Bases fisiopatológicas para una clasificación de la neuropatía diabética / A new physiopathological classification of diabetic neuropathy

Nowadays, Diabetic Neuropathy (DN) is considered the most common cause of peripheral neuropathy in clinical practice. It can affect sensitive, motor or autonomic nerve fibers, with symmetric, asymmetric, acute or chronic presentations. Due to this variability, with multiple physiopathologic mechanisms involved, a complex clinical classification has been used until recently. The aim of this review is to present a new classification of diabetic neuropathy, based on its physiopathology. It is divided in metabolic microvascular and hypoxic, autoimmune and inflammatory, compressive, secondary to complications ofdiabetes and related to treatment. It must be understood that DN is notjust a functional disease, but a complication of diabetes with molecular and pathological substrates caused by hyperglycemia. Therefore, normalization of blood glucose is a fundamental step towards the successful prevention and treatment of DN.

[A new physiopathological classification of diabetic neuropathy]. / Bases fisiopatológicas para una clasificación de la neuropatía diabética.

Nowadays, Diabetic Neuropathy (DN) is considered the most common cause of peripheral neuropathy in clinical practice. It can affect sensitive, motor or autonomic nerve fibers, with symmetric, asymmetric, acute or chronic presentations. Due to this variability, with multiple physiopathologic mechanisms involved, a complex clinical classification has been used until recently. The aim of this review is to present a new classification of diabetic neuropathy, based on its physiopathology. It is divided in metabolic microvascular and hypoxic, autoimmune and inflammatory, compressive, secondary to complications of diabetes and related to treatment. It must be understood that DN is not just a functional disease, but a complication of diabetes with molecular and pathological substrates caused by hyperglycemia. Therefore, normalization of blood glucose is a fundamental step towards the successful prevention and treatment of DN.

Overexpression of hepatic 5α-reductase and 11ß-hydroxysteroid dehydrogenase type 1 in visceral adipose tissue is associated with hyperinsulinemia in morbidly obese patients.

11-ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) converts cortisone to cortisol, mainly in the liver and visceral adipose tissue (VAT), and has been implicated in several metabolic disorders. The absence of systemic hypercortisolism in central obesity could be due to increased inactivation of cortisol to its tetrahydrometabolites by the hepatic enzymes 5α- and 5ß-reductases. Our aim was to assess the expression of the reductases in the liver and of 11ß-HSD1 in the liver and VAT in morbidly obese patients and to analyze their association with clinical, anthropometric, and biochemical parameters. Hepatic and VAT samples were obtained during bariatric surgery. 5α- and 5ß-reductases, 11ß-HSD1, and 18S expression was measured using real-time polymerase chain reaction. Anthropometric and biochemical variables were analyzed. Forty-one patients were recruited (age, 41.8 ± 10.6 years; body mass index, 42.1 ± 6.6 kg/m(2); 71% women). The expression of hepatic 5α- and 5ß-reductases was positively correlated (r = +0.53, P = .004), and their expression levels were correlated with hepatic 11ß-HSD1 expression (r = +0.61, P < .001 for 5α-reductase and r = +0.50, P < .001 for 5ß-reductase). Hepatic 5α-reductase was associated with insulin (r = +0.34, P = .015). Visceral adipose tissue 11ß-HSD1 expression was associated with glucose (r = +0.37, P = .025) and insulin (r = +0.54, P = .002). Our results showed that 5α-reductase and VAT 11ß-HSD1 expressions were associated with insulinemia. These findings suggest that overexpression of 5α-reductase, through a higher inactivation of cortisol in the liver, could have a protective role in preserving hepatic sensitivity to insulin. The overexpression of liver reductases in obesity could be an adaptive response to an increase in cortisol production by the liver and visceral 11ß-HSD1 to avoid systemic hypercortisolism.

Near-optimal glycemic control in Chilean women with pregestational type-2 diabetes: persistent macrosomia relates to maternal pre-pregnancy overweight.

UNLABELLED: After a 10-year program intending to improve glycemic control in diabetic pregnancies, we evaluated whether factors underlying macrosomia are similar for type-1 and -2 pregestational diabetic women. PATIENTS AND METHODS: Twenty-three pregnancies in type-1 diabetics (PDM1, age 28.3+/-1.1 years) and 51 pregnancies in type-2 diabetics (PDM2, age 32.8+/-0.6 years) were followed and treated with intensified insulin therapy. Several factors potentially influencing macrosomia were evaluated. STATISTICS: chi-square, Fisher's exact, Student's "t" and Mann-Whitney "U" tests, and ROC analysis. RESULTS: In PDM1 and PDM2, respectively, large-for-gestational-age (LGA) frequencies were 26.08% and 37.25% (NS), antepartum HbA1c values were 6.5+/-0.32 and 6.1+/-0.16 (NS), and pre-pregnancy body mass indexes (BMI) were 23.03+/-0.66 and 30.01+/-0.89 (p<0.0001). In PDM1 the main predictor of LGA was an antepartum HbA1c> or =6.8% (p=0.046), whereas in PDM2 pregestational BMI> or =24 the variable associated (p=0.032) with LGA newborns. CONCLUSIONS: PDM1 and PDM2 differ in the underlying factors related to macrosomia. Whereas in PDM1 the antepartum HbA1c emerged as the most significant variable, suggesting that glycemic control largely determines macrosomia, in PDM2 with near-optimal glycemic control, macrosomia related to pregestational BMI.