Increased risk of vertebral fracture in patients with diabetes: a meta-analysis of cohort studies

Purpose The relationship between diabetes and risk of fracture has been reported differently in study design and risk estimates, and the relationship between diabetes and risk of vertebral fracture remained unclear. Therefore, we performed a meta-analysis of prospective or retrospective cohort studies to assess the potential relationship between diabetes and vertebral fracture. Methods We searched medical databases for prospective or retrospective cohort studies on the association between diabetes and vertebral fracture risk. Pooled relative risks (RR) and corresponding 95 % confidence intervals (95 % CI) were calculated with a random-effects model of meta-analysis. Results Meta-analysis of eight studies showed that the pooled RR of vertebral fracture for diabetic individuals was 2.03 (95 % CI 1.60-2.59; p < 0.0001). Subgroup analysis by gender showed that the corresponding RRs for male and female were 2.70 (95 % CI 1.34-5.43; p = 0.005) and 1.93 (95 % CI 1.18-3.13; p = 0.008), respectively. Subgroup analysis by study design showed that the corresponding RRs for prospective design and retrospective design were 1.81 (95 % CI 1.19-2.75; p = 0.006) and 2.23 (95 % CI 1.60-3.10; p < 0.0001), respectively. Subgroup analysis by time of follow-up showed that the RR of vertebral fracture for patients with > 20 and < 20 years of follow-up were 2.23 (95 % CI 1.98-3.62; p < 0.0001) and 1.67 (95 % CI 1.29-2.16; p < 0.0001), respectively. Conclusions Diabetes is an independent risk factor for vertebral fracture, primarily being due to diabetic osteoporosis.