Muncie Times, Muncie, Delaware County, 21 March 2002 — Page 16

The Muncie Times, March 21, 2002, page 16

Study: Younger women more likely to die after bypass surgery

Dallas - Women have as much as a three times higher risk of dying during or shortly after a coronary artery bypass surgery then men, researchers repot in the Circulation: Journal of the American Heart Association. “The younger the patients, the greater the mortality difference between women and meii.” said lead author Viola Vaccarino, M.D., Ph.D. of Emory University in Atlanta, Ga. “Although the percentage of bypass surgery patients who died in the hospital was relatively small, the difference in both overall mortality and the death rate for patients under age 60 was significant between the two sexes,” said Vaccarino, an associate professor of

medicine at Emory’s School of Medicine and associate professor of epidemiology at its Rollins School of Public Health. Coronary artery bypass surgery uses blood vessels to reroute blood flow around arterial blockages to improve the supply of blood and oxygen to the heart. Heart surgeons perform about 571,000 of them annually, including about 182,000 in women. Vaccarino and her colleagues were unable to determine why death rates were different between men and women. She says that explanation might be some unknown factor that increases the risk for women who have bypass surgery, or something in the surgical procedure itself that might be subject to change.

“Clearly, we need further investigation in order to determine the causes for these mortality differences,” she said. Women who suffer heart attacks have a higher in-hospital death rate than men. The Emory group has shown that women’s mortality compared to men’s is particularly high among patients yonger than 60. The researchers wondered if the same pattern held true for women undergoing bypass surgery. The researchers reviewed records of 51,187 patients in the National Cardiovascular Network database who underwent bypass surgery at 23 medical centers between October 1993 and December 1999. Of these patients, 15,187 (or 29.7 percent)

were women. A smaller percent of women than men was white and the women were older - an average age of 67.5 compared to 64.1 for the men. The team divided the patients in their study into five age groups: younger than 50, 50 to 59, 60 to 69, 70 to 79, and 8and older. Before determining the risk of death for each age group, they examined the patients’ health characteristics, what other illnesses they suffered besides coronary artery disease, and their heart-disease risk factors. Overall, 5.3 percent of the women in the study died in the hospital, compared with 2.9 percent of the men. In addition, 3.4 percent of women younger than 50 died compared with 1.1 percent

of men. In the 50 to 59 group, 2.6 percent of the women died verses 1.1 percent of the men. The mortality difference between the sexes declined with older age. Among bypass patients 80 and older, the risk of death was only slightly greater for women 9 percent versus 8.3 percent for men. “Women tend to have more pre-existing illnesses and risk factors in their medical history, but they had les extensive coronary atherocsclerosis, and their hearts had better pump function as detected by cardiac catheterizaton,” said Vaccarino. “It seems paradoxical, but that’s what the data show.” In addition, a smaller percentage of women had suffered a heart attack before their bypass.”

Weight loss improves heart health

DALLAS-Losing weight may lower blood levels of a inflammatory marker called C-reactive protein (CRP), a factor associated with an increased rise of heart disease, according to a recent report in Circulation: Journal of the American Heart Association. On average, CRP levels were reduced by 32.3 percent, from 3.06 to 1.63 micrograms per milliliter, after a weight loss of about 15 kilograms (33 pounds), reports primary researcher Andre Tchernof, Ph.D., formerly from the department of medicine at the University of Vermont, Burlington. Tchernof now works in a molecular endocrinology lab in Quebec City, Canada. Researchers measured CRP leve TTefore and after weight loss study conducted in

the greater Burling, Vt., area. The study included 61 obese postmenopausal women, average age 56. Obesity is defined as a body mass index higher than 30kg/m2. Body mass index assesses body weight relative to height, All women in the study were physically inactive, nonsmokers and nondiabetic. Before and after the weight loss protocol, researchers measured body composition and body fat distribution using radiological and imaging techniques. Blood samples were taken to obtain lipid profiles, estrogen measurements and plasma CRP levels. “Other studies have shown that obese patients are usually characterized by increased plasma CRP, possibly because^ fat tissue releases a'Factor caffecl interleukin-6, which in

turn stimulates CRP production in the liver,”says Tchernof. “Based on these previous studies we hypothesized that a reduction in fat tissue mass would lower plasma CRP levels in obese women.” Twenty-five women participated in the weightloss portion of the study. They underwent a weight stabilization period before and after the program. A registered dietitian who helped the women choose their food, with or without using a fasting supplement, supervised the weight-loss program, The weight was lost over an average of 13.9 months, including the stabilization period before metabolic testing. The women were encouraged not to change their level of physical activity during the weight-loss p^rogram^ Average weight loss was 14.5 kg (a 15.6

percent reduction). Including an average loss of 10.4 kg in fat mass (a 25 percent reduction). Abdominal fat was reduced by 36.1 percent, and subcutaneous (under the skin) fat dropped 23.7 percent. Glucose disposal, an index for insulin sensitivity, increased by 33.2 percent. “During the weight loss protocol, total body fat was a better predictor of plasma CRP changes than abdominal fat loss. Thus, from our results, we cannot determine whether the plasma CRP levels are related more closely to abdominal fat distribution or total body fatness,’’Tchernof said.” “The women also lost, approximately 3 kg in muscle mass . However, the loss of muscle mass was not related to the change in CRP. , It, really looked like ft loss is the best piedictor of CRP

changes.” The reduction in CRP was proportional to the magnitude of fat loss. In response to the weight loss, insulin sensitivity and the cardiovascular disease risk profile of women improved significantly. The plasma CRP reduction was not related to estrogen levels or the use of cholesterollowering drugs or aspirin, which are known to affect CRP levels. The mechanisms correlating the degree of obesity to circulating CRP levels have yet to be determined, but Tchernof says one theory is particularly compelling. “The hypothesis that inflammatory factors (particularly interleukin-6 and TNF-alpha) mediate the link between fat accumulation and plasma ,CRP Levels Jias.Jbeen .put forth by several other investigators,” he said.