MRI Findings of Pituitary Gland in Growth Hormone-Deficient Children and Their Correlation with Growth Hormone Peak during Growth Hormone Stimulation Tests

Pitfalls of diagnosing pituitary hypoplasia in the patients with short stature

PURPOSE

Height age (HA) and bone age (BA) delay is well known in the patients with short stature. Therefore assessing pituitary hypoplasia based on chronological age (CA) might cause overdiagnosis of pituitary hypoplasia. We aimed to investigate the diagnostic and prognostic value of the PH and PV based on CA, HA, or BA in the patients with GHD.

METHODS

Fifty-seven patients with severe and 40 patients with partial GHD and 39 patients with ISS assigned to the study. For defining the most accurate diagnosis of pituitary hypoplasia, PH and PV were evaluated based on CA, BA and HA. The relationship of each method with clinical features was examined.

RESULTS

The mean PV was significantly larger in patients with ISS compared to the GH-deficient patients. PV was more correlated with clinical features including height SDS, stimulated GH concentration, IGF-1 and IGFBP-3 SDS, height velocity before and after rGH therapy. We found BA-based PV could discriminate GHD from ISS (Sensitivity: 17%, specificity: 98%, positive predictive value: 94%, negative predictive value: 39%), compared to the other methods based on PH or PV respect to CA and HA. 3% of patients with ISS, 17% of patients with GHD had pituitary hypoplasia based on PV-BA.

CONCLUSION

PV based on BA, has the most accurate diagnostic value for defining pituitary hypoplasia. But it should be kept in mind that there might be still misdiagnosed patients by this method. PV is also a significant predictor for the rGH response.

Auxological, Clinical, and MRI Abnormalities in Pediatric Patients With Isolated Growth Hormone Deficiency

OBJECTIVE

 This study aimed to assess the auxological, clinical, and MRI features of pediatric patients with isolated growth hormone deficiency (GHD) by analyzing the demographic and clinical characteristics of the study cohort.

METHODS

A cohort of 115 pediatric patients diagnosed with isolated GHD was included. The patients were evaluated at a tertiary center in Jeddah, Saudi Arabia. Collected data included demographic information and auxological evaluations, such as height standard deviation (SD), height centile, weight SD, weight centile, and bone age SD. Neuroradiological assessments, particularly magnetic resonance imaging (MRI) of the hypothalamic-pituitary region, were collected to identify any structural abnormalities contributing to GHD.

RESULTS

A total of 67 (SD 58.3) were males. The mean age was 9.55 years (SD 3.45). The mean bone age was 7.37 years (SD 3.24), indicating delayed bone development. Height measurements reflected a significant growth impairment, with a mean height SD of -2.45 (SD 1.12). Out of the 115 pediatric patients in the study cohort, 84 (73%) underwent neuroradiological assessments using brain MRI. Among these, 12% were found to have MRI abnormalities. The prevalence of MRI abnormality in the subgroup with severe growth hormone deficiency was higher, reaching 21%. The peak growth hormone (GH) in the growth hormone stimulation test was 6.38 ng/mL (SD 3.24). There was a significant difference in the peak GH levels between the subgroup of patients with normal MRI findings (mean 6.02 ng/mL, SD 2.47) and those with abnormal MRI findings (mean 3.2 ng/mL, SD 2.8) (p=0.01).

CONCLUSION

Children with isolated GHD exhibited significant growth impairment and clinical characteristics consistent with the disorder. Neuroradiological abnormalities are common among patients with severe growth hormone deficiency; therefore, radiological assessment including MRI of the pituitary gland is recommended in patients with severe isolated growth hormone deficiency.

[Diagnostic significance and considerations of growth hormone stimulation testing and insulin-like growth factor 1 in growth hormone deficiency]

The growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis is an essential component of the hypothalamic-pituitary growth hormone axis and plays a crucial role in childhood growth and development. Disruptions and abnormalities in the GH/IGF-1 signaling pathway and its pathways typically manifest as short stature in children. Children with short stature often undergo GH stimulation testing and IGF-1 level measurements to differentiate growth hormone deficiency (GHD) from other causes of growth delay. This article aims to analyze and elucidate the values of GH stimulation testing and IGF-1 measurement, providing reference for the diagnosis of GHD in children.