Association between nailfold capillaroscopic findings and diabetes: a systematic review and meta-analysis

People with diabetes often experience abnormal microcirculation, which can lead to various complications. This study aimed to investigate the relevance of nailfold capillaroscopy-a non-invasive imaging modality-in characterizing microvascular alterations specific to diabetes mellitus (DM).

PubMed, Web of Science, and Baidu Academic were searched for relavant studies that investigated the associations between nailfold microcirculation abnormalities and DM. The quality of included studies was assessed using the National Institutes of Health (NIH) Quality Assessment tool for Observational Cohort and Cross-Sectional Studies. Meta-analysis was conducted to assess the relationship of various nailfold capillaroscopic findings with DM, and subgroup analysis was used to explore heterogeneity.

Ten studies with 1,423 participants were included. The quality of two studies was rated as Good, one as Poor, and the other seven were rated as Normal. The pooled analysis revealed significant correlations between various nailfold capillaroscopic findings and DM, including tortuosity (odds ratio [OR] 8.33, 95% confidence interval [CI]: 2.31-30.04), abnormal morphology (OR 5.00, 95% CI 3.03-8.26), ectasia (OR 4.86, 95% CI 2.56-9.20), bushy capillaries (OR 29.09, 95% CI 5.90-143.55), hemorrhage (OR 5.33, 95% CI 2.31-12.34), avascular areas (OR 6.14, 95% CI 1.40-26.86), bizarre capillaries (OR 10.33, 95% CI 2.79-38.31), and meander capillaries (OR: 2.84, 95% CI 1.25-6.45). Subgroup analysis showed strong associations between nailfold capillaroscopic findings and type 2 diabetes mellitus (T2DM).

Our findings demonstrated that distinct nailfold capillary abnormalities aresignificantly correlated with DM, particularly T2DM.

Protocol registered in PROSPERO (registration number: CRD42024608214).