TUESDAY, April 29 (HealthDay News) -- Increased levels of exercise can reduce but not eliminate the risk of heart disease in overweight and obese women, a U.S. study finds.

The researchers analyzed data from 38,987 women who took part in the recently completed Women's Health Study. At the start of the study in 1992, information was gathered about the women's height and weight, the average amount of time per week they were physically active, other health habits, and medical history. The women were then followed for an average of 10.9 years.

At the start of the study, 34 percent of the women were considered physically active, 31 percent were overweight, and 18 percent were obese.

During the follow-up, 948 of the women developed coronary artery disease. Both body-mass index (BMI) and physical activity levels were individually associated with the risk of heart disease. The risk was lowest for normal weight women who were active, slightly higher for inactive normal-weight women, higher still for active women who were overweight or obese, and highest for inactive overweight or obese women.

Dr. Amy R. Weinstein, of Beth Israel Deaconess Medical Center in Boston, and colleagues noted that fat cells (adipocytes) release chemicals that may harm the heart by accelerating the hardening of the arteries and increasing inflammation, clotting and dysfunction of the blood vessels.

"We postulate that the beneficial effect of physical activity may directly reduce and combat the ill effect of the prothrombotic factors released by adipocytes," the researchers wrote.

But they noted that exercise didn't eliminate the effects of being overweight.

"Even high quantities of physical activity are unlikely to fully reverse the risk of coronary heart disease in overweight and obese women without concurrent weight loss," the study authors concluded. "Regardless of body weight, these data highlight the importance of counseling all women to participate in increasing amounts of regular physical activity and maintaining a healthy weight to reduce the risks of coronary heart disease."

The study was published in the April 28 issue of the Archives of Internal Medicine.

More information

The U.S. National Women's Health Information Center has more about heart disease.

MONDAY, April 28 (HealthDay News) -- The number of women starting their pregnancies with type 1 or type 2 diabetes has doubled since 1999, but rates of gestational diabetes have stayed the same, new research finds.

In some age groups, the results were even worse. Researchers from Kaiser Permanente found that the number of teenagers who had diabetes before birth jumped fivefold.

"It's important to recognize with the increase in overweight and obesity, more women than ever will be entering their reproductive years with diabetes," said study author Jean Lawrence, a research scientist at Kaiser Permanente Bellflower Medical Center, in Bellflower, Calif.

And, she added, "having diabetes during pregnancy increases the risk of miscarriage early in pregnancy and the risk of stillbirth later in pregnancy. It also increases the chances of having a baby with birth defects, and it may result in larger babies and more difficult deliveries."

Results of the study are published in the May issue of Diabetes Care.

Past research has focused on the number of women who develop diabetes during pregnancy, which is called gestational diabetes, and generally disappears after the baby is born.

The new study, which included 175,249 women who gave birth from 1999 to 2005, also included women with type 1 and type 2 diabetes. All of the women in the study were treated at one of 11 Kaiser Permanente hospitals in southern California. Fifty-two percent of the women were Hispanic, 26 percent were white, 11 percent were Asian/Pacific Islanders, and 10 percent were black, according to the study.

Preexisting diabetes -- type 1 or type 2 -- was found in 1.3 percent of all pregnancies. In 1999, the rate of preexisting diabetes was 0.81 per 100 births; by 2005, that number had jumped to 1.82 per 100 births.

But, during that six-year period, gestational diabetes rates remained nearly unchanged. In 1999, 7.5 women per 100 births had gestational diabetes; in 2005, it was 7.4 women per 100 births.

What did change during the study period was the proportion of preexisting diabetes compared to gestational diabetes. In 1999, of all pregnancies affected by diabetes, 10 percent were due to preexisting diabetes, while 90 percent were due to gestational diabetes. In 2005, 21 percent of women had preexisting diabetes, compared to 79 percent with gestational diabetes, according to the study.

The researchers also noted some differences in race and age. Black, Hispanic and Asian/Pacific women were more likely to have diabetes before birth, and teens and women over 40 experienced dramatic jumps in their pre-pregnancy diabetes rates. Teen mothers saw a fivefold increase in preexisting diabetes, while mothers over 40 saw a 40 increase in the rate of pre-pregnancy diabetes.

Experts blame much of the increase on the rising trend of overweight and obesity.

"We saw an increase in type 2 diabetes. That's due to the increase in overweight and obesity. Also, type 2 is being diagnosed at younger ages," said Lawrence, who suggested that women do whatever they can to reduce their risk of type 2 diabetes by eating a healthful diet, maintaining a proper weight and being active. She said there's no known way to prevent type 1 diabetes.

Dr. Stuart Weiss, an endocrinologist at the New York University Langone Medical Center, said he "was surprised that the incidence of gestational diabetes wasn't up."

For women who know they have diabetes before pregnancy, Weiss advised: "Control your blood glucose levels as aggressively as possible. Control isn't easy to do, because you have to have adequate nutrition and still control your blood sugar."

But, he added, it's crucial to try, because it may help prevent some of the serious complications associated with diabetes.

More information

To learn more about diabetes and pregnancy, visit the U.S. Centers for Disease Control and Prevention.

FRIDAY, April 25 (HealthDay News) Nearly two-thirds (65 percent) of young American women report disordered eating behaviors, and 10 percent report symptoms of eating disorders such as anorexia and bulimia nervosa or binge eating disorder, a new survey finds.

The findings -- from an online poll of more than 4,000 women between the ages of 25 and 45 -- found that 75 percent eat, think and behave abnormally around food. The survey was conducted by SELF magazine in partnership with the University of North Carolina at Chapel Hill.

"Our survey found that these behaviors cut across racial and ethnic lines and are not limited to any one group. Women who identified their ethnic backgrounds as Hispanic or Latina, white, black or African American and Asian were all represented among the women who reported unhealthy eating behaviors," Cynthia R. Bulik, a professor of eating disorders and director of the UNC Eating Disorders Program, said in a prepared statement.

"What we found most surprising was the unexpectedly high number of women who engage in unhealthy purging activities. More than 31 percent of women in the survey reported that in an attempt to lose weight, they had induced vomiting or had taken laxatives, diuretics or diet pills at some point in their lives. Among these women, more than 50 percent engaged in purging activities at least a few times a week, and many did so every day," Bulik said.

Eating habits that some women think are normal -- such as skipping meals, avoiding carbohydrates and, in some cases, extreme dieting -- may actually be signs of disordered eating, which is often linked with emotional and physical distress.

While there's a widespread belief that eating disorders affect mostly young women, the survey found that women in the 30s and 40s had about the same rates of disordered eating as younger women.

Among the other findings:

• 67 percent of the women (excluding those with actual eating disorders) are trying to lose weight.
• 53 percent of dieters are already at a healthy weight and are still trying to lose weight.
• 39 percent of the women said concerns about what they eat or weigh interfere with their happiness.
• 37 percent of respondents said they regularly skip meals to try to lose weight.
• 27 percent said they'd be "extremely upset" if they gained just five pounds.
• 26 percent have eliminated entire food groups from their diet.
• 16 percent have dieted on 1,000 or fewer calories a day.
• 13 percent smoke to lose weight.
• 12 percent often eat when they're not hungry, and 49 percent sometimes do.

The survey was expected to be published in the May issue of SELF and to be presented May 17 at the Academy for Eating Disorders' International Conference on Eating Disorders, in Seattle.

More information

The U.S. National Institute of Mental Health has more about eating disorders.

THURSDAY, April 24 (HealthDay News) -- Women who play sports are prone to tearing the knee ligament that connects the thighbone to the shinbone. Beyond the immediate pain and swelling it can cause, there's now reason to suspect that this type of injury may lead to another vexing health problem.

Researchers at the Mayo Clinic in Rochester, Minn., found that young women who had surgery to repair the anterior cruciate ligament (ACL) suffered significant bone loss around the knee even two years later. And that damage was seen even though they had undergone rehabilitation.

"Despite telling them to weight-bear early and put weight on the leg, people are going to protect an operative limb," said study author Dr. Diane L. Dahm, an assistant professor of orthopedics at Mayo. "So, it's probable that the forces going across that operative limb were not as great as the opposite limb, early on especially."

The findings were first reported at a meeting of the American Academy of Orthopaedic Surgery (AAOS).

Ligaments are tough fibers that hold bones together. The ACL, located toward the front of the knee, gives you stability on your feet. But if you land the wrong way or change direction quickly, that ligament can tear. You might even hear a "popping" sound when it happens.

Each year, an estimated 38,000 women sustain ACL tears. In fact, the incidence of ACL injuries is two to eight times greater among women than men, he AAOS said.

Even in the same sport, women are more likely to injure their ACL than men. Female basketball players, for example, are twice as likely as their male counterparts to tear an ACL, while the incidence of these injuries is four times greater among women soccer players than men who play this sport, the AAOS noted.

Although the reason for this gender gap isn't clear, orthopedic experts suspect hormones and differences in the way women use their muscles may play a role.

Dahm and her colleagues studied 18 female athletes ranging in age from 16 to 40. All were fairly active and involved in some sort of exercise, although not necessarily an organized sport. The researchers chose age 40 as the cutoff to eliminate any patients who might have osteoporosis related to early menopause.

After undergoing ACL reconstruction, the women participated in a rehabilitation program that involved routine visits with physical therapists and sports psychologists.

Before surgery, there were no significant differences in bone density between the injured and uninjured legs. Three months after surgery, however, the researchers found striking differences in bone density between the injured limb and the unaffected one. While there were improvements in the women's injured limbs over two years, "they did not get back to completely normal," Dahm observed.

Dr. Mary Lloyd Ireland, president of the Kentucky Sports Medicine Clinic in Lexington, noted that the study involved a small number of patients, making it difficult to draw definitive conclusions.

Ireland does about 100 ACL surgeries a year, and sometimes, she noted, "the bone on the involved side doesn't look as healthy." Still, she hasn't taken bone-density measurements or followed these patients to document their long-term outcomes.

Another expert questioned whether this study proves that bone loss after ACL surgery is a women's issue, in particular.

"Did they do the same study in men? asked Dr. Christopher D. Harner, professor of orthopaedic surgery at the University of Pittsburgh School of Medicine. "If not, how do they know this is a gender issue?"

Given the incidence of ACL injuries among women, orthopedists urge women athletes to take steps to prevent ligament tears from occurring. The AAOS recommends year-round training and conditioning, including strength training and practicing performing proper landing and cutting maneuvers.

One other bit of advice for the weekend warrior: "Make sure you're ready to do that sport," Ireland cautioned. "I see a lot of women in their 30s and 40s, who haven't been that active, go out and ski and tear their ACL."

More information

The AAOS has more on the ACL and preventing injuries  .