Preeclampsia-exposed children's heart rate variability 8-12 yr after index pregnancy: FINNCARE study

Preeclampsia is related with elevated systolic blood pressure (SBP) in children. We studied if preeclampsia-exposed (PE) children develop alterations in heart rate variability (HRV) and if this is reflected in their blood pressure (BP), as well as overall associations with body size and composition, gestational and perinatal factors. We examined 182 PE (46 early-onset PE) and 85 unexposed (non-PE) children 8-12 yr after preeclampsia exposure. HRV monitoring was performed 5 min in supine followed by 5 min in standing position and compared with office, 24-h ambulatory, and central BPs in relation to body anthropometrics and composition, gestational, and perinatal data. There were no major differences in HRV between PE and non-PE children. HRV in supine position was strongly associated with office and ambulatory heart rates (HRs), and HR was independently associated with office BPs. However, HRV was not related with office or 24-h SBP and PP, nor with elevated SBP in PE compared with non-PE children [adjusted mean differences for office and 24-h SBP 4.8 (P < 0.001) and 2.5 mmHg (P = 0.049), respectively]. In supine position, high-frequency (HF) power [beta, -0.04 (95% CI -0.06 to -0.01)], root mean square of successive differences in R-R intervals (rMSSD) [-0.015 (-0.028 to -0.002)], and the ratio of low-frequency (LF) to HF power [0.03 (0.01-0.04)] were independently associated with child fat mass. LF and HF power and rMSSD displayed independent inverse associations with child age. There were no significant associations between child HRV and gestational and perinatal factors. During prepuberty, the HRV in children with PE is similar to that in non-PE children. Elevated SBP following preeclampsia exposure is not related with HRV. Child adiposity could be related to decreased cardiac vagal tone. NEW & NOTEWORTHY Heart rate variability in preadolescent children exposed to preeclampsia in utero is no different from age-matched controls. Preeclampsia-exposed children's elevated SBP is not related to alterations in heart rate variability, which is a noninvasive measure of the modulation of heart rate by autonomic tone. However, childhood adiposity might be coupled with diminished cardiac vagal tone.