Impact of Mediterranean diet on mortality in vertebral compression fracture patients

Vertebral compression fractures (VCF) is a common fragility fracture with high mortality worldwide. The management and prevention of VCF start with a proper nutrition. The Mediterranean diet (MD) is rich in balanced nutrients and has been shown to be beneficial for several chronic diseases. However, the association of adherence to Mediterranean diet (aMED) and prognosis of VCF patients remains unclear. To explore the association between aMED and all-cause and cardiovascular disease (CVD)-cause morality in VCF patients. In present study, patients aged ≥ 40 years old and with the VCF patients measurement were extracted from the National Health and Nutrition Examination Survey (NHANES) 2013–2014. The bone mineral density (BMD) dual-energy X-ray absorptiometry (DXA) was used to diagnose VCF. We used the weighted univariable Cox proportional hazards model to screen the covariates related to the prognosis of VCF patients. We utilized the weighted multivariable Cox proportional hazards models to explore the association between aMED and the risk of mortality in VCF patients, and were described as hazard ratios (HRs) and 95% confidence intervals (CIs). Subgroup analyses based on different complications were further assessed the association. A total of 2,730 eligible VCF patients were included. Until 12 December 2019, 218 (7.99%) deaths were documented. After adjusting for all VCFs, we found a high risk of all-cause mortality (HR = 1.75, 95%CI: 1.13–2.73, P = 0.041) and CVD-cause mortality (HR = 2.35, 95%CI: 1.12–4.91, P = 0.038); however, we found no significant association between aMED and all-cause mortality or CVD-cause mortality (all P > 0.05). Compared to patients without VCF and with aMED score ≥ 6, patients with VCF and aMED score < 6 has a higher risk of all-cause (HR = 2.27, 95%CI: 1.25–4.13, P = 0.025) and CVD-cause mortality (HR = 4.25, 95%CI: 1.64–11.06, P = 0.013). Our study also suggested that compared to patients with aMED ≥ 6, those patients with aMED < 6 has high all-cause (HR = 2.26, 95%CI: 1.22–4.17, P = 0.002) and CVD-cause mortality (HR = 3.31, 95%CI: 1.28–8.57, P = 0.018), this results suggested that aMED may have a moderating effect on the association of VCF and mortality. Subgroups analysis shown this moderating effect remain robust, especially in patients with dyslipidemia (HR: 2.49, 95%CI: 1.29–4.80, P = 0.009), CVD (HR: 3.48, 95%CI: 1.56–7.74, P < 0.001) and CKD (HR: 3.64, 95%CI: 1.50–8.78, P < 0.001). We found aMED have a moderating effect on the association between VCF patients and mortality. Our research further supports the importance of the MD as a potentially healthy eating pattern.