Short-term high-calorie high-fat feeding induces hyperinsulinemia and blunts skeletal muscle microvascular blood flow in healthy humans.

Skeletal muscle microvascular blood flow (MBF) plays an important role in glucose disposal in muscle. Impairments in muscle MBF contribute to insulin resistance and prediabetes. Animal studies show that short-term (3 day) high-fat feeding blunts skeletal muscle MBF before impairing insulin-stimulated glucose disposal. It is not known whether this occurs in humans. We investigated the temporal impact of a 7-day high-calorie high-fat (HCHF) diet intervention (+52% kJ; 41% fat) on fasting and postprandial cardiometabolic outcomes in 14 healthy adults (18-37 yr). Metabolic health and vascular responses to a mixed-meal challenge (MMC) were measured at pre (day 0)-, mid (day 4)- and post (day 8)-intervention. There were no significant differences in body weight, body fat %, fasting blood glucose, and fasting plasma insulin concentrations at pre-, mid- and postintervention. Compared with preintervention there was a significant increase in insulin (but not glucose) total area under the curve in response to the MMC at midintervention (P = 0.041) and at postintervention (P = 0.028). Unlike at pre- and midintervention, at postintervention muscle MBF decreased at 60 min (P = 0.024) and 120 min (P = 0.023) after the MMC. However, macrovascular blood flow was significantly increased from 0 to 60 min (P < 0.001) and 120 min (P < 0.001) after the MMC at pre-, mid- and postintervention. Therefore, short-term HCHF feeding in healthy individuals leads to elevated postprandial insulin but not glucose levels and a blunting of meal-induced skeletal muscle MBF responses but not macrovascular blood flow responses.NEW & NOTEWORTHY This is the first study to investigate skeletal muscle microvascular blood flow (MBF) responses in humans after short-term high-calorie high-fat (HCHF) diet. The main findings were that HCHF diet causes elevated postprandial insulin in healthy individuals within 3 days and blunts meal-induced muscle MBF within 7 days, despite no impairments in postprandial glucose or macrovascular blood flow.

Cardiac functional adaptation to resistance and endurance exercise training: a randomized crossover study.

Few training studies have assessed the impact of different modes of exercise on changes in cardiac function. This study investigated changes in left ventricular (LV) systolic and diastolic function following endurance (END) and resistance (RES) training in healthy participants. Sixty-four individuals participated in a randomized crossover design trial, involving 12 wk of END and RES training, separated by a 12-wk washout. Echocardiograms assessed systolic function [ejection fraction (EF) and global longitudinal strain (GLS)], diastolic function [mitral valve early velocity (E), tissue Doppler velocity (e'), their ratio (E/e')], and left atrial volume indexed to body surface area (LA ESVi). LV mass (LVM) increased with both RES (Δ5.3 ± 11.9, P = 0.001) and END (Δ7.5 ± 13.9, P < 0.001). Once adjusted for lean body mass (LVMi), changes remained significant following END. E/e' improved following END (Δ-0.35 ± 0.98, P = 0.011) not RES (Δ0.35 ± 1.11, P =0.157; P = 0.001 between modes). LA ESVi increased with END (Δ2.0 ± 6.1, P = 0.019) but not RES (Δ1.7 ± 5.7, P = 0.113). EF and GLS were not impacted significantly by either mode of training. Adaptation in LVM and LA volumes, as well as diastolic function, was exercise mode specific. Twelve weeks of intensive END increased LVM, LA volumes, and increased diastolic function. Following RES, LVM increased, although this was attenuated after accounting for changes in lean body mass. There were no changes in systolic function following either mode of exercise training.NEW & NOTEWORTHY Different types of exercise training induce distinct physiological adaptations however few exercise training studies have assessed the impact of different modes of exercise on cardiac function. This study investigated changes in left ventricular systolic and diastolic function following exercise training. Participants completed both endurance and resistance training separated by a 12-wk washout period so each participant is their own control. We present adaptations in cardiac structure and diastolic function are exercise mode specific.

The Kessler Psychological Distress Scale in Australian adolescents: Analysis of the second Australian Child and Adolescent Survey of Mental Health and Wellbeing.

INTRODUCTION: The 10-item Kessler Psychological Distress Scale (K10) is used to screen adolescents for mental disorders in Australian clinical practice; however, there are no Australian adolescent normative data. METHODS: Data were drawn from a nationally representative sample (N = 2964) of Australian adolescents (11-17 years). This study had three aims: (1) to examine concurrent validity between the K10 and Strengths and Difficulties Questionnaire (SDQ) emotional symptoms subscale, (2) to establish normative Australian adolescent K10 data and (3) to determine optimal K10 cut-off scores for screening for major depressive disorder (MDD) via receiver operator characteristic curve analysis and stratum-specific likelihood ratios. RESULTS: The K10 and SDQ emotional symptoms scales were moderately correlated (rs = 0.63, p < 0.001). Older female adolescents reported higher total K10 scores compared with younger female adolescents (15-17 years: M = 20.2, standard error [SE] = 0.3; 11-14 years: M = 16.8, SE = 0.3) and male adolescents (11-14 years: M = 16.6, SE = 0.2; 15-17 years: M = 16.0, SE=0.2). K10 scores to optimally discriminate those with and without MDD varied by age and sex and had low specificities. Stratum-specific likelihood ratios indicated adolescents with a K10 score of ≥30 will have a 12.9 (95% confidence interval = [10.2, 16.2]) increased likelihood of MDD. CONCLUSION: The K10 has utility for assessing psychological distress in health care and epidemiological research in Australian adolescents. Adolescents with K10 scores in the 'very high' range are at increased risk of MDD. Further assessment of these young people is indicated to identify those with or at risk of developing MDD.

Sex differences in cardiovascular risk factor responses to resistance and endurance training in younger subjects.

This study compared differences in cardiovascular (CV) risk factor responses between males and females following endurance (END) and resistance (RES) training. We present the frequency of responders to each training modality and the magnitude of response. Using a randomized crossover design, 68 healthy adults [age: female (F): 24.5 ± 4.6; male (M): 27.3 ± 6.6] completed 3 mo of RES and END, with 3 mo washout. Peak oxygen consumption (V̇o2peak), strength, body composition, blood pressure, glucose, insulin, and lipids were measured. V̇o2peak (L/min) significantly increased in both sexes following END, but not RES. The magnitude of change was larger in males (F: +0.20 L/min; M: +0.32 L/min), although this did not achieve statistical significance (P = 0.051). Strength significantly increased in both sexes following RES (P < 0.01), with a larger increase in males (Leg press: F: +39 kg; M: +63 kg; P < 0.05). Lean mass significantly increased in both sexes (P < 0.01) following RES and fat mass decreased in females following END (P = 0.019). The change in C-reactive protein following END was significantly different between sexes (F: -0.4 mg/L; M: +0.5 mg/L; P = 0.035). There were no differences between sexes in the proportion of individuals who responded positively to any variable following RES or END; differences between sexes were due to the magnitude of change. Males had a larger increase in V̇o2peak following END and strength following RES. There were no sex differences in other CV risk factors. This suggests differences in physiological responses to strength and V̇o2peak may not translate to changes in CV risk in healthy subjects.NEW & NOTEWORTHY This study investigated sex differences in cardiovascular risk factors in response to different exercise training modalities. Males had a larger improvement in peak oxygen consumption following endurance training and strength following resistance training compared with females. These changes in peak oxygen consumption and strength did not translate to changes in other cardiovascular risk factors. Despite the greater magnitude of change in males, there were no sex differences in the proportion of individuals who responded to training.

The association between child maltreatment and health risk behaviours and conditions throughout life in the Australian Child Maltreatment Study.

OBJECTIVE: To estimate associations between all five types of child maltreatment (emotional abuse, neglect, physical abuse, sexual abuse, and exposure to domestic violence) and health risk behaviours and conditions. DESIGN, SETTING, PARTICIPANTS: Nationally representative survey of Australian residents aged 16 years and older conducted by computer-assisted telephone interviewing. MAIN OUTCOME MEASURES: Associations between child maltreatment and the following health risk behaviours and conditions: current smoker, binge drinking (at least weekly in past 12 months), cannabis dependence (according to the Cannabis Severity of Dependence Scale), obesity (based on body mass index), self-harm in past 12 months, and suicide attempt in past 12 months. RESULTS: A total of 8503 participants completed the survey. All five types of child maltreatment were associated with increased rates of all of the health risk behaviours and conditions that we considered. The strongest associations were in the youngest age group (16-24-year-olds). Sexual abuse and emotional abuse were associated with the highest odds of health risk behaviours and conditions. Cannabis dependence, self-harm and suicide attempts were most strongly associated with child maltreatment. Experiencing more than one type of child maltreatment was associated with higher rates of health risk behaviours and conditions than experiencing one type of child maltreatment. CONCLUSIONS: Child maltreatment is associated with substantially increased rates of health risk behaviours and conditions. Prevention and intervention efforts should be informed by trauma histories, and holistic psychosocial care should be incorporated into programs focusing on behaviour change.

The Australian Child Maltreatment Study (ACMS), a national survey of the prevalence of child maltreatment and its correlates: methodology.

OBJECTIVES: To describe the aims, design, methodology, and respondent sample representativeness of the Australian Child Maltreatment Study (ACMS). DESIGN, SETTING: Cross-sectional, retrospective survey; computer-assisted mobile telephone interviewing using random digit dialling (computer-generated), Australia, 9 April - 11 October 2021. PARTICIPANTS: People aged 16 years or more. The target sample size was 8500 respondents: 3500 people aged 16-24 years and 1000 respondents each from five further age groups (25-34, 35-44, 45-54, 55-64, 65 years or more). MAIN OUTCOME MEASURES: Primary outcomes: Emotional abuse, neglect, physical abuse, sexual abuse, exposure to domestic violence during childhood, assessed with the Juvenile Victimization Questionnaire-R2 Adapted Version (Australian Child Maltreatment Study). SECONDARY OUTCOMES: selected mental disorder diagnoses (Mini International Neuropsychiatric Interview, MINI), selected physical health conditions, health risk behaviours, health service use. RESULTS: The demographic characteristics of the ACMS sample were similar to those of the Australian population in 2016 with respect to gender, Indigenous status, region and remoteness category of residence, and marital status, but larger proportions of participants were born in Australia, lived in areas of higher socio-economic status, had tertiary qualifications, and had income greater than $1250 per week. Population weights were derived to adjust for these differences. Associations between the number of calls required to recruit participants and maltreatment rates and health outcomes were not statistically significant. CONCLUSIONS: The ACMS provides the first reliable estimates of the prevalence of each type of child maltreatment in Australia. These estimates, and those of associated mental health and health risk behaviours reported in this supplement can inform policy and practice initiatives for reducing the prevalence of child maltreatment and its consequences. Our benchmark study also provides baseline data for repeated waves of the ACMS that will assess the effectiveness of these initiatives.

The prevalence of child maltreatment in Australia: findings from a national survey.

OBJECTIVES: To estimate the prevalence in Australia of each type of child maltreatment; to identify gender- and age group-related differences in prevalence. DESIGN, SETTING: Cross-sectional national survey; mobile telephone interviews using random digit dialling (computer-generated), Australia, 9 April - 11 October 2021. Retrospective self-report data using validated questionnaire (Juvenile Victimisation Questionnaire-R2 Adapted Version (Australian Child Maltreatment Study). PARTICIPANTS: People aged 16 years or more. The target sample size was 8500 respondents: 3500 people aged 16-24 years and 1000 respondents each from five further age groups (25-34, 35-44, 45-54, 55-64, 65 years or more). MAIN OUTCOME MEASURES: Proportions of respondents reporting physical abuse, sexual abuse, emotional abuse, neglect, and exposure to domestic violence to age 18 years, assessed with the Juvenile Victimization Questionnaire-R2 Adapted Version (Australian Child Maltreatment Study), overall and by gender and age group, and weighted to reflect characteristics of the Australian population aged 16 years or more in 2016. RESULTS: Complete survey data were available for 8503 eligible participants (14% response rate). Physical abuse was reported by 32.0% of respondents (95% confidence interval [CI], 30.7-33.3%), sexual abuse by 28.5% (95% CI, 27.3-29.8%), emotional abuse by 30.9% (95% CI, 29.7-32.2%), neglect by 8.9% (95% CI, 8.1-9.7%), and exposure to domestic violence by 39.6% (95% CI, 38.3-40.9%). The proportions of respondents who reported sexual abuse, emotional abuse, or neglect were each statistically significantly larger for women than men. The reported prevalence of physical abuse by respondents aged 16-24 years was lower than for those aged 25-34 years, and that of sexual abuse was lower than for those aged 35-44 years, suggesting recent declines in the prevalence of these maltreatment types. CONCLUSIONS: Child maltreatment is common in Australia, and larger proportions of women than men report having experienced sexual abuse, emotional abuse, and neglect during childhood. As physical and sexual abuse may have declined recently, public health policy and practice may have positive effects, justifying continued monitoring and prevention activities.

The prevalence and nature of multi-type child maltreatment in Australia.

OBJECTIVES: To determine the prevalence in Australia of multi-type child maltreatment, defined as two or more maltreatment types (physical abuse, sexual abuse, emotional abuse, neglect, or exposure to domestic violence) and to examine its nature, family risk factors, and gender and age cohort differences. DESIGN: Retrospective cross-sectional survey using a validated questionnaire. SETTING AND PARTICIPANTS: Mobile phone random digit-dial sample of the Australian population aged 16 years and older. MAIN OUTCOME MEASURES: National estimates of multi-type child maltreatment up to age 18 years using the Juvenile Victimisation Questionnaire-R2: Adapted Version (Australian Child Maltreatment Study). RESULTS: Of 8503 participants, 62.2% (95% CI, 60.9-63.6%) experienced one or more types of child maltreatment. Prevalence of single-type maltreatment was 22.8% (95% CI, 21.7-24.0%), whereas 39.4% (95% CI, 38.1-40.7%) of participants reported multi-type maltreatment and 3.5% (95% CI, 3.0-4.0%) reported all five types. Multi-type maltreatment was more common for gender diverse participants (66.1% [95% CI, 53.7-78.7%]) and women (43.2% [95% CI, 41.3-45.1%]) than for men (34.9% [95% CI, 33.0-36.7%]). Multi-type maltreatment prevalence was highest for those aged 25-44 years. Family-related adverse childhood experiences - especially mental illness and alcohol or substance misuse - increased risk. Exposure to domestic violence was the maltreatment type most often present in multi-type maltreatment patterns. CONCLUSIONS: Multi-type child maltreatment is prevalent in Australia and more common in women and gender diverse individuals. Child protection services, health practitioners, and prevention and intervention services must assess and manage multi-type maltreatment in children and address its health consequences across the lifespan. Public health policy should consider prevention services or strategies that target multi-type child maltreatment.

Child maltreatment and health service use: findings of the Australian Child Maltreatment Study.

OBJECTIVES: To examine associations between child maltreatment and health service use, both overall, by type and by the number of types of maltreatment reported. DESIGN, SETTING: Cross-sectional, retrospective survey using the Juvenile Victimization Questionnaire-R2: Adapted Version (Australian Child Maltreatment Study); computer-assisted mobile telephone interviews using random digit dialling, Australia, 9 April - 11 October 2021. PARTICIPANTS: Australians aged 16 years or more. The target sample size was 8500 respondents: 3500 people aged 16-24 years and 1000 respondents each from the five age groups (25-34, 35-44, 45-54, 55-64, 65 years or more). MAIN OUTCOME MEASURES: Self-reported health service use during the past twelve months: hospital admissions, length of stay, and reasons for admission; and numbers of consultations with health care professionals, overall and by type. Associations between maltreatment and health service use are reported as odds ratios adjusted for age group, gender, socio-economic status, financial hardship (childhood and current), and geographic remoteness. RESULTS: A total of 8503 participants completed the survey. Respondents who had experienced child maltreatment were significantly more likely than those who had not to report a hospital admission during the preceding twelve months (adjusted odds ratio [aOR], 1.39; 95% confidence interval [CI], 1.16-1.66), particularly admission with a mental disorder (aOR, 2.4; 95% CI, 1.03-5.6). The likelihood of six or more visits to general practitioners (aOR, 2.37; 95% CI, 1.87-3.02) or of a consultation with a mental health nurse (aOR, 2.67; 95% CI, 1.75-4.06), psychologist (aOR, 2.40; 95% CI, 2.00-2.88), or psychiatrist (aOR, 3.02; 95% CI, 2.25-4.04) were each higher for people who reported maltreatment during childhood. People who reported three or more maltreatment types were generally most likely to report greater health service use. CONCLUSIONS: Child maltreatment has a major impact on health service use. Early, targeted interventions are vital, not only for supporting children directly, but also for their longer term wellbeing and reducing their health system use throughout life.

The association between child maltreatment and mental disorders in the Australian Child Maltreatment Study.

OBJECTIVES: To examine the associations between experiences of child maltreatment and mental disorders in the Australian population. DESIGN: Population-representative survey conducted by computer-assisted telephone interviewing. SETTING, PARTICIPANTS: Australian residents aged 16 years and older. MAIN OUTCOME MEASURES: Mental disorder diagnoses of lifetime major depressive disorder, current alcohol use disorder (mild, moderate and severe), current generalised anxiety disorder and current post-traumatic stress disorder. RESULTS: More than one in three Australians (3606/8503 surveyed participants; 38.0%; 95% CI, 36.7-39.3%) met the diagnostic criteria for a mental disorder. The prevalence of mental disorders in non-maltreated participants was 21.6% (95% CI, 19.9-23.3%; n = 851). This increased to 36.2% (95% CI, 33.5-38.9%; n = 764) for those who experienced a single type of maltreatment and 54.8% (95% CI, 52.6-56.9%; n = 1991) for participants who experienced multi-type maltreatment. Compared with non-maltreated Australians, maltreated participants had about three times the odds of any mental disorder (odds ratio [OR], 2.82; 95% CI, 2.47-3.22), generalised anxiety disorder (OR, 3.14; 95% CI, 2.48-3.97), major depressive disorder (OR, 3.19; 95% CI, 2.68-3.80) and severe alcohol use disorder (OR, 2.62; 95% CI, 1.83-3.76), and almost five times the odds of post-traumatic stress disorder (OR, 4.60; 95% CI, 3.00-7.07). Associations between experiences of child maltreatment and mental disorders were strongest for sexual abuse, emotional abuse and multi-type maltreatment. The strength of the associations did not differ by gender. Adjustment for childhood and current financial hardship and for current socio-economic status did not significantly attenuate the associations. CONCLUSIONS: Mental disorders are significantly more likely to occur in individuals who experience child maltreatment, particularly multi-type maltreatment. Prevention of child maltreatment provides an opportunity to substantially reduce the prevalence of mental illness and improve the health of the Australian population.

Studies of Twin Responses to Understand Exercise THerapy (STRUETH): cerebrovascular function.

We studied monozygotic (MZ) and dizygotic (DZ) twin pairs following resistance (RES) and endurance (END) training to assess genetic and environmental contributions to cerebrovascular function. Cerebrovascular function (rest, autoregulation, hypercapnia, exercise) was assessed in 86 healthy same-sex MZ (30 pairs) and DZ (13 pairs) twins, who underwent 3 months of END and RES. Carbon dioxide ( PETCO2${P_{{\rm{ETC}}{{\rm{O}}_{\rm{2}}}}}$ ), mean arterial pressure (MAP) and middle cerebral artery velocity (MCAv) were measured and MCAv resistance (MCACVRi ) was calculated. Resting MCAv reduced by -2.8 cm/s following RES (P = 0.024), with no change following END (-0.3 cm/s, P = 0.758). Change in MCACVRi following RES was +0.11 mmHg/cm/s (P < 0.001), which was significantly greater than END (+0.02 mmHg/cm/s, P = 0.030). MAP also increased following RES (+4 mmHg, P = 0.010), but not END (+1 mmHg, P = 0.518). No changes were apparent in PETCO2${P_{{\rm{ETC}}{{\rm{O}}_{\rm{2}}}}}$ . At rest, positive response rates following RES ranged from 27 to 71% and from 40 to 64% following END. Intraclass correlations between twins were moderate for most variables at baseline. In response to training, only MZ pairs were significantly correlated for a change in MCAv (P = 0.005) and low frequency phase (P = 0.047) following RES.This study is the first to compare cerebrovascular function following RES and END in MZ and DZ twins. Most individuals who did not respond to one modality were able to respond by switching modality, and baseline heritability estimates were higher than training response. Exercise professionals should therefore consider modality and environmental factors when optimising interventions. KEY POINTS: Characterising individual responses to resistance and endurance exercise training can inform optimal strategies for exercise prescription. This study utilised monozygotic and dizygotic twins in a randomised cross-over study to determine individual responsiveness to different modalities of exercise training. The influence of environment vs. genetics on cerebrovascular responses to training was determined. It is apparent that individuals respond differently to distinct exercise stimuli and that switching modality may be a beneficial way to obtain positive responses in cerebrovascular function. This study has implications for improving individualised exercise prescription to maintain or improve cerebrovascular structure and function.

Empirical and theoretical foundations of family interventions to reduce the incidence and mental health impacts of school bullying victimization.

Bullying victimisation is a serious risk factor for mental health problems in children and adolescents. School bullying prevention programs have consistently produced small to moderate reductions in victimisation and perpetration. However, these programs do not necessarily help all students affected by bullying. Paradoxically whole-school programs lead to higher levels of depression and poorer self-esteem for students who continue to be victimised after program implementation. This may be because some elements of whole-school programs make victims more visible to their peers, thus further eroding their peer social status. Three main identified risk factors for children and adolescents who continue to be victimised following school bullying prevention programs are peer rejection, internalising problems, and lower quality parent-child relationships. All are potentially modifiable through family interventions. A large body of research demonstrates the influence of families on children's social skills, peer relationships and emotional regulation. This paper describes the theoretical foundations and empirical evidence for reducing the incidence and mental health outcomes of school bullying victimisation through family interventions. Family interventions should be available to complement school efforts to reduce bullying and improve the mental health of young people.

Substance use confounds associations between peer victimization and aggression in adolescence with mental disorders in adulthood: A prospective birth cohort study.

INTRODUCTION: Peer victimization and aggression in adolescence are associated with later mental health morbidity. However, studies examining this association have not controlled for adolescent substance use. We aimed to study the associations between peer victimization, peer aggression, and mental disorders in adulthood, adjusting for substance use in adolescence. METHODS: Participants were from the prospective Northern Finland Birth Cohort 1986. Data were available for 6682 individuals (70.8% of the original sample). Peer victimization and peer aggression were assessed with items from the Achenbach Youth Self Report at ages 15-16 years. Outcomes were nonorganic psychosis, anxiety disorder, mood disorder, substance use disorder, and any mental disorder (a none-vs-any indicator) at age 33 years collected from nationwide health care, insurance, and pension registers. Family structure, alcohol intoxication frequency, daily smoking, illicit drug use, and baseline psychopathology using Youth Self-Report total score, and parental mental disorders were considered as confounding factors. RESULTS: In multivariable analyses, the association between peer victimization and psychosis (Hazard ratio [HR]: 2.9, 95% confidence interval [CI]: 1.2-6.9, p = .020) and mood disorder (HR: 1.7, 95% CI: 1.2-2.4, p = .012) in females remained significant after adjusting for confounders. Other associations between female and male peer victimization or aggression and the studied outcomes attenuated after adjustments. CONCLUSIONS: Some associations between peer victimization and aggression and later mental health morbidity are explained by adolescent substance use. For females, substance use does not account for the increased risk of psychosis and mood disorder in those who experience peer victimization.

Resistance, but not endurance exercise training, induces changes in cerebrovascular function in healthy young subjects.

It is generally considered that regular exercise maintains brain health and reduces the risk of cerebrovascular diseases such as stroke and dementia. Since the benefits of different "types" of exercise are unclear, we sought to compare the impacts of endurance and resistance training on cerebrovascular function. In a randomized and crossover design, 68 young healthy adults were recruited to participate in 3 mo of resistance and endurance training. Cerebral hemodynamics through the internal carotid, vertebral, middle and posterior cerebral arteries were measured using Duplex ultrasound and transcranial Doppler at rest and during acute exercise, dynamic autoregulation, and cerebrovascular reactivity (to hypercapnia). Following resistance, but not endurance training, middle cerebral artery velocity and pulsatility index significantly decreased (P < 0.01 and P = 0.02, respectively), whereas mean arterial pressure and indices of cerebrovascular resistance in the middle, posterior, and internal carotid arteries all increased (P < 0.05). Cerebrovascular resistance indices in response to acute exercise and hypercapnia also significantly increased following resistance (P = 0.02), but not endurance training. Our findings, which were consistent across multiple domains of cerebrovascular function, suggest that episodic increases in arterial pressure associated with resistance training may increase cerebrovascular resistance. The implications of long-term resistance training on brain health require future study, especially in populations with pre-existing cerebral hypoperfusion and/or hypotension.NEW & NOTEWORTHY Three months of endurance exercise did not elicit adaptation in any domain of cerebrovascular function in young healthy inactive volunteers. However, resistance training induced decreased pulsatility in the extracranial arteries and increased indices of cerebrovascular resistance in cerebral arteries. This increase in cerebrovascular resistance, apparent at baseline and in response to both hypercapnia and acute exercise, may reflect a protective response in the face of changes in arterial pressure during resistance exercise.

Concordance between adolescents and parents on the Strengths and Difficulties Questionnaire: Analysis of an Australian nationally representative sample.

OBJECTIVE: Differences between adolescent self-reported and parent-reported emotional and behavioural difficulties may influence psychiatric epidemiological research. This study examined concordance between adolescents and their parents about mental health symptoms using the Strengths and Difficulties Questionnaire. METHODS: The study comprised a randomly selected, nationally representative sample of adolescents aged 11-17 years who participated in the Second Australian Child and Adolescent Survey of Mental Health and Wellbeing (N = 2967). Matched adolescent and parent responses across the five Strengths and Difficulties Questionnaire subscales (emotional problems, hyperactivity, peer problems, conduct problems and prosocial behaviour), as well as total difficulties and total impact scores were examined to estimate concordance. Concordance patterns were analysed by sex, after stratifying the sample by age group (younger adolescents: 11-14 years; older adolescents: 15-17 years). RESULTS: Concordance was 86.7% for total difficulties, 77.5% for total impact and ranged from 82.4% to 94.3% across the five Strengths and Difficulties Questionnaire subscales. There were no differences in concordance between sexes on the total difficulties score. Older females were more likely to disagree with their parents about emotional problems compared to males of the same age. Younger males were more likely to disagree with their parents compared to same-aged females about peer problems, hyperactivity, conduct problems and prosocial skills, as well as the impact of their problems. Older males were more likely to disagree with their parents about their prosocial skills compared to older females. CONCLUSION: Overall, concordance between adolescents and parents on the Strengths and Difficulties Questionnaire was largely driven by the high proportion of respondents who reported having no problems. Discordance on a subscale increased as the prevalence of problems in a sex and age demographic subgroup increased. These findings highlight the need for a multi-informant approach to detect emotional and behavioural difficulties in adolescents, particularly when assessing the impact of symptoms, as this subscale had the lowest concordance.

Fitness and strength responses to distinct exercise modes in twins: Studies of Twin Responses to Understand Exercise as a THerapy (STRUETH) study.

KEY POINTS: Exercise is considered medicine; however, the individual degree of responsiveness to a standardized dose of exercise is idiosyncratic. Individual responsiveness between distinct exercise modalities and the genetic/environmental contributions to exercise response are not well understood. In this novel randomized cross-over design study, monozygotic and dizygotic twins, as pairs, underwent 3 months of resistance and endurance training, separated by a 3 month washout period, aiming to assess training responses in strength and fitness outcomes to dichotomous training modalities, as well as the genetic/environmental contributions to exercise response. Our findings indicate that (i) individual responsiveness differs between exercise modalities; (ii) low-responders to one mode may be 'rescued' by switching to an alternate mode of exercise; and (iii) genes may not play as large a role, as previously estimated from cross-sectional data, for exercise training adaptation. The present study has implications for those charged with optimizing the benefits of exercise by means of individualizing the exercise prescription. ABSTRACT: Exercise response is idiosyncratic, although the degree of responsiveness, concordance in response between modalities and genetic contribution to responsiveness are not well understood. We investigated this using a novel randomized cross-over design of dichotomous exercise interventions in mono-(MZ) and di-zygotic (DZ) twin pairs. We studied strength (1RM) and fitness ( V̇O2max ) responses in 84 same-sex untrained twins (30 MZ, 12 DZ pairs; 24.9 ± 5.4 years). Twins, as pairs, underwent 3 months of resistance (RES) and endurance (END) training, separated by a 3 month washout period. Training responses and genetic/environmental contributions to responses were assessed. Leg strength 1RM increased following RES but not END (△47 ± 29 vs. 3 ± 26 kg; P < 0.001), whereas V̇O2max increased following END but not RES (△0.25 ± 0.26 vs. 0.04 ± 0.25 L min-1 ; P < 0.001). A higher percentage of individuals responded to RES for strength and to END for V̇O2max (P < 0.0001). Within-individual responses to each mode were not correlated (P > 0.05). Cross-sectional intraclass correlations were higher for MZ than DZ pairs for all variables, largely as a result of shared environment. Following training, MZ, but not DZ pairs, were significantly correlated for strength change to RES (rMZ = 0.62, P = 0.002) and END (rMZ = 0.36, P = 0.04), and for V̇O2max change to END (L min-1 , rMZ = 0.45, P = 0.02) with a mixture of unshared/shared environmental contributions. Our findings indicate that individual responsiveness differs between modalities and low-responders to one mode may be 'rescued' by switching to an alternate mode. Additionally, genes may not play as large a role as previously estimated from cross-sectional data for training adaptation, and/or cross-sectional data do not reflect longitudinal training effects. The present study has implications for optimizing the individualization of exercise prescription.

Prevalence of traditional bullying and cyberbullying among children and adolescents in Australia: A systematic review and meta-analysis.

BACKGROUND: Despite increased awareness of the adverse impact of bullying on mental health, the prevalence of bullying in Australia is uncertain. The aim of the current study was to conduct a systematic review and meta-analysis to estimate the prevalence of bullying (traditional and cyber) among Australian children and adolescents. This study synthesised bullying prevalence studies on victimisation experiences (being bullied) and perpetration experiences (bullying others). METHOD: A systematic review of electronic databases (A+ Education, EMBASE, ERIC, PubMed, PsycINFO and Scopus up to 27 May 2017) was conducted. In addition, reference lists of included studies, theses recorded at the National Library of Australia, and government websites were surveyed to identify local area data as well as state and nationally representative data. Overall, 898 studies were screened and out of the 126 studies assessed for eligibility, 46 satisfied the pre-determined inclusion criteria. Meta-analyses based on quality-effects models generated pooled prevalence estimates for each of the two types of bullying involvement (victimisation and perpetration), as well as distinct models for traditional bullying and cyberbullying experiences by the type of involvement. RESULTS: Overall, the 12-month prevalence of bullying victimisation was 15.17% (95% confidence interval = [9.17, 22.30]) and perpetration was 5.27% (95% confidence interval = [3.13, 7.92]). The lifetime prevalence for traditional bullying victimisation was 25.13% (95% confidence interval = [18.73, 32.11]) and perpetration was 11.61% (95% confidence interval = [7.41, 16.57]). Cyberbullying victimisation and perpetration were less common with lifetime prevalence of 7.02% (95% confidence interval = [2.41, 13.54]) and 3.45% (95% confidence interval = [1.13, 6.84]), respectively. CONCLUSION: Bullying is common among children and adolescents in Australia. There is a need to improve the measurement of bullying using a standardised instrument and for prevalence estimates to be collected on a regular basis to assess change over time. Wide implementation of anti-bullying programmes in Australian schools is a viable public health approach for the prevention of mental health problems.

Why do children and adolescents bully their peers? A critical review of key theoretical frameworks.

Bullying is a significant public health problem for children and adolescents worldwide. Evidence suggests that both being bullied (bullying victimisation) and bullying others (bullying perpetration) are associated with concurrent and future mental health problems. The onset and course of bullying perpetration are influenced by individual as well as systemic factors. Identifying effective solutions to address bullying requires a fundamental understanding of why it occurs. Drawing from multi-disciplinary domains, this review provides a summary and synthesis of the key theoretical frameworks applied to understanding and intervening on the issue of bullying. A number of explanatory models have been used to elucidate the dynamics of bullying, and broadly these correspond with either system (e.g., social-ecological, family systems, peer-group socialisation) or individual-level (e.g., developmental psychopathology, genetic, resource control, social-cognitive) frameworks. Each theory adds a unique perspective; however, no single framework comprehensively explains why bullying occurs. This review demonstrates that the integration of theoretical perspectives achieves a more nuanced understanding of bullying which is necessary for strengthening evidence-based interventions. Future progress requires researchers to integrate both the systems and individual-level theoretical frameworks to further improve current interventions. More effective intervention across different systems as well as tailoring interventions to the specific needs of the individuals directly involved in bullying will reduce exposure to a key risk factor for mental health problems.

Prevalence and correlates of bullying victimisation and perpetration in a nationally representative sample of Australian youth.

OBJECTIVE: Bullying prevalence studies are limited by varied measurement methods and a lack of representative samples. This study estimated the national prevalence of bullying victimisation, perpetration and combined victim-perpetration experiences in a representative population-based sample of Australian youth. The relationships between the three types of bullying involvement with a range of mental health symptoms and diagnoses were also examined. METHODS: A randomly selected nationally representative sample aged 11-17 years ( N = 2967, Mage = 14.6 years; 51.6% male) completed the youth component of the Second Australian Child and Adolescent Survey of Mental Health and Wellbeing (Young Minds Matter). Parents or carers also completed a structured face-to-face interview that asked questions about a single randomly selected child in the household. The youth survey comprised self-reported bullying victimisation and perpetration (Olweus Bully-Victim Questionnaire-adapted), psychological distress (K10), emotional and behavioural problems (Strengths and Difficulties Questionnaire), as well as self-harm, suicide attempts and substance use. Modules from the Diagnostic Interview Schedule for Children Version IV were administered to all youth and parents to assess for mental disorder diagnoses (major depressive disorder, any anxiety disorder and any externalising disorder [attention-deficit hyperactivity disorder, oppositional defiant disorder and conduct disorder]). RESULTS: The 12-month prevalence of bullying victimisation was 13.3%, perpetration 1.6% and victim-perpetration 1.9%. Logistic regression models showed all forms of involvement in bullying were associated with increased risk of psychological distress, emotional and behavioural problems, substance use, self-harm and attempted suicide. Victimisation and victim-perpetration were associated with youth-reported major depressive disorder. There were also significant associations between bullying involvement and parent-reported diagnoses of major depressive disorder, any anxiety disorder and any externalising disorder. CONCLUSION: Bullying continues to be frequently experienced by Australian adolescents. The current findings showed that involvement in any bullying behaviour was associated with increased risk of concurrent mental health problems. This evidence can be used to inform decisions concerning the allocation of resources to address this important health issue.