having it too low is as dangerous as having it too high

New research, by a team of scientists from institutions in China and the United Kingdom, suggests that low and declining cholesterol levels may be associated with an increased risk of mortality from all causes and cancer.

The work, published in the magazine Engineeringconsisted of a large-scale, prospective, longitudinal cohort analysis, with participants from two Chinese cohorts (the Dongfeng-Tongji cohort and the Kailuan study), as well as from the UK Biobank. A total of 163,115 Chinese and 317,305 British adults, with a mean age of 49 to 61 years, were included in the analysis.

According to Europa Press, the researchers excluded people who were taking lipid-lowering medications, those who had coronary heart disease, stroke, cancer, chronic obstructive pulmonary disease or a low body mass index (BMI < 18.5 kg/m2) at the beginning of the study, as well as deaths that occurred during the first two years of follow-up to minimize reverse causality.

The importance of controlling levels and their changes

The study revealed that both high and low cholesterol levels were associated with different mortality risks. Specifically, high levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol (non-HDL-C) were mainly related to mortality from coronary heart disease (CHD).

In contrast, low levels of these cholesterol fractions were associated with a increased risk of mortality from all causes and from cancer. The optimal cholesterol levels to minimize the risk of all-cause mortality in Chinese adults were TC: 200 mg/dL, LDL-C: 130 mg/dL, and non-HDL-C: 155 mg/dL, which is consistent with guideline recommendations.

Interestingly, the study also examined longitudinal changes in cholesterol levels over a four-year period. He revealed that a decrease of more than 20% in TC, LDL-C and non-HDL-C levels was associated with a 14% to 26% increased risk of mortality from any cause, compared to stable levels. This finding highlights the importance of controlling changes in cholesterol over time, as a significant decrease could indicate underlying health problems.

The researchers used Cox proportional hazards models to estimate risks, adjusting for various factors such as age, sex, BMI, education, smoking, alcohol consumption, physical activity, and history of hypertension and diabetes. The findings highlight the dual risk pattern of cholesterol levelssuggesting that both high and low levels can be harmful, depending on the cause of death.

The strengths of the study include its prospective designthe large sample size and the rigorous selection of participants. The inclusion of nearly 500,000 people from diverse populations facilitates generalization of the findings. However, the authors recognize some limitations, such as the possibility of residual confusion due to the observational nature of the study and the relatively short duration of follow-up in some cohorts.

This study provides Valuable information on the complex relationship between cholesterol and mortality. Highlights the need for Individualized strategies for lipid management and suggests that low cholesterol levels and their longitudinal changes should be considered in future risk prediction models.

The researchers point out that the study’s focus on untreated cholesterol levels does not contradict the effectiveness of cholesterol-lowering therapies in the prevention and treatment of cardiovascular diseases.