Acta Paediatr 81:244-6. 1992
A single pediatric center experience with 1025 children with hypertension T Wyszynska, E Cichocka, A Wieteska-Klimczak, K Jobs and P Januszewicz Deparlmenr of Nephrology. Child Health Cenler-Meniorial Hospiral, Warsaw, Poland
Wyszynska T, Cichocka E, Wieteska-Klimczak A, Jobs K, Januszewicz P. A single pediatric center experiencewith 1025 children with hypertension.Acta Pzediatr 1992;81:244-6. Stockholm.ISSN 0803-
5253
Between January 1982 and December 1989 1025 patients aged between one month and 18 years with increased blood pressure were referred for evaluation. Borderline hypertension was found in 389 children; 636 had sustained significant hypertension. In 35 1 patients, hypertension was secondary to a known disease. Renal parenchymal diseases were present in 68%)of patients while renovascular and endocrine disorders were found in 10%)and 1 1 %, respectively. Of the 258 children aged less than 15 years, all but six children had known causes of hypertension, while 75% of adolescents had essential hypertension. In the 389 children with borderline hypertension, 65Y0 developed fixed hypertension over a period of 2-3 years. 0 Adolescent borderline hjjpertension, blood pressure, reflux nephropathy, renal artery stenosis, renal parenchymal diseases T Wyszynska, Department of Nephrology and Hypertension Clinic, Child Health Center-Memorial Hospital, Al. Dzieci Polskich 20, 04-736 Warsaw. Poland
Concern about adult hypertension and its possible origins earlier in life have resulted in consideration of the significance of blood pressure measurements in childhood. The “Report of the Second Task Force on Blood Pressure Control in Children-1987’’ (1) clearly delineates hypertension as a risk factor in the pediatric age group. Abundant data have been presented in support of many antecedents of adult primary hypertension having their origins during the childhood years. In this report, we analyzed the incidence of various types of hypertension in 1025 children referred to our department. The study had three aims: to establish the causes of secondary hypertension in childhood; to ascertain the incidence of essential hypertension among hypertensive adolescents; and to determine the natural history of borderline hypertension in children.
Patients and methods The records of 1025 children, aged one month to 18 years, consecutively referred for investigation of hypertension, from 1982 to 1989, were reviewed. Blood pressures were taken with a standard mercury-gravity sphygmomanometer with individually chosen cuff sizes. Blood pressure standards, definitions and classification of hypertension by age group used in this study were taken from the Report of the Second Task Force on Blood Pressure Control in Children-I987 (1). Children with borderline hypertension were defined as those who had high normal blood pressure (90-95%) on at least three outpatient visits and had normal blood pressure
without treatment during physical and emotional rest at home or in the hospital. Children whose blood pressures exceeded the 95Y0 confidence limits for age were diagnosed as having high blood pressure.
Results The classification of hypertension in the children according to the Report of the Second Task Force on Blood Pressure Control in Children-I987 is presented in Table 1; the causes of secondary hypertension in various age groups are shown in Table 2. Among patients with significant secondary hypertension, 74%0were aged less than 14 years. Renal parenchymal diseases were responsible for hypertension in 68% of 351 youths. Coarse renal scarring was detected in 50% of patients in this group, hydronephrosis in 9.2%, renal polycystic disease in 7.1 Yo, chronic glomerulonephritis in 2O.6%, and 4.7% were recovering from acute renal failure due to hemolytic uremic syndrome. Among 116 children with scarred kidneys, 99 (28 boys and 71 girls) had reflux nephropathy; 72 had normal plasma creatinine concentrations. In 75 children, reflux nephropathy was present when hypertension was detected, while in 24 reflux nephropathy was diagnosed and had been successfully treated in the past. Bilateral scars were found in 82% of cases. During the course of reflux nephropathy, increased blood pressure was found in 67% of patients aged between five and 15 years and in 20% of patients older than 15 years. Significant hypertension was found in 41 % of children, severe hypertension in 38% and malignant hypertension in 20%0.
Hypertension in a pediatric cenier
ACTA PRDIATR 81 (1992)
Table I.’Classification of hypertension in children according to Report of the Second Task Force on Blood Pressure Control in Children1987 (I).
Diagnosis ~
Number of cases (%)*
~~
Borderline hypertension Age 14- I8 years Significant and severe essential hypertension Age < 14 years Age 15- 18 years Significant and severe secondary hypertension Age < 14 years Age 15-18 years Total
389 (38)
0 285 (27.8) 258 (25.2)) (34.2) 93 (9) 1025 (100)
* Numbers in parentheses are percentages. Renal arterial lesions found in 34 children were characterized as main renal artery stenosis ( 6 0 % ) and segmental branch stenosis (30%), while aneurysms and arteritis were responsible for the remaining cases. In six patients, aged 18 months to six years, the cause of malignant, very high renin hypertension remained unexplained. In three of these patients, blood pressure normalized after two to four years. In this study, in 20% of 14-year-old children with borderline hypertension, blood pressure increased within the first two years of observation (group I) while in 65% of older patients ( 1 5- 18 years) essential hypertension developed (group 11). The prevalence of hypertension in parents was high, 39% and 5 1 %, respectively. In 4.2% of patients with essential hypertension, blood pressure normalized during follow-up.
Discussion The reported incidence of hypertension in pediatric populations varies from approximately 0.6 to 1 1 ‘%I (2-
245
4). The prevalence of childhood hypertension in Poland is 1.04% ( 5 ) . The incidence of secondary hypertension reported in this study is comparable with those reported by others (4,6,7). In our study, reflux nephropathy was the main cause of hypertension in this group. Essential hypertension was diagnosed in 45% of the children studied. This figure, which is higher than that reported by other authors (2,3), can be explained by the fact that 60% of our population were adolescents ( 1 5-1 8 years). In this group 75% had essential hypertension. Renal, endocrine and cardiac causes of hypertension were excluded in this group on the basis of the algorithm for diagnosing children with hypertension. Because these children had a combination of a normal renoscintigram, unremarkable clinical course and good control of hypertension with monotherapy (nifedipine, prazosin or acebutolol), a diagnosis of renovascular hypertension seemed unlikely. In adolescents with a persistent diagnostic or therapeutic problem, renal arteriography was always performed. It should be stressed that in all but six patients aged less than 14 years, we were able to identify the cause of sustained hypertension. Kidney diseases were the most frequent causes of hypertension in this group (68%). This finding is in sharp contrast with data reported by Ogborn (8). In the six children referred to above, who were aged less than six years, the cause of malignant, very high renin hypertension remained unexplained despite an extensive diagnostic evaluation. The natural history of their disease with disappearance of hypertension after two to four years was very similar to those described by New et al. (9) as having transient “bilateral endocrine dysfunction of the kidney”. The outcome of borderline hypertension in adolescents is not known. In some, borderline hypertension is transitory while in others it constitutes the early phase of sustained essential hypertension of adulthood. Our data
Table 2. Causes of secondary hypertension in 351 children.
Age (years) at diagnosis and number of cases Condition Renal parenchymal diseases Renovascular Hyperthyroidism Polycystic ovary syndrome Pheochromocytoma Adrenocortical hyperfunction Turner’s syndrome Coarctation CNS disorders Hypercalcemia Respiratory distress syndrome Unknown Total
0-5
74 (21.0)* 8 (2.3)
I (0.3) I (0.3) 7 (2) 6 (1.7) 2 (0.6) 6(1.7) 105 (29.9)
6-14
15-18
Total (‘%I)
I14 (32.5) 1 I (3.1) 7 (2) 3 (0.9) 4 (1.1) 1 (0.3) I (0.3) 5 (1.4) 4(1.1) 3 (0.9)
50 (14.2) 15 (4.3) I I (3.1) 4(1.1) I (0.3) 4(1.1) 3 (0.9) 3 (0.9) 2 (0.6)
238 (67.7) 34 (9.7) 18 (5.1) 7 (2) 6(1.7) 6 (1.7) 4 (1.2) 8 (2.3)d 13 (3.7) 9 (2.6) 2 (0.6) 6 (1.7)
153 (43.6)
93 (26.5)
351 (100)
During the same time period 246 patients aged one week to 18 years were admitted and subsequently treated by the Cardiology Department because of this malformation. * Numbers in parentheses are percentages.
246
T Wvszyisku e / ul.
show that the older the child with borderline hypertension the more likely is the onset of fixed hypertension within a few years. As parental hypertension seems to be a major risk factor, its presence should also be taken into account in deciding when to start pharmacological treatment. It is interesting that in 4.2% of patients with essential hypertension, blood pressure normalized in time. In conclusion, our data revealed that hypertension in younger children was usually of secondary origin. Kidney diseases, particularly reflux nephropathy, were the leading causes of sustained hypertension. The majority of adolescents (75%) had essential hypertension. In a significant number of youths with borderline hypertension, blood pressure had a tendency to increase over time. A~knowleJ~emenr.-This work was supported by the Grant CPBR 11.6.11.
References I . Report of Second Task Force on Blood Pressure Control in Children-1987. Pediatrics 1987;79:1-25
A C T A PKDIATR XI (1992)
2. Loggie JMH. Evaluation and management of childhood hypertension. Surg Clin North Am 1985;65:1623-49 3. Rocchini AP. Childhood hypertension: Etiology, diagnosis and treatment. Pediatr Clin North Am 1984;31:1259-73 4. Lieberman E. Clinical assessment of the hypertensive patient. In: Kotchen TA, Kotchen JM eds High Blood Pressure in the Young. Boston: John Wright PSG Inc, 1983:237-48 5 . Wyszynska T, Skibicka-Regulska Z, Frelek M, Cichocka E. The incidence of hypertension in school children. Pediatr Pol 1985;60:189-96 6. Broyer M, Bacri J-L, Ryer P. Renal forms of hypertension in children: report on 238 cases. In: Giovanelli G. New MI, Gorini S eds Hypertension in Children and Adolescents. New York: Raven Press, 198 I :201-8 7. Dillon MJ. Investigation and management of hypertension in children. Pediatr Nephrol 1987;1:59-68 8. Ogborn MR. Investigation of pediatric hypertension. Am J Dis Child 1987; 141:1205-9 9. New ML, Oberfield SE, Levine LS. Hypertension in children. In: Genest J ed Hypertension. New York: McGraw Hill Book Company, 1983353-82 Received July 25, 1990. Accepted May 2, 1991
A single pediatric center experience with 1025 children with hypertension T Wyszynska, E Cichocka, A Wieteska-Klimczak, K Jobs and P Januszewicz Deparlmenr of Nephrology. Child Health Cenler-Meniorial Hospiral, Warsaw, Poland
Wyszynska T, Cichocka E, Wieteska-Klimczak A, Jobs K, Januszewicz P. A single pediatric center experiencewith 1025 children with hypertension.Acta Pzediatr 1992;81:244-6. Stockholm.ISSN 0803-
5253
Between January 1982 and December 1989 1025 patients aged between one month and 18 years with increased blood pressure were referred for evaluation. Borderline hypertension was found in 389 children; 636 had sustained significant hypertension. In 35 1 patients, hypertension was secondary to a known disease. Renal parenchymal diseases were present in 68%)of patients while renovascular and endocrine disorders were found in 10%)and 1 1 %, respectively. Of the 258 children aged less than 15 years, all but six children had known causes of hypertension, while 75% of adolescents had essential hypertension. In the 389 children with borderline hypertension, 65Y0 developed fixed hypertension over a period of 2-3 years. 0 Adolescent borderline hjjpertension, blood pressure, reflux nephropathy, renal artery stenosis, renal parenchymal diseases T Wyszynska, Department of Nephrology and Hypertension Clinic, Child Health Center-Memorial Hospital, Al. Dzieci Polskich 20, 04-736 Warsaw. Poland
Concern about adult hypertension and its possible origins earlier in life have resulted in consideration of the significance of blood pressure measurements in childhood. The “Report of the Second Task Force on Blood Pressure Control in Children-1987’’ (1) clearly delineates hypertension as a risk factor in the pediatric age group. Abundant data have been presented in support of many antecedents of adult primary hypertension having their origins during the childhood years. In this report, we analyzed the incidence of various types of hypertension in 1025 children referred to our department. The study had three aims: to establish the causes of secondary hypertension in childhood; to ascertain the incidence of essential hypertension among hypertensive adolescents; and to determine the natural history of borderline hypertension in children.
Patients and methods The records of 1025 children, aged one month to 18 years, consecutively referred for investigation of hypertension, from 1982 to 1989, were reviewed. Blood pressures were taken with a standard mercury-gravity sphygmomanometer with individually chosen cuff sizes. Blood pressure standards, definitions and classification of hypertension by age group used in this study were taken from the Report of the Second Task Force on Blood Pressure Control in Children-I987 (1). Children with borderline hypertension were defined as those who had high normal blood pressure (90-95%) on at least three outpatient visits and had normal blood pressure
without treatment during physical and emotional rest at home or in the hospital. Children whose blood pressures exceeded the 95Y0 confidence limits for age were diagnosed as having high blood pressure.
Results The classification of hypertension in the children according to the Report of the Second Task Force on Blood Pressure Control in Children-I987 is presented in Table 1; the causes of secondary hypertension in various age groups are shown in Table 2. Among patients with significant secondary hypertension, 74%0were aged less than 14 years. Renal parenchymal diseases were responsible for hypertension in 68% of 351 youths. Coarse renal scarring was detected in 50% of patients in this group, hydronephrosis in 9.2%, renal polycystic disease in 7.1 Yo, chronic glomerulonephritis in 2O.6%, and 4.7% were recovering from acute renal failure due to hemolytic uremic syndrome. Among 116 children with scarred kidneys, 99 (28 boys and 71 girls) had reflux nephropathy; 72 had normal plasma creatinine concentrations. In 75 children, reflux nephropathy was present when hypertension was detected, while in 24 reflux nephropathy was diagnosed and had been successfully treated in the past. Bilateral scars were found in 82% of cases. During the course of reflux nephropathy, increased blood pressure was found in 67% of patients aged between five and 15 years and in 20% of patients older than 15 years. Significant hypertension was found in 41 % of children, severe hypertension in 38% and malignant hypertension in 20%0.
Hypertension in a pediatric cenier
ACTA PRDIATR 81 (1992)
Table I.’Classification of hypertension in children according to Report of the Second Task Force on Blood Pressure Control in Children1987 (I).
Diagnosis ~
Number of cases (%)*
~~
Borderline hypertension Age 14- I8 years Significant and severe essential hypertension Age < 14 years Age 15- 18 years Significant and severe secondary hypertension Age < 14 years Age 15-18 years Total
389 (38)
0 285 (27.8) 258 (25.2)) (34.2) 93 (9) 1025 (100)
* Numbers in parentheses are percentages. Renal arterial lesions found in 34 children were characterized as main renal artery stenosis ( 6 0 % ) and segmental branch stenosis (30%), while aneurysms and arteritis were responsible for the remaining cases. In six patients, aged 18 months to six years, the cause of malignant, very high renin hypertension remained unexplained. In three of these patients, blood pressure normalized after two to four years. In this study, in 20% of 14-year-old children with borderline hypertension, blood pressure increased within the first two years of observation (group I) while in 65% of older patients ( 1 5- 18 years) essential hypertension developed (group 11). The prevalence of hypertension in parents was high, 39% and 5 1 %, respectively. In 4.2% of patients with essential hypertension, blood pressure normalized during follow-up.
Discussion The reported incidence of hypertension in pediatric populations varies from approximately 0.6 to 1 1 ‘%I (2-
245
4). The prevalence of childhood hypertension in Poland is 1.04% ( 5 ) . The incidence of secondary hypertension reported in this study is comparable with those reported by others (4,6,7). In our study, reflux nephropathy was the main cause of hypertension in this group. Essential hypertension was diagnosed in 45% of the children studied. This figure, which is higher than that reported by other authors (2,3), can be explained by the fact that 60% of our population were adolescents ( 1 5-1 8 years). In this group 75% had essential hypertension. Renal, endocrine and cardiac causes of hypertension were excluded in this group on the basis of the algorithm for diagnosing children with hypertension. Because these children had a combination of a normal renoscintigram, unremarkable clinical course and good control of hypertension with monotherapy (nifedipine, prazosin or acebutolol), a diagnosis of renovascular hypertension seemed unlikely. In adolescents with a persistent diagnostic or therapeutic problem, renal arteriography was always performed. It should be stressed that in all but six patients aged less than 14 years, we were able to identify the cause of sustained hypertension. Kidney diseases were the most frequent causes of hypertension in this group (68%). This finding is in sharp contrast with data reported by Ogborn (8). In the six children referred to above, who were aged less than six years, the cause of malignant, very high renin hypertension remained unexplained despite an extensive diagnostic evaluation. The natural history of their disease with disappearance of hypertension after two to four years was very similar to those described by New et al. (9) as having transient “bilateral endocrine dysfunction of the kidney”. The outcome of borderline hypertension in adolescents is not known. In some, borderline hypertension is transitory while in others it constitutes the early phase of sustained essential hypertension of adulthood. Our data
Table 2. Causes of secondary hypertension in 351 children.
Age (years) at diagnosis and number of cases Condition Renal parenchymal diseases Renovascular Hyperthyroidism Polycystic ovary syndrome Pheochromocytoma Adrenocortical hyperfunction Turner’s syndrome Coarctation CNS disorders Hypercalcemia Respiratory distress syndrome Unknown Total
0-5
74 (21.0)* 8 (2.3)
I (0.3) I (0.3) 7 (2) 6 (1.7) 2 (0.6) 6(1.7) 105 (29.9)
6-14
15-18
Total (‘%I)
I14 (32.5) 1 I (3.1) 7 (2) 3 (0.9) 4 (1.1) 1 (0.3) I (0.3) 5 (1.4) 4(1.1) 3 (0.9)
50 (14.2) 15 (4.3) I I (3.1) 4(1.1) I (0.3) 4(1.1) 3 (0.9) 3 (0.9) 2 (0.6)
238 (67.7) 34 (9.7) 18 (5.1) 7 (2) 6(1.7) 6 (1.7) 4 (1.2) 8 (2.3)d 13 (3.7) 9 (2.6) 2 (0.6) 6 (1.7)
153 (43.6)
93 (26.5)
351 (100)
During the same time period 246 patients aged one week to 18 years were admitted and subsequently treated by the Cardiology Department because of this malformation. * Numbers in parentheses are percentages.
246
T Wvszyisku e / ul.
show that the older the child with borderline hypertension the more likely is the onset of fixed hypertension within a few years. As parental hypertension seems to be a major risk factor, its presence should also be taken into account in deciding when to start pharmacological treatment. It is interesting that in 4.2% of patients with essential hypertension, blood pressure normalized in time. In conclusion, our data revealed that hypertension in younger children was usually of secondary origin. Kidney diseases, particularly reflux nephropathy, were the leading causes of sustained hypertension. The majority of adolescents (75%) had essential hypertension. In a significant number of youths with borderline hypertension, blood pressure had a tendency to increase over time. A~knowleJ~emenr.-This work was supported by the Grant CPBR 11.6.11.
References I . Report of Second Task Force on Blood Pressure Control in Children-1987. Pediatrics 1987;79:1-25
A C T A PKDIATR XI (1992)
2. Loggie JMH. Evaluation and management of childhood hypertension. Surg Clin North Am 1985;65:1623-49 3. Rocchini AP. Childhood hypertension: Etiology, diagnosis and treatment. Pediatr Clin North Am 1984;31:1259-73 4. Lieberman E. Clinical assessment of the hypertensive patient. In: Kotchen TA, Kotchen JM eds High Blood Pressure in the Young. Boston: John Wright PSG Inc, 1983:237-48 5 . Wyszynska T, Skibicka-Regulska Z, Frelek M, Cichocka E. The incidence of hypertension in school children. Pediatr Pol 1985;60:189-96 6. Broyer M, Bacri J-L, Ryer P. Renal forms of hypertension in children: report on 238 cases. In: Giovanelli G. New MI, Gorini S eds Hypertension in Children and Adolescents. New York: Raven Press, 198 I :201-8 7. Dillon MJ. Investigation and management of hypertension in children. Pediatr Nephrol 1987;1:59-68 8. Ogborn MR. Investigation of pediatric hypertension. Am J Dis Child 1987; 141:1205-9 9. New ML, Oberfield SE, Levine LS. Hypertension in children. In: Genest J ed Hypertension. New York: McGraw Hill Book Company, 1983353-82 Received July 25, 1990. Accepted May 2, 1991
