Caution urged on PSA readings in obese men
GPs should take PSA readings in obese men with a pinch of salt, say researchers who found lower PSA values compared with normal weight men.
In men who were moderately or severely obese, PSA readings were 29% lower than their normal-weight counterparts.
Even in those who were only just tipping the scales on to obese, PSA levels were 14% lower.
The Duke University researchers recently reported deceptively low PSA scores in men who were being treated for prostate cancer - but until now it was unclear what the implications would be for the general population.
Study leader Dr Stephen Freedland said to compensate for the PSA scores, GPs would have to use a lower threshold for what is considered an abnormal result.
‘If we don't do that, we may be missing cancers in obese men, which could lead to delayed diagnosis and poorer outcomes,' he said.
Dr James Kingsland, a member of the National Screening Committee's scientific reference group on prostate cancer and a GP in Merseyside said he would not advocate specific cut-off points. But he warned obesity was something GPs should bear in mind when interpreting tests.
‘We were aware of this research but the most important thing is to not use PSA as a diagnostic tool on its own. You need to assess the individual, understand the implications of a PSA test and the range which can be different in men with different constitutions.'