Association between Insulin-Like Growth Factor-1 and Relative Skeletal Maturation: A Retrospective Cohort Study of Short Children and Adolescents

Table 1

Clinical and laboratory characteristics of the subjects.

Variable	Total	Delayed bone age	Normal bone age
Number (%)	783 (100%)	457 (58.37%)	326 (41.63%)	—
GH treatment (%)	229 (100%)	135 (58.95%)	94 (41.05%)	—
Sex (male %)	553 (70.63%)	342 (74.84%)	211 (64.72%)	0.002
Chronological age (years)				<0.001
Bone age (years)				<0.001
BA-CA (years)	-1.98 (-2.84–-1.28)	-2.70 (-3.32–-2.22)	-1.09 (-1.43–-0.59)	<0.001
Height (cm)				<0.001
Height SDS				0.007
Body weight (kg)				<0.001
BMI (kg/m^2)				<0.001
BMI SDS				0.005
IGF-1 (ng/ml)	164.00 (92.30-253.50)	128.50 (76.62-196.00)	232.00 (139.00-340.00)	<0.001
IGF-1 SDS	-1.03 (-1.86–-0.19)	-1.21 (-1.93–-0.52)	-0.58 (-1.63-0.35)	<0.001
FT3 (pmol/l)				0.306
FT4 (pmol/l)				0.261
TSH (mIU/l)				0.178
ALP (U/l)				<0.001
E2 (pg/ml)	18.15 (11.80-26.31)	16.64 (11.80-23.41)	20.80 (13.48-28.66)	<0.001
T (pg/ml)	0.23 (0.12-0.47)	0.20 (0.10-0.32)	0.29 (0.16-0.97)	<0.001
FSH (mIU/ml)	2.34 (1.01-3.96)	1.75 (0.73-3.43)	3.14 (1.78-4.68)	0.011
LH (mIU/ml)	0.22 (0.10-1.40)	0.10 (0.04-0.94)	0.82 (0.10-1.99)	<0.001
Pubertal stage				<0.001
In prepuberty (%)	579 (73.95%)	385 (84.25%)	194 (59.51%)
In puberty (%)	204 (26.05%)	72 (15.75%)	132 (40.49%)

Abbreviations: GH: growth hormone; BA-CA: bone age-chronological age; height SDS: height standard deviation scores; BMI: body mass index; BMI SDS: body mass index standard deviation scores; IGF-1: insulin-like growth factor-1; IGF-1 SDS: insulin-like growth factor-1 standard deviation scores; FT3: triiodothyronine; FT4: free thyroxine; TSH: thyrotrophic hormone; ALP: alkaline phosphatase; E2: estradiol; T: testosterone; FSH: follicle stimulating hormone; LH: luteinizing hormone. Delayed BA group was defined as , and normal BA group was defined as . Normal distribution of data was presented as ; nonnormal distribution of data was presented as median (interquartile range) and categorical data using number (percentage). is considered to be statistically significant.