TUESDAY, Feb. 5 (HealthDay News) -- The brain circuitry that controls appetite might be wired differently in some people, and that could predispose them to obesity, California researchers suggest.

The study was conducted in rats, not humans, and yet it could ultimately lead to novel obesity treatments, said Philip Smith, director of the Office of Obesity Research at the National Institute of Diabetes and Digestive and Kidney Diseases.

"It is not just about drugs that modify short-term appetite," he said, "there may be drugs that stimulate development of the appropriate neural pathways. So, it is an exciting, but very early, time in this field."

The study was published in the February issue of Cell Metabolism.

Sebastien Bouret, an assistant professor of neuroscience at the University of Southern California, and his colleagues examined neural circuits emanating from the appetite, hunger and body-weight control center of the brain -- the so-called arcuate nucleus of the hypothalamus (ARH) -- in a series of rats bred to be either prone to, or resistant to, obesity.

The team found fewer neural connections projecting from the ARH in obesity-prone animals than in their leaner counterparts. Surprisingly, Bouret said, this deficiency developed very early in life, before the animals became obese, and appeared to extend into adulthood.

"Somehow, these animals are programmed to become obese," Bouret said. "The obesity is hard-wired into the brain."

When the researchers then looked at why the brains of obese rats differed from their normal-weight counterparts, they found that the neurons from obesity-prone animals were less responsive to leptin, a hormone that controls the development of these circuits, and which also signals the body's energy status and controls metabolic rate.

"This paper presumes to say, these animals must be leptin-resistant, and that is why the pathways are not developing," said Smith.

But that doesn't mean they are doomed to a life of severe obesity, said Dr. Barbara Kahn, chief of the Division of Endocrinology, Diabetes and Metabolism at Beth Israel Deaconess Medical Center, in Boston. How they live their lives also matters.

"It is important not to 'blame' the obese person or imply that he/she is responsible for being obese," Kahn noted. "Having said that, reasonable, healthy caloric restriction and a safe and sustainable program of physical activity can help limit weight gain and often bring about some degree of weight loss. In addition, healthy eating and regular exercise can reduce the complications of obesity such as type 2 diabetes and cardiovascular disease."

At the same time, she added, not everyone can wear a size 4.

"There is a certain aspect of genetics that sets somebody in a certain range of possible body weights, and then how that person lives his or her life will determine whether they are at the bottom or top of the range," she explained.

Human obesity has both genetic and environmental roots. The rats used in this study, like most humans, developed obesity when fed a high-energy diet. On a normal diet, they were heavier than normal rats, but not yet obese.

"This is quite an exciting paper," said Smith, "because it links more closely to human behavior than most rodent models we have seen."

The findings also suggest a possible therapeutic approach to combating human obesity. If drugs could be designed to influence the formation of neural circuits during development and targeted to at-risk pregnancies, Smith said, "there is a good likelihood we could have successful interventions that improve the health of the mother, and which have a major impact on disease risk for the infant, during pregnancy."

A related study from Boston University researchers in the same journal found that bulking up muscle mass can lead to a general metabolic improvement in obese individuals. "Interventions designed to increase skeletal muscle mass in at-risk human populations may prove to be critical weapons in the fight against obesity and obesity-related comorbidities, including diabetes, heart disease, stroke, hypertension and cancer," an accompanying editorial stated.

More information

For more on obesity, visit the National Institute of Diabetes and Digestive and Kidney Diseases.

THURSDAY, Jan. 31 (HealthDay News) -- Adults with epilepsy who have failed other treatments may be able to dramatically reduce their number of seizures by following a modified Atkins-like diet, Johns Hopkins researchers report.

The high-protein, low-carbohydrate diet has already been shown to be valuable in controlling seizures in children, and now results from a small study suggest that the diet also works for adults.

"There are a lot of adults with very bad seizures. There are a lot of adults who have failed medicines and are not candidates for other treatments," said lead researcher Dr. Eric H. Kossoff, an assistant professor of neurology and pediatrics at Johns Hopkins School of Medicine.

For the study, Kossoff's team gave the diet to 30 adults who had unsuccessfully tried at least two anti-convulsant drugs and had an average of 10 seizures a week. The eating plan restricts patients to 15 grams of carbohydrates a day. Most of the calories come from fats such as eggs, meats, oils and heavy cream. In addition, patients are free to eat as much protein and no-carb drinks as they want.

"There was good news and bad news," Kossoff said. "The good news was it worked. The bad news it was tough. About 30 percent of the patients stopped the diet. This happened even in patients who had good seizure control who thought the diet was still too tough to do."

After a month on the diet, half the patients reported suffering 50 percent fewer seizures. At three months, about one-third of the patients cut the frequency of seizures by half.

However, by three months, one-third of the patients had dropped out of the study because they found the diet too restrictive, Kossoff said.

The diet's side effects, such as increases in cholesterol or triglycerides, were mild, Kossoff noted.

After six months on the diet, 14 patients continued with it, even though the study was over, he said.

The findings are published in the February issue of the journal Epilepsia.

No one knows how the diet works to reduce seizures, Kossoff said. And, most people find it too hard to follow, so it's probably not a long-term solution for most people with epilepsy, he added.

He also noted that patients who go on the diet need to continue with it, perhaps for years to keep seizures under control.

But Kossoff thinks the diet can be simplified to make it easier to follow. "We are looking at less time in the clinic and fewer restrictions and without a dietitian," he said.

Dr. Gholam Motamedi, director of the epilepsy service at Georgetown University Hospital, thinks the diet can be useful for patients who have no other options.

"The study is promising, especially given that patients with refractory epilepsy in particular -- those who are not surgical candidates -- are left with not much hope," he said.

Normally, the plan for these patients is to try a combination of different drugs or to use vagus nerve stimulation, but none of these options offers much hope of seizure control, Motamedi said.

"Therefore, having another modality available is always welcomed by the neurologists," he said. "It also encourages basic research looking for insight to the underlying reasons for epilepsy."

More information

For more on epilepsy, visit the Epilepsy Foundation  .

MONDAY, Jan. 21 (HealthDay News) -- Caffeine consumption by pregnant women can increase the risk of miscarriage, a new study reports.

And, it doesn't matter if the caffeine comes from coffee, tea, soda or hot chocolate. What does matter is the amount -- the study found that when women drink more than 200 milligrams of caffeine daily, the risk of miscarriage increases twofold.

"What we found was that if women have heavy caffeine intake -- greater than 200 milligrams a day -- they have double the risk of miscarriage than women that don't have any caffeine," said one of the study's authors, Dr. De-Kun Li, a reproductive and perinatal epidemiologist in the division of research at Kaiser Permanente in Oakland, Calif.

Results of the study were published online in the January issue of the American Journal of Obstetrics and Gynecology.

Caffeine, the most frequently consumed drug in the world, crosses the placental barrier and reaches the developing fetus, according to the study. While previous studies have found an association between caffeine intake and miscarriage, it hadn't been clear whether the problem was due to the caffeine or another substance in coffee, or if it had something to do with non-coffee drinkers' lifestyles -- perhaps people who didn't drink coffee ate more fruits and vegetables, for example.

For the new study, the researchers looked at 1,063 women from the Kaiser Permanente Medical Care Program in San Francisco; they were interviewed at an average of 10 weeks' gestation. During the study period, 16 percent of the women -- 172 -- had miscarriages.

The researchers found that 25 percent of the women who miscarried reported consuming no caffeine during their pregnancy. Another 60 percent said they had up to 200 milligrams of caffeine daily, and 15 percent regularly consumed more than 200 milligrams of caffeine each day.

In addition to asking about caffeine intake, the researchers also assessed the other known risk factors for miscarriage, such as smoking, a history of previous miscarriage, alcohol use and more. The researchers also compensated for nausea and vomiting during pregnancy.

"If you have a low risk of miscarriage, the effect of caffeine tends to show more," said Li.

Li said that even among women who drank less than 200 milligrams of caffeine a day, the study found a 40 percent increased risk of miscarriage, but this finding didn't reach the level of statistical significance.

"Women shouldn't drink more than two regular cups of coffee a day, and hopefully they stop drinking totally for at least the first three months. It's not a permanent stop. If they really have to drink, limit the amount to one or two cups -- a regular cup is about seven and half ounces," Li said.

But, not every doctor is convinced that there's a direct cause-and-effect relationship between caffeine and miscarriage.

"The problem with this study is that when people miscarry, a large percentage of those miscarriages are due to genetic abnormalities, and the researchers didn't say whether these were normal or abnormal fetuses," said Dr. Laura Corio, an obstetrician and gynecologist at Mount Sinai Medical Center in New York City.

"Women are always worrying and wondering, 'What did I do?' Before we say a woman drank too much caffeine and that's why she had a miscarriage, let's see if it was an abnormal or normal pregnancy, said Corio.

"I think about 60 to 80 percent of miscarriages are due to genetic abnormalities," she added.

That said, however, Corio does advise her pregnant patients to limit caffeine consumption. "Women have a responsibility to the fetus -- no cigarettes, no alcohol and just one cup of coffee a day," she said, noting that many store-bought cups of coffee contain far too much caffeine, so a woman has to be aware of how much caffeine is in her favorite coffee.

"Have less than 200 milligrams a day," no matter what the source -- coffee, tea, cola, chocolate, etcetera, Corio advised. She said caffeine has also been linked to low birth weights and smaller head circumferences.

Li also advised limiting caffeine to less than 200 milligrams a day, especially in the early months of pregnancy and in the preconception period.

More information

To learn more about caffeine and pregnancy, visit the American Pregnancy Association  .

MONDAY, Jan. 21 (HealthDay News) -- Exercise programs can help ease arthritis symptoms, says a U.S. study that evaluated the effects of an Arthritis Foundation regimen.

The University of North Carolina at Chapel Hill study included 346 people, average age 70, with self-reported arthritis. Some were assigned to a group that followed the Arthritis Foundation Exercise Program, formerly called People with Arthritis Can Exercise (PACE), consisting of basic and advanced exercise classes twice a week for an hour a week for eight weeks. Others were put in a control group that did not take part in the exercise program.

After eight weeks, people in the exercise group showed significant improvements in pain, fatigue and managing arthritis. The pain and fatigue improvements were still evident six months after completing the exercise program.

The Arthritis Foundation Exercise Program emphasizes range-of-motion and low-resistance exercises, but the researchers found that people who completed the program also had increased strength in their upper and lower extremities. This suggested that strength training -- a minor component of the program -- is effective.

People in the exercise program did not show any increase in exercise endurance.

The study was published in the January issue of Arthritis Care & Research.

"Our findings indicate that the basic 8-week PACE (Arthritis Foundation Exercise) Program is a safe program for sedentary older individuals with arthritis to start exercising without exacerbating their symptoms," the researchers concluded.

Further studies should be conducted to determine if offering the program more than twice a week and for longer periods offers additional benefits, they added.

More information

The U.S. National Institute on Aging has more about arthritis  .