The pattern of incident fractures in patients with diabetes mellitus compared to matched controls

Date of ISAC Approval: 
21/12/2018
Lay Summary: 
Diabetes Mellitus (DM) is a chronic disease, wherein the regulation of the blood sugar (glucose) level is disturbed resulting in high glucose levels. On the long-term patients with DM might get complications such as; eye damage (retinopathy), kidney damage (nephropathy), and nerve damage (neuropathy). DM can also damage bones resulting in fractures. How this happens is unclear. Current studies mostly focus on the question whether patients with DM have more fractures compared to people without DM or only focus on one fracture location such as hip fracture. It has been reported that patients who have DM for multiple years, or who have complications due to DM have more fractures compared to patients who have DM for a shorter time period or who have no complications. However, studies who focussed on these subjects are very different and therefore it is hard to compare the results. In addition, it is not clear which fracture types are more common in patients with DM, since most studies only look at the total amount of fractures or one specific fracture type. Therefore, the aim of our study is to observe whether specific fracture types are more common in patients with DM compared to people without DM. Furthermore, we will also determine whether fractures are more common in patients with DM who have complications compared to patients with DM without complications.
Technical Summary: 
The pattern of incident fractures among patients with and without T1DM and T2DM. Within CPRD all patients with a first ever prescription for an insulin or a non-insulin anti-diabetic drug will be selected. Patients will be matched by year of birth, sex and practice to 1 control. Patients with a first ever prescription to an insulin need to have a diagnosis for T1DM before the index date (the date of the first prescription) to be included in our T1DM cohort. Patients with a first ever prescription to a non-insulin anti-diabetic drug need to have a diagnosis of T2DM before the index date to be included in our T2DM cohort. Patients in both cohorts will be followed for incident fractures. Incidence rates will be calculated by dividing the number of fractures over the number of total person years. Incidence rate ratios will be calculated by dividing the incidence rates for patients with diabetes over the incidence rates of the controls. Fracture and sex specific incidence rates will be calculated. For patients with diabetes incidence rates will be stratified by the presence of diabetes complications at baseline.
Health Outcomes to be Measured: 
- The incidence of various fracture types in diabetes compared to healthy controls in men and women, wherein diabetes will be divided in type I and type II - The incidence of various fracture types in diabetic patients with complications versus diabetic patients without complications
Collaborators: 

Frank de Vries - Chief Investigator - Utrecht University
Cindy Sarodnik - Collaborator - Maastricht University
Frank de Vries - Corresponding Applicant - Utrecht University
Johanna Annemariek Driessen - Collaborator - Utrecht University
Joop van den Bergh - Collaborator - Maastricht University
Dr Nicklas Rasmussen - Collaborator - Aalborg University Hospital
Nicolaas Schaper - Collaborator - Maastricht University
Mr Patrick C Souverein - Collaborator - Utrecht University
Peter Vestergaard - Collaborator - Aalborg University Hospital
Sandrine Bours - Collaborator - Maastricht University