People of African American and Hispanic background are at increased risk for many diabetes complications; are fractures among them?
Studies have established diabetes to be a risk factor for fractures. Patients with diabetes have a 60-90% greater chance of getting a fracture than patients without diabetes. Since African American and Hispanic patients are at an increased risk for proteinuria and retinopathy, this study wanted to examine whether their risk of fractures is also increased with diabetes. Previous studies produced conflicting results. However, these studies contained small numbers of minority subjects.
This study gathered data from a multiethnic academic center. They used diagnosis codes for patients who are 40 years of age or older with diabetes. Diabetes was not differentiated between type 1 or type 2. They only included Caucasian, African American, and Hispanic patients. A follow-up protocol was put in place for inclusion. The other comparable group was patients with hypertension, no diabetes (HbA1c less than 6.4%), no antihyperglycemic drug use at any time. Fractures were recognized using diagnosis codes and were differentiated between MOF (major osteoporotic fractures – wrist, humerus, and hip) vs. lower leg fractures. For statistical analysis, they compared groups using t-tests for continuous data or chi-squared for categorical data. Multivariable Cox proportional hazards were used to assess risk.
The group with diabetes (19,153 subjects) included 7,618 Caucasians, 7,456 African Americans, and 4,079 Hispanics. The group with hypertension (26,217 subjects) included 15,138 Caucasians, 8,301 African Americans, and 2,778 Hispanics. The group with diabetes had a higher BMI than the group with hypertension. Caucasians and African Americans in the diabetes group were more likely male and older compared to the hypertension group. Hispanics were similar in both groups regarding age and gender. Regarding MOF, adjusted rates were higher among Caucasians and Hispanics (HR 1.23, 95% CI 1.02-1.48, p=0.026) than African Americans (HR 0.92, 95% CI 0.68-1.23, p=0.56). Regarding lower leg fractures, African Americans and Hispanics had higher unadjusted rates than Caucasians 1.05% and 1.09% vs. 0.74%, p=0.01, and p<0.001, respectively. Regarding multivariable analysis, diabetes mellitus was associated with a rate of MOF among Caucasians and Hispanics (P=0.026) but not in African Americans (P=0.56) when adjusting for age, BMI, gender and prior MOF. However, there was a higher association between MOF and prior MOF in African Americans (HR 10.76, 95% CI 5.47-21.2, p<0.001) than in Caucasians and Hispanics (HR 2.04, 95% CI 1.01-4.11, p=0.046). In patients younger than 65, there was a stronger association among Caucasians and Hispanics (HR 1.44, 95% CI 1.07-1.94, p=0.02). No significant associations regarding lower leg fractures were found, but African Americans did not exhibit to be protected from them (HR 1.15,95% CI 0.93-1.44, p=0.20) like they are in regards to MOF.
This study showed that African Americans with diabetes do not have an additional risk of fractures because of diabetes. At the same time, Hispanics and Caucasians with diabetes have a similar risk in fractures. Future studies should be prospective to confirm these findings. Limitations of this study include using a single center for data instead of multiple, and the possibility of selection bias because patients who care about their health come to the provider’s office more often; therefore, they might be healthier. Lastly, they did not include bone mineral density data to compare.
- The risk of major osteoporotic fractures resulting from diabetes is similar in both Hispanics and Caucasians.
- In African Americans who have diabetes, the risk was not found to be established relating to major osteoporotic fractures. However, they were not found to be protected from lower leg fractures.
- Having had a previous fracture, African Americans exhibit a higher risk of fractures in comparison to Hispanics and Caucasians.
Jain, Rajesh K, et al. “Diabetes-Related Fracture Risk Is Different in African Americans When Compared to Hispanics and Caucasians.” The Journal of Clinical Endocrinology & Metabolism, Jan. 2019
Nour Salhab, Pharm.D. Candidate, USF College of Pharmacy