Seasonal Changes of HbA۱c Levels in Type ۲ Diabetes Mellitus Patients

Objective: There are changes in plasma glucose and HbA۱c of type ۲ diabetes mellitus (T۲DM) patients in different seasons. HbA۱c levels may increase during winter season in most T۲DM patients without weight gain. In this study, we described the seasonal changes of HbA۱c levels in T۲DM patients. Materials and Methods: This analytical cross-sectional study conducted from ۲۰۱۳ to ۲۰۱۷ on ۴۰۲ patients with T۲DM, aged ۲۰–۸۰ years old who referred to Yazd diabetic research center. Body weight, height, waist circumferences (WC), blood pressure (BP), body mass index (BMI), fasting plasma glucose (FPG), ۲ hours post-prandial (۲hpp), and HbA۱c measured and compared during four seasons. Results: Four hundred and two T۲DM patients invited and fulfilled this study. Most of them (۵۶%) were women. The mean age of patients was ۵۸.۹۶ (± ۱۱.۱۰) years old. The mean HbA۱c, ۲hpp, systolic and diastolic blood pressure were significantly different in four seasons (P-value respectively: ۰.۰۲۲, ۰.۰۰۷, ۰.۰۰۱ and ۰.۰۰۵). The mean difference of HbA۱c was significant in the warm and cold seasons (P-value: ۰.۰۴۷). The percentage of people who were below ۷% had a significant difference between the warm and cold seasons (P-value: ۰.۰۱۵). Conclusion: The results of this study showed that, in Yazd with desert climate, postprandial hyperglycemia is more prominent in summer. The seasonal changes of glycemic status are an important factor in management of T۲DM patients.

Keywords:

Type ۲ diabetes mellitus , Glycated hemoglobin A , Seasons