Objective

The occurrence of chronic vascular complications in individuals with type 2 diabetes mellitus(T2DM) is influenced by multiple factors. This study aims to analyze the correlation between serum 25-(OH)D₃ levels and other risk factors with the formation and severity of arterial plaques in the lower extremities, and explore its role in clinical diagnosis and treatment.

Methods

A total of 628 Chinese patients with T2DM were included in this study. Based on the intima-media thickness (IMT) and plaque echogenicity measured by lower extremity vascular ultrasound, the patients were divided into the no plaque group(NP), low-risk plague group(LP), moderate-risk plague group(MP), and severe-risk plague group(SP). Based on 25-(OH)D₃ levels, patients were categorized as vitamin D deficient group (VDD，25-(OH)D₃ ≤ 20 ng/mL), vitamin D insufficient group (VDI，25-(OH)D₃ between>20 ng/mL and < 30 ng/mL), and vitamin D sufficient group (VDS，25-(OH)D₃ ≥ 30 ng/mL). The correlation between the severity of lower extremity arterial plaques and serum 25-(OH)D₃ levels was analyzed, as well as the risk factors for lower extremity arterial plaque formation in patients with T2DM.

Results

The levels of 25-(OH)D₃ in patients with arterial plaques were significantly lower than those in the NP (p = 0.002). Additionally, with the increasing severity of lower extremity arterial plaques, 25-(OH)D₃ levels also decreased significantly (p = 0.01). The proportion of patients with sufficient 25-(OH)D₃ levels was highest in NP, while the proportion of deficient and insufficient groups was higher in LP (p<0.001). Multivariate logistic regression analysis showed that low levels of 25-(OH)D₃ were an independent risk factor for lower extremity arterial plaques in T2DM patients. Compared to patients with 25-(OH)D₃>20 ng/mL, the odds ratios for the formation of moderate-risk plaques were 2.525 (95 % CI: 1.45–4.39) in patients with 25-(OH)D₃ ≤ 20 ng/mL, and 2.893 (95 % CI: 1.59–5.26) for the formation of high-risk plaques.

Conclusion

Serum 25-(OH)D₃ levels may be correlated with the occurrence and severity of lower extremity arterial plaques in patients with T2DM. Low serum 25-(OH)D₃ concentration is a risk factor for lower extremity vascular lesions.