Pediatric Hypertension

1. Pediatric Hypertension Matthew Grinsell, MD, PhD

2. Disclosure • I have no financial disclosures.

3. Outline • Focus will be outpatient HTN in children and adolescents. • Definition of HTN in children and adolescents. • Blood pressure measurement. • Epidemiology. • Etiology. • Diagnosis. • Evaluation. • Therapy. • Monitoring.

4. Definition of Hypertension

5. HTN-Adult vs. Pediatrics • HTN is defined as the BP above which there is increased risk of morbidity and mortality. • In adults, HTN is relatively clearly defined by outcome data such as: • Mortality. • CVD. • Stroke. • This is why 120/80 is considered pre-HTN. • 140/90 is HTN.

6. Hypertension-Adult vs. Pediatrics • In children and teens, there are very limited outcomes data, so we use a statistical standard defined by BP tables. • Use of blood pressure tables available from: (www.nhlbi.nih.gov/ guidelines/hypertension/childtbl. pdf • Easy way is to type in “pediatric blood pressure tables” in Google.

7. Pediatric BP Tables We will come back to BP tables shortly (www.nhlbi.nih.gov/ guidelines/hypertension/childtbl. pdf

8. Pediatric HTN • Approximately 3-5% of children HTN and that number is likely increasing. • Hypertension is an average SBP and/or diastolic BP (DBP) that is above the 95th percentile for gender, age, and height on three separate occasions. • Systolic and diastolic are of equal importance. • Regardless of the charted 95% BP for age, gender and height, any pediatric patient with BP above 120/80 mm Hg should be considered prehypertensive and evaluated. Pediatrics 2004;114;555

9. HTN Classification in Children and Adolescents Pediatrics 2004;114;555

10. HTN as a Global Health Issue • HTN was the leading attributable cause of death worldwide in 2004 according to the WHO. • In the United States: • 33% of adults 20 years and older had HTN. • HTN in 2007 was the 13th leading cause of death in the US but is a known risk factor or complication of: • #1 Heart disease • #4 Cerebrovascular diseases/Stroke • #7 Diabetes Mellitus • #9 Kidney disease http://www.who.int/healthinfo/global_burden_disease/global_health_risks/en/index.html http://www.cdc.gov/nchs/fastats/lcod.htm

11. HTN as a Pediatric Health Issue • Patients 10-17 years with elevated SBP on admission to hospital in Reykjavik, Iceland, 1950 to 1967. • 126 individuals (54 men) invited for a follow-up in 2008. • Median BP was 125/80 mmHg 1950-1967 • Median BP 133/75 mmHg 2008 • 49/126 had been diagnosed with HTN (23 men) • 12/126 with coronary artery disease (10 men). • Significant correlation (P = 0.03) between the diagnosis of coronary artery disease in adulthood and elevated childhood systolic BP. PediatrNephrol. 2010 Feb;25(2):323-8

12. HTN and Early Atherosclerosis • Pathobiological Determinants of Atherosclerosis in Youth (PDAY). • Autopsies of 629 males age 15-34 who died of trauma. • Normal cholesterol (< 160) and HDL (> 35). • Hypertensive males had more raised aortic plaque lesions than normotensive males. • Obese males had more extensive fatty streaks in the abdominal aorta and the left anterior descending coronary artery. • HTN may impact the extent and severity of coronary artery disease and aortic atherosclerosis in adolescents and young adults. JAMA. 1990 Dec 19;264(23):3018-24 Circulation. 2001 Mar 20;103(11):1546-50.

13. Measurement of Blood Pressure

14. BP Measurement • Who should have BP measured? • Selection of correct cuff size. • Oscillometry vs. auscultation. • Confirmation of elevated blood pressures.

15. Who Should Have BP Measured? • AAP recommends: • Children 3 years and older who are seen in a medical setting should have their BP measured at least once during that visit. • Children under 3 years should have BP measured if they have certain risk factors. Pediatrics 2004;114;555

16. When to Measure BP in Children < 3 yrs

17. When to Measure BP in Children < 3 yrs

18. When to Measure BP in Children < 3 yrs

19. When to Measure BP in Children < 3 yrs

20. BP-Measurement • Obtain patient’s height percentile. • Select cuff appropriate for child’s size. • Appropriate size cuff : bladder width = 40% upper arm circumference. • Or, bladder length should encircle 80-100% upper arm circumference. • A cuff too small may lead to high BP values. • When in doubt use a larger cuff.

21. Pediatric Nephrology Clinic Cuffs

22. BP-Measurement • No stimulant drugs or foods for 24 hours. • Sitting quietly for 5 minutes with back supported, and feet on the floor. • Right arm supported with cuff placed at the level of the heart. • Right arm is preferred because standardized measurements are based on right arm BP. • Stethoscope placed over the brachial artery below the bottom edge of the cuff. • Inflate cuff to 99% + 20 initially (in kids 140-150 works). • SBP = 1stKorotkoff sound “opening snap”. • DBP = 5thKorotkoff sound or disappearance of sounds.

23. BP-Measurement

24. BP-Measurement • Once BP is obtained, plot on BP charts as a function of: • Gender. • Age. • Height percentile. • For example: A 7y/o female who is 125 cm tall (75%). • Measured BP is 105/65.

25. Use of Pediatric Tables • A 7y/o female who is 125 cm tall. • Measured BP is 105/65. (www.nhlbi.nih.gov/ guidelines/hypertension/childtbl. pdf

26. Use of Pediatric Tables • A 7y/o female who is 125 cm tall. • Measured BP is 105/65. (www.nhlbi.nih.gov/ guidelines/hypertension/childtbl. pdf

27. Use of Pediatric Tables • A 7y/o female who is 125 cm tall. • Measured BP is 105/65. (www.nhlbi.nih.gov/ guidelines/hypertension/childtbl. pdf

28. Use of Pediatric Tables • A 7y/o female who is 125 cm tall. • Measured BP is 105/65. (www.nhlbi.nih.gov/ guidelines/hypertension/childtbl. pdf

29. Questions About BP Measurement • Is there a significant difference between auscultation and oscillometric (Automated) measurements? • Do stimulants used for ADD/ADHD significantly affect BP in children?

30. Auscultation vsOscillometry • Ausculatation is the preferred method of BP measurement as tables are based on auscultation. • Oscillometricmeasurement • Reduces inter-observer variability. • Highly reproducible. • Oscillometric devices work by measuring MAP and using an algorithm to calculate SBP/DBP. • Proprietary information. • Makes standardization impossible.

31. Auscultation vsOscillometry • 2001: Auscultation and oscillometric BP measurements on 7,208 school children age 5-17 years in San Antonio, TX. • Dinamap 8100 • Cross-over design: Children randomized to either auscultation or Dinamap as first measurement technique, then measured with alternate technique. • On average, Oscillometry had a 10 mmHg higher SBP and 4.7 mmHg DBP. • The difference was more pronounced in younger children. Arch PediatrAdolesc Med/Vol 155,Jan 2001.

32. Stimulants and BP • Placebo controlled studies have found small but statistically significant increases in BP with stimulants. • Generally 2-4 mmHg for SBP. • 1-3 mmHg for DBP. • The clinical significance of these findings remains unclear. • One study did find a sustained BP > 95% in 2.5% of subjects following discontinuation of stimulants. • On a population level, modest BP effect, but certain individuals may be sensitive. • If needed, continue stimulants. Child AdolescPsychiatrClin N Am. 2009 April 1 Biol Psychiatry 2007;61:706–712

33. Epidemiology of Hypertension

34. HTN-Epidemiology • Pre-HTN and HTN have been increasing in children and adolescents over last 2-3 decades. • How much?

35. Pre-HTN Increase 8-17 y/o • % Children with Pre-HTN (BP 90%-95%) Between the 2 time periods, Pre-HTN increased in all groups. Adapted from Circulation 2007, 116:1488-1496

36. HTN-Increase Over Time • The prevalence HTN in 8-17 year olds in the US has increased over the last 20-25 years. % Children with HTN (BP > 95%) 2012? Adapted from Circulation 2007, 116:1488-1496

37. HTN in the Pediatric Age Group • Between 1988-1994 and 1999-2002 in 8-17 y/o patinets: • Pre-HTN and HTN increased significantly in Hispanics, Caucasians and African-Americans of both genders. • So what has caused the increase in adolescent HTN? • Likely mulitfactorial. • However, I would like to go on a brief tangent……

38. Obesity-BMI and HTN in Children • As BMI increases, so does HTN. • So has pediatric BMI been increasing over time? Hypertension 2002, 40:441-447

39. Yes, Obesity and BMI are Rising There are some interesting if not outright causative chronologic associations with rising childhood BMI and obesity. Adapted from: http://www.cdc.gov/obesity/childhood/prevalence.html.

40. Yes, Obesity and BMI are Rising 1971: Legislation signed allowing use of high fructose corn syrup in lieu of cane sugar. Adapted from: http://www.cdc.gov/obesity/childhood/prevalence.html.

41. Yes, Obesity and BMI are Rising 1971: Legislation signed allowing use of high fructose corn syrup in lieu of cane sugar. 1976: High Fructose corn syrup enters widespread use. Adapted from: http://www.cdc.gov/obesity/childhood/prevalence.html.

42. High Fructose Corn Syrup Use of High Fructose Corn Syrup

43. Yes, Obesity and BMI are Rising • 1980’s: • Anything else? 1971: Legislation signed allowing use of high fructose corn syrup in lieu of cane sugar. 1976: High Fructose corn syrup enters widespread use. Adapted from: http://www.cdc.gov/obesity/childhood/prevalence.html.

44. 1985 and the Link to Obesity • Boris Becker becomes the youngest Wimbledon champion at 17 years old. • Television series The Dukes of Hazzard goes off the air. • Microsoft Corporation releases the first version of Windows, Windows 1.0. • These are all exciting, but likely did not contribute to obesity. • Had to be something else………

45. Obesity and Nintendo Not the only cause, but certainly a part of the bigger picture.

46. Obesity and HTN • Obesity and Hypertension are linked. • These health problems do track into adulthood. • Bogalusa Heart Study: • Overweight children were 4.5 times and 2.4 times as likely to have elevated SBP and DBP, respectively. • Possibility related to: • Sympathetic overactivity. • Insulin resistance. • Altered vascular structure. • Increased salt sensitivity.

47. Etiology of HTN

48. Etiology of HTN in Pediatrics • Primary (essential) - no identifiable underlying cause. This has increased with obesity epidemic. • Diagnosis of exclusion. • Thought to be a complex interplay of environmental and genetic factors.

49. Etiology of HTN in Pediatrics • Secondary - Identifiable cause, potentially curable. Can be placed in a few broad categories. • Renal parenchymal diseases. (most common) • Aortic coarctation. • Renovascular: FMD. • Single Gene Disorders: Liddles, Gordons. • Endocrine disorders. • Malignancies: pheo. neuroblastoma • Miscellaneous disorders: Ingestions, Williams syndrome.

50. Secondary HTN-Etiology • University of Texas Southwestern MC, 1994. • 132 children 0-18 years with sustained HTN. • 89 (67%) had secondary HTN due to kidney or renovascular disease. • Most common causes of secondary HTN were: • Glomerulonephritis. • Reflux nephropathy. • Renal Vein Thrombosis most common in neonatal period. PediatrNephrol 1994; 8:186.