The effect of abnormal birth history on ambulatory blood pressure and disease progression in children with chronic kidney disease.
OBJECTIVE
To examine the associations between abnormal birth history (birth weight <2500 g, gestational age <36 weeks, or small for gestational age), blood pressure (BP), and renal function among 332 participants (97 with abnormal and 235 with normal birth history) in the Chronic Kidney Disease in Children Study, a cohort of children with chronic kidney disease (CKD).


METHODS
Casual and 24-hour ambulatory BP were obtained. Glomerular filtration rate (GFR) was determined by iohexol disappearance. Confounders (birth and maternal characteristics, socioeconomic status) were used to generate predicted probabilities of abnormal birth history for propensity score matching. Weighted linear and logistic regression models with adjustment for quintiles of propensity scores and CKD diagnosis were used to assess the impact of birth history on BP and GFR.


RESULTS
Age at enrollment, percent with glomerular disease, and baseline GFR were similar between the groups. Those with abnormal birth history were more likely to be female, of Black race or Hispanic ethnicity, to have low household income, or part of a multiple birth. Unadjusted BP measurements, baseline GFR, and change in GFR did not differ significantly between the groups; no differences were seen after adjusting for confounders by propensity score matching.


CONCLUSIONS
Abnormal birth history does not appear to have exerted a significant influence on BP or GFR in this cohort of children with CKD. The absence of an observed association is likely secondary to the dominant effects of underlying CKD and its treatment.
Division of Nephrology, Seattle Children's Hospital, and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA. Electronic address: joseph.flynn@seattlechildrens.org.
Joseph T
JT
Flynn
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
Derek K
DK
Ng
Division of Medicine Critical Care, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA.
Grace J
GJ
Chan
Division of Pediatric Nephrology and Hypertension, Department of Pediatrics, University of Texas Medical School at Houston, Houston, TX.
Joshua
J
Samuels
Division of Nephrology, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA.
Susan
S
Furth
Division of Nephrology, Children's Mercy Hospital, and Department of Pediatrics, University of Missouri-Kansas City, Kansas City, MO.
Bradley
B
Warady
Division of Pediatric Nephrology, Children's Healthcare of Atlanta, and Department of Pediatrics, Emory University, Atlanta, GA.
Larry A
LA
Greenbaum
D000293:Adolescent; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002648:Child; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D057216:Propensity Score; D011446:Prospective Studies; D012044:Regression Analysis; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis* / Q000503:physiopathology; D017584:Reproductive History; D012307:Risk Factors