Hemoglobin Glycosylation Index is not related with blood glucose

Abstract

Objective: Accurate assessment of blood glucose control is essential to prevent chronic complications in diabetes. Hemoglobin Glycosylation Index (HGI) quantifies the degree to which individuals demonstrate a HbA(1C) higher or lower than average for the population. This study has aimed to assess the relationship between HGI and blood glucose.

Methods: 25 type 1 diabetes subjects (12 men and 13 women), 22.0+/-5.2 (17-34) years old, were instructed to self-monitor glucose with the One Touch Profile capillary glucose meter. HbA(1C) was determined and self-monitored blood glucose levels were studied every 3 months. Diabetic patients were monitored for 3-9 months and 62 measurements of HbA(1C) were included. HbA(1C) was measured by HPLC. Mean blood glucose (MBG) was calculated from self-monitored blood glucose records. A linear regression was calculated between HbA(1C) and MBG during the 60 days before sampling to determine HbA(1C). For each diabetic patient's MBG, a predicted HbA(1C) was calculated from the population regression equation. HGI was then calculated as HGI=observed HbA(1C)-predicted HbA(1C). Blood glucose was analyzed within target range (WTR), below target range (BTR) and above target range (ATR) according to The European Diabetes Policy Group Consensus for type 1 diabetes.

Results: A good linear regression between HbA(1C) and MBG was observed (r=.71, r(2)=.497, P=.000). No correlation was found between HGI and the percentage of WTR, BTR or ATR values. Moreover, the percentage of self-monitored blood glucose ATR and BTR was the same for high glycosylators (HGI<0 and ATR: 56.2+/-20.9%; HGI<0 and BTR: 34.5+/-17.5%) as for low glycosylators (HGI>0 and ATR: 52.8+/-25.5%; HGI>0 and BTR: 25.1+/-15.0%).

Conclusions: HGI is determined for both physiological factors and blood glucose. A prospective study is necessary to assess whether HGI, together with HbA(1C), can predict the incidence and severity of chronic complications in diabetic patients.