A new study, reported in the Journal ofthe American Medical Association (June4, 2008), suggests that lower levelsof high-density lipoprotein (HDL; the"good" cholesterol), in and of itself, isnot associated with an increased risk ofheart disease.
Studies have linked low levels of HDLto an increased risk of ischemic heartdisease. Whether HDL is a main factorin the development of heart disease,however, is unclear, due to other factorsconnected to low HDL cholesterollevels. The current study examined agroup of patients with mutations in theABCA1 gene causing reductions in HDLcholesterol levels but no increase intriglyceride levels.
The researchers concluded that mutationsin ABCA1 are associated with"substantial,lifelong lowering of plasmalevels of HDL cholesterol, but not withcorresponding higher levels of plasmatriglycerides or atherogenic [capable ofproducing a type of plaque in arteries]remnant lipoproteins, did not predict anincreased risk of (heart disease)."
An effort to keep cholesterol down might also help men lowertheir levels of prostate-specific antigen (PSA)—a protein thatcan warn of prostate cancer. Using data collected on 1214 mentaking statins, the researchers found that PSA levels were lowerafter starting the statins, and the reduction in PSA was relativeto the drop in cholesterol.
The results of the study, presented recently at the annualmeeting of the American Urological Association, validate aprevious study that also indicated that lowering cholesterolreduced PSA. The researchers noted that, if confirmed, the findingsof the new study would provide additional evidence thatcholesterol plays a part in the biology of the prostate.
Murugesan Manoharan, MD, an associate professor of urologyat the University of Miami Sylvester Comprehensive CancerCenter, who was not involved in the study, said it was notclear, however, whether reducing PSA with statins may actuallyconceal developing prostate cancer. He said that the currentfindings need further analysis. "Bringing down the PSA levelsartificially does not mean necessarily the chance of developingprostate cancer," Dr. Manoharan said. "It might just bring theblood test reading down without reducing the risk of prostatecancer. In fact, we could miss the prostate cancer, because thePSA readings are on the lower side."
A major reduction in the rate of cancer was detected inpatients who took statins that are soluble in fats, known aslipophilic statins. The researchers examined the associationbetween lipophilic statin use and cancer incidence in >30,000patients discharged from the hospital following treatment fora heart attack in the province of Quebec. The investigatorslinked the Quebec hospital discharge summary database tothe drug claims database. The data indicated that 1099 individualswere hospitalized with a diagnosis of cancer duringfollow-up for up to 7 years.
Reporting in the American Journal of Medicine (April 2008),the researchers found that the overall rate of hospitalizationfor cancer was the equivalent of 13.9 cases per 1000 individualsper year among the high-dose statin group, comparedwith the rate of 17.2 and 20.6 cases per 1000 "person-years"among the low-dose statin patients and nonusers, respectively.In addition, the high-dose statin group had a 25% reducedrisk of being diagnosed with cancer (and the low-dose statinsgroup had an 11% lower risk), compared with patients who didnot take statins.
"This is the first study to suggest a dose-response effect oflipophilic statins on cancer occurrence," said the researchers.
Individuals with high cholesterol and high blood pressure maybe harming their eyesight. The 2 conditions appear to increasean individual's risk for retinal vein occlusion.
The findings were based on analysis of 21 previously publishedstudies involving 2916 patients with retinal vein occlusionand 28,846 patients without the condition. The results,reported in the May 2008 issue of Archives of Ophthalmology,found that elevated cholesterol levels were >2 times as likely tobe found in patients with retinal vein occlusion, compared withthe control group. The results of the study also indicated that63.6% of patients with the eye condition also had hypertension,compared with 36.2% of individuals without retinal vein occlusion.The authors concluded that physicians treating patientswith hypertension, diabetes, and high cholesterol should be asconcerned with the health of their patients' eyes as they arewith the health of an individual's cardiovascular system.
F A S T F A C T: Low-density lipoprotein cholesterol levels of 130 to 150 mg/dL are considered borderline high.