O magnésio é um íon predominantemente intra-celular, que participa como co-fator de mais de 300 reações enzimáticas, dentre elas na atividade da tirosino-cinase. Sua deficiência pode aumentar a resistência periférica à insulina, especialmente em pacientes com síndrome metabólica e diabetes mellitus tipo 2 (DM2). Este trabalho avaliou, em 27 pacientes com DM2 descompensado, o conteúdo intra-celular de magnésio, correlacionando-o com índices laboratoriais de resistência insulínica e controle glicêmico. Hipomagnesemia foi encontrada em 75% dos pacientes e déficit intra-celular em 30,8%. Houve correlação negativa do Mg intra-celular (Mg IC) com HbA1 e com IMC. 59,2% dos pacientes apresentaram HOMA IR > 3,5, e tendência para correlação negativa com o Mg IC, porém sem significância estatística. Apesar do número pequeno de pacientes, ressalta-se que uma vez que deficiência de magnésio é comum em pacientes com diabetes, sua relação com resistência insulínica deve ser mais estudada.

Magnesium is a predominantly intracellular ion, and it is a cofactor in more than 300 enzymatic reactions, like tyrosinokinase activity. Its deficiency may increase insulin resistance, especially in patients with metabolic syndrome or type 2 diabetes. This study evaluated in 27 patients with poorly controlled type 2 diabetes if there was correlation between intracellular magnesium levels, laboratorial indexes of insulin resistance and glycemic control. Decreased serum and intracellular magnesium depletion were found in 75% and 30.8% of patients, respectively. A negative correlation between intracellular magnesium levels (ICMg) and BMI and HbA1 was found. The homeostasis model assessment for insulin resistance (HOMA-IR) was higher than 3.0 in 59.2% of patients and there was a tendency to negative correlation with ICMg levels, although without statistical significance. Despite the small number of patients, this study shows that magnesium deficiency is frequent in patients with diabetes and its correlation with insulin resistance should be more studied.

Com o objetivo de determinar se tolerância diminuída à glicose (TDG) está associada a neuropatia vegetativa realizamos estudo transversal de que participaram 44 pacientes com intolerância a glicose (Grupo 1) os quais foram comparados com 43 indivíduos controles apresentando teste de tolerância à glicose normal (Grupo 2). Os pacientes de ambos os grupos, após aceitarem participar da pesquisa, eram submetidos a anamnese, exames clínico e laboratoriais e estudo da função vegetativa (intervalo QT, prova da arritmia sinusal, manobra de Valsalva e teste postural). Os pacientes com TDG apresentaram mais hipertensão arterial sistêmica, obesidade centrípeta, hiperglicemas de jejum e pós-prandiais e dislipidemias que os controles. O teste de arritmia sinusal estava alterado em 54,5% dos grupo 1 e em 32,5% do grupo 2. A manobra de Valsalva foi anormal em 34,1% no grupo 1 e em 7% dos controles (p=0,004). A prova postural não foi diferente nos dois grupos. O comprometimento do sistema neurovegetativo foi mais freqüente nos pacientes com TDG que nos controles. A maior freqüência de fatores de risco para doença aterosclerótica cardiovascular e o concomitante comprometimento do sistema nervoso vegetativo nos pacientes com TDG podem ser os responsáveis pelas elevadas taxas de letalidade devida a vasculopatias observadas nessa população.

Impaired glucose tolerance (1GT) is a clinical situation characterized by mild hyperglicemia, which is estimated to afflict 7.8% of the Brazilian population. Diabetic neuropathy is the most common: complication in diabetes mellitus and it is related to morbidity and lethality in this disease. The associatior between IGT and peripheral neuropathy is still a matter of great concern. PURPOSE AND METHOD: In order to determine if IGT is associated with autonomic neuropathy a cross-sectional study in 44 patients with impaired glucose tolerance test (Group 1) was performed. The patients were compared to 43 control individuals (Group 2). Every patient in each group underwent anamnesis and standardized autonomic tests which consisted of hear) frequency test, Valsalva maneuver, postural test and sinus arrythmia. Routine hematologic exams as well as GTT were also made. RESULTS: Patients in group 1 had more systemic arterial hypertension, centripetal obesity, fasting and post-feeding hyperglicemia and dyslipidemia when compared with group 2. When we analysed the autonomic tests, the sinus arrythmia test was abnormal in 54.5% of the patients in group 1 and in 32.5% in group 2 (p=0.0039) and the Valsalva maneuver was abnormal in 34.1% of group 1 and in 7% of group 2 (p=0.004). The postural test was not different in both groups (p=0.334). CONCLUSION: Our results show that the involvement of the autonomic nervous system was more frequent in patients with IGT when compared to controls. These findings can explair the increased lethality due to vasculopathies observed in this group of patients and also alert physicians to care for patients with impaired glucose tolerance test.