Hip fractures significantly increase the risk of mortality and morbidity in older adults. As a result, the risk factors (RFs) for this condition are being extensively studied, particularly those related to hip fractures in individuals with T2D. Aging is well known to be associated with decreased bone mineral density (BMD) and reduced bone quality, which lead to fragility fractures. However, elderly individuals with T2D tend to paradoxically exhibit higher BMD [1].

Currently, the relationship between hip fractures and T2D is unclear. Some studies have found no association between the risk of hip fractures and T2D [[2], [3], [4], [5], [6], [7]], while others have reported mild-to-significant association [[8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18]]. These conflicting results may be attributed to factors such as cohort size, heterogeneity, participant age, and the misclassification of type 1 diabetes (which carries a much higher fracture risk) as T2D.

A recent meta-analysis reported an association between T2D and an increased risk of hip fractures: relative risk (RR) 1.34 [95% confidence interval (CI) 1.19;1.51] [19]. However, this risk may have been overestimated due to the inclusion of individuals with type 1 diabetes. Other researchers have demonstrated that pooled estimates can be significantly biased when the effect size is small. After incorporating previously missed studies into the former, the adjusted risk for hip fractures in T2D was found to be smaller: RR 1.24 [1.22;1.26] [20]. On the other hand, a large nationwide cohort study involving 580,127 individuals with T2D and controls, found that the presence of T2D was not a clinically relevant factor for any type of fracture: hip fracture hazard ratio (HR) 1.06 [95% CI 1.04;1.08]. In fact, the majority of these patients (55%) had a small but significantly lower fracture risk compared to controls. The authors suggested that these findings challenge the notion that fracture risk is inherently elevated in T2D. Instead, factors such as BMI < 25 kg/m2, long duration of diabetes, insulin treatment, and low physical activity (PA), were identified as the most significant contributors to increased fracture risk in these patients [7].

Surprisingly, another recently large retrospective study of individuals aged ≥ 65 years, found that 23,314 matched hip fractures were associated with a reduced risk of T2D (HR 0.77 [0.719;0.827]), suggesting that the relationship between bone and glucose metabolism is complex [21]. Currently, the prevalence and risk factors for hip fractures in T2D remain topics of discussion.

To our knowledge, few studies have explored the association between socioeconomic status (SES) and hip fracture in older individuals with T2D. Furthermore, it is not well established whether social inequities in these patients exacerbate the risk of hip fractures. A recent survey suggested that the inverse relationship between SES and fracture risk observed in younger and middle-aged individuals may not necessarily apply to the elderly population [22]. Lower education levels have been linked to a higher incidence of fractures and associated RFs in patients with diabetes. Additionally, community differences, particularly between urban and rural areas, could contribute to fracture risk and should be considered.

With the increasing prevalence of elderly patients with T2D, the population at high risk for hip fractures is likely to grow. Therefore, it is crucial to improve our understanding of the relationship between diabetes and hip fractures, to address the persistent challenges of mortality and morbidity associated with these conditions.

This prospective-based population study aimed to analyze the association between hip fracture incidence and T2D, along with risk factors, such as SES (education and community) and PA, in a cohort of elderly individuals from rural, semi-urban, and urban areas over a median follow-up of three years.