Correlation between 25-hydroxyvitamin D levels and remnant cholesterol in patients with type 2 diabetes

Remnant cholesterol (RC) is an independent predictor of cardiovascular events in type 2 diabetes mellitus (T2DM). Concurrently, vitamin D deficiency is a recognized risk factor for developing T2DM. However, the association between serum 25-hydroxyvitamin D (25(OH)D) levels and RC in patients with established T2DM remains incompletely elucidated. Specifically, potential non-linear relationships and modifications of this association by age and sex are unclear. This study investigates the relationship between 25(OH)D and RC in a cohort of 380 patients with T2DM.

A total of 380 T2DM patients (283 men and 97 women) were evaluated. Demographic data were analyzed descriptively. Statistical tests assessed the association between 25(OH)D levels and RC, and piecewise linear regression was utilized to explore potential threshold effects.

Spearman correlation analysis revealed that female gender was significantly associated with higher RC levels (ρ = 0.163, p = 0.002). Piecewise linear regression identified a threshold effect at 18.8 ng/mL: below this threshold, each 1 ng/mL increase in 25(OH)D was associated with a decrease in RC of 0.01 mmol/L (β = -0.01, 95% CI: -0.02 to -0.00); above this threshold, it was associated with an increase of 0.02 mmol/L (β = 0.02, 95% CI: 0.00 to 0.03).Age significantly modified this association (interaction p < 0.05), suggesting an age-dependent inversion of the effect of vitamin D on RC.

This study demonstrates a complex, non-linear relationship between 25(OH)D levels and Remnant cholesterol in patients with type 2 diabetes. Age significantly modifies this relationship, suggesting that tailored interventions based on vitamin D status may be warranted to inform future interventional studies targeting RC modulation.