Study of Glycosylated Haemoglobin (Hba1c) Levels in Non-Diabetic Patients with Hypothyroidism

Introduction: HbA1c used for the assessment of glycemic status of the diabetic patients is widely recommended for its use for diagnosing diabetes. A positive association between thyroid disorder and diabetes mellitus is well recognized but to study the effect of thyroid disorders on glucose metabolism in non diabetic patients is an area for extensive research. Objective of the study was to study the glycosylated haemoglobin (HbA1c) levels in Non diabetic patients with hypothyroidism. Material and methods: Patients attending teaching hospitals attached to BMCRI who fulfilled the inclusion criteria were taken into study during the period from November 2017-May 2019. It was a cross sectional study. Descriptive statistics like mean, standard deviation were calculated. Inferential statistics like Mann-whitney test was used to compare the parameters between two groups. Results: During the period of study, 130 patients were studied of these, 65 were cases who were non diabetic patients with hypothyroidism, 65 controls who were non diabetic euthyroid patients. Among 65 cases 5 patients had normal HbA1C levels (7.7%) and 60 patients had increased HbA1C levels (Prediabetes) (92.3%), among 65 controls 56 patients had normal HbA1C levels (86.2%) and 9 patients had increased HbA1C levels (13.8%). Conclusion: From the results of the present study it can be concluded HbA1c levels were significantly higher in non diabetic patients with hypothyroidism when compared to non diabetic patients with normal thyroid function (mean HbA1C levels were 5.87± 0.23 vs 5.42 ± 0.24) (P <0.0001) which was statistically significant. Therefore it is suggested that the effects of the hypothyroidism on the HbA1c must be considered when interpreting the HbA1c for the diagnosis of prediabetes.