Endocrine causes of hypertension in children

The association between organophosphate insecticides and blood pressure dysregulation: NHANES 2013-2014

BACKGROUND

Organophosphate (OP) insecticides represent one of the largest classes of sprayed insecticides in the U.S., and their use has been associated with various adverse health outcomes, including disorders of blood pressure regulation such as hypertension (HTN).

METHODS

In a study of 935 adults from the NHANES 2013-2014 cycle, we examined the relationship between systolic and diastolic blood pressure changes and urinary concentrations of three OP insecticides metabolites, including 3,5,6-trichloro-2-pyridinol (TCPy), oxypyrimidine, and para-nitrophenol. These metabolites correspond to the parent compounds chlorpyrifos, diazinon, and methyl parathion, respectively. Weighted, multivariable linear regression analysis while adjusting for potential confounders were used to model the relationship between OP metabolites and blood pressure. Weighted, multivariable logistic regression analysis was used to model the odds of HTN for quartile of metabolites.

RESULTS

We observed significant, inverse association between TCPy on systolic blood pressure (β-estimate = -0.16, p < 0.001) and diastolic blood pressure (β-estimate = -0.15, p < 0.001). Analysis with para-nitrophenol revealed a significant, positive association with systolic blood pressure (β-estimate = 0.03, p = 0.02), and an inverse association with diastolic blood pressure (β-estimate = -0.09, p < 0.001). For oxypyrimidine, we observed significant, positive associations between systolic blood pressure (β-estimate = 0.58, p = 0.03) and diastolic blood pressure (β-estimate = 0.31, p < 0.001). Furthermore, we observed significant interactions between TCPy and ethnicity on systolic blood pressure (β-estimate = 1.46, p = 0.0036). Significant interaction terms were observed between oxypyrimidine and ethnicity (β-estimate = -1.73, p < 0.001), as well as oxypyrimidine and BMI (β-estimate = 1.51 p < 0.001) on systolic blood pressure, and between oxypyrimidine and age (β-estimate = 1.96, p = 0.02), race (β-estimate = -3.81 p = 0.004), and BMI on diastolic blood pressure (β-estimate = 0.72, p = 0.02). A significant interaction was observed between para-nitrophenol and BMI for systolic blood pressure (β-estimate = 0.43, p = 0.01), and between para-nitrophenol and ethnicity on diastolic blood pressure (β-estimate = 2.19, p = 0.006). Lastly, we observed a significant association between the odds of HTN and TCPy quartiles (OR = 0.65, 95% CI [0.43,0.99]).

CONCLUSION

Our findings support previous studies suggesting a role for organophosphate insecticides in the etiology of blood pressure dysregulation and HTN. Future studies are warranted to corroborate these findings, evaluate dose-response relationships between organophosphate insecticides and blood pressure, determine clinical significance, and elucidate biological mechanisms underlying this association.

Left ventricular failure due to a rare variant of congenital adrenal hyperplasia

"Hypertensive" variant of congenital adrenal hyperplasia is rare. The authors describe an interesting case of a 6-y-old boy who presented with an acute respiratory illness and progressive breathlessness since 1 y. Genital hyperpigmentation was noticed since 2 y of age; the onset of pubarche and increasing penile size at 4 y. He was admitted in congestive cardiac failure with a blood pressure of 150/100 mm Hg. Facial acne; slight facial, pubic hair and penile enlargement were additionally noted. Chest radiograph revealed cardiomegaly. Basal ACTH and 17-OHP levels were high. A diagnosis of congenital adrenal hyperplasia (11β-hydroxylase deficiency) was made due to hypertension with virilized genitalia. Cardiac failure was controlled with fluid restriction and diuretics; he was started on prednisolone, spironolactone and nifedipine. This case is presented for its rarity where hypertension can cause complication of cardiac failure, if diagnosis is delayed despite early features of pseudoprecocious puberty.

Efficacy of amlodipine in pediatric bone marrow transplant patients

The calcium antagonist amlodipine may have the potential for expanded use in children owing to its physiochemistry and pharmacokinetic profile that facilitates once-daily dosing in a liquid formulation. Its safety and efficacy have not been previously evaluated in children. A retrospective analysis of 15 pediatric bone marrow transplant patients who had amlodipine incorporated into their antihypertensive drug regimen reveals significantly lower blood pressure as compared with baseline therapy (123.5+/-2.1 mmHg and 117.2+/-2.2 mmHg, systolic blood pressure before and during amlodipine, P<0.05; 81.5+/-1.8 mmHg and 75.5+/-2.6 mmHg, diastolic blood pressure before and during amlodipine, P<0.05). Amlodipine provided improved blood pressure control in this cohort and may provide a valuable pharmacologic alternative for treatment of pediatric hypertension.

[Pheochromocytoma: pediatric features]

Pheochromocytoma is a rare tumor in children which explains, together with its miscellaneous symptomatology, why the diagnosis may be delayed. The localization of the tumor(s) rests mainly on MIBG scintigraphy, and CT scan and/or magnetic resonance imaging. Thanks to a systematic preoperative treatment of hypertension and major progress in anesthesia, the operative mortality of pheochromocytomas in children is nowadays very low. Nevertheless two major problems remain: 1) the difficulty of diagnosing and treating the malignant forms, 2) the high frequency of recurrences, sometimes many years after the removal of the primary tumor. A regular long term supervision is therefore necessary after the surgical treatment.

Pediatric hypertension: clinical perspective

OBJECTIVE

To provide an overview of clinical aspects of hypertension in pediatric patients.

DESIGN

The recommended diagnostic studies and the management options for increased blood pressure levels in prepubertal and adolescent patients are reviewed.

RESULTS

In pediatric patients with three consecutive blood pressure measurements that exceed the 95th percentile, a hypertension-oriented personal and family history should be elicited, and a focused physical examination should be conducted for evidence of target organ damage, left ventricular hypertrophy, and potential causes of secondary hypertension. Subsequently, sequential laboratory and radiologic tests can be performed to validate clinical suspicions. Although children with hypertension usually have few symptoms, the major complaint is headache, which is characteristically frontal and may be throbbing. In the rare pediatric patient with malignant hypertension, severe headache, blurred vision, and seizures can occur, and the main underlying cause is renal parenchymal disorders. The management of children and adolescents with hypertension is based on an overall program for maintenance of cardiovascular health and implementation of measures directed at specific causes. If a young patient with hypertension has no evidence of cardiac involvement and remains asymptomatic during exercise testing, participation in sports can be encouraged.

CONCLUSION

Although blood pressure control is often difficult to achieve in young patients, the best pharmacologic approach is to use the fewest, well-studied drugs in the lowest effective dosage.