Takeaway
Low total testosterone level was not associated with a higher risk of myocardial infarction (MI), ischaemic stroke (IS), haemorrhagic stroke (HS), heart failure (HF), and major adverse cardiovascular events (MACE).
Low calculated free testosterone (cFT) or free testosterone (FTZ) was associated with a marginally lower risk of MACE.
Men with low sex hormone-binding globulin (SHBG) levels had a higher risk of MI but a lower risk of IS and HF.
Why this matters
Whether differences in testosterone levels increase the incidence of cardiovascular events in middle-aged and older men remains controversial.
Study design
A cohort study included 210,700 men (age, 40-69 years), identified from the UK Biobank (2006-2010).
Primary outcome: incident cardiovascular disease (CVD) events (hospitalisations or deaths where the primary diagnosis was MI, HS, IS, and HF).
Secondary outcome: MACE (nonfatal MI, IS, and CVD deaths).
Funding: Western Australian Health Translation Network; Medical Research Future Fund; Lawley Pharmaceuticals.
Key results
During the follow-up, 8790 men (4.2%) reported an MI, HS, IS, HF, and MACE event and 10,318 (4.9%) died.
After adjustment for confounders, lower total testosterone level (quintile 1 vs 5) was not associated with an increased risk of (adjusted HR [aHR]; 95% CI):
MI (0.89; 0.80 to 1.00);
HS (0.94; 0.70 to 1.26);
IS (0.95; 0.82 to 1.10);
HF (1.15; 0.91 to 1.45); and
MACE (0.92; 0.84 to 1.00).
Men with lower cFT or FTZ level (quintile 1 vs 5) had a lower risk of (aHR; 95% CI):
MI (0.86; 0.79 to 0.95); and
MACE (0.90; 0.84 to 0.97).
Lower SHBG level (quintile 1 vs 5) was associated with a higher risk of MI (aHR, 1.23; 95% CI, 1.09 to 1.38) and a lower risk of IS (aHR, 0.79; 95% CI, 0.67 to 0.94) and HF (aHR, 0.69; 95% CI, 0.54 to 0.89).
Lower SHBG level (quintile 1 vs 5) was not associated with a higher risk of HS (aHR, 0.81; 95% CI, 0.57 to 1.14) and MACE (aHR, 1.01; 95% CI, 0.92 to 1.11).
Limitations
Observational study.
