Endocrine Abstracts

Background: Childhood growth monitoring aims to identify growth failure and detect underlying pathology. According to UK guidance, height <-2.7 standard deviation score (SDS) (<0.4th percentile) is used as the referral threshold. Additional referral criteria include height deficit (HSDS-target height SDS) <-2.0 and height velocity (HV) SDS <-1.3. Lack of routine HV and mid-parental height calculation, combined with stricter cut-offs compared to other European countries means that UK screening to detect growth disorders is suboptimal.

Methods: Retrospective review of children referred with short stature to Paediatric Endocrinology clinics at the Royal London Children’s Hospital between 2016-2020. Demographics, HSDS, HVSDS and Height-THSDS were recorded at the time of referral.

Results: 143 patients were referred with short stature (SS). 51 (36%) patients had pathological SS; 28 with primary growth failure: genetic disorder (n = 6), SGA (n = 21), SHOX (n = 1) and 23 with secondary growth failure: GHD (n = 17), GH-IGF axis disorder (n = 4), coeliac disease (n = 1) and hypothyroidism (n = 1). 15 (10%) patients remain short and under investigation with no identified pathology. 48 (34%) had non-pathological SS: FSS (n = 30), CDGP (n = 18). 29 (20%) patients did not have short stature (HSDS >2.0 and <1.6 SDS below TH). Height SDS and height-THSDS were significantly lower in the pathological SS group (n = 66) vs the non-pathological SS/normal stature group (n = 77) (-2.67 ±0.82 vs -1.97 ±0.70; P < 0.001 and -2.07 ±1.02 vs -1.06 ±0.99; P < 0.001, respectively). HV SDS did not differ between the groups (-0.49 ±2.71 vs -0.16 ±2.82; P = 0.49). The sensitivity and specificity to detect pathology was 41% and 83% for height SDS <-2.7, 48% and 83% for HSDS-THSDS <-2.0 and 33% and 68% for HVSDS <-1.3.

Conclusion: Children with pathological short stature were significantly smaller and deviated more from target height. A significant proportion of the children with pathology had height SDS above the referral threshold, suggesting the UK cut-off may be too strict. Routine assessment of target height deficit could improve the sensitivity for identifying pathological short stature and prevent unnecessary referrals.