The Nutrition and Skeletal Health Laboratory is a clinical and translational research lab focused on identifying determinants of peak bone strength, specifically with respect to diet and chronic disease.
Active Research Projects
Defining the role of the "Gut-Bone Axis" in Cystic Fibrosis
Bone metabolism is orchestrated by a closely regulated balance between osteoblasts, which form new bone, and osteoclasts, which break down old bone. These bone-regulating cells are responsive to many stimuli, including nutrient intake and the hormones that regulate metabolism. Experimental studies evaluating changes in bone metabolism following food ingestion in adults report significant decreases in osteoclast-mediated bone degradation, and that gut-derived "incretin" hormones involved in nutrient metabolism help regulate the favorable effects on bone. Cystic fibrosis is among the most common genetic conditions in the United States, and is typically associated with pulmonary dysfunction and infections. Non-pulmonary complications are also common, including maldigestion (and subsequent impaired nutritional status), diabetes, and bone disease. Impaired incretin response and effects are suspected to contribute to development of cystic fibrosis-related diabetes, and our lab is studying involvement of these entero-endocrinopathies in development of cystic fibrosis-related bone disease. These studies involve unique inter-institutional collaborations with the Children's Hospital of Philadelphia's Division of Endocrinology and Emory University's Cystic Fibrosis Center of Excellence, and are supported by the National Institutes of Health (NCATS), the Cystic Fibrosis Foundation, and the University of Georgia's Obesity Initiative.
Growth Disturbances in Children with Avoidant/Restrictive Food Intake Disorder
Avoidant/restrictive food intake disorder (ARFID) is an eating/feeding disturbance characterized by severe food avoidance or restriction that results in faltering growth, nutritional deficiencies, dependence on formula supplementation, and/or significant psychosocial impairment. Compared to other eating disorders, ARFID is observed to have an earlier childhood onset and chronic course without intervention. Childhood represents a sensitive period for longitudinal growth and bone accrual, setting the stage for long-term health outcomes associated with longevity and quality of life, including risk for fracture and osteoporosis. With support from the Marcus Foundation, our lab is partnering with the Marcus Autism Center's Multidisciplinary Feeding Program, a subsidiary of Children's Healthcare of Atlanta, to study growth disturbances in children with ARFID.
Bone Strength in Youth with Type 2 Diabetes
Over 13 million US adolescents are at risk for developing type 2 diabetes, and greater than 366 million people worldwide are expected to develop type 2 diabetes by the year 2030. Compared to type 2 diabetes in adulthood, youth-onset diabetes is a more pervasive condition, associated with an accelerated onset of complications ranging from micro- and macro-vascular complications, kidney failure, and pancreatic beta-cell decline. Adults with type 2 diabetes and children with obesity are at an increased risk for fracture, but the influence of type 2 diabetes on the growing skeleton is unknown. Accordingly, the goal of this project is to understand the influence of type 2 diabetes on the gorwing skeleton.
This project is funded by the American Diabetes Association, and involves an inter-disciplinary and inter-institutional collaboration between the Children's Hospital of Philadelphia and Cincinnati Children's Hospital Medical Center. The first study from this project was recently published in Diabetes Care, reporting the first clinical evidence supporting an adverse influence of type 2 diabetes on peak bone mass attainment. Data collection for a clinical study comparing bone microarchitecture and strength between obese youth with normal glucose control and type 2 diabetes is currently ongoing at the Children's Hospital of Philadelphia.
Obesity and Diabetes-Related Cardiovascular Disease in Youth
Visceral fat plays a key role in type 2 diabetes and cardiovascular disease progression. Gold standard methods for visceral fat assessment including magnetic resonance imaging and computed tomography, but excess cost, time, and radiation exposure limit the application of these techniques in pediatric populations and large-scale clinical studies. Recent advancements in dual-energy X-ray absorptiometry (DXA) technologies allow clinicials and researchers alike to acquire a valid assessment of abdominal fat using a conventional DXA scan. However, it is unknown whether visceral fat from DXA provides added insight with respect to cardiovascular and metabolic risk beyond standard clinical mesures of adiposity such as BMI or waist circumference.
The goal of this project is to assess relationships between visceral fat from DXA and sub-clinical measures of cardiovascular disease (arterial stiffness and atherosclerosis) in a large cohort of youth with healthy weight, obesity, and type 2 diabetes. This study is funded by the University of Georgia Obesity Initiative, and involves an inter-institutional collaboration with Cincinnati Children's Hospital Medical Center. Data collection for this study has been completed, and data analyses are ongoing.
