Diabetes Mellitus and Intervertebral Disc Degeneration: A Meta-Analysis

- BACKGROUND: Diabetes mellitus (DM) has been related to a higher risk of intervertebral disc degeneration (IVDD). However, the previous studies showed inconsistent results. We performed a systematic review and metaanalysis to comprehensively investigate the association between DM and IVDD in adult population. - METHODS: Observational studies relevant to the aim of the meta-analysis were retrieved by search of electronic databases including PubMed, Web of Science, and Embase. A random-effects model was used to combine the data by incorporating the influence of between-study heterogeneity. - RESULTS: Eleven observational studies involving 2,881,170 adults were included. Among them, 1,211,880 had DM. Compared to those with normoglycemia, patients with DM were associated with a higher odds ratio of IVDD (OR: 1.68, 95% confidence interval: 1.24 to 2.29, P < 0.001; I 2 = 98%). Further sensitivity analysis excluding database studies with IVDD diagnosed via International Classification of Diseases codes showed consistent results (odds ratio: 1.47, 95% confidence interval: 1.06 to 2.02, P = 0.02) with no statistical heterogeneity (I 2 = 0%). Subgroup analyses showed a stronger association between DM and IVDD in cohort studies than that in cross-sectional studies, in studies evaluating overall IVDD than that evaluating lumbar disc degeneration, and in studies that adjusted age and body mass index than that did not ( P for subgroup differences all <0.05). Subgroup analyses according to study country and quality score did not significantly affect the association. - CONCLUSIONS: DM may be associated with IVDD in adult population, which seems to be independent of age and body mass index.