Serum pepsinogen I: an early marker of pernicious anemia in patients with type 1 diabetes.

CONTEXT: Pernicious anemia (PA) is an autoimmune organ disease much more common in type 1 diabetic patients (DM1) than in nondiabetic subjects, but it is clinically silent until its end stage. OBJECTIVE: This study aimed to determine biochemical markers of latent PA in a population of DM1 patients attending the endocrinology outpatient clinic of a university hospital. STUDY SUBJECTS: The population studied consisted of 186 unselected patients (32.4 +/- 8.7 yr) and 118 healthy controls (30.9 +/- 9.4 yr). MEASUREMENTS AND INTERVENTIONS: Plasma gastrin and pepsinogen I were determined in patients and controls, whereas hemoglobin A1c, serum cobalamin, hemoglobin, and organ-specific antibodies were determined only in patients. Latent PA was defined as serum pepsinogen I less than 30 microg/liter. In patients with low pepsinogen I concentrations and hypergastrinemia, esophagogastroduodenoscopy (EGD) was performed. RESULTS: DM1 patients showed significantly lower pepsinogen I concentrations (P < 0.001) and higher gastrinemia than controls. Latent PA was present in 12.4% of patients vs. 0.9% of controls. Among patients, more women than men showed low plasma pepsinogen I concentrations (P = 0.002) and thyroperoxidase antibody positivity (P < 0.001). Only the highest parietal cell antibody titers (> or =1:640) identified patients with significantly higher levels of plasma gastrin (P < 0.001) and lower levels of pepsinogen I (P < 0.001). The histopathological EGD findings confirmed different degrees of gastric body mucosa atrophy in all cases. CONCLUSION: The high prevalence of latent PA found in our DM1 patients leads us to recommend its screening using serum pepsinogen I concentrations. In patients with hypergastrinemia and high parietal cell antibody titers, EGD should be considered to confirm gastric mucosa atrophy.

Are prediction equations for glomerular filtration rate useful for the long-term monitoring of type 2 diabetic patients?

BACKGROUND: The aim of this study was to compare the accuracy of prediction equations [modification of diet in renal disease (MDRD), simplified MDRD, Cockcroft-Gault (CG), reciprocal of creatinine and creatinine clearance] in a cohort of patients with type 2 diabetes. METHODS: A total of 525 glomerular filtration rates (GFRs) using (125)I-iothalamate were carried out over 10 years in 87 type 2 diabetic patients. Accuracy was evaluated at three levels of renal function according to the baseline values obtained with the isotopic method: hyperfiltration (GFR: >140 ml/min/1.73 m(2); 140 isotopic determinations in 27 patients), normal renal function (GFR: 140-90 ml/min/1.73 m(2); 294 isotopic determinations in 47 patients) and chronic kidney disease (CKD) stages 2-3 (GFR: 30-89 ml/min/1.73 m(2); 87 isotopic determinations in 13 patients). The annual slope for GFR (change in GFR expressed as ml/min/year) was considered to ascertain the variability in the equations compared with the isotopic method during follow-up. Student's t-test was used to determine the existence of significant differences between prediction equations and the isotopic method (P < 0.05 with Bonferroni adjusted for five contrast tests). RESULTS: In the subgroup of patients with hyperfiltration, a GFR slope calculated with (125)I-iothalamate -4.8 +/- 4.7 ml/min/year was obtained. GFR slope in patients with normal renal function was -3.0 +/- 2.3 ml/min/year. In both situations, all equations presented a significant underestimation compared with the isotopic GFR (P < 0.01; P < 0.05). In the subgroup of CKD stages 2-3, the slope for GFR with (125)I-iothalamate was -1.4 +/- 1.8 ml/min/year. The best prediction equation compared with the isotopic method proved to be MDRD with a slope for GFR of -1.4 +/- 1.3 ml/min/year (P: NS) compared with the CG formula -1.0 +/- 0.9 ml/min/year (P: NS). Creatinine clearance presented the greatest variability in estimation (P < 0.001). CONCLUSIONS: In the normal renal function and hyperfiltration groups, none of the prediction equations demonstrated acceptable accuracy owing to excessive underestimation of renal function. In CKD stages 2-3, with mean serum creatinine > or =133 micromol/l (1.5 mg/dl), the MDRD equation can be used to estimate GFR during the monitoring and follow-up of patients with type 2 diabetes receiving insulin, anti-diabetic drugs or both.