Washington, Nov 19 (IANS): Maintaining healthy weight can help people with a benign blood disorder reduce the risk of its progress into multiple myeloma, a cancer of the blood, new research suggests .

Multiple myeloma is preceded by a blood disorder called monoclonal gammopathy of undetermined significance (MGUS) in which abnormal plasma cells produce many copies of an antibody protein.

This precancerous condition does not cause symptoms and often goes undiagnosed.

"But our findings show that obesity can now be defined as a risk factor for developing multiple myeloma through this condition," said the study's first author Su-Hsin Chang, Assistant Professor at Washington University School of Medicine in St. Louis.

"For patients diagnosed with MGUS, maintaining a healthy weight may be a way to prevent the progression to multiple myeloma, if further confirmed by clinical trials," Chang said.

The researchers analysed data from a US Department of Veterans Affairs database, identifying 7,878 patients, predominately men, diagnosed with the precancerous condition MGUS.

Among these patients, 39.8 per cent were overweight and 33.8 per cent were obese. The researchers then tracked whether the patients developed multiple myeloma.

They found that 4.6 per cent of overweight patients (followed for a median of 5.75 years) and 4.3 percent of obese patients (followed for a median of 5.9 years) developed multiple myeloma, compared with 3.5 percent of people at normal weight (followed for a median of 5.2 years) -- a difference that is statistically significant.

Overweight and obese MGUS patients had a 55 per cent and 98 per cent higher risk of progression to multiple myeloma, respectively, than normal-weight MGUS patients, said the study published in the Journal of the National Cancer Institute.