Vitamin D levels predict risk for diabetic peripheral neuropathy
MedWire News: Vitamin D deficiency is a risk factor for diabetic peripheral neuropathy (DPN) among Type 2 diabetes patients, a study from Kuwait shows.
Supplementation with vitamin D could prevent or delay the onset of DPN, say Dia Shehab (Kuwait University) and colleagues.
As reported in the journal Diabetic Medicine, the team measured vitamin D levels (serum 25-hydroxy-vitamin D [25(OH)D]) in 210 patients with Type 2 diabetes from diabetes clinics at the Mubarak Al Kabeer hospital.
The patients were divided into those who had DPN (n=87) and those who did not (n=123), as determined by neuropathy symptom score, neuropathy disability score, and nerve conduction study score.
The researchers report that the duration of diabetes was significantly different between the two groups. Of the DPN patients, 63 had a duration of diabetes of more than 10 years, compared with only 12 of those who did not have DPN.
The mean glycated hemoglobin (HbA1c) level was also significantly higher among the patients with DPN than it was among those without (9.3 vs 7.9%).
The study revealed that the mean vitamin D level was significantly lower among those with DNP than in it was in those without (36.90 vs 58.32 nmol/mL). In addition, 81.5% of patients with DPN had vitamin D deficiency (defined as 25(OH)D <50 nmol/L), compared with 60.4% of those without DPN.
The team also reports that total cholesterol and low-density lipoprotein (LDL) cholesterol levels showed significant inverse correlations with vitamin D.
These correlations are "compatible with the fact that vitamin D deficiency is a risk factor for atherosclerotic CV disease," say Shehab et al. "Vitamin D deficiency or insufficiency may promote the acute phase response leading to insulin resistance and chronic inflammation in blood vessels," they say.
"Increased inflammation and oxidative stress damage to blood vessels could lead to nerve ischemia [and] promote the formation of advanced glycation end-products and development of DPN," they add.
Logistic regression analysis revealed that DPN was significantly associated with vitamin D deficiency (odds ratio=3.47), after adjustment for potential confounders such as duration of diabetes, HbA1c, and LDL cholesterol.
The researchers say that, as the effect of vitamin D deficiency and supplementation could vary among ethnic groups, further studies in other populations are needed to confirm their observations.
"Furthermore, there is need to explore, prospectively, whether supplementation with vitamin D could prevent the development of DPN in Type 2 diabetes individuals," they conclude.
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By Sally Robertson