Indian Medicine

NEW YORK (Reuters Health) - Changes in nerve activity as we age may help explain why older adults typically drink less in response to thirst than younger people do, new research suggests.

It is known that older people tend to get less satisfaction from drinking water when they are thirsty, and that compared with younger adults, they drink less -- a fact that increases their risk of dehydration and heat illness on hot summer days.

In the new study, Australian researchers used a brain imaging technology called positron emission tomography (PET) to examine the mechanisms that might underlie this age difference.

The study included 12 healthy older men with an average age of 68, and 10 men with an average age of 24. The researchers gave each man an infusion of saline to make them thirsty, then let them drink as much water as they wanted.

They found that, on average, the older group drank only half as much water as the younger group, despite having similar salt levels in their blood and a similar response in a brain region called the anterior cingulate cortex (ACC).

Previous research has shown that the ACC is activated in response to thirst. These latest findings suggest that, in older people, this response may be prematurely shut down.

"Our findings suggest that the brain activity in the anterior cingulate cortex that subserves our motivation to drink when thirsty more rapidly turns off in elderly people after they drink a small amount of water," Dr. Gary Egan, one of the researchers on the study, told Reuters Health.

"This explains why older people drink less even though they have achieved a similar degree of thirstiness as younger people," explained Egan, of the University of Melbourne.

The findings are published in the early online edition of the Proceedings of the National Academy of Sciences.

Since the actual brain response to thirst was similar in younger and older men, Egan and his colleagues speculate that age-related changes in the nerves supplying the brain may be at work.

Egan explained that as we age, there may be changes in the "input" from nerves in the mouth, throat and stomach that sense how much water we've consumed.

According to the researchers, older adults should be careful to drink enough water on hot, humid days or when they are exercising -- possibly taking scheduled water breaks instead of relying on their thirst signals.

"The finding is particularly relevant to ensuring that older people drink regularly and in sufficient quantities, particularly during hot periods," Egan noted.

SOURCE: Proceedings of the National Academy of Sciences Online Early Edition, December 17, 2007.

Copyright © 2007 Reuters Limited.

NEW YORK (Reuters Health) - The general health of elderly hospitalized patients improved, along with their physical and social functioning, when they were given oral nutritional supplements in addition to the normal hospital diet, researchers report.

"Paying attention to and correcting nutrition in older people, specifically those who are ill, can lead to a significant improvement in their well-being," Dr. Salah Gariballa told Reuters Health.

Gariballa, of United Arab Emirates University in Al-Ain, and colleagues studied aspects of the quality of life of 225 hospitalized men and women, aged 75 years on average.

The patients, hospitalized for cardiovascular problems, lung disease, fractures, or infections, received a normal hospital diet plus either a placebo drink or a 995-calorie nutritional supplement twice daily for 6 weeks.

The nutritional supplement provided 100 percent of the Reference Nutrient Intakes for older adults for vitamins A, C, D, E, B1, B6, B12, folic acid, niacin, biotin, and pantothenic acid, as well as the minerals potassium, magnesium, calcium, phosphorous, iron, zinc, iodine, copper, manganese, and selenium, the investigators report in the Journal of the American Geriatrics Society.

Quality of life assessments after 6 weeks did not identify significant differences between the patients who received the supplements compared with those given the placebo.

However, after 6 months the patients given the nutritional supplement showed significantly better quality of life scores compared with patients who got the placebo. Measures of physical and social function were better, vitality was better, and mental health improved among the supplemented compared with non-supplemented patients.

This trial demonstrated that nutritional supplementation in hospitalized older people provides clinically important benefits, the investigators note.

Widespread use of nutritional supplements among older patients could have a substantial impact on the quality of life for older people, Gariballa and colleagues conclude.

SOURCE: Journal of the American Geriatrics Society, December 2007.

Copyright © 2007 Reuters Limited.

GENEVA (Reuters) - The World Health Organization (WHO) confirmed on Thursday a single case of human-to-human transmission of the H5N1 bird flu virus in a family in Pakistan, but said there was no apparent risk of it spreading wider.

A statement from the U.N. agency said tests in its special laboratories in Cairo and London had established the "human infection" through presence of the virus "collected from one case in an affected family".

But it said a WHO team invited to Pakistan to look into an outbreak involving up to nine people, from late October to December 6 had found no evidence of sustained or community human-to-human transmission.

No identified close contacts of the people infected, including health workers and other members of the affected family, had shown any symptoms and they had all been removed from medical observation, the WHO added.

The outbreak followed a culling of infected chickens in the Peshawar region, in which a veterinary doctor was involved. Subsequently he and three of his brothers developed proven or suspected pneumonia.

The brothers cared for one another and had close personal contact both at home and in the hospital, a WHO spokesman in Geneva said. One of them, who was not involved in the culling, died on November 23.

His was the human-to-human transmission case confirmed by the WHO. The others all recovered.

"All the evidence suggests that the outbreak within this family does not pose a broader risk," the WHO spokesman told Reuters. "But there is already heightened surveillance and there is a need for ongoing vigilance."

It was the first human-to-human case of H5N1 transmission in Pakistan, while others have been confirmed in Indonesia and Thailand in similar circumstances of what the WHO calls close contacts in a very circumscribed area.

Global health experts fear the virus -- which has killed 211 people out of 343 infections reported since 2003 -- could mutate into a form that spreads easily from one person to another, possibly triggering a pandemic that could kill millions.

Copyright © 2007 Reuters Limited.

NEW YORK (Reuters Health) - There has been a significant increase in the number of young adults hospitalized with diabetes-related conditions in the United States over the last decade or so, according to a new study.

"Studies indicate that the burden of diabetes, type 1 and type 2, is substantial and rising among U.S. children," Dr. Joyce Lee, of the University of Michigan, Ann Arbor, and colleagues write in the medical journal Diabetes Care. "We wished to evaluate national trends in hospitalizations associated with diabetes for children and young adults."

The researchers found a 38 percent increase from 1993 to 2004 in the number of hospital stays for people between the ages of 0 and 29 years with a diabetes diagnosis.

The trend seemed to be age-dependent. There were significant increases in annual hospitalization rates among patients aged 20 to 29 years, but not among younger subjects.

"Rates of hospitalizations were consistently higher for females than for males throughout the time period," Lee's team reports. "Furthermore, increases in hospitalization rates were significantly greater for females (42 percent) than for males (29 percent)."

Inflation-adjusted annual hospital costs for diabetes increased 130 percent, from $1.05 billion in 1993 to $2.42 billion in 2004.

With the rising rate of diabetes among youngsters, the researchers see the number of hospitalizations increasing even more over coming years.

SOURCE: Diabetes Care, December 2007.

Copyright © 2007 Reuters Limited.

NEW YORK (Reuters Health) - Results of a new study indicate that the so-called statin drugs used to lower cholesterol levels also help prevent chaotic heart beats that can lead to sudden cardiac death.

The study shows that statins are "associated with a significant 19 percent risk reduction for sudden cardiac death."

Sudden cardiac death is caused when the heart stops beating suddenly or goes into a disorganized rhythm, or arrhythmia, that cannot sustain blood flow. In contrast, a heart attack occurs when an artery supplying blood to the heart muscle becomes blocked and the heart can no longer pump properly.

Dr. Giacomo Levantesi and colleagues at Consorzio Mario Negri Sud in Chieti, Italy, analyzed data from 10 large studies, involving 22,275 patients, looking at treatment with statins -- drugs like Lipitor or Zocor, for example -- and that included information on the occurrence of sudden cardiac death.

Over an average follow-up of 4.4 years, the likelihood of sudden cardiac death was 3 percent in patients given statins and 3.8 percent in "control" patients, the researchers report in The American Journal of Cardiology.

The reduction in risk of sudden cardiac death was independent of changes in cholesterol levels.

The Italian researchers conclude that "part of the clinical benefit of statin treatment could be represented by a decrease in life-threatening arrhythmias."

SOURCE: American Journal of Cardiology, December 2007.

Copyright © 2007 Reuters Limited.