Influence of family history of type 2 diabetes on leptin concentration in cord blood of male offspring with high birth weight.

To verify whether a diabetes family history might be a risk factor for the development, in adult age, of metabolic disorders, leptin, anthropometric and endocrine parameters were analysed in 95 babies with grandparents affected by type 2 diabetes (DF) and in 95 matched babies without diabetes family history (NDF). A sexual dimorphism for leptin was present in the NDF group (males: 6.7+/-4.1 ng/ml; females: 12.3+/-6.5; p < 0.0001) but not in the DF group (males: 9.0+/-5.5; females: 10.8+/-6.4), due to the significant increase in DF male leptin level, compared to that of NDF males (p < 0.05). In DF males only, leptin was positively correlated with body length, PI, C-peptide, IGF-1 and IGF1BP3. These results suggest that the increase in DF male leptin could be a compensatory mechanism for reduced insulin sensitivity in a pre-clinical alteration of glucose metabolism.

Antioxidant treatment associated with sildenafil reduces monocyte activation and markers of endothelial damage in patients with diabetic erectile dysfunction: a double-blind, placebo-controlled study.

OBJECTIVE: To investigate the synergic effect of propionyl L-carnitine (PLC) plus sildenafil in reducing monocyte oxidative activity and endothelial dysfunction markers in diabetic patients with erectile dysfunction (ED). METHODS: Thirty-two type 2 diabetic patients with ED (according to the International Index of Erectile Function-5 [IIEF-5]) were randomized to receive PLC (2 g/d) alone (n=8) or combined with sildenafil (50 mg/d twice weekly) (n=8), sildenafil alone (50 mg/d twice weekly) (n=8), or placebo (n=8) in a double-blind, fixed-dose study. Monocyte oxidative activity (stimulation index [SI]), intercellular adhesion molecule-1 [ICAM-1], P-selectin, advanced glycation end product (AGE) levels, Doppler sonography (recording peak systolic velocity [PSV]; end diastolic velocity [EDV]; systolic wave time [SWT]; resistive index [RI]), and IIEF score were evaluated before and after 12 wk of treatment; IIEF-5 was evaluated again 4 wk posttreatment. RESULTS: SI was reduced by treatment with PLC alone or combined with sildenafil (p<0.05). In patients treated with PLC plus sildenafil, a decrease in ICAM-1, P-selectin, and EDV values was observed compared with patients treated with sildenafil alone (p<0.05, p<0.01, p<0.001, respectively). IIEF-5 improved in all patients treated with PLC plus sildenafil or sildenafil alone (p<0.03, p<0.05, respectively). Four weeks posttreatment, patients treated with PLC plus sildenafil maintained the improvement of the IIEF-5 compared with patients on sildenafil alone (p=0.05). In patients on PLC treatment (with or without sildenafil), SI was correlated with IIEF-5 (p<0.001), glycemia with STW (p<0.03), and AGEs with IIEF-5 (p<0.01). CONCLUSION: PLC plus sildenafil was more effective in reducing SI and endothelial dysfunction markers in patients with type 2 diabetes and ED.

Poly(ADP-ribose)polymerase activity is reduced in circulating mononuclear cells from type 2 diabetic patients.

Poly(ADP-ribose)polymerase (PARP-1), a nuclear enzyme activated by DNA strand breaks, is involved in DNA repair, aging, inflammation, and neoplastic transformation. In diabetes, reactive oxygen and nitrogen species occurring in response to hyperglycemia cause DNA damages and PARP-1 activation. Because circulating mononuclear cells (MNCs) are involved in inflammation mechanisms, these cells were chosen as the experimental model to evaluate PARP-1 levels and activity in patients with type 2 diabetes. MNCs were isolated from 25 diabetic patients (18 M, 7 F, age, 63.5 +/- 10.2 years, disease duration 17.7 +/- 8.2 years) and 11 age and sex matched healthy controls. PARP-1 expression and activity were analyzed by semi-quantitative PCR, Western and activity blot, and immunofluorescence microscopy. PARP-1-mRNA expression was increased in MNCs from all diabetic patients versus controls (P < 0.01), whereas PARP-1 content and activity were significantly lower in diabetic patients (P < 0.0001). To verify whether low PARP-1 levels and activity were due to a proteolytic effect of caspase-3 like, the latter activation was measured by a fluorimetric assay. Caspase-3 activity in MNCs was significantly higher in diabetic patients versus control subjects (P < 0.0001). The different PARP-1 behavior in MNCs from patients with type 2 diabetes could therefore be responsible for the abnormal inflammation and infection responses in diabetes.

Advanced glycosylation end product quantification: differently produced polyclonal antisera do not share the recognition of epitopes of different nature.

Advanced glycosylation end products (AGE) which are probably involved in the pathogenesis of diabetic complications, comprise a series of related chemical structures. Thus different antisera might recognize particular AGE epitopes rather than the complete range of epitopes. To test this hypothesis, two antisera were raised using different immunization techniques and different AGE-carrier proteins as immunogens. The antisera reactivity towards different AGE-proteins under various experimental conditions was compared. Both antisera recognized all AGE-proteins, although with different binding curves. Following pre-incubation with carboxymethyllysine-BSA (CML-BSA) (an oxidation-derived AGE) one antiserum partially retained its reactivity, suggesting recognition of non-oxidation-derived AGE. This result was confirmed both in the cross-reactivity and the preincubation experiments and when the reactivity of the antisera was tested against antigens incubated under oxidative and non-oxidative conditions. These results confirmed the hypothesis that differently produced antisera may not share the recognition of epitopes of different nature and suggest the necessity to adopt a standardized methodology for the production of antisera for an accurate and reproductible determination of the in vivo AGE concentration.