The prevalence of obesity is increasing worldwide and affected currently appr. 5-10% children and adolescents in different countries.
I tis well known that increased body weight increases blood pressure and therefore it is not surprising that obese children and adolescence have increased risk of high blood pressure (hypertension). Obese children have about 5times higher risk of having hypertension which is then often called „obesity-related hypertension“ if no other obvious reason for high blood pressure was found. However, it has to be said that most obese children are not hypertensive – „only“ 10-20% of them. Therefore, there must be also other factors that contribute to the blood pressure elevation beyond body weight such as positive family history of hypertension or low birth weight.
In obese children, it is very important to choose the correct arm cuff for the blood pressure measurment. Some children, even prepubertal, will require an adult cuff! To choose the right cuff, we need to measure the arm circumference and then the cuff width should be approx. 40% of the arm circumference. Some children will need arm cuffs even for obese adults!
In the case we have suspition of so-called „white-coat hypertension“ (i.e. elevated blood pressure only in the physicians office but not out-of office) we perform a 24h-ambulatory blood pressure monitoring with special blood pressure devices.
All obese children with repeatedly elevated blood pressure in the physicians office need to be thoroughly investigated for detecting the reason of hypertension and for possible hypertension mediated organ damage such as heart (by ultrasound) or kidney (by blood tests for kidney fiction and urine for proteins). It is also very important to exclude diabetes (by blood glukose test) and elevated blood lipids that are often present in obese children.
The primary treatment of obesity-related hypertension is body weight reduction. This can be achieved by lifestyle changes such as increased physical activity and reduced energy (calory) intake. A diet nurse might be helpful to achieve this task. The whole family of an obese child must adopt the lifestyle changes in the nutrition and lifestyle.
If a hypertensive obese child is able to reduce its body weight the blood pressure usually decrease by a magnitude of 2 mmHg per 1 kilogram body weight reduction. Consequently in some children with obesity-related hypertension hypertemsion will diseappear after successful lifestyle changes.
Unfortunately, most of obese children are not able to reduce their body weight and for those who still suffer from high blood pressure a blood pressure lowering drug therapy is necessary. The metabolic neutral antihypertensive drugs such as angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs) or channel blockers are the drugs of first choice of children with obesity-related hypertension.
For those obese children who progress despite our conservative therapy to morbid obesity with obesity related hypertension a bariatric surgery (reduction of stomach capacity) might be a treatment option.
Tomas Seeman, MD, PhD
Professor of Pediatrics
Department of Pediatrics, Charles University Prague, Czech Republic
