Type 1 diabetes (T1DM) leads to profound skeletal fragility. Adults with T1DM have a hip fracture rate almost 6-fold higher than the general population. The pathophysiology of this increased fracture risk remains poorly understood, hampering efforts to prevent fractures and their significant associated morbidity and mortality. Clinical studies as well as studies in animal models have demonstrated that T1DM leads to suppression of bone formation, a process which peaks during the pubertal growth spurt. These observations suggest that childhood/adolescence is a critical period during which the skeleton is particularly vulnerable to the effects of diabetes. This proposal thus seeks to further characteriz diabetic bone disease with a focus on effects during childhood growth. We will prospectively follow a cohort of children with T1DM and matched controls for 2 years and evaluate the effects of diabetes on bone accrual, skeletal microarchitecture, and estimates of bone strength. We will determine to what extent glycemic control and diabetes-associated metabolic derangements including decreased insulin-like growth factor 1 concentrations affect these measures. These studies will utilize several complementary imaging modalities including DXA and the novel techniques of high-resolution peripheral quantitative CT and individual trabecula segmentation. Dr. Mitchell is an Instructor in Pediatrics at Harvard Medical School and an Assistant in Pediatrics in the Pediatric Endocrine Unit at Massachusetts General Hospital. Her long-term goal is to be an independent clinical investigator in the field of pediatric bone physiology, utilizing both traditional and investigational methods of skeletal assessment to understand the influence of early life factors on long-term bone health with a focus on the effects of T1DM. Her experience in clinical studies of bone mineral metabolism in healthy children equips her well to lead this project. Her career development will be closely guided by her co-mentors, Drs. Madhusmita Misra, Mary Bouxsein, and Enrico Cagliero, who jointly provide expertise in hormonal determinants of bone accrual in children, bone biomechanics, investigational imaging technologies, and diabetes pathophysiology. They have an outstanding track record of mentoring junior investigators and are committed to Dr. Mitchell's success. Execution of the proposed project will provide Dr. Mitchell hands-on training in biochemical and radiological techniques of bone health assessment. In addition, the career development plan incorporates formal instruction in advanced biostatistics and study design at the Harvard School of Public Health. This mentored research award will provide Dr. Mitchell the additional training critical to her success as an independent clinical investigator in pediatric bone physiology and childhood antecedents of osteoporosis. Improved understanding of the deleterious effects of T1DM on bone health will be critical to the design of subsequent interventional trials to optimize bone health in patients with T1DM.

Public Health Relevance

Adults with type 1 diabetes (T1DM) have an extremely high risk of osteoporosis and fractures for reasons that remain poorly understood. The goal of this study is to investigate bone growth and microarchitecture in children with T1DM to determine whether impaired bone acquisition and altered bone properties in early life contribute to this fracture risk decades later. This information may help us design targeted interventions to treat and, ideally, prevent diabetes-associated bone disease

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Mentored Patient-Oriented Research Career Development Award (K23)
Project #
5K23DK105350-02
Application #
9265840
Study Section
Diabetes, Endocrinology and Metabolic Diseases B Subcommittee (DDK-B)
Program Officer
Spain, Lisa M
Project Start
2016-05-01
Project End
2021-03-31
Budget Start
2017-04-01
Budget End
2018-03-31
Support Year
2
Fiscal Year
2017
Total Cost
$197,191
Indirect Cost
$13,838
Name
Massachusetts General Hospital
Department
Type
Independent Hospitals
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
02114
Mitchell, Deborah M; Caksa, Signe; Yuan, Amy et al. (2018) Trabecular Bone Morphology Correlates With Skeletal Maturity and Body Composition in Healthy Adolescent Girls. J Clin Endocrinol Metab 103:336-345
Singhal, Vibha; Tulsiani, Shreya; Campoverde, Karen Joanie et al. (2018) Impaired bone strength estimates at the distal tibia and its determinants in adolescents with anorexia nervosa. Bone 106:61-68
Mitchell, Deborah M; Jüppner, Harald; Burnett-Bowie, Sherri-Ann M (2017) FGF23 Is Not Associated With Age-Related Changes in Phosphate, but Enhances Renal Calcium Reabsorption in Girls. J Clin Endocrinol Metab 102:1151-1160
Mitchell, Deborah M (2017) Growth in patients with type 1 diabetes. Curr Opin Endocrinol Diabetes Obes 24:67-72
Chang, Connie Y; Rosenthal, Daniel I; Mitchell, Deborah M et al. (2016) Imaging Findings of Metabolic Bone Disease. Radiographics 36:1871-1887