Although low serum testosterone is associated with increased adiposity, an adverse metabolic risk profile, and atherosclerosis, few studies have shown a protective link between endogenous testosterone and cardiovascular (CV) events, according to investigators ( J Am Coll Cardiol. 2011;58:1674-1681).
The researchers analyzed baseline levels of testosterone in 2,416 men, aged 69 to 81 years. During a median 5-year follow-up, 485 CV events occurred. Men in the highest quartile of testosterone (>550 ng/dL) had a lower risk of CV events compared with men in the three lower quartiles.
A different team conducted another prospective study, this one to clarify the relationship between insomnia symptoms and acute MI (Circulation. 2011;124:2073-2081). The investigators followed 52,610 men and women for a first acute MI; 2,368 incident acute MIs occurred during 11.4 years of follow-up. Compared with subjects who rarely had trouble sleeping:
- Persons who had trouble falling asleep daily were 45% more likely to have a heart attack
- Persons who had problems staying asleep almost every night were 30% more likely to have a heart attack
- Persons who felt unrefreshed in the morning more than once a week were 27% more likely to have a heart attack