Hypertension in children vevey february 2010

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short review of HTN management, in the light of two cases

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Hypertension in children vevey february 2010

  1. 1. Hypertension in children F. Cachat Pediatrics and Pediatric Nephrology Vevey and Lausanne Switzerland
  2. 2. Disease prevalence in childhood <ul><li>Congenital heart disease 1% </li></ul><ul><li>Epilepsy 3-5% </li></ul><ul><li>ADHD 3-5% </li></ul><ul><li>Hypertension 4-5% </li></ul><ul><li>Asthma 7% </li></ul><ul><li>Obesity 18-25% </li></ul>
  3. 3. HTN is a major killer in adulthood Some HTN originates in childhood Many children with HTN during infancy will still have HTN as adults (blood pressure tracking)
  4. 4. PLAN <ul><li>Definition </li></ul><ul><li>Case presentation </li></ul><ul><li>Physiology of hypertension in children (some aspects) </li></ul><ul><li>Evaluation of the child with hypertension (some aspects) </li></ul><ul><li>Management of the child with hypertension (some aspects) </li></ul><ul><li>Conclusion </li></ul>
  5. 5. Definitions
  6. 6. <ul><li>Update on the 1996 and 1987 Task Force Report on High Blood Pressure in Children and Adolescents: </li></ul><ul><ul><li>60’000 healthy children </li></ul></ul><ul><ul><li>M/F: 50/50 </li></ul></ul><ul><ul><li>White: 56%, African-American: 29%, Spanish: 9%, Asian: 3%, Others: 3% </li></ul></ul>Definitions
  7. 7. Definitions
  8. 8. Classification of Hypertension in Children and Adolescents SBP or DBP Percentile Normal <90 th percentile Prehypertension 90 th percentile to <95 th percentile, or if BP exceeds 120/80 mm Hg, even if below the 90 th percentile up to <95 th percentile Stage 1 hypertension 95 th percentile to the 99 th percentile + 5 mm Hg Stage 2 hypertension >99 th percentile + 5 mm Hg
  9. 9. How to calculate the 95 th percentile of BP for a child? <ul><ul><li>Systolic BP (1-17 years) </li></ul></ul><ul><ul><ul><li>100 + (age in years x 2) </li></ul></ul></ul><ul><ul><li>Diastolic BP (1-10 years) </li></ul></ul><ul><ul><ul><li>60 + (age in years x 2) </li></ul></ul></ul><ul><ul><li>Diastolic BP (11-17 years) </li></ul></ul><ul><ul><ul><li>70 + (age in years) </li></ul></ul></ul>
  10. 10. Case presentation
  11. 11. Case presentations <ul><li>Case 1 : monogenic hypertension </li></ul><ul><ul><ul><li>When a rare single genetic disease helps to understand the pathophysiology of HTN in children </li></ul></ul></ul><ul><ul><ul><li>When HTN treatment benefits are obvious </li></ul></ul></ul><ul><li>Case 2 : obesity related hypertension </li></ul><ul><ul><ul><li>A rising epidemic of HTN in children in the Western World </li></ul></ul></ul><ul><ul><ul><li>When HTN treatment benefits are less obvious (and treatment more difficult) </li></ul></ul></ul><ul><ul><ul><li>Polygenic, multifactorial HTN </li></ul></ul></ul>
  12. 12. HTN Sub-arachn. hemorrhage BP 160/110 mm Hg Hx of surgically-corrected VUR
  13. 13. HTN Sub-arachn. hemorrhage BP 160/110 mm Hg Hx of surgically-corrected VUR
  14. 14. HTN Sub-arachn. hemorrhage BP 160/110 mm Hg Hx of surgically-corrected VUR Premature death 36 years old Sub-arachn. hemorrhage
  15. 15. HTN Sub-arachn. hemorrhage BP 160/110 mm Hg Hx of surgically-corrected VUR Premature death 36 years old Sub-arachn. hemorrhage
  16. 16. HTN Sub-arachn. hemorrhage BP 160/110 mm Hg Hx of surgically-corrected VUR Premature death 36 years old Sub-arachn. hemorrhage
  17. 17. HTN Sub-arachn. hemorrhage BP 160/110 mm Hg Hx of surgically-corrected VUR Premature death 36 years old Sub-arachn. hemorrhage
  18. 18. Physical exam <ul><li>NORMAL except for confirmed severe asymptomatic HTN (discovered during routine school exam) </li></ul>
  19. 19. Laboratory values <ul><li>Plasma chemistries : Na 141 mmol/l, K 2.8 mmol/l , creatinine 71  mol/l, bicarbonates 27 mmol/l, BE + 3.2 mmol/l , glucose 5.3 mmol/l, calcium 2.37 mmol/l </li></ul><ul><li>Urine chemistries : Na 113 mmol/l, K 75 mmol/l , no proteinuria, no glycosuria </li></ul><ul><li>I 123 -Hippuran scintigraphy : normal, no scars </li></ul><ul><li>Father’s plasma potassium : 3.2 mmol/l </li></ul>
  20. 20. Laboratory values <ul><li>Plasma renin activity: extremely low </li></ul><ul><li>Plasma aldosterone: extremely high </li></ul><ul><li>Plasma and urine cortisol : normal values </li></ul>
  21. 21. In summary <ul><li>An autosomal dominant form of severe HTN </li></ul><ul><li>With hypokalemia and alkalosis </li></ul><ul><li>With very high aldosterone levels and suppressed renin activity </li></ul>
  22. 22. Na Intake Kidneys Urinary sodium R e nin Blood volume Blood pressure Na and Cl transport Aldost e rone ACTH GRA Congenital Adrenal hyperplasia Deoxycorticosterone Cortisol Cortisone ENaC (Liddle’s syndrome ) Gordon syndrome AME Monogenic endocrine HTN
  23. 23. 15-year-old boy No past medical history No medication Found by the pediatrician to have sustained HTN 140/85 mm Hg Extensive work-up negative Family history positive for both parents having HTN
  24. 24. Conservative treatment/ diet No major changes in diet continues to eat salty food (salt sensitivity) Pharmacological treatment Poor compliance with drug treatment (drug compliance) Poor BP (and weight) improvement
  25. 25. Pathophysiology
  26. 26. Child at risk Birth weight Sex Genetics Adult with ± cardio- vascular risks Physical activity Job/social factors Weight Weight gain Obesity Truncal obesity Food (fat, sodium) Smoking/environmental factors Renal injury Cardiac abnormality (coarctation of the Aorta) Endocrine abnormality Programmed determinants Secondary insults Life style
  27. 27. Child at risk Birth weight Sex Genetics Adult with ± cardio- vascular risks Physical activity Job/social factors Weight Weight gain Obesity Truncal obesity Food (fat, sodium) Smoking/environmental factors Renal injury Cardiac abnormality (coarctation of the Aorta) Endocrine abnormality
  28. 28. HTN Sub-arachn. hemorrhage BP 160/110 mm Hg Hx of surgically-corrected VUR Premature death 36 years old Sub-arachn. hemorrhage GRA AME Liddle syndrome
  29. 29. Child at risk Birth weight Sex Genetics Adult with ± cardio- vascular risks Physical activity Job/social factors Weight Weight gain Obesity Truncal obesity Food (fat, sodium) Smoking/environmental factors Renal injury Cardiac abnormality (coarctation of the Aorta) Endocrine abnormality
  30. 30. Relationship between blood pressure values and birth weight Barker DJP Schweiz Med Wochenschrift 1999;129:189-196
  31. 31. f/u of BP in former premature infants with or without growth retardation in Lausanne (14-16 years) Systolic BP (mm Hg) Diastolic BP (mm Hg) Controls 123 ±11 71±5 * Premature infants** without growth retardation 129 ±13 86±9 Premature infants** with growth retardation 129 ±17 87±6 *P<0.0001 compared to premature with and without intrauterine growth retardation (unpaired t-test) Premature infants defined as  32 weeks gestational age
  32. 32. % with elevated BP at 12 y (at 1st visit) Etude Chiolero-IUMSP Relation between birth weight and blood pressure (systolic blood pressure) 0% 5% 10% 15% 20% <2.5 kg (270) 2.5-4.0 kg (3979) >4.0 kg (405) 16.7 10.6 16.7 11.2
  33. 33. Child at risk Birth weight Sex Genetics Adult with ± cardio- vascular risks Physical activity Job/social factors Weight Weight gain Obesity Truncal obesity Food (fat, sodium) Smoking/environmental factors Renal injury Cardiac abnormality (coarctation of the Aorta) Endocrine abnormality
  34. 34. <ul><li>Background </li></ul><ul><li>Obesity is increasingly frequent among children worldwide </li></ul><ul><li>There is a fear that obesity related conditions might increase, such as hypertension </li></ul><ul><li>Few data on prevalence of hypertension among children, especially in European countries </li></ul><ul><li>Most epidemiological studies assessed blood pressure (BP) on one visit , hence BP was overestimated </li></ul>
  35. 35. <ul><li>Aims </li></ul><ul><li>To assess prevalence of hypertension measured on up to three visits in a Swiss pediatric population </li></ul><ul><li>To assess the relationship between hypertension, being overweight and other factors </li></ul>
  36. 36. <ul><li>Methods </li></ul><ul><li>All children of the 6 th grade of the schools of canton of Vaud (N=6873) were eligible and 5207 participated (76%) . </li></ul><ul><li>Weight, height, and blood pressure (BP) were measured. </li></ul><ul><li>At initial visit, three BP readings were obtained with a clinically validated automated device. </li></ul>
  37. 37. <ul><li>Methods </li></ul><ul><li>IOTF criteria for use for overweight/obesity . </li></ul><ul><li>Elevated BP was defined for average of two last BP readings > 95th sex-, age- and height specific percentiles (US reference). </li></ul><ul><li>If BP was elevated at the initial visit, BP was measured on up to two additional separate visits. </li></ul><ul><li>Hypertension is defined for elevated BP on the three visits (recommendation of NHBPEP) </li></ul>
  38. 38. <ul><li>Prevalence of elevated BP at each visit </li></ul><ul><li>Four fold decrease in the prevalence of elevated BP between 1 st and 3 rd visit </li></ul><ul><li>Probably lower prevalence than in US children (4-9%). </li></ul>Results 10.5 12.4 4.0 3.7 2.3 2.0 0 5 10 15 1st visit 2nd visit 3rd visit Boys Girls Hypertension
  39. 39. <ul><li>High prevalence of overweight, relatively low compared to other regions of Europe </li></ul><ul><li>Underestimation as some overweight/obese children did not participate </li></ul>Results
  40. 40. <ul><li>BP strongly relates to BMI </li></ul><ul><li>The association between BP and BMI is independent of age and height </li></ul><ul><li>Blood pressure and body mass index </li></ul>BP (mmHg) BMI (kg/m2) Results
  41. 41. Results <ul><li>Prevalence of hypertension according to BMI category </li></ul>1.7 1.2 2.0 3.8 14.9 0 5 10 15 20 <25th 25th-74th 75th-84th 85th-94th >=95th BMI percentile (CDC) Hypertension (%)
  42. 42. Conclusion <ul><li>1) Prevalence of overweight and obesity in children aged 12 years old was high but relatively low compared to other regions of Europe </li></ul><ul><li>2) Prevalence of hypertension was highly dependent on the number of visits at which BP was measured </li></ul><ul><li>3) HTN prevalence was low, and increased with increase in BMI </li></ul>
  43. 43. Evaluation of HTN in children
  44. 44. <ul><li>History taking </li></ul>Child at risk Birth weight Sex Genetics Adult with ± cardio- vascular risks Physical activity Job/social factors Weight Weight gain Obesity Truncal obesity Food (fat, sodium) Smoking/environmental factors Renal injury Cardiac abnormality (coarctation of the Aorta) Endocrine abnormality
  45. 45. <ul><li>Physical exam </li></ul>Child at risk Birth weight Sex Genetics Adult with ± cardio- vascular risks Physical activity Job/social factors Weight Weight gain Obesity Truncal obesity Food (fat, sodium) Smoking/environmental factors Renal injury Cardiac abnormality (coarctation of the Aorta) Endocrine abnormality
  46. 46. Cushing syndrome Henoch-Schoenlein purpura
  47. 47. <ul><li>Lab investigations </li></ul>Child at risk Birth weight Sex Genetics Adult with ± cardio- vascular risks Physical activity Job/social factors Weight Weight gain Obesity Truncal obesity Food (fat, sodium) Smoking/environmental factors Renal injury Cardiac abnormality (coarctation of the Aorta) Endocrine abnormality
  48. 48. Children Secondary causes Renal causes (78%) Reno-vascular causes (12%) Coarctation Aorta (2%) Other causes (endocrine causes, phaeo) (8%) (Essential HTN) Adults Essential HTN (Secondary causes) Age Frequency
  49. 49. Measurement of blood pressure in children
  50. 50. BP measurement : cuff choice Cuff too narrow Good-sized cuff
  51. 51. BP measurement : cuff choice American Family Physician 2006; 7(9) 40% of the circumference or 2/3 of the arm lengt ≥ 80% of the arm circumference
  52. 52. BP measurement : cuff choice
  53. 53. BP measurement methods <ul><li>BP measurement in the office </li></ul><ul><li>ABPM </li></ul><ul><li>Self-blood pressure monitoring at home </li></ul>
  54. 54. BP measurement in the office <ul><li>Most commonly used </li></ul><ul><li>Always obtain at least 3 values to diagnose sustained hypertension </li></ul><ul><li>White coat hypertension: </li></ul><ul><ul><li>Innocent bystander (?) </li></ul></ul><ul><ul><li>Adults data makes the f/u of white coat hypertension mandatory, no data in children </li></ul></ul>
  55. 55. Single office BP measure <ul><li>Is there any difference between arm and wrist cuff? </li></ul>
  56. 56. Blood pressure reactivity in adults Lausanne Study
  57. 57. Single office BP measurement
  58. 58. ABPM Most commonly used method to confirm HTN Prognostic factor of “dipping” Abnormal ABPM linked to left ventricular hypertrophy
  59. 59. Self-measurement of BP at home <ul><li>Advantages: </li></ul><ul><ul><ul><li>Greater numbers of readings </li></ul></ul></ul><ul><ul><ul><li>Avoidance of the white-coat syndrome </li></ul></ul></ul><ul><ul><ul><li>Absence of observer bias </li></ul></ul></ul><ul><ul><ul><li>Increased compliance with anti-hypertensive therapy </li></ul></ul></ul><ul><li>Reference values </li></ul><ul><ul><ul><li>Derived from population studies </li></ul></ul></ul><ul><ul><ul><li>In adults: </li></ul></ul></ul><ul><ul><ul><ul><li>Mean + 2 SD: 137/89 mm Hg </li></ul></ul></ul></ul><ul><ul><ul><ul><li>95 th percentile: 135/86 mm Hg </li></ul></ul></ul></ul>
  60. 61. Treatment of HTN in children
  61. 62. When to treat HTN in children? S/D BP Measure Non-pharm. pharm. treatm. Normal < P90 No measure none none Pre-HTN P90-95 or f/u 6 months low salt diet none unless > 120/80 physical act. CKD or diabetes or cardiac disease
  62. 63. When to treat HTN in children? TA S/D Measure Non-pharm. Pharmacol ttt Stage I HTN P95-99 f/u within diet none unless + 5 mmHg 2 weeks physical activity organ damage or symptomatic Stage II HTN > P99 referral diet yes + 5 mmHg physical activity
  63. 64. Pharmacologic management <ul><li>Pharmacological approach will allow to control: </li></ul><ul><ul><li>hormonal aspect of BP ( IEC or ARBs ) </li></ul></ul><ul><ul><li>Vascular reactivity (arterial and venous) ( calcium channel blockers or peripheral  -blockers ) </li></ul></ul><ul><ul><li>Cardiac output (  -blockers ) </li></ul></ul><ul><ul><li>SNC sympathetic activity ( central  -agonists ) </li></ul></ul>
  64. 66. Why to treat, does it make a difference? <ul><li>Outcome difficult to assess in children: </li></ul><ul><ul><ul><li>Rare complications during childhood </li></ul></ul></ul><ul><ul><ul><li>Classic complications (stroke, heart failure, blindness) occur (very) late </li></ul></ul></ul><ul><ul><ul><li>Notable exception of children with CKD and HTN: </li></ul></ul></ul>
  65. 67. Mortality in children with CKD Death rate per 100,000 0 10 100 1000 10000 0-14 15-19 20-30 Age (years) Adapted from Parekh et al, J Pediatr, 2002 Dialysis Transplant General Population <ul><li>Black </li></ul><ul><li>White </li></ul>
  66. 68. • CrCl < 75ml/min/1.73m 2 • HTN: >95 th % (Task Force) • Normotensive: n=1987 (52%) • Hypertensive: n=1874 (48%) • Endpoint: – CrCl by 10 ml/min/1.73m 2 – Renal replacement therapy P<0.001 Mitsnefes et al, J Am Soc Nephrol 2003 NAPRTCS CRI Database: NAPRTCS CRI Database: 58% 49% Morbidity in children with CKD Non-Hypertension Hypertension % PROGRESSION TO ESRD/CR.CL. DROP 10 0 20 40 60 80 100 MONTHS 0 12 24 36
  67. 69. Conclusions
  68. 70. <ul><li>BP measurement must be done routinely in all children, as soon as possible, at least for the first time when the child in 3 years old, or earlier in children with associated risk factors for HTN </li></ul><ul><li>The vast majority of children with HTN are asymptomatic until their BP is significantly high with potential target organ damage </li></ul>Conclusions
  69. 71. Conclusions <ul><li>Younger children (< 10 years old) often (always) have secondary HTN </li></ul><ul><li>One single abnormal BP value must always be confirmed, either at the office (first), or with ABPM and/or self-monitored blood pressure at home </li></ul>
  70. 72. Conclusions <ul><li>Non-pharmacologic treatment must be started in every child with HTN </li></ul><ul><li>Pharmacologic treatment will be reserved for children with target organ damage or severe HTN </li></ul>
  71. 73. What we know <ul><li>HTN exists in infancy </li></ul><ul><li>In selected cases (monogenic HTN, severe symptomatic HTN) treatment benefits are obvious </li></ul><ul><li>Treatment of HTN should not only rely on mere BP readings but also on associated risk factors such as obesity, diabetes, renal failure, microalbuminuria, metabolic syndrome, family history or end-organ damage </li></ul>
  72. 74. What we do not know <ul><li>What is the best way of measuring BP in children ? (office? Self blood pressure monitoring? ABPM?) </li></ul><ul><li>What is the relationship between pediatric HTN and later adult morbidity/mortality in a non selected population? </li></ul><ul><li>What is the role of biomarkers such as microalbuminuria? </li></ul>
  73. 75. References <ul><li>Hypertension in children . Leonard G Feld. Butterworth-Heinemann Ed. Boston, 1997;233p. </li></ul><ul><ul><ul><li>Excellent review, short, global approach and management of the child with HTN </li></ul></ul></ul><ul><li>Hypertension: pathophysiology, diagnosis and management . Laragh JH, Brenner BM. Raven Press, New-York, 1990, 2 volumes. </li></ul><ul><ul><ul><li>One (the) reference in adult HTN medicine </li></ul></ul></ul><ul><li>The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents . Pediatrics 2004;114:555-576 </li></ul><ul><ul><ul><li>Last recommendations from the AAP regarding investigation and management of HTN in children. The pediatric reference </li></ul></ul></ul>

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