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A major theme of this year’s Annual Scientific Sessions of the American Society of Hypertension deals with hypertension and obesity in adolescents. There has been a tendency to think of hypertension as a condition that increases with age, so most attention has been directed at patients in their 50s, 60s, or older. To many clinicians, high blood pressure (BP) in young people is something that should be evaluated for an underlying secondary form of hypertension rather than accepted as an adult condition.

But the reality is otherwise. Essential hypertension in children and adolescents is being diagnosed with increasing frequency, perhaps driven—although not entirely—by the rapidly increasing prevalence of obesity in young people.

So this is a good time for the Society to turn its attention to this troubling matter. And, in keeping with this commitment, the current issue of the Journal, which is being published to coincide with the Society’s meeting, contains key articles that we believe provide highly valuable information on the subject.

Important Recommendations

  1. Top of page
  2. Important Recommendations
  3. Early Cardiovascular Changes
  4. References

The editors of the Journal are delighted that two of the nation’s leading experts in pediatric hypertension, Dr Joseph Flynn and Dr Bonita Falkner, have provided us with such an authoritative and readable review on the broad subject of hypertension in adolescents.1 For clinicians who see young patients, this article can serve as a highly effective guideline on how to evaluate and treat this condition.

The authors start by giving a concise background to the broad problem of increasing rates of hypertension that appear to parallel the occurrence of obesity in adolescents. Obviously, the presence of overweight status does not necessarily explain hypertension in this age group, and so it remains necessary to consider possible secondary causes for hypertension. Still, much of the time, the clinician’s major task will be to meet the challenge of incentivizing young people to lose weight.

For physicians accustomed to dealing with adult patients, the basis for diagnosing hypertension in children and adolescents at first seems rather complicated. The diagnosis is based on demonstrating that an adolescent’s BP falls above the 95th percentile of BP values adjusted for age, sex, and height. Inevitably, therefore, the prevalence of hypertension in this age group will be rather low when using this method. This, at first, is a challenging concept, for we know that at least one third of adults in this country are hypertensive. And since we also believe that BPs tend to track throughout life, such that children with relatively high BPs become adults with relatively high BPs,2,3 shouldn’t the prevalence of hypertension in the young reflect this relationship?

Drs Flynn and Falkner discuss this dilemma, pointing out—among other things—that the high lability of BP in young patients could lead to a lot of unwarranted diagnoses of hypertension. As well, labeling a child as “hypertensive” potentially creates social, emotional, and even financial implications that can go beyond the condition itself.

The question of prehypertension in adolescents, which is diagnosed by the same criteria (>120/80 mm Hg) as in adults, is also challenging. The usual recommendation for such patients is to adopt appropriate lifestyle changes that include, as Drs Flynn and Falkner emphasize, reducing salt in the diet. This is good advice. Diets that are rich in fresh produce and have appropriate levels of sodium have been shown to effectively reduce BP in children.4 Getting this accomplished, though, may need action at a societal level. Among such strategies is the reduction of salt content in marketed foods in a steady incremental fashion over a period of years. There is encouraging evidence that this important public heath effort is starting to take hold.

Early Cardiovascular Changes

  1. Top of page
  2. Important Recommendations
  3. Early Cardiovascular Changes
  4. References

Several years ago, Graettinger and colleagues5 reported that adolescent students whose parents were hypertensive had echocardiographic evidence of greater left ventricular muscle mass than their fellow students. Those authors also noted that body weight, perhaps even more so than BP, was the strongest predictor of left ventricular hypertrophy at this young age. In this issue of the Journal, Dr Elaine Urbina and colleagues6 provide compelling evidence of early cardiovascular changes in young people with prehypertension. They have studied a group of young people, some with hypertension or prehypertension or with type 2 diabetes, and report evidence for early target organ damage. For instance, increased BP was shown to be associated with increases in left ventricular mass, arterial stiffness, and carotid intima-medial thickness.

It is already known that these signs of cardiovascular change can be predictive of major cardiovascular events, so these provocative findings indicate that there might be an important subgroup of young people with prehypertension who are at increased risk of premature cardiovascular complications.

This work by Dr Urbina and her associates raises important questions. Can we be satisfied simply to assign a diagnosis of prehypertension or hypertension in a young person, or should we go searching for evidence of target organ involvement that would prompt more aggressive management strategies?

Type 1 diabetes is associated with an increased risk of cardiovascular events, certainly at an earlier age than in people without diabetes.7 In the article by Dr Krishnan and colleagues8 it is reported, however, that the presence of type 1 diabetes does not appear to increase cardiac risk factors beyond the changes already produced by increased weight. This is an interesting observation, for with type 2 diabetes, which sadly is now becoming so common in adolescents, we would normally expect a greater association with changes in BP and lipids. Despite the finding by Dr Krishnan and colleagues, it would be prudent to be alerted to the need for managing cardiovascular risk factors in young people who have excess weight in addition to their type 1 diabetes.

Finally, Dr Tulio de Mello and associates9 have studied the possible benefits of aerobic training, with or without additional resistance training, in adolescents with the metabolic syndrome. The good news is that all these young people who undertook training programs experienced beneficial effects on their weight, body mass index, and visceral fat. Interestingly, augmenting aerobic training with resistance training provided further reductions in cholesterol and glucose levels, and even had the effect of increasing adiponectin concentrations (which theoretically should provide anti-inflammatory benefits) and reducing indices of insulin resistance. Exercise represents a strategy that, of all the lifestyle modifications, may be the most appealing to adolescent patients. The Journal of Clinical Hypertension is pleased to report these early but potentially important findings.

References

  1. Top of page
  2. Important Recommendations
  3. Early Cardiovascular Changes
  4. References
  • 1
    Flynn JT, Falkner BE. Obesity hypertension in adolescents: epidemiology, evaluation and management [published online ahead of print May April 2011]. J Clin Hypertens (Greenwich). 323331.
  • 2
    Bao W, Threefoot SA, Srinivasan SR, et al. Essential hypertension predicted by tracking of elevated blood pressure from childhood to adulthood: the Bogalusa Heart Study. Am J Hypertens. 1995;8:657665.
  • 3
    Gidding SS. Measuring children’s blood pressure matters. Circulation. 2008;117:31633164.
  • 4
    Couch SC, Saelens BE, Levin L, et al. The efficacy of a clinic-based behavioral nutrition intervention emphasizing a DASH-type diet for adolescents with elevated blood pressure. J Pediatr. 2008;152:494501.
  • 5
    Graettinger WF, Cheung DE, Lipson JL, et al. Correlates of cardiac structure and function in normotensive adolescents. Am J Hypertens. 1988;1:184186.
  • 6
    Urbina EM, Khoury PR, McCoy C, et al. Cardiac and vascular consequences of pre-hypertension in youth [published online ahead of print April 2011]. J Clin Hypertens (Greenwich). 332342.
  • 7
    Krolewski AS, Kosinski EJ, Warram JH, et al. Magnitude and determinants of coronary artery disease in juvenile-onset, insulin-dependent diabetes mellitus. Am J Cardiol. 1987;59:750755.
  • 8
    Krishnan S, Copeland KC, Bright B, et al. Impact of type 1 diabetes and body weight status on cardiovascular risk factors in adolescent children [published online ahead of print December 10, 2010]. J Clin Hypertens (Greenwich). 351356.
  • 9
    Túlio de Mello M, de Piano A, Carnier J, et al. Long-term effects of aerobic plus resistance training on the metabolic syndrome and adiponectinemia in obese adolescents [published online ahead of print November 8, 2010]. J Clin Hypertens (Greenwich). 343350.