Quan Huynh

Relative contributions of adiposity in childhood and adulthood to vascular health of young adults

OBJECTIVE Vascular damage is suggested to have origins in childhood adiposity, but it is not clear whether this is a direct consequence of being obese in childhood. We aimed to estimate the associations of childhood body size or adiposity with adult vascular health, and to investigate whether these associations were independent of adult body size or adiposity. DESIGN AND METHODS Subjects were 2328 participants aged 7-15 years at baseline in 1985 with follow-up during 2004-2006 when aged 26-36 years. Anthropometric measures were taken at both baseline and follow-up. Carotid intima-media thickness (IMT) and three measures of large artery stiffness (LAS) were measured by ultrasound at follow-up. RESULTS Childhood body size or adiposity was positively associated with both adult IMT and LAS. Participants who were obese in adulthood had the greatest LAS, particularly those who were normal weight in childhood. Adjustment for adult body size or adiposity eliminated effects of childhood body size or adiposity on LAS. For IMT, adjustment for adult body size or adiposity reduced estimated effects of child height by 44% (male) and 27% (female), of child weight by 46% (male) and 70% (female) and, after adjusting for sex, of child body mass index and body surface area by 60% and 53% respectively. CONCLUSIONS Whereas IMT appeared to be influenced by body size or adiposity during childhood and early adulthood, LAS depended primarily on current adiposity and magnitude of adiposity gain between childhood and adulthood.

Childhood Muscular Fitness Phenotypes and Adult Metabolic Syndrome.

PURPOSE The objective of this study is to determine whether childhood muscular fitness phenotypes (strength, endurance, and power) are independently associated with adult metabolic syndrome (MetS). METHODS We conducted a longitudinal study including 737 participants who had muscular fitness measures in 1985 when age 9, 12, or 15 yr and attended follow-up in young adulthood 20 yr later when measures of MetS were collected. Childhood measures of muscular fitness included strength (right and left grip, leg, and shoulder extension and flexion), endurance (number of push-ups in 30 s), and power (distance of a standing long jump). A muscular fitness score was created using all individual muscular fitness phenotypes. In adulthood, waist circumference, blood pressure, HDL cholesterol, triglycerides, and glucose were measured. Adult outcomes were MetS defined using the harmonized definition and a continuous MetS risk score. RESULTS Participants with childhood muscular strength, muscular power, and combined muscular fitness score in the highest third had significantly lower relative risk (RR) for MetS and a lower continuous MetS score in adulthood independent of cardiorespiratory fitness than those in the lowest third (strength: RR = 0.21 (0.09, 0.49) β = -0.46 (-0.59, -0.34) power: RR = 0.26 (0.12, 0.60), β = -0.36 (-0.49, -0.23) fitness score: RR = 0.20 (0.09, 0.47), β = -0.45 (-0.58, -0.33)). However, adjustment for childhood waist circumference reduced the effect sizes for both adult outcomes by 17%-60%. CONCLUSION Phenotypes of childhood muscular fitness can be used to predict adult MetS independent of cardiorespiratory fitness. Although a large proportion of the effect of childhood muscular fitness on adult MetS is potentially being mediated by child waist circumference, these data suggest that promotion of muscular fitness among children might provide additional protection against developing adult MetS.

Prediction of cardiovascular and all-cause mortality at 10 years in the hypertensive aged population

BACKGROUND We have previously developed a score for predicting cardiovascular events in the intermediate term in an elderly hypertensive population. In this study, we aimed to extend this work to predict 10-year cardiovascular and all-cause mortality in the hypertensive aged population. METHODS Ten-year follow-up data of 5,378 hypertensive participants in the Second Australian National Blood Pressure study who were aged 65-84 years at baseline (1995-2001) and without prior cardiovascular events were analyzed. By using bootstrap resampling variable selection methods and comparing the Akaike and Bayesian information criterion and C-indices of the potential models, optimal and parsimonious multivariable Cox proportional hazards models were developed to predict 10-year cardiovascular and all-cause mortality. The models were validated using bootstrap validation method internally and using the Dubbo Study dataset externally. RESULTS The final model for cardiovascular mortality included detrimental (age, smoking, diabetes, waist-hip ratio, and disadvantaged socioeconomic status) and protective factors (female sex, alcohol consumption, and physical activity). The final model for all-cause mortality also included detrimental (age, smoking, random blood glucose, and disadvantaged socioeconomic status) and protective factors (female sex, alcohol consumption, body mass index, and statin use). Blood pressure did not appear in either model in this patient group. The C-statistics for internal validation were 0.707 (cardiovascular mortality) and 0.678 (all-cause mortality), and for external validation were 0.729 (cardiovascular mortality) and 0.772 (all-cause mortality). CONCLUSIONS These algorithms allow reliable estimation of 10-year risk of cardiovascular and all-cause mortality for hypertensive aged individuals.

Predictive Score for 30-Day Readmission or Death in Heart Failure.

Readmissions shortly after heart failure (HF) are common, expensive, and usually considered preventable.1 However, despite the use of several interventions, rates of readmission after HF remain stable.2 An effective risk score might permit the targeting of resource-intensive interventions (such as disease-management programs) specifically on high-risk patients. We sought to determine the combination of clinical and nonclinical factors that would have the best discriminatory power in predicting 30-day readmission or death in HF.

Vigorous physical activity and carotid distensibility in young and mid-aged adults.

Although physical activity (PA) improves arterial distensibility, it is unclear which type of activity is most beneficial. We aimed to examine the association of different types of PA with carotid distensibility (CD) and the mechanisms involved. Data included 4503 Australians and Finns aged 26–45 years. Physical activity was measured by pedometers and was self-reported. CD was measured using ultrasound. Other measurements included resting heart rate (RHR), cardiorespiratory fitness (CRF), blood pressure, biomarkers and anthropometry. Steps/day were correlated with RHR (Australian men r=−0.10, women r=−0.14; Finnish men r=−0.15, women r=−0.11; P<0.01), CRF and biochemical markers, but not with CD. Self-reported vigorous leisure-time activity was more strongly correlated with RHR (Australian men r=−0.23, women r=−0.19; Finnish men r=−0.20, women r=−0.13; P<0.001) and CRF, and was correlated with CD (Australian men r=0.07; Finnish men r=0.07, women r=0.08; P<0.05). This relationship of vigorous leisure-time activity with CD was mediated by RHR independently of potential confounders. In summary, vigorous leisure-time PA but not total or less intensive PA was associated with arterial distensibility in young to mid-aged adults. Promotion of vigorous PA is therefore recommended among this population. RHR was a key intermediary factor explaining the relationship between vigorous PA and arterial distensibility.

Impact of adiposity on cardiac structure in adult life: the childhood determinants of adult health (CDAH) study

BackgroundWe have examined the association between adiposity and cardiac structure in adulthood, using a life course approach that takes account of the contribution of adiposity in both childhood and adulthood.MethodsThe Childhood Determinants of Adult Health study (CDAH) is a follow-up study of 8,498 children who participated in the 1985 Australian Schools Health and Fitness Survey (ASHFS). The CDAH follow-up study included 2,410 participants who attended a clinic examination. Of these, 181 underwent cardiac imaging and provided complete data. The measures were taken once when the children were aged 9 to 15 years, and once in adult life, aged 26 to 36 years.ResultsThere was a positive association between adult left ventricular mass (LVM) and childhood body mass index (BMI) in males (regression coefficient (β) 0.41; 95% confidence interval (CI): 0.14 to 0.67; p = 0.003), and females (β = 0.53; 95% CI: 0.34 to 0.72; p < 0.001), and with change in BMI from childhood to adulthood (males: β = 0.27; 95% CI: 0.04 to 0.51; p < 0.001, females: β = 0.39; 95% CI: 0.20 to 0.58; p < 0.001), after adjustment for confounding factors (age, fitness, triglyceride levels and total cholesterol in adulthood). After further adjustment for known potential mediating factors (systolic BP and fasting plasma glucose in adulthood) the relationship of LVM with childhood BMI (males: β = 0.45; 95% CI: 0.19 to 0.71; p = 0.001, females: β = 0.49; 95% CI: 0.29 to 0.68; p < 0.001) and change in BMI (males: β = 0.26; 95% CI: 0.04 to 0.49; p = 0.02, females: β = 0.40; 95% CI: 0.20 to 0.59; p < 0.001) did not change markedly.ConclusionsAdiposity and increased adiposity from childhood to adulthood appear to have a detrimental effect on cardiac structure.

Mild cognitive impairment predicts death and readmission within 30 days of discharge for heart failure

BACKGROUND Cognitive impairment is highly prevalent in heart failure (HF), and may be associated with short-term readmission. This study investigated the role of cognition, incremental to other clinical and non-clinical factors, independent of depression and anxiety, in predicting 30-day readmission or death in HF. METHODS This study followed 565 patients from an Australia-wide HF longitudinal study. Cognitive function (MoCA score) together with standard clinical and non-clinical factors, mental health and 2D echocardiograms were collected before hospital discharge. The study outcomes were death and readmission within 30days of discharge. Logistic regression, Harrells C-statistic, integrated discrimination improvement (IDI) and net reclassification index were used for analysis. RESULTS Among 565 patients, 255 (45%) had at least mild cognitive impairment (MoCA≤22). Death (n=43, 8%) and readmission (n=122, 21%) within 30days of discharge were more likely to occur among patients with mild cognitive impairment (OR=2.00, p=0.001). MoCA score was also negatively associated with 30-day readmission or death (OR=0.91, p<0.001) independent of other risk factors. Adding MoCA score to an existing prediction model of 30-day readmission significantly improved discrimination (C-statistic=0.715 vs. 0.617, IDI estimate 0.077, p<0.001). From prediction models developed from our study, adding MoCA score (C-statistic=0.83) provided incremental value to that of standard clinical and non-clinical factors (C-statistic=0.76) and echocardiogram parameters (C-statistic=0.81) in predicting 30-day readmission or death. Reclassification analysis suggests that addition of MoCA score improved classification for a net of 12% of patients with 30-day readmission or death and of 6% of patients without (p=0.002). CONCLUSIONS Mild cognitive impairment predicts short-term outcomes in HF, independent of clinical and non-clinical factors.

The contribution of childhood cardiorespiratory fitness and adiposity to inflammation in young adults

Cardiorespiratory fitness and adiposity may influence cardiovascular risk through their effects on inflammation. The long‐term effects of these modifiable factors on adult inflammation remain uncertain. The associations of childhood and adulthood cardiorespiratory fitness and adiposity with adult inflammation [C‐reactive protein (CRP), fibrinogen] were examined.

Associations of childhood and adult obesity with left ventricular structure and function.

Background:Overweight and obesity are associated with left ventricular (LV) dysfunction. We sought whether echocardiographic evidence of abnormal adult cardiac structure and function was related to childhood or adult adiposity.Methods:This study included 159 healthy individuals aged 7–15 years and followed until age 36–45 years. Anthropometric measurements were performed both at baseline and follow-up. Cardiac structure (indexed left atrial volume (LAVi), left ventricular mass (LVMi)) and LV function (global longitudinal strain (GLS), mitral e′) were assessed using standard echocardiography at follow-up. Conventional cutoffs were used to define abnormal LAVi, LVMi, GLS and mitral annular e′.Results:Childhood body mass index (BMI) was correlated with LVMi (r=0.25, P=0.002), and child waist circumference was correlated with LVMi (r=0.18, P=0.03) and LAVi (r=0.20, P=0.01), but neither were correlated with GLS. One s.d. (by age and sex) increase in childhood BMI was associated with LV hypertrophy (relative risk: 2.04 (95% confidence interval (CI): 1.09, 3.78)) and LA enlargement (relative risk: 1.81 (95% CI: 1.02, 3.21)) independent of adult BMI, but the association was not observed with impaired GLS or mitral e′. Cardiac functional measures were more impaired in those who had normal BMI as child, but had high BMI in adulthood (P<0.03), and not different in those who were overweight or obese as a child and remained so in adulthood (P>0.33).Conclusions:Childhood adiposity is independently associated with structural cardiac disturbances (LVMi and LAVi). However, functional alterations (GLS and mitral e′) were more frequently associated with adult overweight or obesity, independent of childhood adiposity.

Association of ambient particulate matter with heart failure incidence and all-cause readmissions in Tasmania: an observational study

Objectives We sought to investigate the relationship between air quality and heart failure (HF) incidence and rehospitalisation to elucidate whether there is a threshold in this relationship and whether this relationship differs for HF incidence and rehospitalisation. Methods This retrospective observational study was performed in an Australian state-wide setting, where air pollution is mainly associated with wood-burning for winter heating. Data included all 1246 patients with a first-ever HF hospitalisation and their 3011 subsequent all-cause readmissions during 2009–2012. Daily particulate matter <2.5 µm (PM2.5), temperature, relative humidity and influenza infection were recorded. Poisson regression was used, with adjustment for time trend, public and school holiday and day of week. Results Tasmania has excellent air quality (median PM2.5=2.9 µg/m3 (IQR: 1.8–6.0)). Greater HF incidences and readmissions occurred in winter than in other seasons (p<0.001). PM2.5 was detrimentally associated with HF incidence (risk ratio (RR)=1.29 (1.15–1.42)) and weakly so with readmission (RR=1.07 (1.02–1.17)), with 1 day time lag. In multivariable analyses, PM2.5 significantly predicted HF incidence (RR=1.12 (1.01–1.24)) but not readmission (RR=0.96 (0.89–1.04)). HF incidence was similarly low when PM <4 µg/m3 and only started to rise when PM2.5≥4 µg/m3. Stratified analyses showed that PM2.5 was associated with readmissions among patients not taking beta-blockers but not among those taking beta-blockers (pinteraction=0.011). Conclusions PM2.5 predicted HF incidence, independent of other environmental factors. A possible threshold of PM2.5=4 µg/m3 is far below the daily Australian national standard of 25 µg/m3. Our data suggest that beta-blockers might play a role in preventing adverse association between air pollution and patients with HF.