Carrying extra weight around the hips will put you on the fast track to needing a hip replacement, a new study suggests.
Research conducted by Statistics Canada reveals that being obese, meaning that 30 percent or more of your body weight consists of fat, increases your odds of developing arthritis by 60 percent.
Being merely overweight, meaning you carry between 25 percent and 30 percent of your body weight as fat, increases a woman's chances of developing arthritis by 30 percent but does not seem to have an immediate impact on the joints of men.
"The data ... support the hypothesis that obesity and overweight led to arthritis -- rather than the reverse -- possibly by increasing stress on the joints," StatsCan health researcher Kathryn Wilkins said.
But she said there are other important factors that influence developing arthritis, including gender, age, genetics and income.
About 31 percent of women and 19 percent of men ages 40 or older have been diagnosed with arthritis. The prevalence of the joint disease rises steadily with age, and by age 80, 57 percent of women and 40 percent of men are affected, according to the study, published in the Statistics Canada journal Health Reports.
The results were derived from two large, ongoing Canadian studies: the Canadian Community Health Survey and the National Population Health Survey.
Fewer died from West Nile
Last year's outbreak of West Nile virus was the largest yet, but fewer people died or had serious brain damage from it compared with 2002, federal officials said yesterday.
The 9,006 cases of the mosquito-borne virus last year were more than double the 4,156 cases in 2002, although officials at the Centers for Disease Control and Prevention said the larger number of cases may reflect more testing.
CDC officials still consider 2002 to be the worst year for the United States because of 284 deaths and 2,944 cases of severe brain damage. Last year, 220 people died and 2,695 suffered severe neurological disease, the CDC said.
The virus is spread to people from mosquitoes that have fed on infected birds, the virus' main host.
Hair dyes linked to cancer
Scientists have found more evidence for a possible link between the long-term use of dark hair dye and non-Hodgkin's lymphoma. A study of more than 1,300 women in Connecticut shows that those who began coloring their hair before 1980 increased their chance of developing the disease by 40 percent.
Among the women who used dark colors -- browns, reds and black -- and dyed their hair frequently (eight times a year or more) for at least 25 years, the risk doubled, said Dr. Tongzhang Zheng, an epidemiologist at Yale University, who led the study. The results are published in the current issue of the American Journal of Epidemiology.
"For those who used light colors, there was no such increase in risk," Zheng noted.
Nor was there significantly in- creased risk among women who used non-permanent dyes. The difference between permanent and non-permanent dyes is that permanent ones are mixed with an oxidizing agent. In that process, new chemicals are created, some of which may be carcinogenic, Zheng said.
Non-Hodgkin's lymphoma is a cancer that begins in the lymph system. The average American woman has a one in 57 chance of developing the disease in her lifetime. For a man, the chance is one in 48.
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