The Haemoglobin Glycation Index Is an Independent Risk Factor for Microvascular Complications in UKPDS Patients with Newly Diagnosed Type 2 Diabetes
Abstract Number: 1001-P
Authors: JI-IN KIM, RICHARD J. STEVENS, RURY R. HOLMAN
Institutions: Oxford, United Kingdom
Results: The haemoglobin glycation index (HGI), defined as the difference between a subjects actual HbA1c and that predicted from regression of HbA1c on plasma glucose, has been reported to predict microvascular disease in type 1 diabetes. We used UK Prospective Diabetes Study data to determine whether HGI is associated with incident microvascular complications in type 2 diabetes, adjusting for fasting plasma glucose (FPG) and potential confounders.
We defined HGI as actual minus expected HbA1c from a linear regression equation fitted to baseline FPG. Microvascular events were defined as the first to occur of retinopathy requiring photocoagulation, vitreous haemorrhage, or fatal or non-fatal renal failure. Cox models were fitted using stepwise selection (5% significance level), based on 309 microvascular events in 3421 subjects with data available during median 10.0 years follow up. Age, sex, ethnicity, body mass index, systolic blood pressure, triglyceride, HDL and LDL cholesterol and smoking measured at baseline were considered as potential confounders. Updated mean FPG and HGI from annual measurements were used as time-dependent variables. In the final model (see table) updated mean HGI had a hazard ratio of 1.31 adjusted for FPG. An alternative model showed HGI to be significant adjusting for updated mean HbA1c instead of FPG.
Our results show HGI is a risk factor for microvascular disease in type 2 diabetes independent of other risk factors, including FPG or HbA1c. HbA1c values in excess of those expected for a given FPG further increase the risk of microvascular complications in type 2 diabetes.
Significant Risk Factors in Final Model
|Variable||Hazard Ratio||95% Confidence Interval||Hazard Ratio per 1 s.d.||Order of Variables in|
|Updated mean FPG (per mmol/L)||1.34||(1.28, 1.40)||2.28||1|
|Updated mean HGI (per unit)||1.31||(1.17, 1.47)||1.35||3|
|Body mass index (per kg/m²)||0.94||(0.92, 0.97)||0.74||2|
|Smoking (vs. never smoked)||0.55||(0.42, 0.73)||4|
|Male (vs. Female)||1.44||(1.13, 1.83)||5|
|Systolic blood pressure (per 10 mmHg)||1.08||(1.02, 1.15)||1.17||6|