Moderately elevated levels of LDL cholesterol and systolic blood pressure (SBP) that persist for a long time are just as dangerous as very elevated values over a shorter timeframe, according to a new study published in PLOS One.
These findings point to the cumulative effect of these risk factors, reported senior author Goodarz Danaei, ScD, and colleagues.
The researchers analyzed observational data from 2,714 adults in the Framingham Offspring Study who were younger than 70 and free of cardiovascular disease at baseline, and then used statistical models to estimate the 16-year risk of coronary heart disease (CHD).
Individuals who maintained moderate LDL (between 130 and 160 mg/dL) had an 8.9 percent 16-year risk of CHD. That figure was similar to the estimated 9 percent CHD risk for eight years of low LDL (less than 130 mg/dL) followed by eight years of high LDL (160-190 mg/dL); as well as the 8.8 percent risk observed with 12 years of low LDL followed by four years of very high LDL (above 190 mg/dL).
A similar relationship regarding blood pressure was observed.
“We found that long-term exposure to moderate levels of LDL cholesterol and SBP has the same impact on CHD risk as shorter exposures to levels considered ‘high’ per clinical guidelines, suggesting that individuals exposed to moderate levels of the risk factors during a longer period may also benefit from intensive lifestyle modification or medication,” Danaei et al. wrote.
A recent meta-analysis in JAMA Cardiology found that dropping already low LDL cholesterol levels even further results in greater cardiovascular risk reduction. According to the authors of the PLOS One study, risk may be underestimated in many clinical trials because blood pressure and cholesterol readings are taken at study initiation, with no knowledge of how long they have been elevated.
“Preventing cardiovascular disease in individuals with long-term exposure to moderately elevated risk factors will be even more important in the next few decades because levels of major cardiovascular risk factors including cholesterol and blood pressure are elevated already in adolescents in many countries,” they noted. “Intensive lifestyle modification is quite challenging for most individuals and it can only be expected that it is even more challenging for patients with long-term exposure to moderately elevated risk factor levels.”
Danaei and colleagues also said seemingly healthy individuals may have low adherence to medication and lifestyle interventions, so it's important to communicate potential risks to them as well as the benefits of treatment.
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.