Dr Muhammad Ahmed, Dr Abdul Muqeet, Dr Umer Anwar
Introduction: Glycated hemoglobin (HbA1c) can be changed in different conditions. We assume that HbA1c levels may change, probably due to a thyroid condition that changes as a result of changes in the red blood cell cycle (RBC). Aim: The objective of this study was to determine the effects of altered thyroid status on HbA1c levels in individuals without diabetes, with overt hyper‑ and hypo‑thyroidism, and if present, whether such changes in HbA1c are reversed after achieving euthyroid state. Place and Duration: In the Endocrinology department of Services Hospital Lahore for one year duration from March 2019 to March 2020. Methods: Euglycemic individuals with overt hypothyroidism or hyperthyroidism were selected. Age and gender controls were obtained. Baseline HbA1c and reticulocyte count (for assessment of red blood cell cycle) were calculated and compared in all patients. Then stable euthyroidism was obtained in a randomly selected subgroup and HbA1c and reticulocyte counts were re-assessed. HbA1c values and reticulocyte counts were compared to baseline in both groups. Results: HbA1c was significantly higher in the group with hypothyroidism in the initially selected patients. HbA1c values in patients with hyperthyroidism did not differ significantly from controls. Reduced HbA1c levels and increased reticulocyte counts were significant in the hypothyroidism group with no significant change in glucose levels after treatment. HbA1c did not change significantly in the hyperthyroidism group after treatment. However, reticulocyte counts have decreased significantly. Conclusion: It was found that the initial levels of HbA1c were significantly high in patients with hypothyroidism and significantly decreased after obtaining euthyroid without changing glucose levels. There were no significant changes in patients with hyperthyroidism at the beginning or after treatment. Our study suggests that caution should be exercised when interpreting HbA1c data in patients with hypothyroidism. Keywords: test interpretation, HbA1c, thyroid function.