Persons with type 1 and type 2 diabetes (T1D, T2D) both have increased fracture risk, attributed to specific deficits in the microarchitecture, material properties and strength of diabetic bone. Sodium-dependent glucose co-transporter 2 (SGLT2) inhibitors are a new class of FDA- approved glucose-regulating agents for use in persons with T2D. These drugs (canagliflozin, dapagliflozin and empagliflozin are FDA-approved in the USA and Europe) increase urinary glucose excretion by inhibiting glucose reabsorption in the renal proximal tubule, and thereby improve glycemic control in persons with type 2 diabetes. They are likely to play a prominent role in the future treatment of T2D because of this unique mechanism of action, and because they provide concurrent beneficial reductions in body weight and blood pressure. However, early clinical studies have demonstrated a possible ~30% increase in bone fractures in patients receiving these medications, with fractures occurring as early as 12 weeks of therapy. At present, very little is known about the effects of SGLT2 inhibition on bone mineral homeostasis, bone turnover or bone microarchitecture, or how these drugs specifically impact diabetic bone disease. Therefore, the objective of this proposal is to utilize several relevant rodent models (slc5a2-functional mutants, STZ-induced diabetes, TallyHo) to investigate potential mechanisms contributing to the adverse effects of SGLT2-inhibitor therapy on the skeleton. Furthermore, we will investigate the efficacy of co-therapy with anti-calciuric thiazide diuretic drugs to potentially mitigate the negative effects of SGLT2-inhibitor therapy on the skeleton. Recognizing that a lifelong increased risk for fragility fracture is now an established comorbidity of diabetes, a better understanding of the effects of SGLT2 inhibitors on bone health is both timely and highly relevant to the future of diabetes treatment.

Public Health Relevance

Persons with either Type 1 or Type 2 diabetes (T1D, T2D) have an increased risk for bone fracture, which is not predicted by bone mineral density testing alone; rather, diabetic bone appears to be more brittle, owing to diabetes-related changes in the microarchitecture and strength of the skeleton. The SGLT2 inhibitor class of drugs is a new class of glucose-regulating agents, which improves glucose control in persons with diabetes by allowing the excess glucose to be excreted in the urine. However, these drugs appear to also further increase the risk of fractures in diabetic patients; therefore, the objectives of this proposal are to study the mechanisms contributing to the increased fracture risk in persons receiving these medications.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AR070620-02
Application #
9304883
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Nicks, Kristy
Project Start
2016-07-01
Project End
2019-06-30
Budget Start
2017-07-01
Budget End
2019-06-30
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of Kentucky
Department
Pediatrics
Type
Schools of Medicine
DUNS #
939017877
City
Lexington
State
KY
Country
United States
Zip Code
40526
Kalaitzoglou, Evangelia; Fowlkes, John L; Popescu, Iuliana et al. (2018) Diabetes pharmacotherapy and effects on the musculoskeletal system. Diabetes Metab Res Rev :e3100
Thrailkill, Kathryn M; Nyman, Jeffry S; Bunn, R Clay et al. (2017) The impact of SGLT2 inhibitors, compared with insulin, on diabetic bone disease in a mouse model of type 1 diabetes. Bone 94:141-151
Kalaitzoglou, Evangelia; Popescu, Iuliana; Bunn, R Clay et al. (2016) Effects of Type 1 Diabetes on Osteoblasts, Osteocytes, and Osteoclasts. Curr Osteoporos Rep 14:310-319