirical study on its benefit. In this dyadic observational study, we sought to investigate the concordance of family members' psychological responses to COVID-19, whether dyad members' risk factors (COVID-19 exposure and financial impact) mutually affected each other's psychological responses, and importantly, whether family resilience was a significant factor in these responses. A total of 200 family dyads from the same household completed the Family Resilience Assessment Scale and questionnaires on COVID-19 threat perception, impacts, and exposure. We found concordant dyad responses for COVID-19 threat perception, but not for psychological impact. Using the Actor-Partner-Interdependence Model framework, we found that one's psychological impact was affected by the financial impact from both dyad members. After controlling for risk factors and demographic covariates, we found that family resilience significantly associated with lower COVID-19 psychological impact, though not with threat perception. The findings suggest that both family and individual factors need to be addressed and there may be benefit in addressing multilevel risk and protective factors using an ecological systems approach, which may help prepare the population for future crises.

Towards a Parsimonious Pathway Model of Modifiable and Mediating Risk Factors Leading to Diabetes Risk.

Modifiable risk factors are of interest for chronic disease prevention. Few studies have assessed the system of modifiable and mediating pathways leading to diabetes mellitus. We aimed to develop a pathway model for Diabetes Risk with modifiable Lifestyle Risk factors as the start point and Physiological Load as the mediator. As there are no standardised risk thresholds for lifestyle behaviour, we derived a weighted composite for Lifestyle Risk. Physiological Load was based on an index using clinical thresholds. Sociodemographics are non-modifiable risk factors and were specified as covariates. We used structural equation modeling to test the model, first using 2014/2015 data from the Indonesian Family Life Survey. Next, we fitted a smaller model with longitudinal data (2007/2008 to 2014/2015), given limited earlier data. Both models showed the indirect effects of Lifestyle Risk on Diabetes Risk via the mediator of Physiological Load, whereas the direct effect was only supported in the cross-sectional analysis. Specifying Lifestyle Risk as an observable, composite variable incorporates the cumulative effect of risk behaviour and differentiates this study from previous studies assessing it as a latent construct. The parsimonious model groups the multifarious risk factors and illustrates modifiable pathways that could be applied in chronic disease prevention efforts.

GABA levels are decreased after stroke and GABA changes during rehabilitation correlate with motor improvement.

BACKGROUND AND OBJECTIVE: γ-Aminobutyric acid (GABA) is the dominant inhibitory neurotransmitter in the brain and is important in motor learning. We aimed to measure GABA content in primary motor cortex poststroke (using GABA-edited magnetic resonance spectroscopy [MRS]) and in relation to motor recovery during 2 weeks of constraint-induced movement therapy (CIMT). METHODS: Twenty-one patients (3-12 months poststroke) and 20 healthy subjects were recruited. Magnetic resonance imaging structural T1 and GABA-edited MRS were performed at baseline and after CIMT, and once in healthy subjects. GABA:creatine (GABA:Cr) ratio was measured by GABA-edited MRS. Motor function was measured using Wolf Motor Function Test (WMFT). RESULTS: Baseline comparison between stroke patients (n = 19) and healthy subjects showed a significantly lower GABA:Cr ratio in stroke patients (P < .001) even after correcting for gray matter content in the voxel (P < .01) and when expressing GABA relative to N-acetylaspartic acid (NAA; P = .03). After 2 weeks of CIMT patients improved significantly on WMFT, but no consistent change across the group was observed for the GABA:Cr ratio (n = 17). However, the extent of improvement on WMFT correlated significantly with the magnitude of GABA:Cr changes (P < .01), with decreases in GABA:Cr ratio being associated with better improvements in motor function. CONCLUSIONS: In patients 3 to 12 months poststroke, GABA levels are lower in the primary motor cortex than in healthy subjects. The observed association between GABA and recovery warrants further studies on the potential use of GABA MRS as a biomarker in poststroke recovery.

Long-term reproducibility of GABA magnetic resonance spectroscopy.

Recent findings suggest that cortical gamma aminobutyric acid (GABA) levels may provide a surrogate marker for a number of psychiatric and neurological conditions, as well as behavioural traits. However, the natural variability of GABA levels in the human brain over long periods of time (>8 days) has not yet been studied. The purpose of this work was to investigate the long-term variability of GABA concentrations in the human occipital cortex. Nineteen healthy male participants were recruited and underwent two sessions of magnetic resonance spectroscopy (MRS) to determine occipital GABA levels with an average between-session interval of 7 months. We assessed between-session variability, as well as the correlation between session 1 and session 2 GABA measurements. The mean coefficient of variation between sessions was 4.3% (bootstrap 95% confidence interval: 2.5, 6.4), which is comparable to reported GABA variability measurements over much shorter time intervals (<8 days). A significant positive correlation was observed between session 1 and session 2 GABA measurements (r=0.53, p=0.014), and the intra-class correlation coefficient was calculated to be 0.52 which was also statistically significant (p=0.012). These findings establish experimentally that GABA concentrations in the occipital cortex, as measured by MRS, are relatively stable over periods as long as 7 months. The findings have significant implications for the internal validity of longitudinal studies of GABA levels in the human brain, and they lend foundational support to studies relating GABA levels to behavioural traits in healthy individuals.

Dietary nitrate facilitates an acetazolamide-induced increase in cerebral blood flow during visual stimulation.

The carbonic anhydrase (CA) inhibitor acetazolamide (AZ) is used routinely to estimate cerebrovascular reserve capacity in patients, as it reliably increases cerebral blood flow (CBF). However, the mechanism by which AZ accomplishes this CBF increase is not entirely understood. We recently discovered that CA can produce nitric oxide (NO) from nitrite, and that AZ enhances this NO production in vitro. In fact, this interaction between AZ and CA accounted for a large part of AZ's vasodilatory action, which fits well with the known vasodilatory potency of NO. The present study aimed to assess whether AZ acts similarly in vivo in the human cerebrovascular system. Hence, we increased or minimized the dietary intake of nitrate in 20 healthy male participants, showed them a full-field flickering dartboard, and measured their CBF response to this visual stimulus with arterial spin labeling. Doing so, we found a significant positive interaction between the dietary intake of nitrate and the CBF modulation afforded by AZ during visual stimulation. In addition, but contrary to studies conducted in elderly participants, we report no effect of nitrate intake on resting CBF in healthy human participants. The present study provides in vivo support for an enhancing effect of AZ on the NO production from nitrite catalyzed by CA in the cerebrovascular system. Furthermore, our results, in combination with the results of other groups, indicate that nitrate may have significant importance to vascular function when the cerebrovascular system is challenged by age or disease.

A NO way to BOLD? Dietary nitrate alters the hemodynamic response to visual stimulation.

Neurovascular coupling links neuronal activity to vasodilation. Nitric oxide (NO) is a potent vasodilator, and in neurovascular coupling NO production from NO synthases plays an important role. However, another pathway for NO production also exists, namely the nitrate-nitrite-NO pathway. On this basis, we hypothesized that dietary nitrate (NO3-) could influence the brain's hemodynamic response to neuronal stimulation. In the present study, 20 healthy male participants were given either sodium nitrate (NaNO3) or sodium chloride (NaCl) (saline placebo) in a crossover study and were shown visual stimuli based on the retinotopic characteristics of the visual cortex. Our primary measure of the hemodynamic response was the blood oxygenation level dependent (BOLD) response measured with high-resolution functional magnetic resonance imaging (0.64×0.64×1.8 mm) in the visual cortex. From this response, we made a direct estimate of key parameters characterizing the shape of the BOLD response (i.e. lag and amplitude). During elevated nitrate intake, corresponding to the nitrate content of a large plate of salad, both the hemodynamic lag and the BOLD amplitude decreased significantly (7.0±2% and 7.9±4%, respectively), and the variation across activated voxels of both measures decreased (12.3±4% and 15.3±7%, respectively). The baseline cerebral blood flow was not affected by nitrate. Our experiments demonstrate, for the first time, that dietary nitrate may modulate the local cerebral hemodynamic response to stimuli. A faster and smaller BOLD response, with less variation across local cortex, is consistent with an enhanced hemodynamic coupling during elevated nitrate intake. These findings suggest that dietary patterns, via the nitrate-nitrite-NO pathway, may be a potential way to affect key properties of neurovascular coupling. This could have major clinical implications, which remain to be explored.

Similarities and differences in arterial responses to hypercapnia and visual stimulation.

Despite the different origins of cerebrovascular activity induced by neurogenic and nonneurogenic conditions, a standard assumption in functional studies is that the consequence on the vascular system will be mechanically similar. Using a recently developed arterial spin labeling method, we examined arterial blood volume, arterial-microvascular transit time, and cerebral blood flow (CBF) in the gray matter and in areas with large arterial vessels under hypercapnia, visual stimulation, and a combination of the two. Spatial heterogeneity in arterial reactivity was observed between conditions. During hypercapnia, large arterial volume changes contributed to CBF increase and further downstream, there were reductions in the gray matter transit time. These changes were not significant during visual stimulation, and during the combined condition they were moderated. These findings suggest distinct vascular mechanisms for large and small arterial segments that may be condition specific. However, the power relationships between gray matter arterial blood volume and CBF in hypercapnia (α=0.69±0.24) and visual stimulation (α=0.68±0.20) were similar. Assuming consistent capillary and venous volume responses across these conditions, these results offer support for a consistent total CBV-flow relationship typically assumed in blood oxygen-level dependent calibration techniques.

Measuring arterial and tissue responses to functional challenges using arterial spin labeling.

The measurement of cerebral blood flow (CBF) in functional MRI studies that aim for non-invasive, quantitative and reliable measurements is a challenge. Here, we tested the feasibility of a recently developed, model-free CBF technique to study vascular dynamics upon functional challenges. Multiple inversion time-point signals were measured from arterial and tissue compartments, allowing for the calculation of CBF through a process of deconvolution. Using graded visual stimulation known to produce increasing hemodynamic responses, we recorded significant and graded DeltaCBF and Deltatau(m) (microvascular arrival time change) that were highly comparable to those estimated by a standard 3-parameter fit based on the general kinetic model, though the absolute values had weaker agreement. Estimated arterial blood volumes (excluding substantial arteriolar contribution) did not show significant change with visual stimulation. Bolus arrival times in the microvascular compartment shortened more as compared to the arrival times from the arterial compartment during visual stimulation, suggesting larger involvement of the microvasculature in local neuronal response. While there are limitations, the model-free analysis method has the potential to offer useful vascular information in fMRI studies.

Hippocampal volumes in first-episode psychosis.

Studies have shown that patients with schizophrenia have smaller hippocampi than healthy comparison subjects. There are, however, inconsistencies regarding the relationship between clinical characteristics and topographical differences in hippocampal volumetry. The authors investigated hippocampal volumes in minimally treated patients with first-episode schizophrenia spectrum disorders, relative to comparison subjects. Thirty-nine consecutive patients and 29 matched comparison subjects were scanned using 1.5 tesla MR system. Patients had significantly smaller right anterior, right, and anterior hippocampal volumes than comparison subjects. There was a gender by diagnosis effect: female patients showed significantly smaller anterior and right hippocampal volumes than female comparison subjects, an effect not seen in male patients. Our results suggest that smaller hippocampal volumes are present even in early stages of the illness.

Functional magnetic resonance imaging in adult craniopagus for presurgical evaluation.

Cranially conjoined twins are rare and pose unique challenges in the preoperative evaluation of cerebral language function. The authors report on their experience in the functional magnetic resonance (fMR) imaging evaluation of adult craniopagus (temporoparietooccipital fusion) to evaluate hemispheric language dominance and the eloquent language areas in the preoperative planning stages. Conventional clinical imaging hardware originally designed for individuals was adapted and tailored for use in the twins. They were assigned a selection of language tasks while undergoing fMR imaging. Significant blood oxygen level-dependent activations were detected in the main language regions in each twin, that is, the inferior frontal gyrus (around the Broca area), the middle and superior temporal lobes (around the Wernicke area) together with the inferior parietal lobe, and the middle and superior frontal gyri. Overall, the right-handed twin was strongly left lateralized for language, whereas the left-handed twin showed more bilateral activation during language tasks. Noninvasive language mapping with the aid of fMR imaging has been demonstrated for the first time in total craniopagus.

Parallel imaging techniques in functional MRI.

Originally developed for increased scanning velocity in cardiac imaging, parallel imaging (PI) techniques have recently also been applied for the reduction of artifacts in single-shot techniques. In functional brain imaging (fMRI) techniques, PI has been used for several purposes. It has been applied to reduce the distortions caused by the length of the echo-planar imaging readout, diminution of the gradient-related acoustic noise, as a means to increase acquisition speed or to increase the achievable brain coverage per unit time. In this article, the different applications of PI techniques in fMRI are reviewed, together with the basic theoretical background and the recently developed hardware necessary to achieve rapid, high signal-to-noise ratio PI-fMRI.