FINAL HEIGHT AND PREDICTED HEIGHT IN BOYS WITH UNTREATED CONSTITUTIONAL GROWTH DELAY

We report on 49 boys with constitutional growth delay (CGD) who were i nitially seen in our clinic at a mean chronological age of 13.3 years (range, 7.3-16.4) and a bone age of 11.1 years (range, 6.0-13.5). All were below the 5th height percentile for chronological age. A positive family history with delayed growth and puberty in one or both parents could be elicited in 75%. All 49 patients were re-examined at a mean age of 22.9 years (range, 20.4-31.2). Measured final height was 171.3 cm (range, 161.2-181.7), which was slightly, but significantly lower t han mean target height of 173.0 cm. Final height expressed as standard deviation score (SDS) of a male adult population standard was -1.0 (r ange, -2.4 to +0.5), also significantly lower than initial height SDS related to bone age (SDSBA) of -0.5 (range, -1.6 to +1.2). If related to target height (Tanner), final height was found to correlate positiv ely with the initial bone age deficit and the initial height SDS,,. Ob served final height was also compared with the predicted adult height by the methods of Bayley-Pinneau (BP), Tanner-Whitehouse Mark II (TW I I) and Roche-Wainer-Thissen. Regression equations between all three pr e diction methods and final height showed an excellent correlation (P < 0.0001). However, only by the BP method was predicted height very cl ose to and no different from measured final height (paired t-test). De spite this, final height in 16 of 49 patients (32.6%) differed by more than 5.0 cm from BP predicted height. An overwhelming majority of The patients (88.6%) expressed complete or reasonable satisfaction with t heir adult height. Conclusion In our sample of male patients with CGD, adult height came crose to but did not quite reach mean target height . The BP prediction method offers a good compromise between simplicity and accuracy but must be used judiciously because individual discrepa ncies with attained final height may be large and unexplained.