Why Fractures and Falls in Type 2 Diabetes?

A prospective study found an increased risk for fractures and falls among older women with type 2 diabetes.

Fractures among older adults is a common complication in T2DM, occurring three times more than in people without T2DM. Fracture incidences can lead to increased health care costs, postoperative complications, loss of physical function, and more prolonged hospitalizations. Additional risk factors include female sex, low bone density, history of falls, comorbidities, and alcohol use. Although the mechanism behind the increased fracture risk among patients with diabetes is not entirely understood, potential reasons could be that poor glucose control results in falls and reduced bone quality associated with hypoglycemia. Hypoglycemia is a common adverse event with antidiabetic medications, shown to increase fracture risk by increasing falls. Previous studies in this population group have been based on few individuals or clinical samples. A study in the U.K utilizing an electronic database showed that patients with T2DM and hypoglycemic events had a 1.24 times greater incidence of fractures, which is relevant when selecting antidiabetic medications. The Study of Osteoporotic Fractures showed that women with diabetes receiving insulin had a doubled risk of falls, but further research was needed to determine if diabetes treatment reduces fall risk. Additionally, intensive lowering of HbA1c levels has not been shown to prevent fracture, and this large group of patients remains untreated. Risk stratification is challenging in older patients with T2DM as they do not fit the standard of low bone density and low body weight, so further studies are needed to identify risk factors for fractures in patients with T2DM. 

A prospective study was conducted to identify clinical characteristics contributing to fragility fractures in older patients with T2DM, including Framingham Original and Offspring Cohorts members. The baseline observation for everyone was characterized as the clinic exam for which T2DM was first diagnosed, and fracture event data was collected at each clinic visit. Additionally, the skeletal site of the fracture, reasoning for fracture, and treatment was obtained. The correlation between risk factors and fracture incidence in patients with T2DM was analyzed using a repeated-measures approach. Cox proportional hazards regression models were also used to calculate hazard ratios and confidence intervals. When analyzing insulin use and fracture incidence, age, sex, T2DM duration, height, and weight were adjusted.

This study included 793 patients with T2DM, in which 36% of patients used antidiabetic medications and 11% used insulin. More than 25% of participants had falls or fractures within the previous year, and more than 50% had bone mineral density T scores greater than or equal to -1.0. The most common fracture sites were the hip (27%), upper arm (18%), foot (17%), wrist (15%), and ribs (14%). In the adjusted analysis, increased age and female sex were associated with higher fracture incidence. Two or more falls within the previous year (HR 3.29; 1.34–8.09) and history of fractures (HR 2.05; 1.34–3.12) were significantly associated with increased fracture risk in the adjusted analysis. While grip strength remained a predictor for fracture risks, bone mineral density was insignificant. Current estrogen use, antidiabetic medications, and other chronic diseases were not associated with increased fracture incidences.

Previous fractures and falls, increased age, female sex, and lower grip strength were significant risk factors for fracture incidences in older patients with T2DM. Lower BMI, bone mineral density, comorbidities, and the use of medications were not strong predictors of fracture in this study population. This study found an increased risk of fractures in patients with an HbA1c between 6.5 to 7.49%. Complications of diabetes, such as poor vision, decreased peripheral nerve and renal function, have previously shown an association with increased risk of falls. It was challenging to determine thresholds for drug treatment in older patients with T2DM who have average or elevated bone mineral density. However, this study shows additional risk factors such as age, sex, and lower grip strength among patients with diabetes. These results can be used in clinical practice when evaluating opportunities for early intervention to reduce fracture incidence in a high-risk group.

Practice Pearls:

• Fractures are common in older patients with T2DM; however, the specific risk factors such as medications and hypoglycemia are unknown.
• This prospective study found an increased risk of fractures and falls among older women who had T2DM, lower grip strength, and higher levels of HbA1c.
• Bone mineral density, other medications, and BMI were not substantial risk factors for fracture incidences.

Oei, Ling et al. “High bone mineral density and fracture risk in type 2 diabetes as skeletal complications of inadequate glucose control: the Rotterdam Study.” Diabetes care

Ntouva, Antiopi et al. “Hypoglycaemia is associated with increased risk of fractures in patients with type 2 diabetes mellitus: a cohort study.” European journal of endocrinology 

Valderrábano, Rodrigo J, and Maria I Linares. “Diabetes mellitus and bone health: epidemiology, etiology, and implications for fracture risk stratification.” Clinical diabetes and endocrinology 

Schwartz, Ann V. “Epidemiology of fractures in type 2 diabetes.” Bone

Dufour, Alyssa B et al. “Risk Factors for Incident Fracture in Older Adults With Type 2 Diabetes: The Framingham Heart Study.” Diabetes care

Dalia Elabed, PharmD Candidate 2022, University of South Florida Taneja College of Pharmacy