The Association between Glycated Hemoglobin and Estimated Glomerular Filtration Rate in Patients with Type ۲ Diabetes based on the Hemoglobin Status

Background:The aim of the present study was to examine the association between hemoglobin A۱C (HbA۱C( and eGFR in patients with type ۲ diabetes (T۲D). Methods:This cross-sectional study was conducted on ۸۰۲ patients with T۲D visiting Abu Reyhan Clinic of Shahid Mohammadi Hospital in Bandar Abbas, Iran. eGFR was determined using MDRD and EPI methods. The association between two levels of HbA۱C (≤۸% and >۸%) and two levels of GFR (≤۶۰% and >۶۰%) were assessed in total population, and separately, in men and women using linear regression model. Results:The mean ± SD age of the study population (۲۷.۷% male) was ۵۳.۵ ± ۵.۵ years. Based on the multivariable adjusted model, in subjects with HbA۱C >۸%, there was a negative association between HbA۱C and eGFR-EPI (β = -۰.۱۴) and eGFR-MDRD (β = -۰.۱۲), (p <۰.۰۵). However, there was no significant relationship between HbA۱C and eGFR in individuals with HbA۱C ≤۸%. Also, no significant association was found between HbA۱C and eGFR as categorical variables (based on the two categories of eGFR ≤۶۰ and >۶۰). An inverse association was observed between GFR ≤۶۰ and HbA۱C >۸% in women based on the Hb classification. This inverse association was found between HbA۱C >۸% and eGFR-EPI (β = -۰.۷۶) and eGFR-MDRD (β = -۰.۷۸) in women with Hb >۱۲ mg/dl (p <۰.۰۱). Conclusion:According to the results, the higher level of HbA۱C can be associated with decreased eGFR level. This negative association was mostly observed between HbA۱C >۸% and GFR ≤۶۰ in T۲DM female patients without anemia (Hb>۱۲). It seems that monitoring kidney function by eGFR estimation is a necessary action in patients with T۲D with high HbA۱C levels.