No abstract

Background Glycated albumin (GA) reflects glycemic control in patients with neonatal diabetes mellitus (NDM). However, GA in NDM patients is apparently low in relation to glycemia. Objective To establish the reference intervals for GA in healthy infants. Subjects and Methods Fifty‐eight healthy, full‐term newborn infants were used to define the GA reference values and to investigate its relationship to plasma glucose (PG) and serum albumin. The infants were categorized into three groups according to age: group A, 5 (4–6) median (range) d: n = 18; group B, 33 (30–38) d: n = 19; and group C, 181 (50–352) d: n = 21. We also studied 212 non‐diabetic adults [group D, 53 (28–78) yr old] and the 5 NDM patients previously reported for GA comparisons. Results In the infants, GA was strongly positively correlated with logarithmic transformation of age [log (age)] (p = 0.831, p < 0.0001). The GA in groups A, B, C, and D were 7.3 ± 1.0%, 8.6 ± 1.1%, 10.9 ± 0.8%, and 14.0 ± 1.1%, respectively. The GA was more strongly positively correlated with serum albumin (r = 0.768, p < 0.0001) than with PG (r = 0.596, p < 0.0001). When GA levels were compared with the age‐dependent reference values, GA in the transient NDM patient was normalized although GA in the four permanent NDM patients decreased but remained high after insulin therapy. Conclusions This study showed that the reference range for GA in infants is lower than that of adults and increases with age, with which we confirmed that GA in the NDM patients reflected the clinical course. Consequently, GA in NDM patients should be compared with the age‐based reference values to assess the accurate glycemic status.

Background: We previously reported that glycated albumin (GA) levels increased in an age-dependent manner in infancy. In order to determine whether this phenomenon is true from infancy to adulthood, we investigated the GA levels in non-diabetic subjects of a wide range of age. Methods: GA levels of 376 non-diabetic subjects [average age, 31.8 AE 23.8 years (4 days-78 years)] were determined. A relationship between GA and logarithmically transformed age [log(age)] was analysed. Results: GA levels were significantly positively correlated with log(age) [R ¼ 0.865, P < 0.0001, GA ¼ 1.77 Â log(day) þ 6.55]. Based on a regression line, we established the formula for adjusting GA levels according to age. Conclusion: We showed that GA increases with age from infancy to adulthood and that normal GA levels are demonstrated as a simple regression formula with log(age). This formula allowing us to use the adult reference range has the potential for treatment monitoring of diabetic patients regardless of age.

GHb measured using the affinity method may be a useful glycemic control marker in infants. Although adj-HbA1c measured using the LA method was correlated with GA, it may not be a practical measure because it was not correlated with PG and determining HbF levels using HPLC method can be troublesome. Adj-HbA1c measured using the HPLC method should not be used as a glycemic marker in infants.

Our novel method for NTBI measurement is high-throughput and may be a useful and powerful tool in the study of the physiological and clinical importance of NTBI.