抗自由基 降肥仔心脏病危险
路透社纽约健康消息 肥胖人士可能会因为血流不通畅而容易患心脏病。现在，有研究者报导说大量自由基的存在亦可能是让肥胖者患上心脏病的原因之一。自由基是一种由机体自然产生的化合物，可以破坏细胞，引起疾病。
由意大利研究员对76名健康人士的血管反应进行了测试。结果发现，肥胖者比较容易在腹部积聚脂肪，而且他们对胰岛素的反应不正常，血液流动也不通畅。胰岛素是调节血糖的激素，患有II型糖尿病的病人就是由于对胰岛素的反应不正常，因此导致血糖升高。当参加实验的肥胖病患者服用了维生素C之后，血管就变宽了、血流也通畅了。报告发表在美国糖尿病协会所的《糖尿病》杂志一月版上。
之前已经有研究表明，像维生素C和E这一类的抗氧化剂可帮助动脉扩张、保持血流通畅，因为抗氧化剂可以使自由基的作用减弱。然而，目前还没有证据表明维生素C确实有降低心脏病发病率的功能。因此该研究支持“自由基损伤是血管问题的重要机制”的假说。
, http://www.100md.com
尽管减肥及运动可能会对增大血流量、降低心脏病的发病率有益，但仍需要更进一步的研究搞清楚到底肥胖及抗胰岛素作用会是怎样引起血流不畅。
来源：《糖尿病》2001;50:159-165
Free Radicals Implicated in Obesity Heart Risk
NEW YORK -- People who are overweight may have impaired blood flow that can increase their risk of heart disease. Now, a team of Italian researchers report that an abundance of free radicals -- naturally-occurring compounds that damage cells and lead to disease -- may be partly to blame.
, http://www.100md.com
Dr. Francesco Perticone, from the University of Catanzaro Magna Graecia in Catanzaro, Italy, and colleagues tested blood vessel response in 76 healthy people.
The investigators found that obese people, individuals who tended to gain weight around their abdomen, and those who did not respond normally to insulin had impaired blood flow compared with normal-weight people. Insulin is the hormone that regulates blood sugar. People with type 2 diabetes do not respond normally to insulin, which results in high levels of glucose (sugar) in their blood.
, http://www.100md.com
When the obese participants were given vitamin C, their blood vessels widened, improving blood flow, according to the report in the January issue of Diabetes, a journal of the American Diabetes Association.
Previous research has found that antioxidant vitamins such as C and E may help arteries dilate and keep blood flowing smoothly. Antioxidants blunt the effects of free radicals.
The new study "reinforces the hypothesis" that damage caused by free radicals may be considered an important mechanism behind blood vessel problems in obesity, Perticone and colleagues explain.
, http://www.100md.com
The authors note, however, that there is no evidence that vitamin C actually lowers heart disease risk.
They write that weight loss and exercise may help improve blood flow and lower the risk of heart disease. Further research is needed to determine exactly how obesity and insulin-resistance prevent blood from flowing smoothly through vessels.
SOURCE: Diabetes 2001;50:159-165., 百拇医药
由意大利研究员对76名健康人士的血管反应进行了测试。结果发现，肥胖者比较容易在腹部积聚脂肪，而且他们对胰岛素的反应不正常，血液流动也不通畅。胰岛素是调节血糖的激素，患有II型糖尿病的病人就是由于对胰岛素的反应不正常，因此导致血糖升高。当参加实验的肥胖病患者服用了维生素C之后，血管就变宽了、血流也通畅了。报告发表在美国糖尿病协会所的《糖尿病》杂志一月版上。
之前已经有研究表明，像维生素C和E这一类的抗氧化剂可帮助动脉扩张、保持血流通畅，因为抗氧化剂可以使自由基的作用减弱。然而，目前还没有证据表明维生素C确实有降低心脏病发病率的功能。因此该研究支持“自由基损伤是血管问题的重要机制”的假说。
, http://www.100md.com
尽管减肥及运动可能会对增大血流量、降低心脏病的发病率有益，但仍需要更进一步的研究搞清楚到底肥胖及抗胰岛素作用会是怎样引起血流不畅。
来源：《糖尿病》2001;50:159-165
Free Radicals Implicated in Obesity Heart Risk
NEW YORK -- People who are overweight may have impaired blood flow that can increase their risk of heart disease. Now, a team of Italian researchers report that an abundance of free radicals -- naturally-occurring compounds that damage cells and lead to disease -- may be partly to blame.
, http://www.100md.com
Dr. Francesco Perticone, from the University of Catanzaro Magna Graecia in Catanzaro, Italy, and colleagues tested blood vessel response in 76 healthy people.
The investigators found that obese people, individuals who tended to gain weight around their abdomen, and those who did not respond normally to insulin had impaired blood flow compared with normal-weight people. Insulin is the hormone that regulates blood sugar. People with type 2 diabetes do not respond normally to insulin, which results in high levels of glucose (sugar) in their blood.
, http://www.100md.com
When the obese participants were given vitamin C, their blood vessels widened, improving blood flow, according to the report in the January issue of Diabetes, a journal of the American Diabetes Association.
Previous research has found that antioxidant vitamins such as C and E may help arteries dilate and keep blood flowing smoothly. Antioxidants blunt the effects of free radicals.
The new study "reinforces the hypothesis" that damage caused by free radicals may be considered an important mechanism behind blood vessel problems in obesity, Perticone and colleagues explain.
, http://www.100md.com
The authors note, however, that there is no evidence that vitamin C actually lowers heart disease risk.
They write that weight loss and exercise may help improve blood flow and lower the risk of heart disease. Further research is needed to determine exactly how obesity and insulin-resistance prevent blood from flowing smoothly through vessels.
SOURCE: Diabetes 2001;50:159-165., 百拇医药