Roberto Da Ros

Evidence for an Independent and Cumulative Effect of Postprandial Hypertriglyceridemia and Hyperglycemia on Endothelial Dysfunction and Oxidative Stress Generation Effects of Short- and Long-Term Simvastatin Treatment

Background—Postprandial hypertriglyceridemia and hyperglycemia are considered risk factors for cardiovascular disease. Evidence suggests that postprandial hypertriglyceridemia and hyperglycemia induce endothelial dysfunction through oxidative stress; however, the distinct role of these two factors is a matter of debate. Methods and Results—Thirty type 2 diabetic patients and 20 normal subjects ate 3 different meals: a high-fat meal; 75 g glucose alone; and high-fat meal plus glucose. Glycemia, triglyceridemia, nitrotyrosine, and endothelial function were assayed during the tests. Subsequently, diabetics took 40 mg/d simvastatin or placebo for 12 weeks. The 3 tests were performed again at baseline, between 3 to 6 days after the start, and at the end of each study. High-fat load and glucose alone produced a decrease of endothelial function and an increase of nitrotyrosine in normal and diabetic subjects. These effects were more pronounced when high fat and glucose were combined. Short-term simvastatin treatment had no effect on lipid parameters but reduced the effect on endothelial function and nitrotyrosine observed during each different test. Long-term simvastatin treatment was accompanied by a lower increase in postprandial triglycerides, which was followed by smaller variations of endothelial function and nitrotyrosine during the tests. Conclusions—This study shows an independent and cumulative effect of postprandial hypertriglyceridemia and hyperglycemia on endothelial function, suggesting oxidative stress as common mediator of such effect. Simvastatin shows a beneficial effect on oxidative stress and endothelial dysfunction, which may be ascribed to a direct effect as well as the lipid-lowering action of the drug.

Effect of Atorvastatin and Irbesartan, Alone and in Combination, on Postprandial Endothelial Dysfunction, Oxidative Stress, and Inflammation in Type 2 Diabetic Patients

Background—Postprandial hypertriglyceridemia and hyperglycemia are considered risk factors for cardiovascular disease. Evidence suggests that postprandial hypertriglyceridemia and hyperglycemia induce endothelial dysfunction and inflammation through oxidative stress. Statins and angiotensin type 1 receptor blockers have been shown to reduce oxidative stress and inflammation, improving endothelial function. Methods and Results—Twenty type 2 diabetic patients ate 3 different test meals: a high-fat meal, 75 g glucose alone, and a high-fat meal plus glucose. Glycemia, triglyceridemia, endothelial function, nitrotyrosine, C-reactive protein, intercellular adhesion molecule-1, and interleukin-6 were assayed during the tests. Subsequently, diabetics took atorvastatin 40 mg/d, irbesartan 300 mg/d, both, or placebo for 1 week. The 3 tests were performed again between 5 and 7 days after the start of each treatment. High-fat load and glucose alone produced a decrease in endothelial function and increases in nitrotyrosine, C-reactive protein, intercellular adhesion molecule-1, and interleukin-6. These effects were more pronounced when high-fat load and glucose were combined. Short-term atorvastatin and irbesartan treatments significantly counterbalanced these phenomena, and their combination was more effective than either therapy alone. Conclusions—This study confirms an independent and cumulative effect of postprandial hypertriglyceridemia and hyperglycemia on endothelial function and inflammation, suggesting oxidative stress as a common mediator of such an effect. Short-term treatment with atorvastatin and irbesartan may counterbalance this phenomenon; the combination of the 2 compounds is most effective.

Constant and intermittent high glucose enhances endothelial cell apoptosis through mitochondrial superoxide overproduction

It has been previously shown that hyperglycemia enhances free radical production, inducing oxidative damage, which in its turn activates the death pathways implicated in cell apoptosis and necrosis. But the possible involvement of this pathway in the hyperglycemia‐induced apoptosis of endothelial cells has not yet been reported.

Use of a retrograde nail for ankle arthrodesis in Charcot neuroarthropathy: a limb salvage procedure.

Background: Charcot neuroarthropathy is a serious complication associated with diabetic neuropathy. This complication probably is most serious when the ankle is involved because of the instability and progressive deformity, which often leads to ulceration, osteomyelitis, and amputation. Arthrodesis before the ulcerated lesion appears is considered a limb salvage treatment. One of the most effective techniques for an unstable ankle in Charcot neuroarthropathy is retrograde transcalcaneal nailing. Methods: Eighteen diabetic patients, without a history of ulceration, were treated from July, 2003, to November, 2005, with panarthrodesis of the ankle using intramedullary retrograde transcalcaneal nailing. The average follow up was 14 ± 10.1 months. All patients completed the unloaded postoperative period with a fiberglass cast (3 months nonweightbearing and 3 months partial weightbearing) and commenced walking in shoes with a stiff rocker sole and a molded insole. Results: During the followup period there were no major complications. In three patients, removal of one of the proximal screws used for anchoring the nail to the tibia was done because of protrusion causing skin breakdown. Fourteen patients had a stable fusion and four patients had fibrous union. The percentage of limb salvage was 100% in the followup period. Conclusions: Our study confirms that this operative technique is effective and safe.