Loss of Y chromosome ups MI risk in older men

Loss of the Y chromosome (LOY) in older men tend to increase their risk of myocardial infarction (MI), but not ischaemic stroke, suggests a study.

Men aged ≥65 years (n=5,131) from the ASPREE trial with no previous cardiovascular disease at baseline were included in this study. Microarrays and the log-R-ratio method were used to measure the LOY percentage in peripheral blood.

The investigators collected data on major adverse cardiovascular events (MACEs), including MI and ischaemic stroke, during the trial and subsequent observational follow-up. They also explored the associations of LOY as a continuous (per SD) and categorical (decile-based) variable using Cox regression. Deciles 1‒6 (reference) represented no LOY, deciles 7‒9 moderate, and decile 10 substantial.

Of the men, 505 (9.8 percent) experienced MACEs (256 MI and 207 ischaemic stroke) over a median follow-up of 8.4 years. In the fully adjusted model, each SD increase in LOY resulted in 14-percent higher MI risk (HR per SD, 1.14, 95 percent confidence interval [CI], 1.02‒1.28).

Notably, men with substantial LOY (decile 10) had the highest MI risk (HR, 1.68, 95 percent CI, 1.16‒2.54) compared with those without. LOY showed no significant association with ischaemic stroke. These results were consistent in sensitivity analyses.

Furthermore, in an analysis of 191,340 men aged 40 to 70 years from the UK Biobank, LOY also correlated with MI risk (HR per SD, 1.03, 95 percent CI, 1.01‒1.06).

“LOY from a percentage of circulating leukocytes is common in older men and is associated with cardiovascular risk,” the investigators said.