Men with obesity have been found to have lower serum levels of prostate specific antigen (PSA) than non-obese men of the same age. This has potential implications for the use of PSA for prostate cancer detection in obese men.

Aref and colleagues examined the cause of this difference, with pre-existing theories suggesting the role of haemodilution, or of lower serum testosterone. They used data from the Florey Adelaide Male Ageing Study (FAMAS) cohort, which included more than 1,000 adult men. They excluded data from subjects with known prostate cancer, or with persistently abnormal PSA elevation.

In agreement with previous studies, PSA was found to increase with age, and to decrease with obesity. Using mixed-effects models on the anthropometric, biochemical and haematological data collected, the authors suggest that reduced PSA in obese men can be explained by an elevated oestradiol/testosterone ratio, with a lesser contribution of haemodilution. They also suggest that this hormonal imbalance seen in obesity may contribute to the higher grade and more advanced stage of prostate cancer found in obese men.

Read the full article in Endocrine-Related Cancer doi:10.1530/ERC-17-0438