Letter by Ke and Shen Regarding Article, "Long-Term Association of Low-Density Lipoprotein Cholesterol With Cardiovascular Mortality in Individuals at Low 10-Year Risk of Atherosclerotic Cardiovascular Disease: Results From the Cooper Center Longitudinal Study"

Association of triglyceride-glucose index, low and high-density lipoprotein cholesterol with all-cause and cardiovascular disease mortality in generally Chinese elderly: a retrospective cohort study

Background

The impact of baseline triglyceride-glucose (TyG) index and abnormal low or high-density lipoprotein cholesterol (LDL-C or HDL-C) levels on all-cause and cardiovascular disease (CVD) mortality remains unclear. This study aimed to investigate the relationship between TyG index and LDL-C or HDL-C and all-cause and CVD mortality.

Methods

This retrospective cohort study analyzed data from health examinations of 69,068 older adults aged ≥60 in Xinzheng City, Henan Province, China, between January 2013 and January 2023. Cox proportional risk regression models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of the TyG index and LDL-C or HDL-C about all-cause and CVD mortality. Restricted cubic spline was used to assess the dose-response relationship.

Results

During 400,094 person-years of follow-up (median follow-up 5.8 years [interquartile range 3.0-9.12]), 13,664 deaths were recorded, of which 7,045 were due to CVD. Compared with participants in the second quartile of the TyG index, participants in the fourth quartile had a 16% increased risk of all-cause mortality (HR: 1.16, 95% CI: 1.12,1.22), and an 8% increased risk of CVD mortality (HR: 1.08, 95% CI: 1.01,1.16). Similar results were observed in LDL-C and HDL-C, with all-cause and CVD mortality risks for participants in the fourth quartile compared with participants in the third quartile for LDL-C of (HR: 1.07, 95% CI: 1.02,1.12) and (HR: 1.09, 95% CI: 1.01,1.17), respectively. The risk of all-cause and CVD mortality in participants in the fourth quartile group compared with those in the second HDL-C quartile group was (HR: 1.10, 95% CI: 1.05,1.16) and (HR: 1.11, 95% CI: 1.04,1.18), respectively. We found that the TyG index was nonlinearly associated with all-cause and CVD mortality (P non-linear <0.05), and LDL-C was nonlinearly associated with all-cause mortality (P non-linear <0.05) but linearly associated with CVD mortality (P non-linear >0.05). HDL-C, on the other hand, was in contrast to LDL-C, which showed a non-linear association with CVD mortality. We did not observe a significant interaction between TyG index and LDL-C or HDL-C (P >0.05).

Conclusion

TyG index and LDL-C or HDL-C increased the risk of all-cause and CVD mortality, especially a high TyG index combined with abnormal LDL-C.

Efficacy and Mechanism of Buyang Huanwu Decoction in Patients With Ischemic Heart Failure: A Randomized, Double-Blind, Placebo-Controlled Trial Combined With Proteomic Analysis

Objective: Buyang Huanwu Decoction (BYHW), a famous herbal prescription in traditional Chinese medicine (TCM), has been used for 200 years for treating ischemic heart failure (IHF). This study aims to assess the efficacy and safety of BYHW combined with guideline-guided pharmacotherapy in patients with IHF and explore the biological mechanism by which BYHW exerts its efficacy. Methods: In the multicenter, double-blind, randomized controlled trial, a total of 80 patients with IHF were randomized to receive BYHW or placebo for 3 months. The primary efficacy endpoints were New York Heart Association (NYHA) classification, TCM syndrome scores, N-terminal pro-B-type natriuretic peptide (NT-ProBNP), whereas the mechanism exploration endpoints included energy metabolism parameters and coagulation function parameters. In addition, we performed the proteomic study of the serum of patients after treatment by label-free quantification technology to verify the candidate target proteins and pathways. Results: After 3 months of treatment, the NYHA classification, TCM syndrome scores, and the percentage of subjects with at least 30% reduction in NT-ProBNP were significantly improved in the BYHW group, compared with the control group (p < 0.05); BYHW treatment also significantly regulated blood glucose, blood lipid levels, ameliorated energy metabolism and improved coagulation function parameters. There were no significant differences in safety endpoints between the two groups. In addition, we obtained 56 differentially expressed proteins by proteomics, including 20 upregulated proteins and 36 downregulated proteins. Bioinformatic analysis revealed the mechanism of BYHW treatment was significantly related to complement and coagulation cascades, cholesterol metabolism, NF-kappa B signaling pathway, PI3K-Akt signaling pathway, and metabolic pathways. Among these differentially regulated proteins, fibrinogen gamma (FGG), fibrinogen beta (FGB), Carboxypeptidase B2 (CPB2), Coagulation factor XIII A (F13A1), Intercellular adhesion molecule1 (ICAM1), Apolipoprotein C-II(APOC2), Apolipoprotein C-I(APOC1), and CD44 were found to be signature proteins associated with the efficacy of BYHW against IHF. Conclusion: BYHW treatment can further improve cardiac dysfunction and clinical symptoms in IHF based on standard therapy without apparent adverse effects. Additionally, BYHW may play a therapeutic role in IHF by improving energy metabolism and regulating coagulation function through multiple targets and pathways.

Low-density lipoprotein cholesterol and all-cause mortality: findings from the China health and retirement longitudinal study

OBJECTIVES

To investigate the relationship between low-density lipoprotein cholesterol (LDL-C) and all-cause mortality among middle-aged and elderly Chinese population.

DESIGN

Prospective cohort study.

SETTING

This study used data from the China Health and Retirement Longitudinal Study.

PARTICIPANTS

Middle-aged and elderly participants with complete data were enrolled for a 4-year follow-up of total mortality and plasma levels of LDL-C, including 4981 male respondents and 5529 female respondents.

RESULTS

During a 4-year follow-up, there were 305 and 219 deaths in men and women, respectively. Compared with the first quintile (Q1) of LDL-C, the adjusted HRs (95% CIs) were 0.818 (0.531 to 1.260) for Q2, 0.782 (0.507 to 1.208) for Q3, 0.605 (0.381 to 0.962) for Q4 and 0.803 (0.506 to 1.274) for Q5 in men. The results from restricted cubic spine (RCS) showed that when the 20th percentile of LDL-C levels (84 mg/dL) was used as the reference, a lower LDL-C concentration (<84 mg/dL) was associated with a higher 4-year all-cause mortality risk. By contrast, both quintile analysis and RCS analysis did not show a statistically significant association in women.

CONCLUSIONS

Compared with moderately elevated LDL-C (eg, 117-137 mg/dL), a lower plasma level of LDL-C (eg, ≤84 mg/dL) was associated with an increased risk of 4-year all-cause mortality in middle-aged and elderly Chinese men. The results suggest the potential harmful effect of a quite low level of LDL-C on total mortality.