Glycated Hemoglobin Level and Risk of Hip Fracture in Older People with Type 2 Diabetes: A Competing Risk Analysis of Taiwan Diabetes Cohort Study

Abstract

Hip fracture, which is associated with substantial morbidity and long-term mortality, imposes a major burden on the healthcare system. Diabetes is a risk factor for osteoporosis, which is a crucial risk factor of hip fracture. However, epidemiological studies investigating the risk of hip fracture among patients with type 2 diabetes are limited. This study explored the association between hemoglobin A1c (HbA1c) and the risk of hip fracture in people with type 2 diabetes aged 65 years and older. We conducted a retrospective cohort study of 20 025 older patients with type 2 diabetes who participated in the National Diabetes Case Management Program in Taiwan. The HbA1c level at the baseline and hip fracture incidence over an average of 7.41 years of follow-up were analyzed (maximum and standard deviation were 10.9 and 2.42 years, respectively). A total of 1514 hip fracture cases were recorded. The incidence rates of hip fracture were 9.15, 8.02, 9.58, 10.61, 12.51, and 13.43 per 1000 person-years in patients with baseline HbA1c levels of < 6%, 6-7%, 7%-8%, 8%-9%, 9%-10%, and ! 10%, respectively. After multivariate adjustment, the risk of hip fracture increased among patients with HbA1c levels of 9%-10% and ! 10.0% compared with patients with HbA1c levels of 6-7% (hazard ratio, 1.24; 95% confidence interval, 1.02-1.49 and 1.32; 1.09-1.58, respectively). Significant linear trends among various HbA1c levels were observed (P < 0.05). Patients with type 2 diabetes whose HbA1c levels exceeded 9.0% exhibited an increased risk of hip fracture, confirming a linear relationship. Our study's findings demonstrated the importance of glycemic control for fracture prevention in older adults with type 2 diabetes.

Epidemiology of fractures in type 2 diabetes

“…In the largest study, based in Taiwan, with 1514 hip fracture cases in T2D patients, those with baseline A1C levels of 9-10% (HR = 1.24; 1.02-1.49) and 10% + (HR = 1.32; 1.09-1.58) had higher hip fracture rates compared with A1C levels of 6-7% (Fig. 3) [73].There was a suggestion of a higher rate in those with A1C b 6% (HR = 1.19; 0.97-1.45) compared with 6-7%, but the difference was not statistically significant. Those with a baseline A1C of 7-8% had a slight increase in hip fracture (HR = 1.07; 0.92-1.25) compared with A1C of 6-7%.…”

“…However, this trial cannot determine whether poor glycemic control has an effect on these outcomes. Several longitudinal observational studies are now available that have directly addressed this issue [73][74][75][76]. In the largest study, based in Taiwan, with 1514 hip fracture cases in T2D patients, those with baseline A1C levels of 9-10% (HR = 1.24; 1.02-1.49) and 10% + (HR = 1.32; 1.09-1.58) had higher hip fracture rates compared with A1C levels of 6-7% (Fig.…”

MECHANISMS IN ENDOCRINOLOGY: Diabetes mellitus, a state of low bone turnover – a systematic review and meta-analysis

“…Another study in 18 patients with type 1 diabetes did not show any differences in bone turnover compared to non-diabetes subjects (7). These patients were well controlled with a mean HbA1c of 6.8% (7), which may influence the results as the fracture risk is highest in patients with HbA1c levels above 9% (39).…”

Bone fractures in patients with type 2 diabetes mellitus: prevalence and risk factors

“…В настоящем исследовании различий по уровню гликированного гемоглобина у пациентов с переломами и без выявлено не было. Однако в одной из работ плохая компенсация СД была фактором риска переломов [19]. Дополнительным фактором риска переломов считается дефицит инсулина [20].…”