Being obese more than doubles the risk of acute myelogenous leukaemia (AML) in older women, according to a US study.

The report in the November issue of Cancer Epidemiology, Biomarkers and Prevention is based on analysis of data from more than 40,000 women, between 55 and 69 years of age, who participated in the Iowa Women's Health Study.

The subjects completed a health and lifestyle questionnaire when the study began in 1986 and then were followed until 2001.

During follow-up, 74 women developed AML and 88 developed chronic lymphocytic leukemia, the investigators note. Compared with normal weight status, obesity and overweight status increased the risk of AML by 140% and 90%, respectively.

'Given that about 65% of adults in the US are overweight or obese, the projection we can make from our study is that about 30% of AML in older adult women could be due to being overweight or obese,' say the authors.

Reference: Ross J et al (2004) Body Mass Index and Risk of Leukemia in Older Women Cancer Epidemiol Biomarkers Prev 13 (11) 1810-1813