Intensive exercise answer to psoriasis prevention
MedWire News: Vigorous physical activity may reduce a person's risk for developing psoriasis, show results from a US study.
The authors found that women who participated in the equivalent of 1-3 hours of running, swimming, or playing tennis a week were 25-30% less likely to develop psoriasis than those who did not participate in intensive exercise.
Previous studies have suggested a link between physical exercise and psoriasis, but results have been conflicting.
To investigate the connection further, Abrar Qureshi (Harvard Medical School, Boston, Massachusetts) and colleagues analyzed data from the Nurses' Health Study II.
In total, 86,655 women (aged 27-44 years in 1991) from the Nurses' Health Study who reported whether or not they had been diagnosed with psoriasis were eligible for inclusion in the current study.
The women completed detailed questionnaires in 1991, 1997, and 2001 regarding the amount of physical activity they participated in on a regular basis. Physical activity level was calculated based on its metabolic equivalent task (MET) value, which is the ratio of the rate of energy consumption during a specific physical activity to a reference metabolic rate (1 MET=1 kcal/kg per hour).
Between 1991 and 2005, 1026 cases of incident psoriasis occurred in the cohort. To make the results as accurate as possible, the researchers used the data from the physical activity questionnaire completed at the closest point in time to diagnosis of psoriasis.
They found that the most physically active group of women (31.9 MET hours/week) had a significant 28% reduced risk for developing incident psoriasis compared with the least active group (0.2-3.8 MET hours/week), but this became nonsignificant when adjusted for body mass index (BMI; 15% reduced risk after adjustment).
Vigorous physical exercise, which was defined as 6 MET hours/week or more of exercise, was associated with an even greater reduction in risk than exercise in general, with those completing 20.9 MET hours/week or more having a 34% reduction in risk for psoriasis compared with those who did not exercise vigorously. This association was maintained after adjustment for BMI (27% reduced risk after adjustment).
"In addition to providing other health benefits, participation in vigorous exercise may represent a new preventive measure for women at high risk of developing psoriasis," write Qureshi et al in the Archives of Dermatology.
"Additional corroborative studies and further investigations into the mechanisms by which physical activity protects against new-onset psoriasis are needed," they conclude.
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By Helen Albert