Table 1.
Anthropomethrical data of healthy controls and children with CGD, GHD and SGA.
Table 2.
Growth factors and HRV data of healthy controls and children with CGD, GHD and SGA.
Table 3.
rMSSD values during clonidine testing and healthy controls.
Table 4.
HF/LF values during clonidine testing and healthy controls.
Fig 1.
Effect of clonidine on rMSSD in normal and short stature children.
Effect of clonidine given at 9:00 a.m. on the vagus parameter rMSSD in children with constitutional growth delay (n = 36) (♦) compared to baseline data of age-matched healthy controls (◊). Children with growth hormone deficiency (n = 14) and small for gestational age (n = 6) show reduced vagal activation after clonidine administration (♦).
Fig 2.
Effect of clonidine on HF/LF in normal and short stature children.
Effect of clonidine given at 9:00 a.m. on the autonomic balance indicated by the parameter HF/LF compared to baseline data of age-matched healthy controls(◊). Children with constitutional growth delay (n = 36) show a clear rise of HF/LF ratio indicating sympathetic inhibition (♦). The effect is smaller in growth hormone deficient children (n = 14) and absent in children small for gestational age (n = 6) (♦).
Fig 3.
rMSSD-Circadian Data of SGA with and without clonidine.
Effect of clonidine given at 9:00 a.m. on the vagus parameter rMSSD in children with SGA (n = 6) after clonidine administration (■) compared to age-matched SGA without clonidine (♦) and to age-matched healthy controls (▲).
Fig 4.
Our model of autonomic imprinting.
Early life stress during pregnancy or short time after birth imprints the hypothalamic α2-adrenoreceptor. Depending on its regulatory properties the pituitary axis as well as the autonomic nervous system are altered resulting in growth delay, altered adrenal function and reduced HRV.