Rigorous Methodology Adds Value
Bradley D. Anawalt, MD, with the University of Washington School of Medicine in Seattle, pointed out in an accompanying editorial that the study’s findings are particularly valuable because of the team’s rigorous methodology. The team measured testosterone with the gold standard, mass spectrometry, which can also measure DHT and estradiol more accurately than widely available commercial immunoassays, which “are inaccurate for measurement of these sex steroids in men, who typically have low serum concentrations of these two metabolites of testosterone,” Dr. Anawalt said.
Also, the researchers obtained raw data from the nine IPD studies and reanalyzed the combined data, which allows for more sophisticated analysis when combining data from multiple studies, Dr. Anawalt explained.
The main finding from the Yeap et al. study, he wrote, is that high testosterone concentrations at baseline were not linked with increased deaths from CVD or from all causes “but very low serum total testosterone concentrations at baseline were.
“It is tempting to hypothesize that testosterone therapy might have cardiovascular benefits solely in patients with very low concentrations of serum total testosterone,” Dr. Anawalt wrote.
He pointed out as particularly interesting the findings for DHT and estradiol.
“The finding that a low serum estradiol concentration is associated with higher all-cause mortality adds another reason (in addition to the adverse effects on body fat and bone health) to avoid aromatase inhibitors that are commonly taken by persons who use anabolic steroids,” he wrote. “The prospect of a U-shaped curve for the relationship between serum DHT and higher cardiovascular risk warrants further study.”
The work is funded by the Government of Western Australia and Lawley Pharmaceuticals. The authors’ and editorial writer’s conflicts of interest are listed in the full study.