Relatively lower body mass index is associated with an excess of severe truncal asymmetry in healthy adolescents: Do white adipose tissue, leptin, hypothalamus and sympathetic nervous system influence truncal growth asymmetry?

Abstract

BMI is a surrogate measure for body fat and circulating leptin levels. The finding that girls with relatively lower BMI have significantly later menarche, and a significant excess of TAs, suggests a relation to energy homeostasis through the hypothalamus. The hypothesis we suggest for the pathogenesis of severe TA in girls and boys has the same mechanism as that proposed recently for AIS girls, namely: severe TAs are initiated by a genetically-determined selectively increased hypothalamic sensitivity (up-regulation, i.e. increased sensitivity) to leptin with asymmetry as an adverse response to stress (hormesis), mediated bilaterally mainly to the growing trunk via the sympathetic nervous system (leptin-hypothalamic-sympathetic nervous system (LHS) concept). The putative autonomic dysfunction is thought to be increased by any lower circulating leptin levels associated with relatively lower BMIs. Sympathetic nervous system activation with asymmetry leads to asymmetries in ribs and/or vertebrae producing severe TA when beyond the capacity of postural mechanisms of the somatic nervous system to control the shape distortion of the trunk. A test of this hypothesis testing skin sympathetic responses, as in the Rett syndrome, is suggested.

Abnormal Leptin Bioavailability in Adolescent Idiopathic Scoliosis

“…6 However, in the study of Qiu et al , 26 20% of circulation and enhance the leptin bioavailability in CSF. 37 , 44 Along with other studies, 6,9,10,14,16,45,46 AIS girls were found to have signifi cantly lower BMI and longer arm span than the healthy controls. This matches our observation on the change of sOB-R and FLI level in AIS girls.…”

Hypothesis on the Pathogenesis of Idiopathic Scoliosis

“…The maturation of the ocular and postural control systems coincides with the secondary rapid growth period. Some workers believe that not only the somatic nervous system is involved but the autonomic nervous system as well (Burwell, 2003;Grivas et al, 2009;Burwell et al, 2009). AIS in girls may then be the result from developmental disharmony expressed in spine and trunk between autonomic and somatic nervous systems.…”

How to Improve Progress in Scoliosis Research

“…This is important because it highlights the impact of factors other than genetic make-up in developing scoliosis and has spawned the concept of epigenetics where factors other than genetics are considered to be major contributing factors (Grivas et al, 2002a(Grivas et al, , 2002b(Grivas et al, , 2006(Grivas et al, , 2007(Grivas et al, , 2008a(Grivas et al, , 2008b(Grivas et al, , 2009(Grivas et al, , 2001. Factors that might be considered must certainly include environmental conditions and their influence on spinal curve development and might present alternative treatment strategies (Hermus et al, 2007).…”