Trends in incidence of proximal humerus fractures, surgical procedures and outcomes among elderly hospitalized patients with and without type 2 diabetes in Spain (2001–2013)

BACKGROUND Several studies have reported that diabetic persons have an increased risk for fractures than non-diabetes patients. The association between proximal humerus fractures and type 2 diabetes (T2DM) is unclear and some studies point to insulin treatment, hypoglycaemic episodes consequently to inadequate control of diabetes or, more recently, to an alteration of trabecular bone. We examined trends in the incidence of proximal humerus fractures, surgical procedures and outcomes among hospitalized patients aged ≥65 years, with and without T2DM in Spain, 2001-2013. METHODS This retrospective, observational study was conducted using the Spanish National Hospital Discharge Database to select all hospital admissions with proximal humerus fracture. We calculated incidences overall and stratified by diabetes status, year and sex. We analyzed surgical procedures, comorbidities, length of stay, in-hospital complications and in-hospital mortality. RESULTS We identified 43,872 patients with proximal humerus fracture (18.3% had a T2DM diagnosis). Age-adjusted incidence rates elevated steadily over the study period for men and women with and without T2DM, independently of diabetes status, although we found a stable trend in the later years. Patients with T2DM had lower relative risk of proximal humeral fracture incidence: 0.87 (95%IC 0.82-0.93) for men and 0.97 (95%IC 0.95-1.00) for women. In-hospital complications were 4.0% of diabetic men vs. 2.6% in non-diabetic (p < 0.001) and 2.9% among T2DM women vs. 1.7% in those without (p < 0.05). The use of open reduction of fracture with internal fixation and arthroplasty is increasing overtime and closed reduction with internal fixation is decreasing. Presence of T2DM in women was associated with higher in-hospital mortality (OR 1.67; 95%CI 1.29-2.15). Comorbidities, in-hospital complications and older age were predictors of higher in-hospital mortality in both sexes. CONCLUSIONS The incidence of proximal humerus fractures seems to be increasing in Spain. The incidence is lower among men with than without T2DM. T2DM is associated to higher in-hospital complications in both sexes. The use of open reduction of fracture with internal fixation and arthroplasty is increasing overtime beside diabetes status. Women with T2DM have higher in-hospital mortality than those without the disease.