Study suggests benefits of statin therapy in older adults may be "exaggerated"
Ref: The Guardian;The Times;Daily Mail;NHS Choices;The Telegraph;BMJ Open
Findings published in the BMJ Open journal from a systematic review of cohort studies indicate that high LDL cholesterol is "inversely associated with mortality" in most people aged 60 years and older. The authors, who remarked that their "analysis provides reason to question the validity of the cholesterol hypothesis," are calling for guidelines on the prevention of cardiovascular disease and atherosclerosis in older adults to be re-evaluated as they said "the benefits from statin treatment have been exaggerated."
Investigators conducted a search of the PubMed database and identified cohort studies in which LDL cholesterol had been investigated as a risk factor for all-cause and/or cardiovascular (CV) mortality in individuals from the general population aged 60 years or more. In all, 19 English-language studies met the criteria for review, and these included 30 cohorts involving a total of 68 094 participants. All-cause mortality was recorded in 28 cohorts and CV mortality in nine cohorts.
Researchers found that there was an inverse association between LDL cholesterol and all-cause mortality in 16 cohorts, representing 92 percent of the studied patients, with statistical significance observed in 14 cohorts, while no link was observed in the remaining 12 cohorts. In the studies assessing a CV mortality link specifically, there was no association seen in seven cohorts, while the other two found that those with LDL cholesterol levels in the lowest quartile had the highest CV mortality.
"What we found in our detailed systematic review was that older people with high LDL levels…lived longer and had less heart disease," remarked co-author Malcolm Kendrick, adding "many of us suspected this may be true but the consistency of the results was astonishing." Kendrick also predicted that the findings would likely stir controversy, but he defended them as "robust" and "thoroughly reviewed."
Still, some experts have pointed to limitations in the study, including the reliance on a single database, not looking at levels of other blood lipids, and the possibility that other health and lifestyle factors might be influencing the link. Further, the study authors acknowledged that their findings do not take into account the statin use by some participants during the observation period, which "may have increased the lifespan for the group with high LDL cholesterol."
Jeremy Pearson, associate medical director at the British Heart Foundation, said some of the study's results were not surprising "because, as we get older, many more factors determine our overall health, making the impact of high cholesterol levels less easy to detect." Nevertheless, he added that "the evidence from large clinical trials demonstrates very clearly that lowering LDL cholesterol reduces our risk of death overall and from heart attacks and strokes, regardless of age."
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