Relationship Between Vitamin D Status and the Relevant Parameters of Glucose in Patients with Type 2 Diabetes

INTRODUCTION: Clarifying the prevalence of vitamin D deficiency in diabetic patients, and the relationship between vitamin D concentration and insulin resistance, fasting plasma glucose, and HbA1C in patients in Hue City, Vietnam. METHODS: A cross-sectional study on 110 diabetic patients examined at Hue Central Hospital and Hue University of Medicine and Pharmacy Hospital. These patients were collected venous blood sampling, and the 25(OH)D test, fasting plasma glucose test, fasting insulin test, HOMA-IR and QUICKI calculation. RESULTS: Vitamin D deficiency and insufficiency prevalence were 51.8%. The average concentration of 25(OH)D (ng/mL) was 30.67 ± 8.55; this concentration in fasting glucose level ≤8 mmol/l group and >8 mmol/l group was 32.08 ± 9.26 and 28.55±6.91 (p = 0.033); it was 32.95 ± 8.58 and 28.97 ± 8.17 in HOMA-IR ≤3.5 and HOMA-IR >3.5 group, (p = 0.015); in QUICKI ≤0.32 group, it was 29.16 ± 8.12; in QUICKI >0.32 group, it was 32.85 ± 8.76 (p = 0.025). Patients with an ideal exercise level have higher average levels of 25(OH)D (32.11±8.62 vs 26.83±7.16, p=0.003). The average levels of 25(OH)D in male patients are higher than in female patients (33.47±0.08 vs 29.01±8.43, p=0.008). Vitamin D deficiency and insufficiency prevalence in patients with HOMA-IR ≤3.5 and QUICKI >0.32 were 36.2% and 37.8%, whereas in those with HOMA-IR >3.5 and QUICKI ≤0.32 they were 63.5% and 61.5% (p = 0.007 and 0.02, respectively). 25(OH)D is negative correlation with fasting glucose level and HOMA-IR, with r = −0.229 and −0.192, respectively (p = 0.016 and 0.045); 25(OH)D was positively correlated with QUICKI, with r = 0.235, p = 0.008. CONCLUSION: Patients who have better glucose-related parameters, such as fasting blood sugar, HOMA-IR and QUICKI, have a better vitamin D status. Some blood sugar-related factors, such as exercise level and sex, are related to vitamin D status.