Testosterone testing has risen almost four-fold in the UK in ten years but it appears GPs are targeting the right men, according to a UK-US comparison of testing and treatment published in the Journal of Clinical Endocrinology & Metabolism.
The researchers evaluated GP records in the UK and insurance claims in the US between 2001 and 2011 and identified 64,140 UK men who had their testosterone levels checked and 1,114,329 US men.
In the UK the testing rate rose from 13 per 10,000 person-years in 2001 to 46 in 2010. But it appears GPs are targeting the right men, as the proportion of those tested who had low testosterone levels increased from 19% in 2001 to 27% ten years later. There was a corresponding drop in normal and high assay results.
Only 10% of men with low levels were started on replacement therapy- a rate that has stayed constant over the period studied – although there has been a move away from IM testosterone to topical preparations, with gels now the most popular.
However the situation in the US is markedly different. The testosterone testing rate has soared from 40 per 10,000 person-years in 2001 to 170 in 2011, while the proportion of normal results went up from 64% to 73%.
In 2007 about 36% of US men found to have low testosterone received supplementation, rising to 43% by 2011.
Perhaps most worryingly up to 9% of US men with normal to high testosterone levels were given supplementation, compared to less than 1% of UK men.