Evaluation of Metabolic and Nutritional Biomarkers across varying Glycaemic Control States in Type 2 Diabetes Mellitus

Abstract

Background: Type 2 Diabetes Mellitus (T2DM) is a multifactorial metabolic
disorder with rising global prevalence, particularly in India. Glycemic control,
commonly monitored using glycated hemoglobin (HbA1c), influences not only
glucose homeostasis but also several metabolic and nutritional biomarkers. Among
these, Vitamin D₃ has garnered interest for its emerging role in glucose metabolism
and insulin sensitivity. However, the association of glycemic control with serum
Vitamin D₃, fasting blood sugar (FBS), total cholesterol (TC), and body mass index
(BMI) remains underexplored in Indian diabetic populations.
Objective: To evaluate the association of varying glycemic control states (good,
unsatisfactory, and poor) with metabolic and nutritional biomarkers—serum Vitamin
D₃, FBS, TC, and BMI—in patients with Type 2 Diabetes Mellitus.
Methods: A cross-sectional observational study was conducted from December 2023
to December 2024 at Index Medical College and Hospital, Indore. A total of 200
T2DM patients aged 30–70 years were enrolled. HbA1c was used to categorize
participants into three groups: good control (HbA1c 5.7–8%), unsatisfactory control
(HbA1c 8.1–8.9%), and poor control (HbA1c ≥ 9%). Serum 25-hydroxy Vitamin D₃
[25(OH)D] was estimated using the VIDAS Immunoassay analyzer; HbA1c, FBS,
TC, and BMI were also assessed using standard methods. Statistical analysis was
performed using SPSS v22, employing descriptive statistics, one-way ANOVA, and
multivariate regression.
Results: Among 200 participants, 47% were male and 53% female. The mean HbA1c
was 8.72 ± 0.70%, indicating overall poor glycemic control. A significant inverse
relationship was observed between HbA1c levels and Vitamin D₃ levels (p < 0.001),
with patients in the good control group having the highest mean Vitamin D₃ levels
(26.53 ± 6.45 ng/mL) and the poor control group the lowest (12.51 ± 5.73 ng/mL).
FBS also showed significant variation across glycemic control groups (p < 0.001).
However, total cholesterol (p = 0.086) and BMI (p = 0.72) did not differ significantly
among groups.
Conclusion: This study highlights a significant inverse association between Vitamin
D₃ levels and glycemic control in T2DM patients, along with significant variations in
fasting glucose. These findings suggest that Vitamin D₃ may play a contributory role
in glycemic regulation. Regular screening and potential correction of Vitamin D₃
deficiency could support better metabolic outcomes in diabetic care. Further
longitudinal and interventional studies are needed to establish causality and
therapeutic benefit.