# Association Between Serum Vitamin D and Albuminuria in Type 2 Diabetes Independent of Inflammatory Markers and Renal Function

## TL;DR

Low vitamin D levels are strongly linked to kidney damage in type 2 diabetes patients, even after accounting for kidney function and inflammation.

## Contribution

Shows vitamin D deficiency correlates with albuminuria in T2D, independent of GFR and inflammatory markers.

## Key findings

- Vitamin D deficiency was 7.34 times more likely in T2D patients with albuminuria.
- High TNF-α levels were 6.77 times more common in T2D patients with albuminuria.
- Elevated hs-CRP levels were 4.7 times more frequent in T2D patients with albuminuria.

## Abstract

To explore the relationship between serum high‐sensitivity C‐reactive protein (hs‐CRP), tissue necrosis factor‐α (TNF‐α) and 25‐Hydroxyvitamin D (25(OH) vitamin D) with albuminuria in patients with type 2 diabetes mellitus (T2D).

This was a cross‐sectional study of 86 T2D patients divided into categories of with and without albuminuria based on the urine albumin‐to‐creatinine ratio (UACR). A 25(OH) vitamin D concentration ≤ 15 ng/mL was defined as vitamin D deficiency, within 15–30 ng/mL as vitamin D insufficiency, and > 30 ng/mL as serum 25(OH) vitamin D sufficiency. A hs‐CRP level ≤ 2.5 mg/L was considered low, whereas a hs‐CRP level > 2.5 mg/L was considered high. TNF‐α was classified as low or high with an 8.2 pg/mL cutoff level based on receiver operating characteristic (ROC) curve analysis. P values < 0.05 were considered to be significantly associated with albuminuria.

Vitamin D deficiency was significantly more commonly observed among T2D patients with albuminuria than those without albuminuria (adjusted OR = 7.34, 95% CI = 2.3–23.6, p = 0.001). Higher serum TNF‐α levels (TNF‐α > 8.2 pg/mL) were more frequently associated with the presence of albuminuria in T2D patients (adjusted OR = 6.77, 95% CI = 1.61–28.4; p = 0.009). Similarly, elevated serum hs‐CRP levels (hs‐CRP > 2.5 mg/L) were more commonly found among patients with T2D and albuminuria than in those without (adjusted OR = 4.7, 95% CI = 1.4–15.8; p = 0.012).

Vitamin D deficiency is a significant correlate of albuminuria in T2D patients, independent of glomerular filtration rate (GFR) and basic inflammatory markers including hs‐CRP and TNF‐α. Moreover, serum hs‐CRP > 2.5 mg/L and TNF‐α > 8.2 pg/mL were each individually associated with a significantly increased likelihood of albuminuria in T2D patients.

Vitamin D deficiency is a significant correlate of albuminuria in T2D patients, independent of eGFR and basic inflammatory markers including hs‐CRP and TNF‐α. Serum hs‐CRP > 2.5 mg/L and TNF‐α > 8.2 pg/mL were each individually associated with a significantly increased likelihood of albuminuria in T2D patients.