Introduction: Patients with type 1 diabetes mellitus (DM1) present a high prevalence of autoimmune associated diseases. Recently, we described a prevalence of latent pernicious anemia (LPA) of 12.4% in DM1.
Objectives: A 5-year follow-up study of a cohort of DM1 patients in order to evaluate the evolution of biochemical markers of LPA, defined as a serum pepsinogen I (PI) concentration below normal limits.
Material and methods: One hundred and eighty six DM1 patients (93 men, aged 30±9.4 years). In 2001 and 2006, in all of them we measured the serum concentration of PI and gastrin, HbA1c, cobalamin and parietal cell antibodies (PCA).
Results: Twenty-three of 186 DM1 patients presented LPA at baseline in 2001. In 2006, 17 of these patients confirmed with low serum PI and in five the levels normalized. One patient was lost at follow-up. All those patients whose PI levels normalized in 2006 had normal gastrin concentrations and negative PCA in 2001, while 13/18 (72%) of patients with low serum PI in 2001 and 2006 had positive PCA at baseline. In 2006, PI was low in 6 new patients who presented normal PI in 2001. From these, two patients presented positive PCA and other two high gastrin concentrations. The cobalamin concentration in 2001 was similar in patients with or without LPA, but in 2006 it was significantly lower in the group with LPA diagnosed in 2001 (P=0.007).
Conclusions: Most DM1 patients with low serum PI concentrations present positive PCA, while in those in which PI normalize during the follow-up the PCA are negative. The prevalence of LPA in DM1 patients increases with the follow-up. The detection of low PI concentrations allows the identification and treatment of patients with low cobalamin concentrations before they develop clinical anemia and neurological complications.