Association between Bone Turnover Markers, Leptin and Nutritional Status in Girls with Adolescent Idiopathic Scoliosis (AIS)

Abstract

The link between scoliotic deformity and bone metabolism in adolescent idiopathic scoliosis (AIS) has not been well researched. Moreover, the data concerning the cross-talk between fat tissue content/hormonal activity and bone markers in this group of patients are lacking. The objective of this study was to correlate the extent of scoliotic-curve severity with the bone turnover vs. leptin level and nutritional status in girls with AIS. The study encompassed 77 AIS girls, aged 14.7 ± 2.17 years. Scoliotic curve severity assessed by Cobb’s angle was categorized as mild (10-19o) moderate (20-39º) or severe (≥40º). Corrected height, weight, waist and hip circumferences were measured and body mass index (BMI), corrected height Z-score, BMI Z-score and waist/height ratio (WHtR) were calculated for the entire group. Body composition parameters: fat mass (FAT), fat-free mass (FFM) and predicted muscle mass (PMM) were determined using a bioelectrical impedance analyzer. Bone turnover markers (osteocalcin (OC) and amino terminal of collagen cross-links NTx) and leptin levels were assessed in serum. Multiple regression analysis showed that, OC, NTx (negatively with p<0.05) and leptin (positively with p<0.01) were significantly associated with curve severity in AIS girls. Moreover, Cobb’s angle was positively correlated with W/HtR (p<0.01)and FAT (p<0.05). One-way analysis of variance (ANOVA) revealed significant differences in leptin (p<0.05 vs. mild only), OC (p<0.05 vs. mild and moderate)) and W/HtR (p<0.01 and p<0.05 vs. mild and moderate respectively) between the three AIS severity subgroups. OC was significantly lower in the severe AIS subgroup, while leptin and W/HtR were significantly higher. Significant correlations between leptin and anthropometrical parameters as BMI z-score and W/HtR were shown. Leptin level correlated also significantly with BMI z score (p<0.001), W/HtR (p<0.0001) and body composition parameters (p<0.000001). Moreover, there was a significant negative correlation between NTx and leptin level (p<0.05). Bone metabolism in AIS girls seems to be altered and significantly related to the scoliotic curve severity. Leptin may be a crucial link in the cross-talk between bone turnover and body composition in this group of patients. Further studies concerning this topic are needed.

The role of endocrine hormones in the pathogenesis of adolescent idiopathic scoliosis

“…AIS has also been shown to be related to low body mass index (BMI) and low bone mass. In these conditions, several hormones involved in body growth and development including leptin, adiponectin, growth hormone (GH), and ghrelin also appear related to AIS 9‐11 . Studies in animal models of scoliosis (pineal gland removal induces scoliosis in chickens and rats) suggest that AIS may be related to melatonin levels 12 .…”

“…In these conditions, several hormones involved in body growth and development including leptin, adiponectin, growth hormone (GH), and ghrelin also appear related to AIS. [9][10][11] Studies in animal models of scoliosis (pineal gland removal induces scoliosis in chickens and rats) suggest that AIS may be related to melatonin levels. 12 In addition, other factors such as calmodulin and vitamin D may be involved in the effects of these hormones.…”

Effect of miR-192-5p on Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells in Idiopathic Scoliosis by Regulating Wnt/β-catenin Signaling Pathway via RSPO1

“…About the osteogenic differentiation related proteins OC, OPN and RUNX2 in IS, a new study claimed that the level of OC in the severe adolescent IS patients was signi cantly lower. [19] Besides, OPN was at a low level in adolescent IS bone tissues. [15] And RNA and protein analyses revealed lower RUNX2 levels in adolescent IS.…”