Type 2 diabetes and bone mineral density: A meta-analysis and systematic review

Type 2 diabetes (T2D), a widespread chronic metabolic disorder, presents frequently in clinical settings. The relationship between T2D and bone mineral density (BMD) has been subject to ongoing investigation, yielding inconclusive results.

A systematic literature search was conducted across several databases, including CNKI, VIP, CBM, Wanfang, PubMed, Cochrane Library, and Embase, targeting observational studies that explored the impact of microangiopathy associated with T2D on BMD or bone metabolism. The search spanned from the inception of each database to July 1, 2023. The Newcastle-Ottawa Scale was employed for quality assessment, and RevMan 5.3 software was utilized for data analysis. Stata 14.0 was used for the quantitative evaluation of publication bias regarding outcome measures.

The inclusion criteria were met by 30 observational studies, comprising 6470 participants-3121 with diabetes and 3349 without. The meta-analysis revealed no significant difference in overall BMD between the nondiabetic and T2D groups (mean difference [MD] = -0.07, 95% confidence interval [CI] [-0.17, 0.03], Z = 1.45, P = .15). However, BMD at the lumbar vertebrae was significantly higher in nondiabetic individuals compared with those with T2D (MD = -0.14, 95% CI [-0.22, -0.06], Z = 3.32, P = 0.0009), as was the case with femoral neck BMD (MD = -0.11, 95% CI [-0.18, -0.04], Z = 3.08, P = .002). A difference in femoral neck BMD between nondiabetics and individuals with T2D approached but did not reach statistical significance (MD = -0.14, 95% CI [-0.27, 0.00], Z = 1.94, P = .05). An inverted funnel plot analysis suggested possible publication bias, as evidenced by an asymmetrical distribution of studies around the axis of symmetry, with overlap observed in several cases.

The findings indicate a significant association between T2D and reduced BMD at critical sites such as the lumbar vertebrae and femoral neck, highlighting an increased risk of osteoporosis or osteoporotic fractures in these regions.