ACTA ENDOCRINOLOGICA (BUC)

Background. Heart rate recovery after exercise is a predictor of mortality that is thought to reflect autonomic imbalance. The association between heart rate recovery and prediabetic stages is unclear. Aim. To evaluate the heart rate recovery in patients with diabetes and prediabetes. Patients and Methods. Thirtyfive patients with impaired fasting glucose, 32 patients with impaired glucose tolerance, and 34 patients with diabetes mellitus were included. The control group consisted of 30 healthy individuals. All study participants underwent a maximal graded exercise test, and heart rate recovery was calculated by subtracting the 1st, 2nd and 3rd minute heart rates from the maximum heart rate achieved during the stress testing. Results. The 1st, 2nd and 3rd minute heart rate recovery values of the diabetes mellitus, impaired glucose tolerance and impaired fasting glucose groups were significantly lower than that of the control group. For the 1st minute, heart rate recovery values of the diabetes mellitus patients were significantly lower than that of the control group (19.8±9.4 vs. 25.4±9.9, p<0.001) and the impaired fasting glucose group (19.8±9.4 vs. 22.1±9.3, p<0.01), and the 1st minute heart rate recovery of the diabetes mellitus patients was similar to that of the impaired glucose tolerance group (19.8±9.4 vs. 20.7±5.8, p=0.88). Similar results were obtained in the 2nd and 3rd minute heart rate recovery measurements. The heart rate recovery values of the impaired fasting glucose were significantly higher than those of the diabetes mellitus and impaired glucose tolerance patients. In comparing the impaired glucose tolerance and diabetes mellitus groups in terms of heart rate recovery values, there was no significant difference.

Background. Heterozygous gain-of-function mutations in the glucokinase (GCK) gene cause hyperinsulinaemic hypoglycaemia (GCK-HI), while lossof- function mutations lead to a monogenic type of diabetes (GCK-MODY). We, herein, report a heterozygous GCK gene mutation in a large family with GCK-MODY and insulinoma in one individual from the same family. Patients and methods. The proband, an 11-yearold male, was referred for asymptomatic mild hyperglycemia (fasting glucose:121 mg/dL) and HbA1c of 6.1%. Segregation analysis of the family revealed multiplex members with asymptomatic fasting hyperglycaemia or non-insulindependent diabetes and 33-year-old maternal uncle of the proband case had a history of distal pancreatectomy due to the diagnosis of insulinoma. His preoperative investigations were revealed fasting glucose of 31 mg/dL, insulin: 7μU/ mL, C-peptide: 2.6 mg/dL, and a low HbA1c(4.0%) which was suggestive for recurring hypoglycaemia episodes. Postpancreatectomy he developed mild fasting hyperglycemia (115-136 mg/dL). Results. Genetic analysis revealed heterozygous p.Ser453Leu(c.1358C> T) mutation in the GCK gene in the proband. In segregation analysis, the identical heterozygous p.Ser453Leu(c.1358C> T) GCK gene mutation was detected in all of the other affected family members for whom a DNA analysis was applicable. The maternal uncle was first diagnosed with insulinoma and underwent a pancreatectomy. He also had an identical mutation in a heterozygous state. Conclusion. We, to the best of our knowledge, firstly identified these two entirely distinct phenotypes of glucose metabolism, GCK-MODY and GCK-HI, due to an identical heterozygous p.Ser453Leu (c.1358C> T) mutation in the GCK. Further studies required to elucidate this new phenomenon and understanding the genotype-phenotype relationship of GCK gene mutations.

Context. Red cell distribution width (RDW) has been associated with type 2 diabetes (T2DM), however data in relation to diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar non-ketotic acidosis (HONK) remains unclear. Objective. The aim of this study was to evaluate the association between RDW, MCV, and RDW/MVC values and acute complications in T2DM. Patients and Methods. RDW was measured in 90 T2DM patients (30 DKA, 30 HONK and 30 T2DM without acute complications). Clinical variables were analyzed by One –Way ANOVA, Kruskal-Wallis and Pearson analysis with SPSS software. Diagnostic screening tests and ROC curve analysis determined the cut-off point of MCV,RDW and RDW/MCV values. Results. DKA patients had higher levels of plasma glucose (524.20±201.43mg/dL, p<0.001), HbA1c (10.73±2.29%, p<0.001), osmotic pressure (310.32 mosm/L, p<0.001), RDW (14.61±1.75g/L, p<0.01), and the RDW/MCV ratio (0.17±0.04%, p<0.01), compared to HONK patients. RDW/MCV cut-off value was 0.15 with 90% sensitivity 50% specifity these values for only MCV were 76.67%-70%, for only RDW were 76.67%- 63.33% respectively. The area under curve values for the ability to reflect DKA for RDW and the RDW/MCV ratio were 0.708 and 0.766, respectively (p<0.001). Conclusions. RDW and RDW/MCV ratio were found associated with DKA and valuable in predicting DKA. However these parameters were not valuable in predicting HONK.