Large waist may predict poor lung functionNEW YORK (Reuters Health) — In a study of normal-weight, overweight and obese adults, researchers found that waist circumference was consistently negatively associated with lung function across all weight categories.Study chief Dr. Yue Chen of the University of Ottawa told Reuters Health that waist circumference is a better predictor of lung impairment than body mass index (BMI) — a measure of weight in relation to height used to determine how thin or fat a person is.

Obesity is associated with a wide range of health problems including respiratory dysfunction. “In our previous studies, we have found that obesity is associated with asthma and chronic obstructive pulmonary disease, and BMI is an important predictor,” Chen said.

In the current study, Chen and colleagues determined the predictive value of waist circumference and BMI for lung function in 1,674 normal-weight, overweight, or obese adults.

They report in the American Journal of Clinical Nutrition that waist circumference was negatively associated with several standard measures of lung function and the associations were unchanged by sex, age or BMI category (normal-weight, overweight and obese).

On average, a one centimetre increase in waist circumference was associated with a 13-mL reduction in “forced vital capacity” — a measure of the total lung volume of air that can be exhaled — and an 11-mL reduction in “forced expiratory volume in one second” — the maximum volume of air expired in one second.

In contrast, a negative association between BMI and lung function was observed only in adults who were overweight or obese.

These results show that waist circumference as a measure of abdominal fat has a somewhat more consistent predictability for lung function, the researchers conclude.Report calls for focus on lung cancer in womenNEW YORK (Reuters Health) — Greater awareness and more research dollars need to go towards lung cancer, particularly as it affects women, according to a new report.Women may be more likely to fear breast or ovarian cancer, but more actually die from lung cancer than from breast, ovarian and uterine cancers combined, experts point out in the report, a summary of a recent meeting of top cancer specialists.

Historically, lung cancer was largely a man’s disease, but as women’s smoking rates climbed, so did their lung cancer risk. In 2000, the lung cancer death rate among US women was eight times what is was in the 1960s.

And although smoking rates have declined in recent decades, women and teenage girls are still about as likely as males to smoke, according to the report authors, led by Dr. Chandra P. Belani of the University of Pittsburgh Cancer Institute.

What’s more, they say, recent research is showing that women may be more susceptible than men are to the cancer-causing substances in tobacco smoke.

“Reducing the incidence of lung cancer death in women requires renewed efforts towards smoking cessation and prevention,” Belani and her colleagues write in the journal Lung Cancer.

Besides greater public awareness, there is an “urgent need” for more research into the sex differences that mark lung cancer, according to the panel.

A number of studies have found that female smokers seem to be more likely than males to develop lung cancer. And recent research into the biology of lung tumours suggests that women may be more susceptible to the toxins in tobacco smoke; some studies have found, for example, that women’s tumours are more likely to have mutations in the p53 gene, which normally suppresses tumour formation.

On the other hand, research also shows that women with lung cancer have better survival odds than men. This suggests, according to the report authors, that women may respond better to certain chemotherapy drugs.

A clinical trial focusing on female lung cancer patients is now underway to see whether a newer form of the cancer drug paclitaxel is more effective than standard paclitaxel. It’s the first clinical trial, the researchers note, to try to “take advantage” of sex differences in lung tumours and improve treatment for one group of patients, in this case women.

Traditionally, much of the research on lung cancer, as in other diseases, has focused on male patients. The report calls for continuing research into the differences between men and women in their susceptibility to lung cancer and their treatment responses. “An urgent need exists to increase awareness and research funding to improve lung cancer care,” the authors conclude, “particularly in women.”Genes play bigger role than environment in anorexia specialistNEW YORK (Reuters Health) — There is no scientific evidence to back up recent statements by fashion supermodel Gisele Bundchen that unsupportive families can cause the eating disorder anorexia nervosa, experts say.Misguided claims that families are responsible for anorexia nervosa — a disorder characterised by the relentless pursuit of thinness, emaciation and the obsessive fear of gaining weight — cause harm on a number of levels, warns Dr. Allan S. Kaplan, a specialist in eating disorders at the University of Toronto.

“By contributing to the stigma, it drives sufferers underground and creates obstacles to seeking help. Such thinking also misinforms third party payors who may not want to pay for the treatment of these biologically based illnesses if they think the primary cause is family dysfunction.”

A number of recent studies involving identical and non-identical twins have shown “pretty conclusively that genes are very important — and probably outweigh environment — in terms of susceptibility to developing anorexia,” Dr. Walter H. Kaye, professor of psychiatry at the University of Pittsburgh, told Reuters Health.

“Many people diet but relatively few end up with anorexia nervosa,” Kaye points out. “You really have to have some sort of susceptibility to really be vulnerable to developing anorexia because only a very small percentage of women — less than half a percent — develop anorexia.”

That’s not to say that societal pressure to be thin isn’t irrelevant, Kaye added; it may be the environmental trigger that releases a person’s genetic risk.

Clues are emerging as to precisely where those genes are and how they are related to behaviour and the development of anorexia, he said.