Glycated albumin is not significantly correlated with body mass index in patients with acute-onset type 1 diabetes

Glycated serum proteins and albumin but not glycated albumin show negative correlation with BMI in an overweight/obese, diabetic population from the United States

BACKGROUND AND AIMS

Multiple previously published studies have shown a weak to medium, negative correlation between BMI and glycated albumin (GA). However, many of these studies were in populations with a narrow range of BMI. It is unknown whether this trend exists if a wider BMI range is used. This is an important question for proper interpretation of GA levels in obese populations.

MATERIALS AND METHODS

A retrospective analysis of clinical trial data (NCT02519309) was performed. After appropriate exclusions, 334 subjects remained. These included 73.7% with type 2 diabetes (T2D) diagnosis and 26.3% with prediabetes. BMI ranged from 24.8-86.9 kg/m2. Laboratory data were measured in a CLIA-certified laboratory using commercially available, automated methods.

RESULTS

No significant, negative correlation was seen between GA and BMI. However, individual components (glycated serum proteins and albumin) as well as the GA/HbA1c ratio show a weak, negative correlation with BMI for all subjects and those with T2D. The strongest negative correlation was with albumin. Examination by traditional BMI subgroups also showed statistically significant differences for those with T2D, but not for the prediabetic cohort. Correlations between BMI and C-reactive protein were similar in those with diabetes and prediabetes; however, correlation between BMI and insulin was stronger in those with diabetes.

CONCLUSION

Negative correlations between BMI and albumin or BMI and glycated serum proteins persist in diabetic populations that are obese and overweight, even when a statistically significant negative correlation is not observed between BMI and GA. Inflammation or insulin-mediated changes in protein synthesis could be contributors to these negative correlations, but BMI-related changes to the glomerulus could also affect clearance of albumin or glycated proteins and should be examined.

The Glycated Albumin (GA) to HbA1c Ratio Reflects Shorter-Term Glycemic Control than GA: Analysis of Patients with Fulminant Type 1 Diabetes

BACKGROUND

Glycated albumin (GA) reflects shorter-term glycemic control than HbA1c. We have reported that HbA1c is paradoxically increased in diabetic patients whose glycemic control deteriorated before ameliorating. In this study, we analyzed paradoxical increases of glycemic control indicators after treatment in patients with fulminant type 1 diabetes (FT1D). We also investigated whether the GA/HbA1c ratio may reflect shorter-term glycemic control than GA.

METHODS

Five FT1D patients whose post-treatment HbA1c and GA levels were measured were enrolled. We also used a formula to estimate HbA1c and GA from the fictitious models of changes in plasma glucose in FT1D patients. In this model, the periods during which HbA1c, GA, and the GA/HbA1c ratio were higher than at the first visit were compared. In addition, the half-life for the GA/HbA1c ratio was calculated in accordance with the half-lives for HbA1c and GA (36 and 14 days, respectively).

RESULTS

In all FT1D patients, HbA1c levels 2-4 weeks after treatment were increased, with three patients (60%) experiencing an increase of GA levels. In contrast, an increase of the GA/HbA1c ratio was observed in only one patient. In all of the different models of changes in plasma glucose in FT1D patients, the length of time during which the values were higher than at the first visit was in the order of HbA1c > GA > GA/HbA1c ratio. The half-life for the GA/HbA1c ratio was 9 days, shorter than GA.

CONCLUSIONS

These findings suggest that the GA/HbA1c ratio reflects shorter-term glycemic control than GA.

Serum albumin-adjusted glycated albumin is a better indicator of glycaemic control in diabetic patients with end-stage renal disease not on haemodialysis

Backgrounds

Diabetic patients with end-stage renal disease who are not on haemodialysis show low concentrations of HbA1c and glycated albumin due to renal anaemia and proteinuria, respectively. In the present study, we examined whether serum albumin-adjusted glycated albumin could accurately reflect glycaemic control in these patients.

Methods

To examine the correlation between glycated albumin and serum albumin (Study 1), 49 diabetic patients with end-stage renal disease not on haemodialysis were used. To evaluate the association between the glycaemic control indicators and the glycaemic control state (Study 2), 30 diabetic patients with end-stage renal disease were enrolled. The estimated HbA1c and the estimated glycated albumin concentrations were calculated based on the mean blood glucose concentrations obtained from the diurnal variation. The adjusted glycated albumin concentrations were calculated from the regression formula between the serum albumin and glycated albumin obtained from Study 1.

Results

No significant correlation was found between the measured HbA1c and estimated HbA1c concentrations. The estimated HbA1c (inversely) and measured HbA1c/estimated HbA1c ratio (positively), but not measured HbA1c, showed a significant correlation with Hb concentrations. The estimated glycated albumin was positively associated with the measured glycated albumin and adjusted glycated albumin concentrations. Although measured glycated albumin/estimated glycated albumin ratio was positively correlated with serum albumin, there was no significant association between the adjusted glycated albumin/estimated glycated albumin ratio and serum albumin, Hb and estimated glomerular filtration rate.

Conclusions

We found for the first time that the adjustment of glycated albumin by serum albumin could be useful to determine glycaemic control in diabetic patients with end-stage renal disease not on haemodialysis. These findings suggest that adjusted glycated albumin might be a better indicator of glycaemic control than measured HbA1c and measured glycated albumin in these patients.