IGF1 as reassessment method of GH deficiency in adulthood

Ariza-Jimenez Ana Belen; Ariza-Jimenez Jose Antonio; Martinez-Aedo Ollero Maria Jose; Lopez-Siguero Juan Pedro

Background: GH deficiency may not persist into adulthood. Thus, it is recommended to reassess it after reaching adult height. However, according to stimulation tests, they have poor specificity, reproducibility, and poor standardization of hormonal measurement, and they are expensive and involve risks.

Objective and hypotheses: Establish if IGF1 would be a better reassessing method than stimulation tests in adult GH deficiency.

Method: Retrospective descriptive study for comparison of IGF1 and GH stimulation tests in reassessment of children with isolated GH deficiency into adulthood, in a tertiary hospital in the last 10 years.

Results: We reassessed 61 patients in adult height, previously diagnosed of isolated GH deficiency. Deficit persists according stimulation test in 26/61 (34.66%), and 9/61 (12 %) according to IGF1, with a correlation coefficient of 0.24. Differences between samples with abnormal and normal GH stimulation tests, and patients with abnormal and normal IGF1 in reassessment, are shown in Table 1 (P 0.034).

Table 1. Results
	Patients with abnormal GH in reappraisal(GH<5.6ng/ml)(n=26)	Patients with abnormal IGF1 in reappraisal(IGF1<-2SDS)(n=9)	Patients with normal GH in reappraisal(GH>5,6ng/ml) (n=35)	Patients with normal IGF1 in reappraisal (IGF1>-2SDS) (n=52)
Age (years)	10.45	10	10.6	10.55
Symptoms	Short Stature	Short Stature	Short stature	Short stature
Initial Height (SDS)	-2.85	-3.17	-2.64	-2.63
Parental Height(SDS)	-1.35	-0.54	-1.49	-1.47
Predictive Height(SDS)	-1.88	-1.73	-1.27	-1.46
Age of puberty girls/boys (years)	12.47/13.14	12.5/13.36	11.54/12.66	11.81/12.64
Puberty Height(SDS)	-1.93	-1.96	-2.15	-2.06
Adult Height (SDS)	-1.52	-1.33	-1.74	-1.62
Pubertal gain of height (cm)	20.15	18.63	22.54	22.96
Total gain (SDS)	1.33	1.84	0.9	1.01
GH (mg/l) in reappraisal	1.63	3.54	13.91	9.88
IGF1 (SDS) in reappraisal	-1.27	-4.36	0.22	0.34

Conclusion:

In our study:

- Deficits diagnosed by stimulation tests did not present an abnormal mean of IGF1, while low IGF1 was related to abnormal stimulation test. Therefore, low IGF1 is in favor of GH deficiency.

- Initial size is worse in children with abnormal stimulation test and IGF1 in reassessment, with greater involvement of second one.

- Children with abnormal stimulation test and IGF1, have more delayed puberty and less pubertal gain of height than those with normal reassessment.

- There is greater adult height and total gain of height in patients with abnormal stimulation test and IGF1, with better results in those with abnormal IGF1, so low IGF1 in GH deficiency could be related to a better response to treatment.

ESPE Abstracts

P2-152