Final Adult Height of Children with Inflammatory Bowel Disease is Predicted by Parental Height and Patient Minimum Height Z-score

Background: This study was designed to elucidate the contribution of parental height to the stature of children with inflammatory bowel disease (IBD), who often exhibit growth impairment. Accordingly, we compared patients' final adult heights and target heights based on measured parental heights and examined predictors of final adult height in pediatric IBD patients. Methods: We prospectively analyzed the growth of 295 patients diagnosed between ages 1 and 18 (211 Crohn's disease [CD], 84 ulcerative colitis [UC]) and their family members (283 mothers, 231 fathers, 55 siblings). Results: Twenty-two percent had growth impairment (height for age Z-score <-1.64, equivalent to <5th percentile on growth curve) in more than 1 measurement since diagnosis; most growth-impaired patients had CD (88% CD versus 12% UC). Parents of the growth-impaired group had lower mean height Z-scores compared to parents of nongrowth-impaired patients (-0.67 versus 0.02 for mothers [P < 0.001]; -0.31 versus 0.22 for fathers [P = 0.002]). For 108 patients who reached adult heights and had available parental heights, the growth-impaired group continued to demonstrate lower adult height Z-scores (-1.38 versus 0.07; P < 0.001). Adult heights were within 1 SD of target heights even for the growth-impaired group. Only 11.3% remained persistently growth-impaired in adulthood. Multivariate regression analysis demonstrated lower parental height and minimum patient height Z-score as significant predictors of lower final adult height in IBD. Conclusions: Parental height is a powerful determinant of linear growth even in the presence of chronic inflammation, and should be an integral part of the evaluation of growth in IBD children.