Isolated diastolic high blood pressure: a distinct clinical phenotype in US children.

BACKGROUND

Screening studies have shown that 0.7-4.5% of generally healthy children have isolated diastolic high BP. We therefore studied the characteristics of children with diastolic BP in the elevated and hypertensive ranges according to current guidelines in US children from the National Health and Nutrition Examination Survey (NHANES, 1999-2016).

METHODS

We studied 17,362 children (8-18 years) with BP measured by sphygmomanometry. High BP was categorized as isolated systolic (iSH), isolated diastolic (iDH), or Mixed.

RESULTS

Overall, 86.0% (95% CI =  85.0-87.0) of the population had normal BP, 8.7% (8.0-9.3) elevated BP, 4.9% (4.4-5.5) Stage 1, and 0.4% (0.4-0.6) Stage 2. Moreover, 11.1% (10.3-12.0) had iSH, 1.9% (1.5-2.2) iDH, and 1.0% (0.8-1.2) Mixed. Children with iDH were more likely to be female, younger, white, and leaner than those with iSH, with lower rates of overweight/obesity. iDH was generally between normals and iSH. Resting heart rate was significantly higher in iDH even after adjustment for known covariates.

CONCLUSIONS

Children with iDH may have a distinct clinical picture. A leaner habitus and higher resting heart rate may reflect differences in underlying pathophysiology. Longitudinal follow-up studies are needed to better define the pathogenesis, progression, and long-term prognosis in iDH.

IMPACT

Using gold-standard auscultation and 2017 guidelines, isolated diastolic high BP (iDH) is found in 1.9% (95% CI 1.5-2.2) of American children; these children are younger, leaner, more female, and have fewer cardiometabolic risks. Resting heart rate is significantly higher in iDH compared to both normals and iSH even after adjustments for known covariates. Autonomic hyperactivity in iDH may speak to both etiology and therapeutic approaches. iDH appears to be a distinct clinical phenotype characterized by differences in anthropometric measures, sex, age, and resting heart rate. Follow-up studies are clearly needed to clarify its pathogenesis, progression, and prognosis.