- Email: [email protected]
Twenty years of cardiovascular risk prevention in Czech children
cor et vasa 56 (2014) e164–e168
Available online at www.sciencedirect.com
ScienceDirect journal homepage: http://www.elsevier.com/locate/crvasa
Review article – Special issue: Cardiovascular Prevention
Twenty years of cardiovascular risk prevention in Czech children Milan Šamánek a,*, Zuzana Urbanová b a b
Dětské kardiocentrum FN Motol, Praha, Czech Republic Klinika dětského a dorostového lékařství 1. LF UK a VFN, Praha, Czech Republic
article info
abstract
Article history:
Coronary heart disease is the leading cause of death in the Czech Republic. Pathological data
Received 23 October 2013
have shown that atherosclerosis begins in childhood and that the extent of atherosclerosis
Received in revised form
in children can be correlated with the presence of cardiovascular risk factors such as:
27 January 2014
hypercholesterolemia, obesity, hypertension and cigarette smoking. Pediatric preventive
Accepted 28 January 2014
program in the Czech Republic, which started in 1992, identifies children at high risk of
Available online 5 March 2014
atherosclerosis. At the age of 5 and 13 years, pediatricians are obliged to measure not only
Keywords:
and triglycerides) in children with positive family history. This obligation is incorporated in
Atherosclerosis
the health certificate of everyone born in the Czech Republic. The lipoprotein profiling is also
blood pressure and BMI, but also lipid profile (plasma total cholesterol, LDL, HDL cholesterol
Prevention
offered to other family members. Children identified as being at an increased risk of
Cardiovascular risk factors
ischemic heart disease are referred to pediatric cardiologists or specialized centers to be
Childhood
followed up and treated. During the past two decades this strategy has promoted cardiovascular health for all children and contributed significantly to progress in the reduction of mortality for cardiovascular diseases in the Czech Republic. # 2014 The Czech Society of Cardiology. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Beginning of prevention of atherosclerosis from childhood in the Czech Republic Dyslipidemia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overweight and obesity in children . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hypertension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Smoking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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* Corresponding author. Tel.: +420 605563984. E-mail address: [email protected] (M. Šamánek). http://dx.doi.org/10.1016/j.crvasa.2014.01.005 0010-8650/# 2014 The Czech Society of Cardiology. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
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cor et vasa 56 (2014) e164–e168
Introduction Manifest myocardial infarction and stroke in children is rare, but risk factors of cardiovascular disease begin in childhood. Vsevolod A. Zinserling was the first to show already in 1924 that the fatty streaks are present in arteries of children. He described that the fatty streaks contain cholesterol and are precursors of atherosclerosis [1]. His finding was verified in 1953 in Korean war casualties [2] and later in the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study [3] and the Bogalusa Heart Study [4]. Both the presence and extent of atherosclerotic lesions at autopsy after unexpected deaths in children correlate with established risk factors: namely high cholesterol, high blood pressure, elevated body mass index, and evidence of cigarette smoking. This is why the prevention of coronary heart disease logically started moving to childhood [5].
Beginning of prevention of atherosclerosis from childhood in the Czech Republic The prevention of coronary heart disease from childhood was officially launched in the Czech Republic in 1992 (Ministry of Health Decree No. 56/1992 Coll.). The decree imposes general practitioners for children to include a preventive examination in children from high-risk families for dyslipidemia; this examination is carried out for each child in 5 and 13 years, to search in children from high-risk families for dyslipidemia. All the information is recorded in the health certificate, which has each child. Children, in which the findings are proved and are beyond the practical capabilities of the children's doctor, are then sent to the relevant professionals where the lipoprotein profiling is offered also to other members of the family. A significant number of parents at high risk for coronary heart disease can be identified through their children. More than 2000 general practitioners for children and adolescents, 150 specialized pediatric cardiologists, obesitologists and diabetologists as well as other professions like nutritionists and physical therapeutists are engaged in the prevention of coronary heart disease [6]. It is of paramount importance to carefully evaluate family history at each checkup. Doctors are searching for coronary death or disease, stroke, peripheral vascular disease, diabetes mellitus in fathers younger than 55 years or mothers under the age of 65, but also in grandparents and other close relatives. Also included in a positive family history is the presence of obesity, severe hypertension and increased levels of total cholesterol in parents (6.0 mmol/l). When a positive family history is determined, or if there are present significant risk factors of the child, the total HDL cholesterol and triglyceride levels are measured after overnight fasting [7].
Dyslipidemia Dyslipidemia belongs to the most severe but easily detectable risk factors of atherosclerosis. Young adults with an increased level of total cholesterol (>5.2 mmol/l) had five times the
risk of developing cardiovascular disease 40 years later compared with those who had a total cholesterol level lower (<3.1 mmol/l) [8]. Children with pathological levels of non-HDL cholesterol, increased LDL or total cholesterol should be sent in our country to the pediatric cardiologist or lipidologist. In children with familial hypercholesterolemia it is recommended to start after two years of age with an adjustment of diet. For other children with persistent but not familial hypercholesterolemia diet starts from 5 years of age. Pharmaceutical treatment of a child should always be carefully decided by a pediatric lipidologist or cardiologist. Of the current pharmacological treatment options for children, it should be referred only to the treatment with statins. Previously, the only recommended medication for a child was resins, which are currently difficult to obtain, have a bad taste and have low adherence. Fibrates are contraindicated in children due to their side effects and Ezetrol is used in monotherapy in children only if they cannot be treated with statins. When considering to start pharmacological treatment, it should be realized that this treatment is usually long lasting and often throughout the child's lifetime. Therefore, we always have to consider whether the risk of hypolipidemic therapy is not greater than its benefits. Usually pharmacotherapy is started only in children aged 8–10 years with a very serious family history of hypercholesterolemia, when the total cholesterolemia did not fall after 6–12 months of nonpharmacological treatment under 8.0 mmol/l, if the value of LDL cholesterol did not fall below 4, 9 mmol/l, or when hypecholesterolemia occurs in a child who has two or more risk factors (Table 1). In 1997 we tried to find the value of total cholesterol in Czech children [9]. In examinations of 1378 children and adolescents aged 1–17 years (707 boys and 671 girls) from different regions of the Czech Republic, we found that 60% of children aged 7–13 years had an increased total cholesterol over 4.4 mmol/l. In total, 26% of them already belonged to the ‘‘high risk’’ category with the level of total cholesterol above 5.2 mmol/l. Normal and pathological values of lipids and children's age are laid down in Table 2. These values are
Table 1 – Classification of hyperlipidemias in children. Lipoprotein
Total cholesterol LDL cholesterol HDL cholesterol Triglycerides
Values Acceptable
Marginal
Pathologic
<4.4 <2.9 >1.2 <1.0
4.4–5.0 2.9–3.3 1.0–1.2 1.0–1.5
>5.0 >3.3 <1.0 >1.5
Table 2 – Criteria for pharmacological treatment of familial hypercholesterolemia in children. Total cholesterol 8 mmol/l 4.9 mmol/l LDL cholesterol 4.1 mmol/l + positive family history LDL cholesterol 2 risk factors (high triglycerides, low HDL, obesity, smoking, hypertension)
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cor et vasa 56 (2014) e164–e168
probably much higher at the present time. The increase of lipid levels was demonstrated in the United States. Just over a decade lipid levels in the pediatric population had increased significantly. In the Lipid Research Clinics Prevalence Study from 1970 to 1976 in children aged 0–19 years the mean total cholesterol level was 4.1 mmol/l, with the 95th percentile of 5.1 mmol/l [10]. The NHANES III collected cholesterol levels in more than 7000 U.S. children ages 0–19 years from 1988 to 1994. The mean total cholesterol level was 4.4 mmol/l, and the 95th percentile was 5.5 mmol/l [11].
Table 4 – Overweight and obesity measured in 7427 Czech children in 2006. Age (years)
Overweight
Obesity
2.0% 2.2% 0.9%
3.0% 5.4% 3.0%
1.0% 3.0% 1.2%
4.3% 5.9% 3.0%
Boys 5 13 18 Girls 5 13 18
Overweight and obesity in children Table 5 – Classification of hypertension in children. Epidemiological studies show that being overweight and obese during childhood are among the most serious and underlying risk factors for premature atherosclerosis and coronary disease in adult life [12]. About three-quarters of children with obesity continue to have obesity into adulthood. The recent Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents recommends that children and adolescents ages 2–18 years with a BMI at or greater than the 95th percentile be described as ‘‘obese’’. For children with a BMI between the 85th and 95th percentiles, the term ‘‘overweight’’ should be used [13]. Our criterion for overweight was selected as 90th to 97th percentile of BMI and obese children were considered those at 97th percentile and higher. Incidence of being overweight and obese on All-state Anthropological Investigation of Children and Youth in the Czech Republic carried out in 1991 and in 2001 in the Czech Republic has shown that the obesity proportions are below those detected in a number of other developed countries [14,15] (Table 3). The further investigation of prevalence of overweight and obesity in the Czech Republic was performed in 2006 by 57 physicians in a total of 7427 children (51% of boys) since birth till their 18 years of age. The examination was made at the age categories of 5, 13 and 18 years. These measurements showed results similar to those measured in the year 1991 and 2001 on All-state Anthropological Investigation. Overweight was established in 1.8% and obesity in 4.2% of children. Obesity is most commonly observed in boys and girls at the age of 13 while the incidence of obesity declines after the age of 18. A similar trend can also be found in overweight children (Table 4) [16].
Table 3 – Overweight and obesity among Czech children in 1991 and 2001.
Boys Overweight Obesity Total Girls Overweight Obesity Total
1991
2001
7.0% 3.0% 10.0%
7.1% 6.0% 13.1%
7.0% 3.0% 10.0%
6.3% 5.6% 11.9%
Systolic (SBP) or diastolic blood pressure (DBP) Percentilea <90th 90 to <95 or if BP exceeds 120/80 mmHgb 95th to 99th plus 5 mmHg >99th plus 5 mmHg
Normal High normal Stage 1 hypertension Stage 2 hypertension a
For gender, age, and height measured on at least 3 separate occasions b This occurs typically at 12 years old for SBP and at 16 years old for DBP.
Hypertension High blood pressure is a major risk factor for coronary heart disease, stroke and peripheral vascular disease. A metaanalysis of 50 cohort studies confirmed that blood pressure tracks from childhood into adulthood [17]. Adults with elevated blood pressure from childhood had increased risk of atherosclerosis [18]. Blood pressure rises with the age of the child and is also determined by gender, body height and weight. Therefore, blood pressure in children should not be classified by body mass index as in adulthood but by using percentiles. We are using the classification of hypertension listed in a table (Table 5) [19]. For practical reasons there is used the height of a child at the relevant age for assessment of blood pressure in the table which shows the highest normal values (Table 6) [20].
Table 6 – The upper limit of normal blood pressure, depending on the age and height of the characters. Age (years)
1 6 12 17
Girls
Boys
Percentiles of height
Percentiles of height
50th
75th
50th
75th
104/58 111/74 128/80 129/81
105/59 113/74 124/81 130/85
103/56 111/74 123/81 136/87
104/58 115/75 125/82 137/87
cor et vasa 56 (2014) e164–e168
Table 7 – Hypertension in obese children in the Czech Republic. Age (years) 5 13 18 Total
Normal weight
Overweight
Obesity
44% 12% 43% 30%
50% 16% 7% 17%
6% 72% 50% 53%
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them from smoking, and to optimize lipid levels and blood pressure individually with appropriate treatment in adulthood. In conclusion, it can be stated that the twenty years of preventive medicine starting from childhood has contributed significantly to the progress in reduction of mortality from cardiovascular diseases in the Czech Republic.
Conflict of interest Table 8 – The prevalence of smoking among children in the Czech Republic. Age (years)
1994
1998
2002
11 13 15
1.9% 5.8% 13.9%
1.4% 8.6% 19.9%
2.0% 11.1% 29.7%
Anthropometric data, and blood pressure measurements were obtained from 7427 children across the Czech Republic. Hypertension (above 95 percentile) was diagnosed in 115 (1.54) of the 7427 children examined, being present more often in boys than in girls (1.02% vs. 0.52%). In the 5-year-old, hypertension was present in only 0.86%, in the 15-year-old in 1.88%, and in the 18-year-old in 1.75%. Hypertension was predominating in boys at all ages [21]. Prevalence of hypertension increases in parallel with childhood obesity [22]. Hypertension was more common among overweight and obese children also in our study. Up to 72% of children with hypertension were obese at the age of 13. About the same trend was demonstrated also at a later age (Table 7) [21].
Smoking Smoking, particularly cigarette smoking, is a major risk factor that leads to vascular dysfunction and coronary disease. The evidence that smoking is harmful is unequivocal [23]. Moreover, involuntary tobacco smoke exposure by secondhand smoke, impair the health of fetuses, infants, children and adolescents [24]. The goal of clinical intervention is complete cessation of tobacco use. Children have been observed to start with smoking in the Czech Republic at the age of 11. By 13 years, 11.1% of children are regularly smoking and by 15 years of age, 29.7% of children (Table 8) [25]. The prevalence of smoking at all ages was found to have increased, in 13-year-olds from 5.8% in 1994 to 11.1% in 2002, and in 15-year-olds from 13.9% in 1994 to 29.7% in 2002. The prevalence of smoking in girls reached in 2002 even higher value than in boys. This trend was finished in 2006 and the prevalence of regular smokers decreased to 15% in boys and to 18% in girls.
Conclusion The aims of prevention of coronary heart disease from childhood is to check the development of all risk factors (obesity, hypercholesterolemia, hypertension), to teach children a healthy lifestyle, include regular physical activities, deter
No conflict of interest.
Funding body No financial support was used for the conduct of the research and/or preparation of the article.
Ethical statement The research was done according to ethical standards.
references
[1] R.J. Bing (Ed.), Cardiology: The Evolution of the Science and the Art, Rutgers University Press, New Brunswick, 1990. [2] W.F. Enos, R.H. Holmes, J. Beyer, Coronary disease among United States soldiers, Journal of the American Medical Association 152 (1953) 1090–1093. [3] H.C. McGill Jr., C.A. McMahan, S.S. Gidding, Preventing heart disease in the 21st century: implications of the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study, Circulation 117 (2008) 1216–1227. [4] G.S. Berenson, S.R. Srinivasan, W. Bao, et al., Association between multiple cardiovascular risk factors and atherosclerosis in children and young adults. The Bogalusa Heart Study, New England Journal of Medicine 338 (1998) 1650–1656. [5] S.R. Daniels, I. Benuck, D.A. Christakis, et al., Expert Panel on integrated guidelines for cardiovascular health and risk reduction in children and adolescents, Pediatrics 128 (Suppl 5) (2011) S213–S256. [6] M. Šamánek, Z. Urbanová, Prevention of Atherosclerosis in Childhood, Galén, Praha, 2003. [7] Z. Urbanová, M. Šamánek, R. Češka, et al., Recommendations for diagnosis and treatment of dyslipidemia in children and adolescents prepared by the committee of the Czech Society for Atherosclerosis, Časopis lékařů českých 137 (1998) 89–92. [8] P.O. Kwiterovich Jr., Recognition and management of dyslipidemia in children and adolescents, Journal of Clinical Endocrinology and Metabolism 93 (2008) 4200–4209. [9] M. Šamánek, Z. Urbanová, Cholesterol and triglyceride levels in children between 2 and 17 age, Časopis lékařů českých 136 (1997) 380–385. [10] J.C. LaRosa, L.E. Chambless, M.H. Criqi, et al., Patterns of dyslipoproteinemia in selected North American populations. The Lipid Research Clinics Program Prevalence Study, Circulation 73 (1986) 12–29. [11] T.B. Hickman, R.R. Briefel, M.D. Carroll, et al., Distributions and trends of serum lipid levels among United States children and adolescents ages 4–19 years: data from the
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Available online at www.sciencedirect.com
ScienceDirect journal homepage: http://www.elsevier.com/locate/crvasa
Review article – Special issue: Cardiovascular Prevention
Twenty years of cardiovascular risk prevention in Czech children Milan Šamánek a,*, Zuzana Urbanová b a b
Dětské kardiocentrum FN Motol, Praha, Czech Republic Klinika dětského a dorostového lékařství 1. LF UK a VFN, Praha, Czech Republic
article info
abstract
Article history:
Coronary heart disease is the leading cause of death in the Czech Republic. Pathological data
Received 23 October 2013
have shown that atherosclerosis begins in childhood and that the extent of atherosclerosis
Received in revised form
in children can be correlated with the presence of cardiovascular risk factors such as:
27 January 2014
hypercholesterolemia, obesity, hypertension and cigarette smoking. Pediatric preventive
Accepted 28 January 2014
program in the Czech Republic, which started in 1992, identifies children at high risk of
Available online 5 March 2014
atherosclerosis. At the age of 5 and 13 years, pediatricians are obliged to measure not only
Keywords:
and triglycerides) in children with positive family history. This obligation is incorporated in
Atherosclerosis
the health certificate of everyone born in the Czech Republic. The lipoprotein profiling is also
blood pressure and BMI, but also lipid profile (plasma total cholesterol, LDL, HDL cholesterol
Prevention
offered to other family members. Children identified as being at an increased risk of
Cardiovascular risk factors
ischemic heart disease are referred to pediatric cardiologists or specialized centers to be
Childhood
followed up and treated. During the past two decades this strategy has promoted cardiovascular health for all children and contributed significantly to progress in the reduction of mortality for cardiovascular diseases in the Czech Republic. # 2014 The Czech Society of Cardiology. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Beginning of prevention of atherosclerosis from childhood in the Czech Republic Dyslipidemia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overweight and obesity in children . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hypertension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Smoking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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* Corresponding author. Tel.: +420 605563984. E-mail address: [email protected] (M. Šamánek). http://dx.doi.org/10.1016/j.crvasa.2014.01.005 0010-8650/# 2014 The Czech Society of Cardiology. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
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Introduction Manifest myocardial infarction and stroke in children is rare, but risk factors of cardiovascular disease begin in childhood. Vsevolod A. Zinserling was the first to show already in 1924 that the fatty streaks are present in arteries of children. He described that the fatty streaks contain cholesterol and are precursors of atherosclerosis [1]. His finding was verified in 1953 in Korean war casualties [2] and later in the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study [3] and the Bogalusa Heart Study [4]. Both the presence and extent of atherosclerotic lesions at autopsy after unexpected deaths in children correlate with established risk factors: namely high cholesterol, high blood pressure, elevated body mass index, and evidence of cigarette smoking. This is why the prevention of coronary heart disease logically started moving to childhood [5].
Beginning of prevention of atherosclerosis from childhood in the Czech Republic The prevention of coronary heart disease from childhood was officially launched in the Czech Republic in 1992 (Ministry of Health Decree No. 56/1992 Coll.). The decree imposes general practitioners for children to include a preventive examination in children from high-risk families for dyslipidemia; this examination is carried out for each child in 5 and 13 years, to search in children from high-risk families for dyslipidemia. All the information is recorded in the health certificate, which has each child. Children, in which the findings are proved and are beyond the practical capabilities of the children's doctor, are then sent to the relevant professionals where the lipoprotein profiling is offered also to other members of the family. A significant number of parents at high risk for coronary heart disease can be identified through their children. More than 2000 general practitioners for children and adolescents, 150 specialized pediatric cardiologists, obesitologists and diabetologists as well as other professions like nutritionists and physical therapeutists are engaged in the prevention of coronary heart disease [6]. It is of paramount importance to carefully evaluate family history at each checkup. Doctors are searching for coronary death or disease, stroke, peripheral vascular disease, diabetes mellitus in fathers younger than 55 years or mothers under the age of 65, but also in grandparents and other close relatives. Also included in a positive family history is the presence of obesity, severe hypertension and increased levels of total cholesterol in parents (6.0 mmol/l). When a positive family history is determined, or if there are present significant risk factors of the child, the total HDL cholesterol and triglyceride levels are measured after overnight fasting [7].
Dyslipidemia Dyslipidemia belongs to the most severe but easily detectable risk factors of atherosclerosis. Young adults with an increased level of total cholesterol (>5.2 mmol/l) had five times the
risk of developing cardiovascular disease 40 years later compared with those who had a total cholesterol level lower (<3.1 mmol/l) [8]. Children with pathological levels of non-HDL cholesterol, increased LDL or total cholesterol should be sent in our country to the pediatric cardiologist or lipidologist. In children with familial hypercholesterolemia it is recommended to start after two years of age with an adjustment of diet. For other children with persistent but not familial hypercholesterolemia diet starts from 5 years of age. Pharmaceutical treatment of a child should always be carefully decided by a pediatric lipidologist or cardiologist. Of the current pharmacological treatment options for children, it should be referred only to the treatment with statins. Previously, the only recommended medication for a child was resins, which are currently difficult to obtain, have a bad taste and have low adherence. Fibrates are contraindicated in children due to their side effects and Ezetrol is used in monotherapy in children only if they cannot be treated with statins. When considering to start pharmacological treatment, it should be realized that this treatment is usually long lasting and often throughout the child's lifetime. Therefore, we always have to consider whether the risk of hypolipidemic therapy is not greater than its benefits. Usually pharmacotherapy is started only in children aged 8–10 years with a very serious family history of hypercholesterolemia, when the total cholesterolemia did not fall after 6–12 months of nonpharmacological treatment under 8.0 mmol/l, if the value of LDL cholesterol did not fall below 4, 9 mmol/l, or when hypecholesterolemia occurs in a child who has two or more risk factors (Table 1). In 1997 we tried to find the value of total cholesterol in Czech children [9]. In examinations of 1378 children and adolescents aged 1–17 years (707 boys and 671 girls) from different regions of the Czech Republic, we found that 60% of children aged 7–13 years had an increased total cholesterol over 4.4 mmol/l. In total, 26% of them already belonged to the ‘‘high risk’’ category with the level of total cholesterol above 5.2 mmol/l. Normal and pathological values of lipids and children's age are laid down in Table 2. These values are
Table 1 – Classification of hyperlipidemias in children. Lipoprotein
Total cholesterol LDL cholesterol HDL cholesterol Triglycerides
Values Acceptable
Marginal
Pathologic
<4.4 <2.9 >1.2 <1.0
4.4–5.0 2.9–3.3 1.0–1.2 1.0–1.5
>5.0 >3.3 <1.0 >1.5
Table 2 – Criteria for pharmacological treatment of familial hypercholesterolemia in children. Total cholesterol 8 mmol/l 4.9 mmol/l LDL cholesterol 4.1 mmol/l + positive family history LDL cholesterol 2 risk factors (high triglycerides, low HDL, obesity, smoking, hypertension)
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probably much higher at the present time. The increase of lipid levels was demonstrated in the United States. Just over a decade lipid levels in the pediatric population had increased significantly. In the Lipid Research Clinics Prevalence Study from 1970 to 1976 in children aged 0–19 years the mean total cholesterol level was 4.1 mmol/l, with the 95th percentile of 5.1 mmol/l [10]. The NHANES III collected cholesterol levels in more than 7000 U.S. children ages 0–19 years from 1988 to 1994. The mean total cholesterol level was 4.4 mmol/l, and the 95th percentile was 5.5 mmol/l [11].
Table 4 – Overweight and obesity measured in 7427 Czech children in 2006. Age (years)
Overweight
Obesity
2.0% 2.2% 0.9%
3.0% 5.4% 3.0%
1.0% 3.0% 1.2%
4.3% 5.9% 3.0%
Boys 5 13 18 Girls 5 13 18
Overweight and obesity in children Table 5 – Classification of hypertension in children. Epidemiological studies show that being overweight and obese during childhood are among the most serious and underlying risk factors for premature atherosclerosis and coronary disease in adult life [12]. About three-quarters of children with obesity continue to have obesity into adulthood. The recent Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents recommends that children and adolescents ages 2–18 years with a BMI at or greater than the 95th percentile be described as ‘‘obese’’. For children with a BMI between the 85th and 95th percentiles, the term ‘‘overweight’’ should be used [13]. Our criterion for overweight was selected as 90th to 97th percentile of BMI and obese children were considered those at 97th percentile and higher. Incidence of being overweight and obese on All-state Anthropological Investigation of Children and Youth in the Czech Republic carried out in 1991 and in 2001 in the Czech Republic has shown that the obesity proportions are below those detected in a number of other developed countries [14,15] (Table 3). The further investigation of prevalence of overweight and obesity in the Czech Republic was performed in 2006 by 57 physicians in a total of 7427 children (51% of boys) since birth till their 18 years of age. The examination was made at the age categories of 5, 13 and 18 years. These measurements showed results similar to those measured in the year 1991 and 2001 on All-state Anthropological Investigation. Overweight was established in 1.8% and obesity in 4.2% of children. Obesity is most commonly observed in boys and girls at the age of 13 while the incidence of obesity declines after the age of 18. A similar trend can also be found in overweight children (Table 4) [16].
Table 3 – Overweight and obesity among Czech children in 1991 and 2001.
Boys Overweight Obesity Total Girls Overweight Obesity Total
1991
2001
7.0% 3.0% 10.0%
7.1% 6.0% 13.1%
7.0% 3.0% 10.0%
6.3% 5.6% 11.9%
Systolic (SBP) or diastolic blood pressure (DBP) Percentilea <90th 90 to <95 or if BP exceeds 120/80 mmHgb 95th to 99th plus 5 mmHg >99th plus 5 mmHg
Normal High normal Stage 1 hypertension Stage 2 hypertension a
For gender, age, and height measured on at least 3 separate occasions b This occurs typically at 12 years old for SBP and at 16 years old for DBP.
Hypertension High blood pressure is a major risk factor for coronary heart disease, stroke and peripheral vascular disease. A metaanalysis of 50 cohort studies confirmed that blood pressure tracks from childhood into adulthood [17]. Adults with elevated blood pressure from childhood had increased risk of atherosclerosis [18]. Blood pressure rises with the age of the child and is also determined by gender, body height and weight. Therefore, blood pressure in children should not be classified by body mass index as in adulthood but by using percentiles. We are using the classification of hypertension listed in a table (Table 5) [19]. For practical reasons there is used the height of a child at the relevant age for assessment of blood pressure in the table which shows the highest normal values (Table 6) [20].
Table 6 – The upper limit of normal blood pressure, depending on the age and height of the characters. Age (years)
1 6 12 17
Girls
Boys
Percentiles of height
Percentiles of height
50th
75th
50th
75th
104/58 111/74 128/80 129/81
105/59 113/74 124/81 130/85
103/56 111/74 123/81 136/87
104/58 115/75 125/82 137/87
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Table 7 – Hypertension in obese children in the Czech Republic. Age (years) 5 13 18 Total
Normal weight
Overweight
Obesity
44% 12% 43% 30%
50% 16% 7% 17%
6% 72% 50% 53%
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them from smoking, and to optimize lipid levels and blood pressure individually with appropriate treatment in adulthood. In conclusion, it can be stated that the twenty years of preventive medicine starting from childhood has contributed significantly to the progress in reduction of mortality from cardiovascular diseases in the Czech Republic.
Conflict of interest Table 8 – The prevalence of smoking among children in the Czech Republic. Age (years)
1994
1998
2002
11 13 15
1.9% 5.8% 13.9%
1.4% 8.6% 19.9%
2.0% 11.1% 29.7%
Anthropometric data, and blood pressure measurements were obtained from 7427 children across the Czech Republic. Hypertension (above 95 percentile) was diagnosed in 115 (1.54) of the 7427 children examined, being present more often in boys than in girls (1.02% vs. 0.52%). In the 5-year-old, hypertension was present in only 0.86%, in the 15-year-old in 1.88%, and in the 18-year-old in 1.75%. Hypertension was predominating in boys at all ages [21]. Prevalence of hypertension increases in parallel with childhood obesity [22]. Hypertension was more common among overweight and obese children also in our study. Up to 72% of children with hypertension were obese at the age of 13. About the same trend was demonstrated also at a later age (Table 7) [21].
Smoking Smoking, particularly cigarette smoking, is a major risk factor that leads to vascular dysfunction and coronary disease. The evidence that smoking is harmful is unequivocal [23]. Moreover, involuntary tobacco smoke exposure by secondhand smoke, impair the health of fetuses, infants, children and adolescents [24]. The goal of clinical intervention is complete cessation of tobacco use. Children have been observed to start with smoking in the Czech Republic at the age of 11. By 13 years, 11.1% of children are regularly smoking and by 15 years of age, 29.7% of children (Table 8) [25]. The prevalence of smoking at all ages was found to have increased, in 13-year-olds from 5.8% in 1994 to 11.1% in 2002, and in 15-year-olds from 13.9% in 1994 to 29.7% in 2002. The prevalence of smoking in girls reached in 2002 even higher value than in boys. This trend was finished in 2006 and the prevalence of regular smokers decreased to 15% in boys and to 18% in girls.
Conclusion The aims of prevention of coronary heart disease from childhood is to check the development of all risk factors (obesity, hypercholesterolemia, hypertension), to teach children a healthy lifestyle, include regular physical activities, deter
No conflict of interest.
Funding body No financial support was used for the conduct of the research and/or preparation of the article.
Ethical statement The research was done according to ethical standards.
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