Association of vitamin D, HbA1c, and pain severity in T2DM patients with peripheral neuropathy

Horm Mol Biol Clin Investig. 2026 Jul 8. doi: 10.1515/hmbci-2026-0035. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the association of vitamin D linked with HbA1c level and pain severity in T2DM patients with peripheral neuropathy.

METHODS: In this cross-sectional study, we included 51 patients diagnosed with T2DM and peripheral neuropathy from a main diabetes center in Kurdistan Region-Iraq.

RESULTS: The study included 51 participants, predominantly female (82.35 %), with a mean age of 55.9 ± 7.55 years. Most participants had low educational attainment, with 74.51 % being illiterate, and 76.47 % were housewives. Disease duration was commonly 1-5 and 11-15 years (25.49 % each). Half of the patients used oral antidiabetic drugs, while 41.18 % used combined therapy. Medication adherence was high (94 %), and metformin use averaged 11.61 years. Statins were used by 66.67 %, and most participants were non-smokers (90.20 %). Lifestyle patterns were suboptimal, with limited fish intake and low physical activity. Obesity was prevalent (60.78 %), and glycemic control was poor, with mean fasting glucose of 225.43 mg/dL and HbA1c of 10.42 %. Vitamin D deficiency was universal. A significant association was found between pain severity, lower vitamin D, and higher HbA1c, while no associations were observed with demographic or lifestyle factors.

CONCLUSIONS: The study highlights a high burden of uncontrolled diabetes, obesity, and vitamin D deficiency among predominantly female patients. Severe neuropathic pain is significantly associated with poor glycemic control and low vitamin D levels.

PMID:42412924 | DOI:10.1515/hmbci-2026-0035