Intra-individual variability of total cholesterol is associated with cardiovascular disease mortality: A cohort study

• Published in: Nutrition, metabolism, and cardiovascular diseases metabolism, and cardiovascular diseases, 2019-11, Vol.29 (11), p.1205-1213
• Main Authors: Zhu, Yao, Lu, Jie-Ming, Yu, Zhe-Bin, Li, Die, Wu, Meng-Yin, Shen, Peng, Lin, Hong-Bo, Wang, Jian-Bing, Chen, Kun
• Format: Article
• Language: English
• Subjects: Aged; Biological Variation, Individual; Biomarkers - blood; Cardiovascular disease; Cardiovascular Diseases - blood; Cardiovascular Diseases - diagnosis; Cardiovascular Diseases - mortality; China - epidemiology; Cholesterol; Cholesterol - blood; Female; Humans; Male; Middle Aged; Mortality; Neoplasms - blood; Neoplasms - mortality; Prognosis; Retrospective Studies; Risk Assessment; Risk Factors; Time Factors; Variability
• ISSN: 0939-4753; 1590-3729
• DOI: 10.1016/j.numecd.2019.07.007

The relationship between serum total cholesterol (TC) and mortality remains inconsistent. Additionally, intra-individual variability of cholesterol has been of increasing interest as a new indicator for health outcomes. We aimed to examine the association between TC and its variability and risk of mortality. We performed a retrospective cohort study with 122,645 individuals aged over 40 years in Ningbo, China. The intra-individual variability was calculated using four metrics including standard deviation, coefficient variation, variation independent of mean and average successive variability. Hazard ratios and 95% confidence intervals were estimated for the associations of baseline and variability in TC with risk of mortality by Cox proportional hazards regression models. During 591,585.3 person-years of follow-up, 4563 deaths (including 1365 from cardiovascular disease, 788 from stroke and 1514 from cancer) occurred. A U-shaped association was observed for baseline TC level and risk of total, cardiovascular and cancer mortality, with lowest mortality at 5.46 mmol/L, 5.04 mmol/L and 5.51 mmol/L, respectively. As compared with subjects with TC variability in the lowest quartile, individuals in the highest quartile had 21% higher risk of all-cause mortality (HR = 1.21, 95% CI: 1.05 to 1.40), and 41% higher risk of CVD mortality (HR = 1.41, 95%CI: 1.10 to 1.81). Both too low and too high baseline TC level were associated with higher risk of total, cardiovascular disease and cancer mortality. Variability of TC could be a risk factor of total and CVD mortality, independent of mean TC level. Future studies are needed to confirm these findings. •Both too low and too high baseline TC level were associated with higher risk of total, CVD and cancer mortality.•Intra-individual variability of TC could be a risk factor of cardiovascular mortality, irrespective of mean TC level.•Maintaining the stability of serum cholesterol could help prevent cardiovascular events and mortality.