Comment
The high burden of cardiovascular disease risk factors in adolescents in low-income and middle-income countries is a global health concern. Data suggest that cardiovascular disease risk factors present during adolescence might persist during adulthood2,3 and that clustering of these risk factors leads to early atherosclerosis.3,4 Therefore, adolescence represents a clear window of opportunity for cardiovascular disease risk assessment and promotion of lifestyles that will affect progression of cardiovascular disease. Adherence to optimum health behaviours during adolescence is vital to maintain low cardiovascular disease risk and to prevent disease in adulthood. For example, low cardiovascular disease-risk status maintained to 50 years of age is associated with very low future risk of disease.5 Therefore, the monitoring of risk behaviours and promotion of optimum health behaviours in adolescents are important strategies for prevention of cardiovascular disease in adulthood.6,7 In The Lancet Diabetes & Endocrinology, Caleyachetty and colleagues1 present the findings of their study based on a survey done in 169 446 school-going adolescents aged 12–15 years from 65 low-income and middleincome countries. The findings clearly show that adolescents in these countries carry a substantial burden of behavioural cardiovascular disease risk factors, with wide heterogeneity evident within and across regions. Two of every three adolescents reported less than recommended levels of physical activity (60 min of daily physical activity at least 5 days per week) and fruit and vegetable intake (>five servings per day). Furthermore, tobacco use was prevalent in one of eight adolescents and alcohol use in one of six adolescents. Researchers noted that clustering of cardiovascular disease risk factors is the tenet, even in adolescents from lowincome and middle-income countries. However, the study has some limitations.1 First, the data represent only children enrolled in schools in these countries. The school enrolment rates are poor and dropout rates are high in low-income and middle-income countries. For example, as per the 2012 World Bank data,8 nearly 55 million children (26 million boys and 29 million girls) from low-income www.thelancet.com/diabetes-endocrinology Vol 3 July 2015
and middle-income countries are out of school in the primary school age category. The dropout rate further affects the net enrolment rate in secondary school age category (the age group mostly represents adolescents). More than a third of children (39%) are not attending school in this age group from low-income and middleincome countries.8 Adolescents not studying in a school might not be similar to those adolescents who are enrolled in a school and continuing their studies in terms of both their socioeconomic status and optimum health behaviours. It is known that socioeconomic gradient exists in cardiovascular disease risk factors even in low-income and middle-income settings9 with high prevalence of tobacco use and low recommended level of fruits and vegetables intake in the socially disadvantaged groups. Therefore, the current estimates of the burden of risk behaviours are probably an underestimate of the true burden. Second, missing data for key indicators in some countries make it difficult to estimate the clustering effect of cardiovascular disease risk factors flawlessly. Thus, the prevalence estimate of three or more risk factors presented in this study is probably another underestimate of the true burden. Finally, underreporting of socially undesirable behavioural risk factors such as tobacco and alcohol use in adolescents might lead to underestimation of the true burden. Data sources are clearly inadequate to compare health risk behaviours and states, risk and protective factors, and social role transitions that are relevant to the health of the adolescents in low-income and middle-income countries.10 Caleyachetty and colleagues1 fill this gap by providing comparable data for behavioural risk factors of cardiovascular disease, collected with standardised methods in adolescents in 65 low-income and middleincome countries. However, sparse data exist for other intermediate levels cardiovascular risk factors such as blood pressure, blood sugar, and blood cholesterol in adolescents from low-income and middle-income countries. Therefore, increased harmonisation of schoolbased surveys, incorporation of key additional risk factor variables that cover the entire range of chronic noncommunicable disorders (eg, substance misuse, mental health, and intermediate level physiological risk factors
Damien Lovegrove/Science Photo Library
Cardiovascular health promotion in adolescents: a vital investment
Published Online May 7, 2015 http://dx.doi.org/10.1016/ S2213-8587(15)00095-9 See Articles page 535
493
Comment
of cardiovascular disease), and strategies for inclusion of socially marginalised adolescents are important for eliciting relevant policy responses both nationally and worldwide. A standardised framework for health indicators of common chronic disorders in adolescents is highly desirable and necessary in the current context of the disease transition from mainly infectious and nutritional disorders to the growing burden of chronic non-communicable diseases. Information systems using standardised framework for core health indicators need to be developed to improve the global picture of adolescent’s health especially in low-income and middle-income countries. Panniyammakal Jeemon Centre for Control of Chronic Conditions, Public Health Foundation of India, New Delhi 110070, India jeemon.p@phfi.org I am supported by a career development fellowship from the Wellcome Trust, Public Health Foundation of India and a consortium of UK Universities.
1
2 3
4
5
6 7
8
9 10
Caleyachetty R, Echouffo-Tcheugui JB, Tait CA, Schilsky S, Forrester T, Kengne AP. Prevalence of behavioural risk factors for cardiovascular disease in adolescents in low-income and middle-income countries: an individual participant data meta-analysis. Lancet Diabetes Endocrinol 2015; published online May 7. http://dx.doi.org/10.1016/S2213-8587(15)00076-5. Celermajer DS, Ayer JG. Childhood risk factors for adult cardiovascular disease and primary prevention in childhood. Heart 2006; 92: 1701–06. Davis PH, Dawson JD, Riley WA, Lauer RM. Carotid intimal-medial thickness is related to cardiovascular risk factors measured from childhood through middle age: The Muscatine Study. Circulation 2001; 104: 2815–19. Laitinen TT, Pahkala K, Magnussen CG, et al. Ideal cardiovascular health in childhood and cardiometabolic outcomes in adulthood: the Cardiovascular Risk in Young Finns Study. Circulation 2012; 125: 1971–78. Lloyd-Jones DM, Leip EP, Larson MG, et al. Prediction of lifetime risk for cardiovascular disease by risk factor burden at 50 years of age. Circulation 2006; 113: 791–98. Daniels SR, Pratt CA, Hayman LL. Reduction of risk for cardiovascular disease in children and adolescents. Circulation 2011; 124: 1673–86. Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents; National Heart, Lung, and Blood Institute. Expert panel on integrated guidelines for cardiovascular health and risk reduction in children and adolescents: summary report. Pediatrics 2011; 128 (suppl 5): S213–56. The World Bank. School enrollment, primary (% net). http://data. worldbank.org/indicator/SE.PRM.NENR/countries/1W?display=graph (accessed April 24, 2015). Jeemon P, Reddy KS. Social determinants of cardiovascular disease outcomes in Indians. Indian J Med Res 2010; 132: 617–22. Patton GC, Coffey C, Cappa C, et al. Health of the world’s adolescents: a synthesis of internationally comparable data. Lancet 2012; 379: 1665–75.
John Cole/Science Photo Library
Metabolic syndrome in adult survivors of childhood cancer: the intersection of oncology, endocrinology, and cardiology
Published Online April 12, 2015 http://dx.doi.org/10.1016/ S2213-8587(15)00031-5 See Series pages 545, 556, and 568
494
Improved survival rates for children diagnosed with cancer have brought recognition of clinically significant long-term effects of cancer treatment. These outcomes might not present until years after exposure, and estimates suggest that up to 90% of childhood cancer survivors will have a chronic health disorder by age 45 years.1 Results of several studies2 have shown that the prevalence of metabolic syndrome—visceral adiposity, insulin resistance, dyslipidaemia, and hypertension—is higher in childhood cancer survivors than in the general population. This cluster of abnormalities affects several organ systems, and a comprehensive understanding of the prevalence and pathological mechanisms of the metabolic syndrome in childhood cancer survivors is crucial to the development of early, directed interventions to limit long-term health implications. Finnish investigators were among the first to notice that childhood cancer survivors develop a constellation of endocrine and cardiovascular abnormalities. Talvensaari and colleagues3 compared 50 childhood cancer survivors with age-matched and sex-matched controls. Survivors had a significantly increased risk
for obesity (odds ratio [OR] 4·5, 95% CI 1·3–15·8), hyperinsulinaemia (OR 3·0, 1·0–8·6), and reduced HDL cholesterol concentration (OR 7·9, 2·2–29·6).3 Taskinen and colleagues4 reported similar findings in children aged 3–18 years after stem-cell transplantation. The prevalence of metabolic syndrome was 39% in transplant survivors, 8% in children treated for leukaemia without a transplant, and 0% in healthy controls.4 The pathogenesis of the metabolic syndrome in childhood cancer survivors is largely speculative. In children treated for cancer, interactions between lifestyle (eg, inactivity, overnutrition, smoking), treatment (chemotherapy, radiation, surgery), and environmental factors all probably contribute to the clustering of metabolic abnormalities. On the basis of prospective assessment, using the National Cholesterol Education Program–Adult Treatment Panel III criteria, Nottage and colleagues5 identified metabolic syndrome in 259 (34%) of 784 survivors of acute lymphoblastic leukaemia assessed in the St Jude Lifetime Cohort Study. Risk factors for metabolic syndrome included older age (relative risk [RR] 1·1, 95% CI 1·1–1·2) and exposure to www.thelancet.com/diabetes-endocrinology Vol 3 July 2015
The high burden of cardiovascular disease risk factors in adolescents in low-income and middle-income countries is a global health concern. Data suggest that cardiovascular disease risk factors present during adolescence might persist during adulthood2,3 and that clustering of these risk factors leads to early atherosclerosis.3,4 Therefore, adolescence represents a clear window of opportunity for cardiovascular disease risk assessment and promotion of lifestyles that will affect progression of cardiovascular disease. Adherence to optimum health behaviours during adolescence is vital to maintain low cardiovascular disease risk and to prevent disease in adulthood. For example, low cardiovascular disease-risk status maintained to 50 years of age is associated with very low future risk of disease.5 Therefore, the monitoring of risk behaviours and promotion of optimum health behaviours in adolescents are important strategies for prevention of cardiovascular disease in adulthood.6,7 In The Lancet Diabetes & Endocrinology, Caleyachetty and colleagues1 present the findings of their study based on a survey done in 169 446 school-going adolescents aged 12–15 years from 65 low-income and middleincome countries. The findings clearly show that adolescents in these countries carry a substantial burden of behavioural cardiovascular disease risk factors, with wide heterogeneity evident within and across regions. Two of every three adolescents reported less than recommended levels of physical activity (60 min of daily physical activity at least 5 days per week) and fruit and vegetable intake (>five servings per day). Furthermore, tobacco use was prevalent in one of eight adolescents and alcohol use in one of six adolescents. Researchers noted that clustering of cardiovascular disease risk factors is the tenet, even in adolescents from lowincome and middle-income countries. However, the study has some limitations.1 First, the data represent only children enrolled in schools in these countries. The school enrolment rates are poor and dropout rates are high in low-income and middle-income countries. For example, as per the 2012 World Bank data,8 nearly 55 million children (26 million boys and 29 million girls) from low-income www.thelancet.com/diabetes-endocrinology Vol 3 July 2015
and middle-income countries are out of school in the primary school age category. The dropout rate further affects the net enrolment rate in secondary school age category (the age group mostly represents adolescents). More than a third of children (39%) are not attending school in this age group from low-income and middleincome countries.8 Adolescents not studying in a school might not be similar to those adolescents who are enrolled in a school and continuing their studies in terms of both their socioeconomic status and optimum health behaviours. It is known that socioeconomic gradient exists in cardiovascular disease risk factors even in low-income and middle-income settings9 with high prevalence of tobacco use and low recommended level of fruits and vegetables intake in the socially disadvantaged groups. Therefore, the current estimates of the burden of risk behaviours are probably an underestimate of the true burden. Second, missing data for key indicators in some countries make it difficult to estimate the clustering effect of cardiovascular disease risk factors flawlessly. Thus, the prevalence estimate of three or more risk factors presented in this study is probably another underestimate of the true burden. Finally, underreporting of socially undesirable behavioural risk factors such as tobacco and alcohol use in adolescents might lead to underestimation of the true burden. Data sources are clearly inadequate to compare health risk behaviours and states, risk and protective factors, and social role transitions that are relevant to the health of the adolescents in low-income and middle-income countries.10 Caleyachetty and colleagues1 fill this gap by providing comparable data for behavioural risk factors of cardiovascular disease, collected with standardised methods in adolescents in 65 low-income and middleincome countries. However, sparse data exist for other intermediate levels cardiovascular risk factors such as blood pressure, blood sugar, and blood cholesterol in adolescents from low-income and middle-income countries. Therefore, increased harmonisation of schoolbased surveys, incorporation of key additional risk factor variables that cover the entire range of chronic noncommunicable disorders (eg, substance misuse, mental health, and intermediate level physiological risk factors
Damien Lovegrove/Science Photo Library
Cardiovascular health promotion in adolescents: a vital investment
Published Online May 7, 2015 http://dx.doi.org/10.1016/ S2213-8587(15)00095-9 See Articles page 535
493
Comment
of cardiovascular disease), and strategies for inclusion of socially marginalised adolescents are important for eliciting relevant policy responses both nationally and worldwide. A standardised framework for health indicators of common chronic disorders in adolescents is highly desirable and necessary in the current context of the disease transition from mainly infectious and nutritional disorders to the growing burden of chronic non-communicable diseases. Information systems using standardised framework for core health indicators need to be developed to improve the global picture of adolescent’s health especially in low-income and middle-income countries. Panniyammakal Jeemon Centre for Control of Chronic Conditions, Public Health Foundation of India, New Delhi 110070, India jeemon.p@phfi.org I am supported by a career development fellowship from the Wellcome Trust, Public Health Foundation of India and a consortium of UK Universities.
1
2 3
4
5
6 7
8
9 10
Caleyachetty R, Echouffo-Tcheugui JB, Tait CA, Schilsky S, Forrester T, Kengne AP. Prevalence of behavioural risk factors for cardiovascular disease in adolescents in low-income and middle-income countries: an individual participant data meta-analysis. Lancet Diabetes Endocrinol 2015; published online May 7. http://dx.doi.org/10.1016/S2213-8587(15)00076-5. Celermajer DS, Ayer JG. Childhood risk factors for adult cardiovascular disease and primary prevention in childhood. Heart 2006; 92: 1701–06. Davis PH, Dawson JD, Riley WA, Lauer RM. Carotid intimal-medial thickness is related to cardiovascular risk factors measured from childhood through middle age: The Muscatine Study. Circulation 2001; 104: 2815–19. Laitinen TT, Pahkala K, Magnussen CG, et al. Ideal cardiovascular health in childhood and cardiometabolic outcomes in adulthood: the Cardiovascular Risk in Young Finns Study. Circulation 2012; 125: 1971–78. Lloyd-Jones DM, Leip EP, Larson MG, et al. Prediction of lifetime risk for cardiovascular disease by risk factor burden at 50 years of age. Circulation 2006; 113: 791–98. Daniels SR, Pratt CA, Hayman LL. Reduction of risk for cardiovascular disease in children and adolescents. Circulation 2011; 124: 1673–86. Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents; National Heart, Lung, and Blood Institute. Expert panel on integrated guidelines for cardiovascular health and risk reduction in children and adolescents: summary report. Pediatrics 2011; 128 (suppl 5): S213–56. The World Bank. School enrollment, primary (% net). http://data. worldbank.org/indicator/SE.PRM.NENR/countries/1W?display=graph (accessed April 24, 2015). Jeemon P, Reddy KS. Social determinants of cardiovascular disease outcomes in Indians. Indian J Med Res 2010; 132: 617–22. Patton GC, Coffey C, Cappa C, et al. Health of the world’s adolescents: a synthesis of internationally comparable data. Lancet 2012; 379: 1665–75.
John Cole/Science Photo Library
Metabolic syndrome in adult survivors of childhood cancer: the intersection of oncology, endocrinology, and cardiology
Published Online April 12, 2015 http://dx.doi.org/10.1016/ S2213-8587(15)00031-5 See Series pages 545, 556, and 568
494
Improved survival rates for children diagnosed with cancer have brought recognition of clinically significant long-term effects of cancer treatment. These outcomes might not present until years after exposure, and estimates suggest that up to 90% of childhood cancer survivors will have a chronic health disorder by age 45 years.1 Results of several studies2 have shown that the prevalence of metabolic syndrome—visceral adiposity, insulin resistance, dyslipidaemia, and hypertension—is higher in childhood cancer survivors than in the general population. This cluster of abnormalities affects several organ systems, and a comprehensive understanding of the prevalence and pathological mechanisms of the metabolic syndrome in childhood cancer survivors is crucial to the development of early, directed interventions to limit long-term health implications. Finnish investigators were among the first to notice that childhood cancer survivors develop a constellation of endocrine and cardiovascular abnormalities. Talvensaari and colleagues3 compared 50 childhood cancer survivors with age-matched and sex-matched controls. Survivors had a significantly increased risk
for obesity (odds ratio [OR] 4·5, 95% CI 1·3–15·8), hyperinsulinaemia (OR 3·0, 1·0–8·6), and reduced HDL cholesterol concentration (OR 7·9, 2·2–29·6).3 Taskinen and colleagues4 reported similar findings in children aged 3–18 years after stem-cell transplantation. The prevalence of metabolic syndrome was 39% in transplant survivors, 8% in children treated for leukaemia without a transplant, and 0% in healthy controls.4 The pathogenesis of the metabolic syndrome in childhood cancer survivors is largely speculative. In children treated for cancer, interactions between lifestyle (eg, inactivity, overnutrition, smoking), treatment (chemotherapy, radiation, surgery), and environmental factors all probably contribute to the clustering of metabolic abnormalities. On the basis of prospective assessment, using the National Cholesterol Education Program–Adult Treatment Panel III criteria, Nottage and colleagues5 identified metabolic syndrome in 259 (34%) of 784 survivors of acute lymphoblastic leukaemia assessed in the St Jude Lifetime Cohort Study. Risk factors for metabolic syndrome included older age (relative risk [RR] 1·1, 95% CI 1·1–1·2) and exposure to www.thelancet.com/diabetes-endocrinology Vol 3 July 2015
