Adolescence: A Critical Period for Long-Term Tracking of Risk for Coronary Heart Disease?

Clustering and Tracking the Stability of Biological CVD Risk Factors in Adolescents: The Malaysian Health and Adolescents Longitudinal Research Team Study (MyHeARTs)

Background: Cardiovascular disease (CVD) risk factors tend to cluster and progress from adolescence to young adulthood. Reliable and meaningful clustering of CVD risk factors is essential to circumvent loss of information. Tracking adverse and high-risk profiles of adolescents is hoped to curb CVD progression later in life. The study aims to investigate the clustering of biological CVD risk factor among adolescents in Malaysia and the transitions between clusters over time.

Method: The Malaysian Health and Adolescents Longitudinal Research Team study (MyHeARTs) examined school students aged 13 in 2012 and re-examined them in 2014 and 2016. In a two-stage stratified cluster sampling, 1,361 students were recruited, of which, 1,320 had complete data. In the follow-up, there were 881 and 637 students in 2014 and in 2016, respectively. Pearson's correlation coefficients were used to identify and remove highly correlated CVD risk factors. All risk factors were standardized into z-scores. The hierarchical and non-hierarchical (k-means) cluster analyses were used to classify students into high, medium and low risk clusters in each screening year. The tracking and stability of cluster transitions through cross-classification were enumerated with Pearson's inter-age correlations and percentages.

Results: Three significant clusters of high, medium and low risk groups were derived from the clustering of eight biological CVD risk factors. The transitions between risk clusters from one screening year to the other were categorized as either stagnant, improved or adverse. The number of students who had adverse transitions increased from 15.5% (13–15 year) to 19.5% (15–17 year), 13.8 to 18.2% among the girls and 19.9 to 22.8% among the boys. For girls, the number of them who remained at high risk over the two transition periods were about the same (13.6 vs. 13.8%) whereas for boys, the percentage reduced from 14.6 to 12.3%.

Conclusion: Over time, more than 12% of adolescents remained in the high risk cluster. There were sizable adverse transitions over time as more adolescents appear to be shifting toward an increased risk of having CVD. Collaborative and constant measures should be taken by parents, school, health promotion boards and policy makers to curb the multiplicative effect of clustering CVD risk factors among adolescents.

Sustainability of the results of a non communicable diseases prevention program among youth in the region of Sousse, Tunisia

INTRODUCTION

Implementation of a healthy lifestyle at an early age is described as a successful intervention to prevent non communicable diseases. However, successful programs are not necessarily sustainable. The purpose of this study was to evaluate a 1-year sustainability of a 3-year comprehensive intervention conducted to promote a healthy lifestyle among schoolchildren.

MATERIALS AND METHODS

A cohort study of 204 schoolchildren enrolled in middle schools was conducted after a quasi-experimental study in the region of Sousse, Tunisia. The survey lasted 1 year. An exposed group (n=105) was selected from the intervention group and the not-exposed group (n=99) was selected from the control group. The exposition was the intervention. The same questionnaire used at pre-intervention and post-intervention was self-administered to collect data about tobacco use, physical activity and eating habits. The biometric measurements were taken by trained medical doctors at schools.

RESULTS

After 1 year of follow-up, none of participants became smokers in the exposed group. However, in the not-exposed group five (5.1%) participants became smokers. The proportion of schoolchildren who experimented with tobacco for the first time increased insignificantly by 2.9% (p=0.77) in the exposed group versus a significant increase by 11.1% (p=0.001) in the not-exposed group. Concerning the recommended physical activity practice, fast food and fried food consumption and overweight, there were no significant changes in the two groups.

CONCLUSION

A 3-year non communicable diseases prevention program has limited sustainable effects among schoolchildren in the short-term. Its repetition or a continued program through multisectoral actions is required.

Motivations, Barriers, and Behaviors Related to Obtaining and Discussing Family Health History: A Sex-Based Comparison Among Young Adults

Background

Genetic predisposition is a risk factor for many chronic diseases, yet little is known about the frequency in which college students seek out their family health history or with whom they communicate relevant information.

Purpose

This study examines motivations and barriers associated with obtaining one’s family health history and discussing it with others.

Methods

Data were analyzed from 625 college students using an internet-delivered questionnaire, which comprised of questions about intentions and motivations to obtain and share family health history as well as barriers encountered when obtaining family health history. Responses were bifurcated by participants’ sex. Chi-squared and t statistics were used to identify response differences by sex.

Results

Females were significantly more likely than males to be motivated to obtain their family health history, and more likely to have shared their family health history with others; state that they would share their family health history with others; and express a preference for sharing their family health history with a wider range of people.

Discussion

Educational interventions and improved student health services could be effective mechanisms to increase college students’ knowledge, awareness, and perceived importance of obtaining their family health history.

Carotid stiffness in young adults: a life-course analysis of its early determinants: the Amsterdam Growth and Health Longitudinal Study

Cardiovascular risk factors affecting arterial stiffness in adulthood may develop at different critical periods earlier in life. We examined whether the trajectories, from adolescence to young adulthood, of blood pressure, body fatness and fat distribution, blood lipids, cardiorespiratory fitness, and heart rate determined levels of arterial stiffness in young adults. We investigated 373 apparently healthy adults in whom cardiovascular risk factors were repeatedly examined between the ages of 13 and 36 years and carotid stiffness estimates were obtained at the age of 36 years. Differences in the mean levels and the trajectories of risk factors throughout the 24-year longitudinal period between subjects with different levels of carotid stiffness at age 36 years were analyzed with generalized estimating equations. Compared with individuals with less stiff carotid arteries, those with stiffer carotid arteries at the age of 36 years were characterized from ages 13 to 36 years by greater levels of and steeper increases in blood pressure and central fatness, independently of each other and other risk factors. These increases were already present in adolescence, preceded the development of poorer levels of blood lipids, cardiorespiratory fitness, and heart rate, which were evident during adulthood only, and explained to a great extent the deleterious association between these risk factors and carotid stiffness at the age of 36 years. Multiple and intertwined mechanisms involved in the pathogenesis of arterial stiffness have their origins in early life. Blood pressure and central fatness have a pivotal role herein and should be specifically targeted to prevent arterial stiffening and its cardiovascular sequelae.

How does socioeconomic development affect risk of mortality? An age-period-cohort analysis from a recently transitioned population in China

During the 20th century, the Hong Kong Chinese population experienced 2 abrupt but temporally distinct macroenvironmental changes: The transition from essentially preindustrial living conditions to a rapidly developing economy through mass migration in the late 1940s was followed by the emergence of an infant and childhood adiposity epidemic in the 1960s. The authors aimed to delineate the effects of these 2 aspects of economic development on mortality, thus providing a sentinel for other rapidly developing economies. Sex-specific Poisson models were used to estimate effects of age, calendar period, and birth cohort on Hong Kong adult mortality between 1976 and 2005. All-cause and cause-specific mortality, including mortality from ischemic heart disease (IHD), cardiovascular disease excluding IHD, lung cancer, other cancers, and respiratory disease, were considered. Male mortality from IHD and female mortality from other cancers increased with birth into a more economically developed environment. Cardiovascular disease mortality increased with birth after the start of the infant and childhood adiposity epidemic, particularly for men. Macroenvironmental changes associated with economic development had sex-specific effects over the life course, probably originating in early life. The full population health consequences of these changes are unlikely to manifest until persons who have spent their early lives in such environments reach an age at which they become vulnerable to chronic diseases.

The tracking of dietary intakes of children and adolescents in Sweden over six years: the European Youth Heart Study

BACKGROUND

The stability of dietary habits through various life-stages is not well understood. A better understanding of the tracking of diet over time could have implications for health promotion as well as for the planning of nutritional epidemiology studies. We examined the stability of dietary intakes of children and adolescents over six years.

METHODS

As part of the European Youth Heart Study, in 1998-9, a 24-h dietary recall was performed on over one thousand 9- and 15-year-olds in Sweden. In 2004-5, 40% returned to the follow-up study. These 452 subjects (273 15- and 179 21-year-olds) were assigned to age- and gender-specific tertiles of intakes of food groups, energy, selected nutrients and energy density (low, mid and high) at each time point. The agreement between the classification of subjects into tertiles at both time points was examined using Cohen's weighted kappa and other stability coefficients. We included a dropout analysis and considered the effect that energy mis-reporting might have on our results.

RESULTS

Fair tracking was seen between childhood and adolescence for the milk, fil and yoghurt food group (kappa = 0.30), and between adolescence and young adulthood for fruit (kappa = 0.24). Slight tracking was observed for most other food groups and fair to slight tracking for all nutrients studied. Only membership of the high milk, fil and yoghurt tertile could be predicted from membership at baseline, in children. Excluding potential energy mis-reporters did not affect the results.

CONCLUSIONS

Despite the long time between data collections, and the method of dietary data collection used, evidence for slight tracking was observed for most food groups and nutrients over these six years.

Does economic development contribute to sex differences in ischaemic heart disease mortality? Hong Kong as a natural experiment using a case-control study

BACKGROUND

The male excess risk of premature ischemic heart disease (IHD) mortality may be partially due to an unknown macro-environmental influence associated with economic development. We examined whether excess male risk of IHD mortality was higher with birth in an economically developed environment.

METHODS

We used multivariable logistic regression in a population-based case-control study of all adult deaths in Hong Kong Chinese in 1998 to compare sex differences in IHD mortality (1,189 deaths in men, 1,035 deaths in women and 20,842 controls) between Hong Kong residents born in economically developed Hong Kong or in contemporaneously undeveloped Guangdong province in China.

RESULTS

Younger (35-64 years) native-born Hong Kong men had a higher risk of IHD death than such women (odds ratio 2.91, 95% confidence interval 1.66 to 5.13), adjusted for age, socio-economic status and lifestyle. There was no such sex difference in Hong Kong residents who had migrated from Guangdong. There were no sex differences in pneumonia deaths by birth place.

CONCLUSION

Most of these people migrated as young adults; we speculate that environmentally mediated differences in pubertal maturation (when the male disadvantage in lipids and fat patterning emerges) may contribute to excess male premature IHD mortality in developed environments.

Growth environment and sex differences in lipids, body shape and diabetes risk

Background

Sex differences in lipids and body shape, but not diabetes, increase at puberty. Hong Kong Chinese are mainly first or second generation migrants from China, who have shared an economically developed environment for years, but grew up in very different environments in Hong Kong or contemporaneously undeveloped Guangdong, China. We assessed if environment during growth had sex-specific associations with lipids and body shape, but not diabetes.

Methodology and Principal Findings

We used multivariable regression in a population-based cross-sectional study, undertaken from 1994 to 1996, of 2537 Hong Kong Chinese residents aged 25 to 74 years with clinical measurements of ischaemic heart disease (IHD) risk, including HDL-cholesterol, ApoB, diabetes and obesity. Waist-hip ratio was higher (mean difference 0.01, 95% CI 0.001 to 0.02) in men, who had grown up in an economically developed rather than undeveloped environment, as was apolipoprotein B (0.05 g/L, 95% CI 0.001 to 0.10), adjusted for age, socio-economic status and lifestyle. In contrast, the same comparison was associated in women with lower waist-hip ratio (−0.01, 95% CI −0.001 to −0.02) and higher HDL-cholesterol (0.05 mmol/L, 95% CI 0.0004 to 0.10). The associations in men and women were significantly different (p-values<0.001). There were no such differences for diabetes.

Conclusions

Growth in a developed environment with improved nutrition may promote higher sex-steroids at puberty producing an atherogenic lipid profile and male fat pattern in men but the opposite in women, with tracking of increased male IHD risk into adult life.