Trends in blood pressure in 9 to 11-year-old children in the United Kingdom 1980-2008: the impact of obesity. J Hypertens. 2012;30:1708-1717. [PMID: 22828085 DOI: 10.1097/hjh.0b013e3283562a6b]

Prevalence of hypertension and its associations with body composition across Chinese and American children and adolescents

BACKGROUND

The age of onset of hypertension (HTN) is decreasing, and obesity is a significant risk factor. The prevalence and racial disparities in pediatric HTN and the association between body composition and blood pressure are insufficiently studied. This study aimed to evaluate the prevalence of HTN in Chinese and American children and adolescents and to assess the relationship between various body composition indices and HTN.

METHODS

Seven thousand, five hundred and seventy-three Chinese and 6239 American children and adolescents aged 8-18 years from the 2013-2015 China Child and Adolescent Cardiovascular Health study and the 2011-2018 National Health and Nutrition Examination Surveys were analyzed. Blood pressure and body composition (fat and muscle) were measured by trained staff. The crude prevalence and age-standardized prevalence rate (ASPR) of primary HTN and its subtypes [isolated systolic hypertension (ISH) and isolated diastolic hypertension (IDH)] were calculated based on 2017 American Academy of Pediatrics guidelines. Multivariable-adjusted linear regression coefficients and odds ratios (ORs) were calculated to assess the associations of body composition indicators with HTN, ISH and IDH.

RESULTS

The ASPR of HTN was 18.5% in China (CN) and 4.6% in the United States (US), whereas the obesity prevalence was 7.4% and 18.6%, and the population attributable risk of HTN caused by overweight and obesity was higher in the US than in CN. Increased fat mass, muscle mass and body fat percentage mass were associated with a higher risk of HTN in both countries. The percent of muscle body mass had a protective effect on HTN and ISH in both countries [HTN (CN: OR = 0.83, 95% CI = 0.78-0.88; US: OR = 0.72, 95% CI = 0.64-0.81); ISH (CN: OR = 0.87, 95% CI = 0.80-0.94; US: OR = 0.71, 95% CI = 0.62-0.81)], and the protective effect was more common among children and adolescents with high levels of physical activity.

CONCLUSIONS

The burden of HTN in Chinese children and adolescents was substantial and much greater than that in the US, and the contribution of obesity to HTN was higher in the US than in CN. Augmenting the proportion of muscle mass in body composition has a protective effect against HTN in both populations. Optimizing body composition positively influences blood pressure in children and adolescents, particularly those with high-level physical activity. Video abstract (MP4 149982 KB).

Children who appeared or remained overweight or obese predict a higher follow-up blood pressure and higher risk of hypertension: a 6-year longitudinal study in Yantai, China

Few longitudinal studies have examined the effect of weight status change on blood pressure change over time and incidence of hypertension among Chinese children. The longitudinal study enrolled 17,702 Chinese children aged 7 years in Yantai in 2014 as baseline, with a continuous 5 years of follow-up to 2019. Generalized estimating equation model was fitted to examine the main and interaction effects of weight status change and time with blood pressure and the incidence of hypertension. Compared with the participants who remained normal weight, the participants who remained overweight or obese had higher systolic blood pressure (SBP) (β = 2.89, p < 0.001) and diastolic blood pressure (DBP) (β = 1.79, p < 0.001). Significant interactions were identified between weight status change and time with SBP (χ2interaction = 697.77, p < 0.001) and DBP (χ2interaction = 270.49, p < 0.001). The odds ratio (OR) and 95% confidence interval (CI) of hypertension were 1.70 (1.59-1.82) for participants who appeared overweight or obese, 2.26 (2.14-2.40) for participants who remained overweight or obese, compared with the participants who remained normal weight. Those who switched from overweight or obesity to normal weight had almost the same risk of developing hypertension (OR = 1.13, 95% CI: 1.02 to 1.26) as children who remained normal weight. Children who appeared or remained overweight or obese predict a higher follow-up blood pressure and higher risk of hypertension, whereas losing weight could reduce blood pressure and the risk of hypertension. Children who appeared or remained overweight or obese predict a higher follow-up blood pressure and higher risk of hypertension, whereas losing weight could reduce blood pressure and the risk of hypertension.

Trends in the association between body mass index and blood pressure among 19-year-old men in Korea from 2003 to 2017

The strength of association between the body mass index (BMI) and blood pressure (BP) varies with population and time. Therefore, identifying the trends in BMI-BP association in adolescents can help predict the upcoming metabolic and cardiovascular disease burden. For this reason, from physical examination data collected from 2003 to 2017, a total of 5,133,246 Korean men aged 19 years were assessed for the annual trends and changes in the BMI-BP association. During the 15-year period, the mean BMI increased from 22.5 to 23.5 kg/m², and the prevalence of obesity increased from 16.7 to 21.4%. Meanwhile, the mean systolic BP (SBP) decreased from 122.8 to 122.3 mmHg in the first year and gradually increased to 125.9 mmHg afterward. The diastolic BP (DBP) decreased from 71.5 to 70.0 mmHg in the first 4 years and then rose to 74.8 mmHg in the following years. The association analysis between BMI and SBP resulted in an annual increase in the correlation coefficient (SBP: 0.257-0.495, DBP: 0.164-0.413). The regression coefficient similarly increased between 2003 and 2015 but slightly decreased between 2015 and 2017 (SBP: 0.896-1.569, DBP: 0.405-0.861). The BMI-BP association increased over time (coefficient of the interaction term > 0, P < 0.001). Moreover, as the BMI increased, the annual increase in BP and BP per unit BMI also increased. In conclusion, this study emphasized a continuous shift towards obesity in BMI distribution and intensifying BMI-BP association over time in young men. Further research on factors affecting this BMI-BP association is needed to fully validate the potential applications of this hypothesis.

Assessment of Knowledge and Practices toward Salt Intake among Adolescents

Background:High salt intake is linked to risk of development of renal disease, stomach cancer and osteoporosis.Raised BP typically present in adulthood but its origin commonly begins in childhood.The aim of this study is toassess of knowledge and practices towards salt intake among adolescents.Methods: This was a cross – sectional that carried out in Mansoura governorate. A convenience sample of 240 adolescents between 12 -17 years was taken from community recreation places and clubs. A Pre tested questionnaires were developed to assesssociodemographic characteristics, knowledge towards salt consumption, knowledge towards salt hazards and trials to control salt consumption.A modified food frequency questionnaire was used to assess their nutritional practices.Results:Nearly half of study group was aged 14-15 years(40.9%).Nearly two third of study participants was females (64.2%) and three quarter was from urban areas (75%).More than half of study group believed to consume moderate amount of salty food (57.1 %), and about half of them had good knowledge about salt harms and value of reduction of salt consumption (50.8% & 53.3% respectively),.Unfortunately majority of them did not attempt any trial of mentioned trials to control their salt intake. Only less than 50 % try to minimize outdoors food and processed food consumption. Conclusion:Although study participants knew the harm of salt consumption, unfortunately majority of them did not attempt any trial of mentioned trials to control their salt intake. Recommendations: These findings highlighted the importance of nutritional counseling among adolescents towards healthy eating practices Key words Salt Intake-Knowledge-Practices-Adolescents    

Reference values of inside leg length and inside leg length to stature ratio for Japanese children, 0-12 years of age

BACKGROUND

Large datasets of detailed anthropometric measurements are scarce in children. The Japanese Standard Association 1978-1981 survey provides a rare opportunity to use high quality data from Japanese children.

AIM

To construct inside leg length (ILL) and inside leg length to stature ratio (ILL/S) reference centile curves for Japanese children.

SUBJECTS AND METHODS

The study sample consisted of 14,825 boys and 14,577 girls age 0 to 18 years for stature and weight measurements, and 9,064 boys and 8,796 girls age 0 to 12 years for ILL measurements, who participated in the 1978-1981 national survey on body sizes. LMS method was used to construct the reference centile curves. The reference centile curves for stature, weight, ILL and ILL/S were compared to those of British children.

RESULTS

The L, M, S reference values for Japanese children are presented for stature, weight, ILL and ILL/S. Compared with British children of 0-12 years of age, Japanese children of 0-12 years of age had shorter median stature, shorter median ILL and shorter median ILL/S.

CONCLUSIONS

We presented the first reference values for ILL and ILL/S in Japanese children. Japanese children had relatively shorter legs compared to British children since infancy.

Secular trends in blood pressure trajectories in Chinese children and adolescents: the impact of changing physical growth

BACKGROUND

Globally, 80% of cardiovascular disease (CVD) occur in low-income /middle-income countries. High blood pressure (BP), a major risk factor for CVD, has its origins in early-life. We investigated how age trajectories of BP (childhood to late-adolescence) have changed recently in China and the mediating roles of physical growth.

METHODS

Using the longitudinal data on 3785 children from the China Health and Nutrition Survey 1991-2015, we estimated mean BP trajectories (7-18 years) for cohorts born in 1981-1985, 1986-1990, 1991-1995 and 1996-2000 using random effect models. Models were adjusted for BMI and/or height growth to assess their impact on BP trends.

RESULTS

BP trajectories shifted upwards across cohorts. Compared with the earliest cohort, mean BP was higher in the latest cohort throughout childhood to late adolescence. For example, the increment in SBP was 4.4 mmHg (95% confidence interval: 2.9-5.8) in boys and 4.0 mmHg (2.6-5.5) in girls at 9 years, narrowed slightly during adolescence, and was 3.0 mmHg (0.7-5.4) and 2.6 mmHg (0.4-4.8) respectively at 17 years. BMI and height trajectories also shifted upwards. The overall increment was greater for height than BMI. When adjusting for physical growth, the increment in BP trajectories reduced (more for height than BMI), but remained in childhood (P < 0.05).

CONCLUSION

The upward shift of BP trajectories among Chinese youths was largely explained by trends in physical growth, especially increasing height. Other early-life factors might have also contributed to the BP trends. Substantial increases in mean BP in children within a short time frame is a public health concern and will affect future CVD, especially in the developing world.

A Study on Burden of Prehypertension in Youth (or Pediatric Hypertension) in West Bengal, India

Hypertension is a silent threat to the developing countries in recent times. The aim of this article was to determine the burden of prehypertension and hypertension among school-going children and the risk factors associated with those conditions. A cross-sectional study was conducted among school-going children (6–18 years) in seven schools of Burdwan, West Bengal, India, selected by stratified random sampling from March 2017 to August 2018. Anthropometric and blood pressure measurements were obtained along with sociodemographic parameters. Prehypertension and hypertension were defined as per American Pediatric Society's definition. Mean age of the study population was 11.3 ± 3.8 years (n = 604). Prevalence of prehypertension and hypertension was estimated to be 5% and 4.6%, respectively. Both prehypertension and hypertension were more common among children aged > 15 years (10.3% and 15.5%). In logistic regression, the independent determinants of hypertension were higher socioeconomic condition, increasing age, obesity, increased intake of junk food, parental hypertension, and obesity among first-degree relatives. Proper preventive measures are the need of the hour to tackle the emerging epidemic at its root. Periodic measurements of blood pressure at regular intervals are advisable at community levels to recognize high-risk children, control obesity, and prevent irreversible end organ damages.

Predictive capacity of anthropometric indicators of body fat in identifying hypertension in adolescents

BACKGROUND

Hypertension (HTN) is a major health problem affecting different populations including adolescents worldwide, and it is strongly associated with obesity.

OBJECTIVES

This study examined the predictive capacity of anthropometric proxies of body fat and determined the threshold values that would identify HTN among Nigerian adolescents.

SETTING AND DESIGN

A cross-sectional study with a total of 2228 in-school adolescents aged 12-16 years.

MATERIALS AND METHODS

Participants were evaluated for physical characteristics including five anthropometric indices of body fat and blood pressure. Receiver operating characteristics curves were used for the analysis of sensitivity, specificity, area under curve (AUC) of the fat indices in detecting HTN.

RESULTS

All body fat indicators with the exception of waist-to-height ratio in boys, had significant (P < 0.0005) AUC with total fat mass (TFM) in girls and waist circumference (WC) in boys as the best fat indicators for predicting systolic HTN in adolescents. The TFM cut-point for girls was 8.0 kg and the WC cut-point for boys was 66.3 cm. Both TFM and WC demonstrated a stronger association with systolic HTN than other fat indicators in both genders. The likelihood of a girl developing HTN is 1.1 (95% confidence interval [CI] =1.05-1.20) times with a unit increase in TFM, while boys with unhealthy WC had 3.2 (95% CI = 1.83-5.67) times odd of developing HTN compared to their healthy peers.

CONCLUSIONS

This study showed that TFM and WC are useful tools for detecting HTN in Nigerian adolescent girls and boys, respectively. The fat indicators used in this study generally showed low predictive capacity.

Trajectories of Systolic Blood Pressure in Children: Risk Factors and Cardiometabolic Correlates

OBJECTIVE

To identify systolic blood pressure (SBP) percentile trajectories in children and to describe the early-life risk factors and cardiometabolic correlates of those trajectories.

STUDY DESIGN

Using age-, sex-, and height-specific SBP percentiles based on the American Academy of Pediatrics reference, we examined SBP trajectories using latent class mixed models from ages 3 to 8 years (n = 844) from the Growing Up in Singapore Towards healthy Outcomes-study, a Singaporean mother-offspring cohort study. We analyzed associations between SBP trajectories and early-life risk factors using multinomial logistic regression and differences across trajectories in cardiometabolic outcomes using multiple linear regression.

RESULTS

Children were classified into 1 of 4 SBP percentile trajectories: "low increasing" (15%), "high stable" (47%), "high decreasing" (20%), and "low stable" (18%). Maternal hypertension during early pregnancy was a predictor of the "high stable" and "low increasing" SBP trajectories. Rapid child weight gain in the first 2 years of life was only associated with the "high stable" trajectory. Compared with children in the "low stable" trajectory, children in the "high stable" SBP trajectory had greater body mass index z scores, sum of skinfold thicknesses, waist circumference from ages 3 to 8 years, and abdominal adipose tissue (milliliters) at 4.5 years (adjusted mean difference [95% CI]: superficial and deep subcutaneous abdominal adipose tissue: 115.2 [48.1-182.3] and 85.5 [35.2-135.8]). Their fat mass (kilograms) (1.3 [0.6-2.0]), triglyceride levels (mmol/L) (0.10 [0.02-0.18]), and homeostasis model assessment of insulin resistance (0.28 [0.11 0.46]) at age 6 years were also greater but not their arterial thickness and stiffness.

CONCLUSIONS

Reducing maternal blood pressure during pregnancy and infant weight gain in the first 2 years of life might help to prevent the development of high SBP.

Blood pressure and resting heart rate in 3-17-year-olds in Germany in 2003-2006 and 2014-2017

To track blood pressure (BP) and resting heart rate (RHR) in children and adolescents is important due to its associations with cardiovascular outcomes in the adulthood. Therefore, the aim of this study was to examine BP and RHR over a decade among children and adolescents living in Germany using national examination data. Cross-sectional data from 3- to 17-year-old national survey participants (KiGGS 2003–06, n = 14,701; KiGGS 2014–17, n = 3509) including standardized oscillometric BP and RHR were used for age- and sex-standardized analysis. Measurement protocols were identical with the exception of the cuff selection rule, which was accounted for in the analyses. Different BP and RHR trends were observed according to age-groups. In 3- to 6-year-olds adjusted mean SBP and DBP were significantly higher in 2014–2017 compared to 2003–2006 (+2.4 and +1.9 mm Hg, respectively), while RHR was statistically significantly lower by −3.8 bpm. No significant changes in BP or in RHR were observed in 7- to 10-year-olds over time. In 11- to 13-year-olds as well as in 14- to 17-year-olds lower BP has been observed (SBP −2.4 and −3.2 mm Hg, respectively, and DBP −1.8 and −1.7 mm Hg), while RHR was significantly higher (+2.7 and +3.7 bpm). BP trends did not parallel RHR trends. The downward BP trend in adolescents seemed to follow decreasing adult BP trends in middle and high-income countries. The increase in BP in younger children needs confirmation from other studies as well as further investigation. In school-aged children and adolescents, the increased RHR trend may indicate decreased physical fitness.

Associations of body mass index, physical activity and sedentary time with blood pressure in primary school children from south-west England: A prospective study

Elevated blood pressure in children is a significant risk factor for the development of cardiovascular disease in adulthood. We examined how children’s body mass index (BMI), physical activity and sedentary time at ages 9 and 11 are associated with blood pressure at age 11. Data were from 1283 children from Bristol, UK, who participated in the study aged 11 years, 797 of whom also participated in the study aged 9 years. Child height, weight and blood pressure were measured, and children wore accelerometers for five days, from which moderate-to-vigorous-intensity physical activity and sedentary minutes per day were derived. Multiple imputation of missing data and adjusted linear and logistic regression models were used to examine associations. Child BMI at 11 years was cross-sectionally associated with higher systolic and diastolic blood pressure (mean difference [95% confidence interval]: 0.91 [0.32 to 1.50] mm Hg and 1.08 [0.54 to 1.62] mm Hg, respectively, per standard deviation (SD) of BMI). BMI at age 9 was also positively associated with diastolic blood pressure at age 11 (1.16 mmHg per two years [0.49 to 1.84], per SD of BMI). For girls, sedentary time at age 9 years was associated with increased odds of having high systolic blood pressure at age 11 (odds ratio: 1.08 [1.01 to 1.16], per 10 minutes per day). There was no evidence of associations between sedentary time and blood pressure among boys. Similarly, there was little evidence that physical activity was associated with blood pressure in either cross-sectional or prospective analyses. Effective strategies are needed to prevent excess bodyweight among children in order to reduce cardiovascular disease risk.

Effect of Overweight and Obesity on High Blood Pressure in Chinese Children and Adolescents

OBJECTIVE

This study aimed to compare the secular trends of high blood pressure (HBP) and the effects of overweight and obesity on HBP between Chinese ethnic minority and Han children and adolescents .

METHODS

Data were collected from 224,151 Chinese ethnic minority and 664,094 Han children and adolescents aged 7 to 18 years during three successive, national cross-sectional surveys (2005, 2010, and 2014). Logistic regression and population-attributable risk analyses were used to evaluate the association between HBP and overweight and obesity.

RESULTS

HBP prevalence in ethnic minorities increased from 4.8% in 2005 to 6.3% in 2014, which was significantly higher than the variable HBP trends (4.1% to 5.5%) in Han children and adolescents. Both ethnic minority and Han children and adolescents experienced a rapid increase in overweight and obesity, but the pace of growth for HBP, overweight, and obesity was faster in ethnic minorities than in their Han peers. Moreover, the effects of obesity on HBP in ethnic minorities showed a sustained increase over time but were stable for the Han.

CONCLUSIONS

Higher HBP prevalence, faster obesity increases, and a stronger impact of obesity on HBP in children and adolescents of Chinese ethnic minorities predict their looming burden of HBP, which suggests that attention to the cardiovascular disease risks in children and adolescents from ethnic minorities is indicated to reduce their future adult risk.

Secular Trends in Blood Pressure and Overweight and Obesity in Chinese Boys and Girls Aged 7 to 17 Years From 1995 to 2014

The current study aimed to assess the secular trends in overweight and obesity status and high blood pressure (HBP) in Chinese children and adolescents for 2 decades. Data on 943 128 participants aged 7 to 17 years were obtained from the Chinese National Survey on Students' Constitution and Health from 1995 to 2014. The population attributable risk of overweight status for HBP was calculated. The prevalence of overweight increased from 4.3% in 1995 to 18.4% in 2014, whereas HBP prevalence fluctuated in the range of 4.4% to 6.4% during the same time period, the lowest in 2005. Within each survey year, blood pressure levels and HBP prevalence increased with higher body mass index. Notably, the population attributable risk of HBP because of being overweight steadily increased from 6.3% in 1995 to 19.2% in 2014. The same trends of linear growth for obesity, fluctuating blood pressure, and its sustained increasing population attributable risk for overweight also occurred among the domestic 29 provinces. Despite dramatic increases in overweight prevalence among Chinese children from 1995 to 2014, the HBP prevalence remained relatively stable, suggesting that other independent factors are affecting HBP trends to a greater extent. Yet, over time, the magnitude of the impact of being overweight or obese on HBP increased sharply, predicting looming heavy burden of HBP. Reductions in overweight status may aid in preventing HBP so as to prevent coronary risk in adulthood.

Elevated blood pressure among primary school children in Dar es salaam, Tanzania: prevalence and risk factors

Background

Whilst the burden of non-communicable diseases is increasing in developing countries, little data is available on blood pressure among Tanzanian children. This study aimed at determining the blood pressure profiles and risk factors associated with elevated blood pressure among primary school children in Dar es Salaam, Tanzania.

Methods

We conducted a cross sectional survey among 446 children aged 6–17 years from 9 randomly selected primary schools in Dar es Salaam. We measured blood pressure using a standardized digital blood pressure measuring machine (Omron Digital HEM-907, Tokyo, Japan). We used an average of the three blood pressure readings for analysis. Elevated blood pressure was defined as average systolic or diastolic blood pressure ≥ 90th percentile for age, gender and height.

Results

The proportion of children with elevated blood pressure was 15.2% (pre-hypertension 4.4% and hypertension 10.8%). No significant gender differences were observed in the prevalence of elevated BP. Increasing age and overweight/obese children were significantly associated with elevated BP (p = 0.0029 and p < 0.0001) respectively. Similar associations were observed for age and overweight/obesity with hypertension. (p = 0.0506 and p < 0.0001) respectively. In multivariate analysis, age above 10 years (adjusted RR = 3.63, 95% CI = 1.03–7.82) was significantly and independently associated with elevated BP in this population of school age children.

Conclusions

We observed a higher proportion of elevated BP in this population of school age children. Older age and overweight/obesity were associated with elevated BP. Assessment of BP and BMI should be incorporated in school health program in Tanzania to identify those at risk so that appropriate interventions can be instituted before development of associated complications.

Elevated blood pressure is associated with higher prevalence of low visual acuity among adolescent males in Northeast China

The purpose of this study is to track the trends of low visual acuity (VA) from 2005 to 2014, and to investigate its associations with systemic blood pressure (BP) components among adolescents in Northeast China. A total of 55320 students of Han nationality aged 13 to 18 years were included. There has been a significant increase in the prevalence of low VA, with 31.3% in 2005, 40.2% in 2010 and 43.4% in 2014. In multivariable-adjusted logistic regression models, each 1-mm Hg increment in systolic BP (SBP) was associated with 0.8% (95% confidence interval [CI]: 0.1–1.6%), 0.5% (95% CI: 0.1–0.9%) and 1.1% (95% CI: 0.6–1.6%) increased odds of low VA for males in 2005, 2010 and 2014; each 1-mm Hg increment in pulse pressure (PP) was associated with 1.6% (95% CI: 0.7–2.5%), 0.8% (95% CI: 0.4–1.2%) and 1.2% (95% CI: 0.7–1.7%) increased odds of low VA. Higher PP categories had greater odds for low VA compared with the reference group. Similar associations were not observed for females. We conclude that higher prevalence of low VA was significantly associated with higher SBP and PP in males. Furthermore, there was a dose-dependent association between the prevalence of low VA and the levels of PP.

Factors That Influence Blood Pressure in 3- to 5-Year-Old Children: A Pilot Study

While incident elevations in blood pressure (BP) are apparent in preschool years, factors influencing BP in this population have received little attention. The purposes of this pilot study were to determine the feasibility of collecting data from preschoolers and their mothers and to determine effect sizes of relationships between BP and sex, race, birth status, body mass index (BMI), waist circumference (WC), geographic location, serum C-reactive protein (CRP), and salivary cortisol (morning, afternoon). A hypothesis-generating correlational design was used; 56 children, aged 3–5 years, were enrolled from six rural and urban Head Start programs in a southeastern state. On Day 1 of data collection, mothers completed demographic questionnaires and children had blood drawn by finger stick. On Day 2, children gave saliva samples for cortisol, were measured for height by stadiometer, weight by digital scales, and WC by tape measure and had their BP measured by Dinamap. Incident elevations in BP were found in 30% of children (17/56), the majority of which were of systolic BP; 65% of those with elevations were of normal weight. Data collection was feasible with few problems. Small-to-medium effect sizes were noted for BP status (normal, prehypertensive, and hypertensive) and cortisol p.m. and birth status (parent-reported prematurity or term); small effect sizes were seen for BP status and BMI, race, sex, and geographic location. CRP and cortisol had medium- and small-to-medium effect sizes, respectively, with diastolic blood pressure. Studies with larger, more diverse samples need to be conducted to test hypotheses posited from these estimated effect sizes.

Prevalence of elevated blood pressure in children and adolescents in Africa: a systematic review and meta-analysis

BACKGROUND

Despite substantial attention paid to the threat of elevated blood pressure in children and adolescents in high-income countries and the epidemic of hypertension in African adult populations, data on the burden of elevated blood pressure in African children and adolescents have not yet been synthesised. We did a systematic review and meta-analysis to provide estimates of the prevalence of elevated blood pressure and assess associated factors among children and adolescents in Africa.

METHODS

We searched Embase, PubMed, African Journals Online, and African Index Medicus to identify articles published from Jan 1, 1996, to Feb 2, 2017, and searched the reference list of retrieved articles. Each study was independently reviewed for methodological quality. We used a random-effects model to estimate the prevalence of elevated blood pressure across studies and heterogeneity (I²) was assessed via the χ² test on Cochran's Q statistic. This review is registered with PROSPERO, number CRD42015019029.

FINDINGS

We included 51 studies in qualitative synthesis and 25 in the meta-analysis reporting data of a pooled sample of 54 196 participants aged 2-19 years. Study quality was high with only four medium-quality studies and no low-quality studies. Prevalence of elevated blood pressure varied widely across studies (range 0·2-24·8%). The pooled prevalence of elevated blood pressure (systolic or diastolic blood pressure ≥95th percentile) was 5·5% (95% CI 4·2-6·9), whereas that of slightly elevated blood pressure (systolic or diastolic blood pressure ≥90th percentile and <95th percentile) was 12·7% (2·1-30·4). The prevalence of elevated blood pressure was largely associated with body-mass index (BMI), with a prevalence of elevated blood pressure six times higher in obese (30·8%, 95% CI 20·1-42·6) versus normal-weight children (5·5%, 3·1-8·4; p<0·0001).

INTERPRETATION

This study suggests a high prevalence of elevated blood pressure among children and adolescents in Africa, with overweight and obesity being an important risk factor. Efforts to address this burden of elevated blood pressure in children and adolescents should mainly focus on primary prevention at the community level, by promoting healthy lifestyles and avoiding other cardiovascular risk factors, especially overweight and obesity. This study also stresses the need for more elaborate studies using uniform and reliable diagnostic methods to reliably map the burden of elevated blood pressure in children and adolescents in Africa.

FUNDING

None.

Divergent secular trends in blood pressure and body mass index in children and adolescents in Hong Kong

Secular trends in blood pressure (BP) and body mass index (BMI) during childhood and adolescence are sentinels for the future population cardiovascular disease burden. We examined trends in BP z-score (ages 9-18 years from 1999 to 2014) and BMI z-score (ages 6-18 years from 1996 to 2014) in Hong Kong, China. Overall, BP z-score fell, systolic BP from 0.08 to -0.01 in girls and from 0.31 to 0.25 in boys. However, the trends were not consistent, for both sexes, systolic BP z-score was stable from 1999, decreased slightly from 2002 to 2005 and increased slightly to 2014, diastolic BP z-score decreased slightly from 1999 to 2004 and then remained stable to 2014. In contrast, BMI z-score rose from -0.15 to -0.01 in girls and from 0.14 to 0.34 in boys, mainly during 1997 to 2010. The upper tail of the systolic (except boys) and diastolic BP distribution shifted downwards, whereas the entire BMI distribution shifted upward. BP declined slightly whereas BMI rose in Hong Kong children and adolescents during the last 20 years, with systolic BP and BMI in boys above the reference. This warrants dual action in tackling rising BMI and identifying favorable determinants of BP, particularly targeting boys.

Prevalence of high blood pressure and association with obesity in Spanish schoolchildren aged 4-6 years old

Background

The prevalence of high blood pressure in children is increasing worldwide, largely, but not entirely, driven by the concurrent childhood obesity epidemic. The aims of this study were to examine the prevalence of prehypertension and hypertension in 4-to-6-year-old Spanish schoolchildren, and to evaluate the association between different blood pressure (BP) components with different adiposity indicators.

Methods

Cross-sectional study including a sample of 1.604 schoolchildren aged 4-to-6-years belonging to 21 schools from the provinces of Ciudad Real and Cuenca, Spain. We measured height, weight, body mass index (BMI), fat mass percentage (%FM), triceps skinfold thickness (TST), waist circumference (WC), systolic and diastolic BP, mean arterial pressure and pulse pressure.

Results

The estimates of prevalence of prehypertension and hypertension were 12.3% and 18.2%, respectively. In both sexes, adiposity indicators were positively and significantly associated with all BP components (p<0.001), thus schoolchildren in the higher adiposity categories had significantly higher BP levels (p<0.001).

Conclusions

Our results show a high prevalence of high blood pressure in Spanish children. Moreover, high levels of adiposity are associated with high blood pressure in early childhood, which support that it could be related to cardiovascular risk later in life.

Trends in cardiometabolic parameters among Spanish children from 2006 to 2010: The Cuenca study

OBJECTIVE

The aim of this study was to examine the trends in cardiometabolic risk factors among schoolchildren in Cuenca, Spain, from 2006 to 2010.

METHODS

Data were taken from two cross-sectional surveys conducted in 2006 and 2010 among schoolchildren aged 8-12 years from 20 public schools in the province of Cuenca. The final sample consisted of 2148 participants with measured anthropometric variables, biochemical assessment, and blood pressure.

RESULTS

We observed an increase in mean serum total cholesterol (8.5 mg/dL and 10.7 mg/dL), LDL-cholesterol (13.7 mg/dL and 17.3 md/dL), triglycerides (3.6 mg/dL and 2.6 md/dL), fasting insulin (1.2 µU/mL and 0.3 µU/mL) and HOMA-IR (0.2 and 0.02) and a decrease in mean serum HDL-cholesterol (4.4 mg/dL and 5.7 mg/dL), systolic blood pressure (3.8 mmHg and 5.4 mmHg) and diastolic blood pressure (0.8 mmHg and 2.0 mmHg) in both sexes. In girls, mean arterial pressure (3.2 mmHg) also decreased in this period. In addition, we found an increase in the prevalence of adverse total cholesterol concentration (≥200 mg/dL) (7.8% and 8.9%), HDL-cholesterol concentration (<40 mg/dL) (1.9% in boys and 3.5% in girls) and LDL cholesterol concentration (≥130mg/dL) (4.8% and 5.8%) in boys and girls, respectively.

CONCLUSIONS

There has been a worsening of the lipid profile in schoolchildren from Cuenca, independent of weight status and age.

Pediatric Blood Pressure and Adult Preclinical Markers of Cardiovascular Disease

A high blood pressure level in adults is considered the single most important modifiable risk factor for global disease burden, especially those of cardiovascular (CV) origin such as stroke and ischemic heart disease. Because blood pressure levels have been shown to persist from childhood to adulthood, elevations in pediatric levels have been hypothesized to lead to increased CV burden in adulthood and, as such, might provide a window in the life course where primordial and primary prevention could be focused. In the absence of substantive data directly linking childhood blood pressure levels to overt adult CV disease, this review outlines the available literature that examines the association between pediatric blood pressure and adult preclinical markers of CV disease.

Trends in High Blood Pressure among United States Adolescents across Body Weight Category between 1988 and 2012

OBJECTIVE

To examine trends in pre-high blood pressure (BP [HBP]) and HBP among US adolescents by body weight category during 1988-2012.

STUDY DESIGN

We estimated pre-HBP and HBP prevalence among 14,844 participants aged 12-19 years using National Health and Nutrition Examination Surveys from 1988-1994, 1999-2002, 2003-2006, and 2007-2012. Pre-HBP and HBP were defined based on age-sex-height-specific BP percentiles. We examined the temporal trends in pre-HBP and HBP across category of body weight (normal weight vs overweight/obese), adjusted for potential explanatory factors, and estimated the number of adolescents with pre-HBP and HBP.

RESULTS

Between 1988 and 2012, the prevalence of HBP decreased and pre-HBP did not change. Among normal weight adolescents, multivariable adjusted pre-HBP prevalence was 11.0% during 1988-2012, and 10.9% during 2007-2012 (P = .923 for trend); adjusted HBP prevalence increased from 1988-1994 (0.9%) to 1999-2002 (2.3%), then declined significantly to 1.4% during 2007-2012 (P = .049). Among overweight/obese adolescents, adjusted pre-HBP prevalence was 17.5% during 1988-2012, and 20.9% during 2007-2012 (P = .323); adjusted HBP prevalence declined significantly from 7.2% during 1988-1994 to 3.2% during 2007-2012 (P = .018). Because of population growth, estimated number of adolescents with pre-HBP or HBP increased, from 4.18 million during 1988-1994 to 5.59 million during 2007-2012.

CONCLUSIONS

Between 1988 and 2012, pre-HBP prevalence was consistently higher among overweight/obese adolescent than those of normal weight, and the pattern remain unchanged. HBP prevalence declined significantly, especially among overweight/obese adolescent that are not completely explained by sociodemographic or lifestyle characteristics.

Trends in Elevated Blood Pressure Among US Children and Adolescents: 1999-2012

BACKGROUND

The prevalence of elevated blood pressure (BP) has been reported to increase significantly among the US children and adolescents from 1988-1994 to 1999-2008. We aimed to examine the recent trends in BP levels and prevalence of elevated BP, as well as related influencing factors among US children and adolescents.

METHODS

Data of National Health and Nutrition Examination Survey (NHANES) 1999-2012 were combined into 3 time periods (1999-2002, 2003-2008, and 2009-2012) for the analysis. A total of 14,270 US children and adolescents aged 8-17 years were included in the current analysis. The sex-, age-, and height-BP standards recommended by the US Fourth Report were used to define high BP and elevated BP (including pre-HBP and HBP).

RESULTS

Mean systolic BP (SBP) and diastolic BP (DBP) decreased by 0.7 and 4.2mm Hg from 1999-2002 to 2009-2012, respectively. In 2009-2012, the prevalence of elevated BP and HBP in children and adolescents were 9.6% and 1.6%, with the absolute reduction of 2.8% and 1.3% from 1999-2002 to 2009-2012, respectively. In addition, daily intakes of total energy, carbohydrate, total saturated fatty acids, and caffeine decreased during the period between 1999-2002 and 2009-2012 (all P < 0.05), whereas daily intake of total polyunsaturated fatty acids and dietary fiber increased (P < 0.05).

CONCLUSIONS

Mean BP levels as well as the prevalence of elevated BP and HBP among US children and adolescents have declined during the past decade. In addition, there might be an associated change in dietary factors.

Development of hypertension in overweight adolescents: a review

The upward trend in adolescent hypertension is widely attributed to the adolescent obesity epidemic. Secular trends in adolescent prehypertension and hypertension have risen in congruence with increasing trends in the prevalence of overweight and obesity. The correlation between body mass index and blood pressure in adolescence is moderate to strong in most studies and strongest in those classified as overweight or obese. The mechanisms relating to the development of hypertension in overweight adolescents are unclear; however, a number of nonmodifiable and modifiable factors have been implicated. Importantly, certain clinical and biochemical markers in overweight adolescents are indicative of high risk for hypertension, including family history of hypertension and hyperinsulinemia. These characteristics may prove useful in stratifying overweight adolescents as high or low risk of comorbid hypertension. The treatment of overweight and obesity related hypertension in this population focuses on two key modalities: lifestyle change and pharmacotherapy. These approaches focus almost exclusively on weight reduction; however, a number of emerging strategies target hypertension more specifically. Among adolescents with overt hypertension there are also several factors that indicate higher risk of concurrent subclinical disease, persistent adult hypertension, and adult cardiovascular disease. This group may benefit substantially from more aggressive pharmacological treatments. Limitations in the literature relate to the paucity of studies reporting specific effects for the adolescent age group of overweight and obese individuals. Nonetheless, intervention for adiposity-related hypertension in adolescence may partially mitigate some of the cardiovascular risk in adulthood.

Understanding trends in blood pressure and their associations with body mass index in Chinese children, from 1985 to 2010: a cross-sectional observational study

OBJECTIVE

Understanding trends in blood pressure (BP) in childhood is crucial to addressing and reducing the burden of adulthood hypertension and associated mortality in the future. In view of growing obesity in Chinese children, we sought to investigate the trends in BP and the influence of body mass index (BMI) on them.

DESIGN, SETTING AND PARTICIPANTS

We included 1,010,153 children aged 8-17 years, with completed records from a large national successive cross-sectional survey, the Chinese National Survey on Students' Constitution and Health, between 1985 and 2010.

MAIN OUTCOME MEASUREMENTS

BP was measured according to the recommendation of the National High Blood Pressure Education Program Working Group, and the elevated BP was based on sex-, age- and height-specific 95th centile of the recommendation.

RESULTS

The adjusted mean systolic BP in boys and girls decreased by 3.9 and 5.6 mm Hg between 1985 and 2005, and increased by 1.3 and 1.0 mm Hg between 2005 and 2010, respectively. Corresponding adjusted prevalence of elevated systolic BP in boys and girls declined from 5.1% and 5.5% to 3.5% and 2.5% between 1985 and 2005, and increased to 4.9% and 3.5% in 2010, respectively. Adjusted mean BMI of boys and girls in 2010 was 2.0 and 1.2 kg/m(2) higher than those in 1985, respectively. The prevalence of obesity rose from 0% to 3.4% in boys and 0.9% in girls. Further adjusting for BMI did not change these trends in systolic BP. A similar pattern was also observed in diastolic BP.

CONCLUSIONS

After declining for 20 years, BP levels in Chinese children started to climb upwards. These trends in BP cannot be fully explained by BMI. The investigation of other determinants of BP may provide additional opportunity to curb the current upward BP trend in Chinese children.

Change in the association of body mass index and systolic blood pressure in Germany - national cross-sectional surveys 1998 and 2008-2011

Background

A recent weakening and even decoupling of the association of body mass index (BMI) and systolic blood pressure (SBP) in population data was reported, i. a. for Western Europe.

Methods

The association of BMI and SBP in recent cross-sectional population data from Germany was investigated in participants aged 18–79 years with BMI 17.5-40 kg/m² from national health examination surveys 1998 (n = 6,931) and 2008–2011 (n = 6,861) in Germany. The association was analyzed both in the overall samples and in participants without antihypertensive medication.

Results

From 1998 to 2008–11, age- and sex-standardized mean SBP decreased from 129.0 (CI 128.2-129.7) to 124.1 (123.5-124.6) mmHg in all participants and from 126.0 (125.4-126.7) to 122.3 (121.7-122.8) mmHg among persons not on antihypertensive medication. The proportion of persons treated with antihypertensives augmented from 19.2 % (17.7-20.8) to 25.3 % (24.0-26.6). Mean BMI remained constant at around 27 kg/m² with a slight increase in obesity prevalence. BMI was positively associated with SBP both in 1998 and 2008–11, yet the association tended to level out with increasing BMI suggesting a non-linear association. The strength of the BMI-SBP-association decreased over time in all and untreated men. In women, the association weakened in the overall sample, but remained similarly strong in untreated women. The unadjusted linear regression models were used to estimate the increase in SBP within 5-unit BMI increases. E. g. for men in 1998, SBP was higher by 7.0 mmHg for a BMI increase from 20 to 25 kg/m² and by 3.6 mmHg for BMI 30 to 35 kg/m². The corresponding values for 2008–11 were 3.8 mmHg and 1.7 mmHg.

Conclusions

The cross-sectional association of BMI and SBP decreased between 1998 and 2008–11 in Germany, however it did not disappear and it is in part explained by improvements in the diagnosis and treatment of high blood pressure.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2023-8) contains supplementary material, which is available to authorized users.

Effectiveness of physical exercise to reduce cardiovascular risk factors in youths: a randomized clinical trial

Background

The aim of the current study was to test the effectiveness of a physical activity and exercise-based program in a clinical context to reduce cardiovascular risk factors in children and adolescents.

Methods

A randomized clinical trial was conducted in a pediatric preventive outpatient clinic. Intervention was 14 weeks of exercise for the intervention group or general health advice for the control group. The primary and the secondary outcomes were reduction of cardiovascular risk factors and the feasibility and the effectiveness of clinical advice plan to practice physical exercises at home.

Results

A total of 134 children were screened; 26 met eligibility criteria. Of these, 10 were allocated in the exercise intervention group and nine were included in the control group until the end of the intervention. Those patients who discontinued the intervention had the lowest scores of z-BMI (P = 0.033) and subscapular skin fold (P = 0.048). After 14 weeks of intervention, no statistical differences were found between the groups. High-density lipoprotein cholesterol (HDL-C) was higher in the exercise group, with a mild tendency to be significant (P = 0.066). Patients who adhere to treatment had diastolic blood pressure decreased from baseline to the end of the follow-up period in the control group (P = 0.013). Regardless of this result, the other comparisons within the group were not statistically different between T0 and T14.

Conclusion

A low-cost physical activity advice intervention presented many barriers for implementation in routine clinical care, limiting its feasibility and evaluation of effectiveness to reduce cardiovascular risk factors.

Epidemiology of elevated blood pressure in youth and its utility for predicting adulthood outcomes: A review

Elevated blood pressure has been demonstrated to track from youth to adulthood and some have demonstrated an association between early-life blood pressure and subsequent atherosclerosis and cardiovascular disease. In addition, reports regarding the strength of tracking are inconsistent and the modifiable risk factors that affect the trajectory of blood pressure from youth to adulthood remain unclear. This paper comprehensively evaluated the existing classifications of youth hypertension and the current trends of youth hypertension. Further, evidence for the consequences of hypertension in youth has been comprehensively evaluated. Importantly, a review of the studies examining tracking from youth to adulthood has been performed and a number of studies investigating the factors affecting tracking has also been investigated. The overall consideration of this body of literature highlights the vital importance of identifying hypertension in youth to prevent complications in adulthood. Adiposity is regarded to be a factor affecting the progression of hypertension from youth to adulthood yet there is little evidence available for other modifiable factors. It is apparent that further research is necessary within this field in order to create effective preventative strategies to target youth hypertension.

Trends in resting pulse rates in 9-11-year-old children in the UK 1980-2008

OBJECTIVE

Little is known about whether levels of physical fitness, which is related to adiposity and physical activity (PA), have changed in children, particularly the progressive increase in childhood obesity levels. We aimed to examine the time trends in resting pulse rate (a marker of physical fitness) among UK children, in order to better understand the trends in levels of physical fitness in recent decades.

DESIGN AND SETTING

We used a cross-sectional study design and included data on over 22 000 children aged 9-11 years (mean 10.3 years) from five population-based studies conducted in the UK between 1980 and 2008.

MAIN OUTCOME MEASURES

Resting pulse rate (bpm).

RESULTS

Observed mean resting pulse rate was higher for girls than boys (82.2 bpm vs 78.7 bpm). During the study period mean pulse rate increased by 0.07 bpm/year (95% CI 0.04 to 0.09) among boys and to a lesser extent among girls, by 0.04 bpm/year (0.01 to 0.06) (p<0.05 for gender interaction). For boys, there was an indication that the trend was steeper after the mid-1990 s, compared to that prior to 1994 (annual increase 0.14 vs 0.04 bpm). The trends for Body Mass Index (BMI) accounted for only 13.8% (11.3% to 16.3%) of increase in pulse rate for boys and 17.2% (9.4% to 24.9%) for girls.

CONCLUSIONS

Increases in mean resting pulse rate have occurred during the period 1980-2008 in girls and especially in boys. The increase was not explained by increased BMI. The observed trends in children, though modest, could have important public health implications for future cardiovascular risk.