Presence of NNAL in urine may be linked to development of lung cancer in smokers, research finds
NEW YORK New research has found that the presence of the metabolite NNAL in urine might be the reason that some smokers are afflicted with lung cancer while others are not, according to data presented at the American Association for Cancer Research 100th Annual Meeting. NNAL has been shown to induce lung cancer in laboratory animals, but the effect in humans had not yet been studied.
“A history of smoking has always been thought of as a predictor of lung cancer, but it is actually not very accurate,” said Jian-Min Yuan, Ph.D., M.D., associate professor of public health at the University of Minnesota. “Smoking absolutely increases your risk, but why it does so in some people but not others is a big question.”
Researchers collected data from 18,244 men enrolled in the Shanghai Cohort Study and 63,257 men and women from the Singapore Chinese Health Study. Researchers collected blood and urine samples from more than 50,000 patients, in addition to in-person interviews to assess levels of cigarette smoking, dietary and other lifestyle factors. To evaluate the impact of NNAL, researchers identified 246 current smokers who later developed lung cancer and 245 smokers who did not develop lung cancer during the 10-year period following initial interview and collection of urine samples.
Levels of NNAL in the urine were divided into three groups. Compared with those with the lowest levels, patients with a mid-range level of NNAL had a 43% increased risk of lung cancer, while those at the highest level had a more than two-fold increased risk of lung cancer after taking into account the effect of number of cigarettes per day, number of years of smoking and urinary levels of cotinine on lung cancer risk.
Levels of nicotine in the urine also were calculated. Those with the highest levels of nicotine and NNAL had an 8.5-fold increase in the risk of lung cancer compared with smokers who had the lowest levels after accounting for smoking history.
“Smoking leads to lung cancer, but there are about 60 possible carcinogens in tobacco smoke, and the more accurately we can identify the culprit, the better we will become at predicting risk,” said Yuan.
Study: Taking epilepsy drug during pregnancy can impair child’s cognitive development
ATLANTA Exposure to the epilepsy drug Depakote (valproate) during pregnancy can impair a child’s cognitive development, according to a study published in the April 16 edition of the New England Journal of Medicine.
Three-year-olds whose mothers took the antiepileptic drug valproate during pregnancy had average IQs six to nine points lower than children exposed to three other antiepileptic drugs, according to the research.
The study’s authors say that women of childbearing age should avoid valproate as a first choice drug for the treatment of epilepsy.
The Neurodevelopmental Effects of Antiepileptic Drugs study is following more than 300 children born to women with epilepsy between 1999 and 2004. Investigators at 25 epilepsy centers in the United States and the United Kingdom are participating. At enrollment, the women were taking a single antiepileptic agent: carbamazepine, lamotrigine, phenytoin or valproate.
The NEAD study previously found that valproate exposure also increases the risk of anatomical birth defects, even though it was not designed to look for them.
“There are clear risks associated with valproate, and physicians have an obligation to inform women about them,” stated lead study author Kimford Meador, professor of neurology at the Emory University School of Medicine. “Valproate still has an important role in treating epilepsy, because some patients’ seizures can only be controlled with valproate. However, we are recommending that women with epilepsy try another drug first.”
Around 15% of patients with primary generalized epilepsy respond only to valproate, but this selectivity does not apply to other forms of epilepsy, Meador said.
A child’s IQ is usually strongly influenced by the mother’s IQ. Out of the four antiepileptic drugs studied, only valproate disrupted this relationship.
Valproate is also prescribed for bipolar disorder and migraine headaches. It is sold under the brand name Depakote. Last year the FDA approved a generic version.
Study finds racial bias in measuring of BMI, obesity rates
NEW YORK The rise in obesity in the United States over the last 20 years has been dramatic, but a new study indicates that existing statistics may not be accurate.
The study, published online April 6 in the British Journal of Nutrition, has found evidence of racial bias in the use of body mass index as a measurement of obesity, overstating the prevalence of obesity among blacks while understating it among Hispanic and Asian women.
The BMI uses “cut-scores” based on studies conducted long ago that used white adults, and the researchers in the study found that scores greater than 30 might more accurately reflect obesity for blacks, while lower scores might be a more suitable indicator for Hispanic, Asian and South Asian women. Under current measurements, a BMI of 30 indicates obesity for anyone of any race or sex.