Childhood hypertension does not increase risk of atherosclerosis in adulthood if BP is normalised

Juhola J, Magnussen CG, Berenson GS, et al.
Circulation. 2013 Jun 18

Background

Hypertension is an important modifiable risk factor for atherosclerosis [1]. Autopsy studies indicated that childhood elevated blood pressure (BP) is associated with atherosclerotic lesions [2,3]. The atherosclerotic process begins in childhood. Childhood BP has also been found to predict increased occurrence of subclinical atherosclerosis [4-8]. It is as yet unclear whether the effects of elevated BP in childhood on atherosclerotic markers are permanent or reversible.
The International Childhood Cardiovascular Cohort (i3C) Consortium [9] aims to determine the combined effect of child and adult elevated BP on common carotid intima-media thickness (cIMT), which is an early marker of structural atherosclerosis. The central question was whether a change from elevated BP in childhood to normal BP in adulthood is associated with an attenuated risk of developing increased cIMT. Data from four prospective cohorts in the USA, Finland and Australia were analysed, yielding data for 4210 participants [10], with a mean follow-up of 23 years.

Main results

• 1632 (39%) participants had high BP in childhood, and 2078 (49%) in adulthood. 42% of children with a normal BP and 60% of children with elevated BP had high BP as an adult.
• The risk of high cIMT (>90^th percentile) among participants whose elevated BP was resolved in adulthood did not differ significantly from those in the control group (RR:1.24, 95%CI:0.92-1.67, P=0.17). Sensitivity analyses using more stringent elevated BP definitions were consistent with this observation.
• Participants who had elevated BP in adulthood (incident and persistent groups) had a higher risk of elevated cIMT than the control group (incident: RR: 1.57, 95%CI: 1.22-2.02, P<0.001), persistent: RR: 1.47, 95%CI: 1.47-2.38, P<0.001).
• People with resolved elevated BP in adulthood had lower risks of increased cIMT than those with persistently elevated BP (RR: 0.66, 95%CI: 0.50-0.88).
• Changes in adiposity status from childhood to adulthood paralleled BP status changes.

Conclusion

Individuals who had elevated BP in childhood but normal BP in adulthood did not have a statistically significantly increased cIMT in adulthood, as compared to those with normal BP throughout life. Participants who had elevated BP in adulthood, irrespective of whether they had high BP in childhood, had a significantly increased risk of high cIMT. These findings suggest that the effects of elevated BP in childhood on early atherosclerosis can be reversed to a large extent if BP is normalised in adulthood. It remains important to treat childhood elevated BP, since it is the strongest predictor of adult hypertension.

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