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It has been proposed that girls with adolescent idiopathic scoliosis (AIS) tend to have a taller stature and a lower body mass index. Energy homeostasis, that is known to affect bone growth, could contribute to these characteristics. In circulation, dipeptidyl peptidase-4 (DPP-4) inactivates glucagon-like peptide-1 (GLP-1), an incretin that promotes insulin secretion and sensitivity. Our objectives were to investigate DPP-4 status in plasma and in osteoblasts of AIS subjects and controls and to evaluate the regulatory role of metabolic effectors on DPP-4 expression. DPP-4 activity was assessed in plasma of 113 girls and 62 age-matched controls. Osteoblasts were isolated from bone specimens of AIS patients and controls. Human cells were incubated with glucose, insulin, GLP-1 and butyrate. Gene and protein expressions were evaluated by RT-qPCR and Western blot. Our results showed 14% inferior plasma DPP-4 activity in AIS patients when compared to healthy controls (P = 0.0357). Similarly, osteoblasts derived from AIS subjects had lower DPP-4 gene and protein expression than controls by 90.5% and 57.1% respectively (P < 0.009). DPP-4 expression was regulated in a different manner in osteoblasts isolated from AIS participants compared to controls. Our results suggest a role for incretins in AIS development and severity.

Purpose of the studyAdolescent idiopathic scoliosis (AIS) is a tridimensional spine deformation of unknown cause that affects 2–3% of children and mostly girls. Studies have suggested that girls with AIS are taller and leaner than controls, but more studies are needed to confirm these results. While differences in energy metabolism and nutritional intake could explain these discrepancies, they have been poorly studied in AIS. This study aims to thoroughly characterize the anthropometric, metabolic and nutritional profiles of girls affected by AIS and to compare them to age‐matched healthy controls.Methods20 girls with AIS and 20 healthy controls are being enrolled. Anthropometric parameters (weight, standing and sitting height, body mass index (BMI), waist circumference and arm spam) are measured. Fasting glucose, insulin and lipid profile (total cholesterol, LDL‐cholesterol, HDL‐cholesterol, triglycerides and apolipoprotein B) are assessed. Bone mineral density and body composition are determined by osteodensitometry scan and questionnaires are administered to assess food intake and physical activity level.ResultsTo this day, 17 AIS (14.9 ± 1.9 yrs, mean Cobb angle of 27.2 ± 10.0°) and 12 healthy girls (15.2 ± 1.6 yrs) have completed the study. Compared to controls, we observed in AIS girls tendencies for lower BMI (BMI‐for‐age z‐score: −0.50 ± 0.90 vs. 0.09 ± 1.20, P=0.3669), fat percentage (−15%, P=0.1213), waist circumference (−7%, P=0.0706) and bone mineral density (−8%, P=0.0217). There was no difference in fasting glucose (4.98 ± 0.27 vs. 4.84 ± 0.27 mmol/L, P=0.1852) and insulin (52.46 ± 19.87 vs. 54.12 ± 19.41 ρmol/L, P=0.8365) between groups. A tendency for a perturbed lipid profile was also found in AIS girls with higher triglycerides (18%, P=0.2866), LDL‐cholesterol (16.5 %, P=0.0306), apolipoprotein B (19%, P=0.0071) and total cholesterol (12%, P=0.0374). 47% of AIS girls had at least one abnormal lipid value. Calorie intake and physical activity levels were similar between groups. However, compared to controls, there was a tendency for higher caloric balance (consumption vs. needs) in AIS girls (+60.5 ± 417.7 vs. −223.4 ± 625.7 kcal, P=0.1706). AIS girls and controls had similar vitamin D (4.60 ± 2.30 vs. 5.40 ± 3.01 μg, P=0.4469) and calcium intake (954.78 ± 326.20 vs. 928.78 ± 385.12 mg, P=0.8509).Conclusion: Our pilot study revealed tendencies for different anthropometrical features, lipid profile and energy balance in AIS. Increasing the number of participants might confirm these results.Support or Funding InformationFondation Yves Cotrel‐Institut de FranceThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.