The glycated albumin to HbA1c ratio is elevated in patients with fulminant type 1 diabetes mellitus with onset during pregnancy.

Fulminant type 1 diabetes mellitus (FT1DM) develops as a result of very rapid and almost complete destruction of pancreatic β cell. The most common form of type 1 diabetes mellitus with onset during pregnancy has been shown to be FT1DM at least in Japan. We previously reported that the ratio of glycated albumin (GA) to HbA1c (GA/HbA1c ratio) is elevated in FT1DM patients at the diagnosis. In the present study, we investigated whether the GA/HbA1c ratio is also elevated in FT1DM with onset during pregnancy (P-FT1DM). The study subjects consisted of 7 patients with P-FT1DM. Ten patients with untreated type 2 diabetes mellitus (T2DM) discovered during pregnancy (P-T2DM) and 9 non-pregnant women with untreated T2DM (NP-T2DM) were used as controls. All study patients satisfied HbA1c < 8.7%, the diagnostic criteria for FT1DM. The GA/HbA1c ratio in the P-FT1DM patients at the diagnosis was significantly higher than that in the P-T2DM patients and the NP-T2DM patients. The GA/HbA1c ratio was ≥ 3.0 in all P-FT1DM patients, whereas it was < 3.0 in 8 of 10 P-T2DM patients and all NP-T2DM patients. The GA/HbA1c ratio was also elevated in P-FT1DM patients at the diagnosis compared with T2DM with or without pregnancy.