The association between high levels of total cholesterol and the increased risk of mortality in young and middle-aged people is well established.
However, studies are unclear regarding the association in older adults. In addition, the effects of cholesterol-treating drugs, like statins, on all-cause and specific-cause mortality require investigation in an older population.
Total Cholesterol and Mortality in Older Adults
A study, published by Liang and colleagues in BMC Geriatrics, investigates the association between total cholesterol and all-cause or cause-specific mortality in geriatric patients.
They also explore whether the association varies or is altered in patients using cholesterol-lowering medication. The study included a total of 3,090 participants, aged 60 years or older, from the population-based Swedish National study on Aging and Care in Kungsholmen.
Researchers used interviews, clinical exams, and laboratory tests to collect patient data, including demographic factors, lifestyle factors, cardiovascular risk factors, use of medication, global cognitive function, mobility limitations, and apolipoprotein E genotype status. They collected non-fasting peripheral blood samples to measure total cholesterol levels.
Over the ten-year study period, deaths were recorded and classified into cardiovascular disease or non-cardiovascular disease deaths.
Higher Total Cholesterol Linked to Lower Mortality
A total of 1,059 participants died by the end of the study period. The researchers found that a higher level of total cholesterol was associated with a reduced risk of all-cause mortality.
More careful analysis revealed that the association was primarily due to a reduced risk of non-cardiovascular disease mortality. No significant association was observed between high total cholesterol and cardiovascular disease mortality.
The study also found that the association between high total cholesterol and low risk of all-cause and non-cardiovascular morality was statistically evident only among individuals who did not use cholesterol-lowering medications.
In conclusion, the researchers discovered an inverse association between total cholesterol levels and all-cause mortality in a geriatric population: the higher the total cholesterol levels, the lower the all-cause mortality.
These findings are consistent with previous epidemiological studies that have also found reduced all-cause mortality in patients with high total cholesterol levels. However, the exact biological and pathophysiological mechanisms linking serum cholesterol to mortality in older adults remain unknown and warrant further investigation.
Researchers propose that lipids and lipoproteins may play protective roles by modifying inflammation markers and thus confer health benefits in older patients.
Other theories suggest that low cholesterol content is a marker of poor nutritional status, frailty, and the clinical complexity of chronic health conditions. Therefore, these patients are inherently less healthy and more likely to die earlier.
This study indicates that healthcare practitioners should exercise caution when therapeutically controlling blood pressure in older adults.
Reference: Liang, Y., Vetrano, D. L., & Qiu, C. (2017). Serum total cholesterol and risk of cardiovascular and non-cardiovascular mortality in old age: a population-based study. BMC Geriatrics, 17(1), 294.
