title: Insulin growth factor-1 correlates with higher bone mineral density and lower inflammation status in obese adult subjects.
abstract: OBJECTIVE
  Obesity is a severe public health problem worldwide, leading to an insulin-resistant state in liver, adipose, and muscle tissue, representing a risk factor for type 2 diabetes mellitus, cardiovascular diseases, and cancer. We have shown that abdominal obesity is associated with homeostasis derangement, linked to several hormonal and paracrine factors. Data regarding potential link between GH/IGF1 axis, bone mineral density, and inflammation in obesity are lacking. Thus, aim of this study was to evaluate correlation among IGF-1, BMD, and inflammation in obese individuals.
  
  
  METHODS
  The study included 426 obese subjects, mean age 44.8 ± 14 years; BMI 34.9 ± 6.1. Exclusion criteria were chronic medical conditions, use of medications affecting bone metabolism, hormonal and nutritional status, recent weight loss, and prior bariatric surgery. Patients underwent measurements of BMD and body composition by DEXA and were evaluated for hormonal, metabolic profile, and inflammatory markers.
  
  
  RESULTS
  In this population, IGF-1 was inversely correlated with abdominal FM% (p < 0.001, r2= 0.12) and directly correlated with osteocalcin (OSCA) (p < 0.002, r2= 0.14). A negative correlation was demonstrated between IGF-1 levels and nonspecific inflammatory index, such as fibrinogen (p < 0.01, r2= 0.04) and erythrocyte sedimentation rate (p < 0.0001, r2= 0.03). IGF-1 was directly correlated with higher BMD, at both lumbar (p < 0.02, r2= 0.03) and femoral site (p < 0.04, r2= 0.03).
  
  
  CONCLUSIONS
  In conclusion, our results show that higher levels of serum IGF-1 in obese patients correlate with lower inflammatory pattern and better skeletal health, as demonstrated by higher BMD and osteocalcin levels. These results lead to speculate the existence of a bone-adipose-muscle interplay modulating energy homeostasis, glucose, bone metabolism, and chronic inflammation in individuals affected by abdominal obesity.
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Endocrinology and Nutrition, University "Sapienza", Rome, Italy.
authors.forename: Rachele
authors.initials: R
authors.lastname: Fornari
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Endocrinology and Nutrition, University "Sapienza", Rome, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Marocco
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Endocrinology and Nutrition, University "Sapienza", Rome, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Francomano
authors.affiliation: IRCCS SDN, Naples, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Fittipaldi
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Endocrinology and Nutrition, University "Sapienza", Rome, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Lubrano
authors.affiliation: Department of Movement, Human and Health Sciences, Section of Health Sciences, University "Foro Italico", Largo Lauro De Bosis 6, 00135, Rome, Italy.
authors.forename: Viviana M
authors.initials: VM
authors.lastname: Bimonte
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Endocrinology and Nutrition, University "Sapienza", Rome, Italy.
authors.forename: Lorenzo M
authors.initials: LM
authors.lastname: Donini
authors.affiliation: IRCCS SDN, Naples, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Nicolai
authors.affiliation: Department of Experimental and Clinical Medicine, University Magna Graecia, Catanzaro, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Aversa
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Endocrinology and Nutrition, University "Sapienza", Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Lenzi
authors.affiliation: Department of Experimental Medicine, Section of Medical Pathophysiology, Endocrinology and Nutrition, University "Sapienza", Rome, Italy.
authors.forename: Emanuela A
authors.initials: EA
authors.lastname: Greco
authors.affiliation: Department of Movement, Human and Health Sciences, Section of Health Sciences, University "Foro Italico", Largo Lauro De Bosis 6, 00135, Rome, Italy. silvia.migliaccio@uniroma4.it.
authors.forename: Silvia
authors.identifier: http://orcid.org/0000-0002-4563-6630
authors.initials: S
authors.lastname: Migliaccio
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D015675:Osteocalcin / Q000097:blood
chemical_list: D015415:Biomarkers; D015675:Osteocalcin; D007334:Insulin-Like Growth Factor I
keywords: Bone mineral density; IGF-1; Inflammation; Obesity