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Evaluation and Management of Hypertension in Children. John Brandt, MD MPH Division of Nephrology Dept Pediatrics, UNMSOM. Objectives. Why Hypertension is important in Pediatrics. The Association Between Childhood Obesity and Hypertension.
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Evaluation and Management of Hypertension in Children John Brandt, MD MPH Division of Nephrology Dept Pediatrics, UNMSOM
Objectives • Why Hypertension is important in Pediatrics. • The Association Between Childhood Obesity and Hypertension. • How to Evaluate and Manage Hypertension in Your Practice
Hypertension Definitions • Normal BP: Both systolic and diastolic BP < 90th % for age, gender, and height • Pre-HTN: BP ≥ 90 but < 95% • In adolescents if BP >120/80 mmHg (even if < 90th % by the tables) • HTN: Systolic and/or Diastolic BP ≥ 95 % measured upon 3 separate occasions • Stage 1 HTN • Systolic and/or diastolic BP between the 95% and the 99% + 5 mmHg. • Stage 2 HTN • Systolic and/or diastolic BP ≥ 99% +5 mmHg • Masked HTN: Normal office BP, with HTN on ABPM • White Coat HTN • Office BP readings ≥ 95% but with normal BP outside on ABPM
HTN Definitions • Primary (Essential) • No underlying etiology identified. • Secondary • An underlying disorder identified.
Hypertension: Prevalence 1989 2002 Adults 25% 30% Children 1.1% 4.5%* *Sorof J, et al.Pediatrics. 2004 Mar;113(3 Pt 1):475-82. (n=5102, Age 10-19 yrs)
Prevalence of Hypertensionin the United States by Age Group* Hypertension Prevalence † Age *Based on data from the 19992000National Health and Nutrition Examination Survey. Hypertension is defined as blood pressure 140/90 mm Hg or as receiving antihypertensive treatment. †Low reliability due to large relative error. Hypertension Online www.hypertension.org Fields LE, et al. Hypertension. 2004;44:398-404.
Cardiovascular Mortality RiskIncreases as Blood Pressure Rises* 8x 8 7 6 5 4x CardiovascularMortality Risk 4 3 2x 2 1 0 115/75 135/85 155/95 175/105 Systolic/Diastolic Blood Pressure (mm Hg) *Measurements taken in individuals aged 40–69 years, beginning with a blood pressure of 115/75 mm Hg. Lewington S, et al. Lancet. 2002;360:1903-1913; Chobanian AV, et al. JAMA. 2003;289:2560-2572. Hypertension Online www.hypertension.org
Hypertension Complications of Hypertension:End-Organ Damage Hemorrhage, Stroke LVH, CHD, CHF Peripheral Vascular Disease Renal Failure, Proteinuria Retinopathy CHD = coronary heart disease CHF = congestive heart failure LVH = left ventricular hypertrophy Hypertension Online www.hypertension.org Chobanian AV, et al. JAMA. 2003;289:2560-2572.
The Effects of Hypertension Start in Childhood Left Ventricular Hypertrophy Carotid Intimal Thickness Pediatr Nephrol (2009) 24:1545–1551 Hypertension (2006) 48;40-48
What are the Characteristics of Hypertension in Kids? • Is it Primary or Secondary? • Does it vary with Age, Body size or Ethnicity?
Kids have mostly Secondary HTN, Right? All in pediatric nephrology practices: referral bias may lead to an overestimate of the prevalence of severe (secondary) disease. Feld L, (1988) Curr Probl Pediatr 18:317–373 Arar MY, (1994) Pediatr Nephrol 8:186–189 Flynn JT, Pediatr Nephrol (2005) 20:961–966.
HTN Etiology by Age • Acta Paediatr 1992 81(3):244-6
HTN Etiology in Children • In children with Pre-HTN, 2/3rd progresses to overt HTN within 3 years. • N=1025, age 1 mo.–18 yrs, referred to Pediatric Nephrologist for HTN, • may over-estimate secondary disease. Acta Paediatr 1992 Mar;81(3):244-6
Is HTN Accurately Identified in Children? • In a study of >14,000 children seen for well-child care with at least 3 visits. • 0.9% had a diagnosis of HTN • 3.6% met BP criteria for diagnosis of HTN. • Only 1 out of 4 children with HTN were identified in the medical record as having HTN. Underdiagnosis of Hypertension in Children and Adolescents Hansen ML, JAMA. 2007;298(8):874-879
Does Obesity contribute to HTN in Children? Average SBP and DBP at first screening for each BMI percentile category Sorof, J. M. et al. Pediatrics 2004;113:475-482
Overweight (BMI>85%) by Age Flynn JT. Amer J Hypertension. 21(6) 605-12
Weight in NM Children Child and Adolescent Health Initiative. CAHMIhttp://www.cahmi.org
Obesity and HTN in Children • HTN in children has increased 3-fold since the 1980s. • Obesity prevalence has tripled in the last 30 years. • Obesity brings with it glucose intolerance, dyslipidemia, hepatic disease, orthopedic problems, psychological disorders and future cardiovascular disease.
Hypertension Prevalence by BMI Brown C., et al. Body Mass Index and the Prevalence of Risk Factors for Cardiovascular Disease
BMI and Cardiovascular Disease Risk in Children Harris CV, Pediatrics 2008
What Does it all Mean? • HTN is increasing in children. • HTN is under-diagnosed in children. • Identification and treatment of HTN in childhood can decrease adult CV morbidity. • Although Children with HTN have a high incidence of Secondary disease compared to adults,…Essential HTN is increasing rapidly in childhood. • This increase is largely due to adolescents (> 14 yrs) with Obesity.
What should we be doing now?Clinical Guidelines PEDIATRICS 2004, 114:2;555 Journal of Hypertension 2009, 27:1719–1742
Who should have their BP Checked? • Children > 3 years old who are seen in a medical setting should have their BP measured, at least yearly. • Correct measurement requires an appropriately size cuff. • Current commercial cuff designations (infant, child, adult) are often inappropriate. • Confirm high BP x 3 before diagnosing hypertension. • 3 measures separated by > 1 week , unless severe (>99%) or symptomatic. PEDIATRICS 2004, 114:2;555
When should Children < 3 years old have a BP check? • Prematurity, LBW, or NBICU grad. • Chronic illness; especially renal, cardiac, neurologic or endocrine. • Treatment with drugs known to raise BP. • Systemic conditions associated with hypertension (Neurofibromatosis, Tuberous Sclerosis, Hyperthyroid, etc). PEDIATRICS 2004, 114:2;555
Measuring BP in Children • Choose appropriate cuff for body size (not just age). • Child should be quiet and calm for 3-5 minutes prior to measurement. • Measures taken when child is moving or obviously anxious are suspect. • Cuff or stethoscope bell should be at heart level. • Record BP 2-3 times and take the average for the best estimate. • Normal values are based on auscultative measures. • If possible, confirm elevated BP obtained by machine with manual measure.
Problems with Traditional Child BP Cuff Sizing Prineas J, et al. 2007, Blood Press Monit 12:75–80 • Mid Arm Circumference (MAC) measured in > 5000 children in the 1999-20004 NHANES increased compared to 1988-1994 survey. • In children 7-12 years • 40% need a adult cuff • In children aged 13-17 years • 52% of boys and 42% of girls need an adult cuff. • The need for a large adult cuff increased 6 fold in boys and 2 fold in girls from the 1994 to 2004 survey.
Measuring the BP: Determining proper cuff size by patient arm size The cuff bladder width should be 40% of the circumference of the arm measured at mid arm. www.uptodate.com
Measuring the BP: Determining proper cuff size • The cuff bladder length should cover 80% to 100% of the circumference of the arm.
Auscultative BP Measurement • Blood pressure should be measured with cubital fossa at heart level. • The arm should be supported. • The stethoscope bell is placed over the brachial artery pulse, proximal and medial to the cubital fossa, below the bottom edge of the cuff. • If the leg is used in children, the same size and position criteria apply.
Confirming High BPs • To confirm HTN, BP should be measured in both arms and in one leg. • Normally, BP is 10 to 20 mm Hg higher in the legs than the arms. • If the leg BP is lower than the arm BP or if femoral pulses are weak or absent, coarctation of the aorta may be present. • Obesity alone is an insufficient explanation for diminished femoral pulses in the presence of high BP.
Automated BP machines Common in many Hospital and office settings Measure mean arterial pressure (MAP) and calculate SBP and DBP. Concerns: • The algorithms used by companies are proprietary and not standardized. • These machines must be calibrated regularly • High BPs with machines should be confirmed with manual BP.
New 2004 BP tables • Includes 50%, 90%, in addition to 95% and 99% BP data. • BP grouped by age, gender and height % • Height data based on new CDC growth charts www.cdc.gov/growthcharts PEDIATRICS 2004, 114:2;555
Using BP Tables Example 1: Age = 5 years • BP 107/65 mmHg • Gender = Male • Height = 105 cm (25%)
Using the New BP Tables 5 y.o. Boy BP 107/65 Height: 25% BP% mmHg 95% 110/71 99% 118/79 99%+5 123/84 Dx: No HTN
Infants: Use Systolic BP 90% SBP95%SBP < 7 days 90 mmHg 95 mmHg 8-30 days 100 105 1-12 months 105 110 *Task Force on Blood Pressure Control in Children. Report of the Second Task Force on Blood Pressure Control in Children—1987. Pediatrics.1987;79:1–25(PR)
Hypertension Staging SBP or DBP (x 3) Classification < 90% Normal BP 90 to < 95% Pre-HTN >120/80 mmHg in adolescent 95 to 99% + 5 mmHg* Stage 1 HTN > 99% + 5 mmHg* Stage 2 HTN *The difference between 95% and 99% is only 7-10 mmHg. The 4th report recommends a little leeway before starting evaluation or meds.
Hypertension Staging. Why? • Guides the pace of diagnostic and therapeutic approach. • Helps determine: • Who needs Observation? • Who needs Evaluation? • Who needs Therapy?
Clinical Evaluation of Child with Pre-HTN(90% to <95% or >120/80 in adolescent) • Complete H & P • If History indicates a risk: • Sleep study or Drug screen • If co-morbid risk factors present* • Retinal exam • Echocardiogram • Fasting lipids and glucose *Diabetes or Chronic kidney dis., Fmhx of HTN or CVD, or Diabetes
Clinical Evaluation of Stage 1 and 2 HTN • In all kids rule out common secondary causes of HTN: • Renal: Ultrasound, BUN, Creatinine, UA, Renin • Cardiac: Femoral pulses, CBC, Echocardiogram • Endocrine: Electrolytes • In all kids screen for metabolic syndrome and CVD risk: • Fasting lipids, triglycerides and glucose • In selected patients look for rare causes of HTN • Severe HTN (>>99%), very young (<10 years) or patients with targeted symptoms to suggest a rare cause: • Malignancy, neurologic, drugs, pregnancy, Reno-vascular disease, Thyroid disease, etc.
Clinical Evaluation of HTN 4. Consider Essential HTN if • Child is > 14 years with mild-moderate BP elevation • Family history of HTN • Elevated BMI • 24 hour Ambulatory BP monitoring (ABPM) is good first step in these patients. • If elevated BMI coexists, assess co-morbid risks • Fasting Glucose, lipids and insulin *Flynn J, et al. Pediatrics 2002;110:89–9;
24 hour ABPM Records BP q 15-30 minutes for 24 hrs • Diagnosis of White coat HTN or Pre-HTN. • Diagnosis of Masked HTN. • Tracking kids with Pre-HTN. • Adjusting medication dosing.
Which kids with high BP should you treat? • Treat everyone with Therapeutic Lifestyle Changes (TLC) • Healthy diet, weight loss if indicated, exercise. • Treat with medication if the child has: • Secondary HTN or Stage 2 HTN • Stage 1 or Pre-HTN if: • Their is co-existing co-morbid disease*. • Stage 1 HTN with evidence of end organ effect • Symptomatic HTN, LVH, Hypertensive Retinal changes • Stage 1 HTN with failure to improve after of 6-12 mo. trial of TLCs • BP goal: < 90% , < 75% if co-morbid disease* *Co-morbidity: Renal or Cardiac disease or diabetes mellitus
Therapeutic Lifestyle Changes • If obese, make a goal to gradually get BMI < 85% • Set realistic, achievable, pace of weight loss. • Exercise: • Moderate to vigorous aerobic activity for 40 min, 3-5 days/week • Avoid sedentary activity > 2 hrs / day • Diet: • Avoid sugary foods/drinks and saturated fats. Less salt. • Eat fruit, vegetables, lean meats and whole grains. • 50/50 plate • Involve the whole family as partners. • Develop a health promoting reward system. • Set achievable goals!
Does obesity intervention really help with BP reduction or CV risk factors in Children? 2 yr Obesity intervention study (N=240) • 1yr intervention program of physical exercise, nutrition education, and behavior therapy, followed by 1 year of observation. • 174 children finished study • 72% achieved a reduction in BMI • In those who reduced their BMI: • Systolic and Diastolic BP was reduced • Lipid panel improved • Fasting Insulin and glucose improved • Improvements were sustained at 2 year follow-up. Am J Clin Nutr 2006;84:490–6.
Pre-Hypertension BP at 90-95% for age, height and gender. • Many have other risk factors for CV Disease. • Many of these kids progress to stage 1 HTN. • 67% progress within 3 years*. • If co-morbid disease present (renal, cardiac, diabetes) treat with medications (goal BP < 75%). • Otherwise follow yearly, encourage TLC. *Acta Paediatr 1992 Mar;81(3):244-6
White coat HTN • Elevated BP at clinical setting, but normal BP at home or on 24 hr ABPM. • Many of these kids have BP in pre-hypertensive range or risk factors for HTN or CV disease. • They need ongoing follow-up like pre-HTN • If random BP is always high, a yearly ABPM is helpful.
Sports Participation for Hypertensive Children • Stage 1 HTN (95-99%) If no end organ damage and no coexisting heart disease • May play all sports, monitor BP every 2 months. 2) Stage 2 HTN (>99%+5) • Restricted from competitive sports and highly static (isometric) activities especially static sports, until BP controlled and they have no evidence of end organ damage. • Since cardiovascular conditioning may be less strenuous than competitive athletics, complete restriction of exercise may not be necessary for those with severe hypertension. 3) HTN and CV disease • Restricted participation dependent on nature of CV disease. AAP Committe on Sports Medicine and Fitness, 1995