Efeito da sitagliptina nos potenciais evocados (somato-sensitivo e visual) e no controle metabólico do diabetes mellitus tipo 2

Abstract

Diabetes mellitus (DM) is a syndrome associated with deficient insulin secretion, resistance to insulin action or the combination of both. It is characterized by chronic hyperglycemia that in a long term can cause retinopathy, nephropathy, peripheral and autonomic neuropathy. The present interventional, prospective and open study was designed to evaluate therapeutic efficacy of sitagliptin in metabolic control of diabetes mellitus type 2 recently diagnosed (less than 6 months) and in pathways of visual and somatosensory nerve conduction. Blood pressure and anthropometric data were colected before treatment. Measures of fasting triglycerides, total cholesterol, high density lipoprotein cholesterol gamma glutamyl transpeptidase, alanine aminotransferase, aspartate aminotransferase, microalbumin, nitric oxide, glucose, glycated hemoglobin (A1C), C-peptide, insulin and glucagon were also collected. Also during the pre-study, after a feeding stimulus of 566 Kcal, biochemical evaluations were conducted of the metabolism in fasting and during 3 hours, in standard intervals of 5, 15, 30, 45, 60, 90, 120, 150 and 180 minutes for glucose, insulin and glucagon for design of the area under curve (AUC) of these analytes. In a subgroup of 20 patients were performed dosages in pre-fixed times of incretins (active Glucagon Like Peptide -1, GLP-1, and total Glucose-dependent Insulinotropic polypeptide, GIP) after feeding stimulus and electroneurophysiological tests (somatosensory evoked potentials - SEP, and visual - VEP). After these evaluations, the patients received sitagliptin 100 mg (1 tablet a day) for 3 months and then returned for clinical evaluation and to repeat all the biochemical dosages, SEP and VEP exams. From 41 patients evaluated, 28 were female and 13 male, the average age was 53.2 ± 9.43 years, in average obese and 50% were hypertensive. After treatment, improvement was observed in all anthropometric and laboratory parameters, specially fasting glucose (pre: 174,43 ± 67,18 mg/dL and post: 129,07 ± 29,19 mg/dL), A1c (pre: 8,76 ± 2,68 and post: 6,64 ± 1,11%), and nitric oxide (pre: 85,21 ± 44,02 and post: 39,91 ± 20,99 µM), all with P<0.0001, and also increase in the concentration of the AUC of active GLP-1 (P=0.003), decrease of the AUC of total GIP (P=0.001), and decrease of the N9D (P<0.0001), N13E (P=0.036 ), N20D (P=0.028) latencies and of the central conduction time N13-N9E (P=0.045), N20-N13D (P=0.044). There were also statistically significant correlations between biochemical and electrophysiological parameters. This study concluded that there was clinical, metabolic and somatosensory and visual nerve impulse conduction pathways improvement in patients treated with sitagliptin.