Background: Previous studies reported the prognostic value of the atherogenic index of plasma (AIP) in the course of atherosclerosis and other cardiovascular diseases (CVDs). Still, the predictive utility of the AIP is unknown among patients with type 2 diabetes mellitus (T2DM). Methods: This was a secondary analysis of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study, which randomized 10,251 patients with long-lasting T2DM. ROC curve analysis was used to determine an optimal threshold for AIP, and the study population was divided into high and low AIP groups. Univariable and multivariable Cox proportional hazards regression analyses were used to determine the association between AIP and primary (major adverse cardiovascular events [MACEs], including nonfatal myocardial infarction, nonfatal stroke, and/or death from cardiovascular causes) and secondary outcomes (all-cause mortality). Stratified analyses were performed to control for the confounding factors. Results: AIP was an independent risk factor for the prognosis of T2DM (HR = 1.309; 95% CI 1.084–1.581; P = 0.005). The threshold for AIP was determined to be 0.34 in the study population. After adjustments for confounding factors, multivariable analysis showed that AIP was associated with the risk of MACEs (Model 1: HR = 1.333, 95% CI 1.205–1.474, P < 0.001; Model 2: HR = 1.171, 95% CI 1.030–1.333, P = 0.016; Model 3: HR = 1.194, 95% CI 1.049–1.360, P = 0.007), all-cause mortality (Model 1: HR = 1.184, 95% CI 1.077–1.303, P < 0.001), cardiovascular death (Model 1: HR = 1.422, 95% CI 1.201–1.683, P < 0.001; Model 3: HR = 1.264, 95% CI 1.015–1.573, P = 0.036), and nonfatal myocardial infarction (Model 1: HR = 1.447, 95% CI 1.255–1.669, P < 0.001; Model 2: HR = 1.252, 95% CI 1.045–1.499, P = 0.015; Model 3: HR = 1.284, 95% CI 1.071–1.539, P = 0.007). Subgroup stratified analyses showed that AIP might interact with sex, a classical risk factor of cardiovascular events. Conclusions: This study showed that AIP might be a strong biomarker that could be used to predict the risk of cardiovascular events in patients with T2DM. Trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000620.

OBJECTIVE: Remnant cholesterol (remnant-C) predicts atherosclerotic cardiovascular disease, regardless of LDL-cholesterol (LDL-C) levels. This study assessed the associations between remnant-C and cardiovascular outcomes in type 2 diabetes. RESEARCH DESIGN AND METHODS: This post hoc analysis of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial used patient (type 2 diabetes >3 months) remnant-C and major adverse cardiovascular event (MACE) data from the study database. The associations between remnant-C and MACEs were evaluated using Cox proportional hazards regression analyses. We examined the relative MACE risk in remnant-C versus LDL-C discordant/concordant groups using clinically relevant LDL-C targets by discordance analyses. RESULTS: The baseline analysis included 10,196 participants, with further visit-to-visit variability analysis including 9,650 participants. During follow-up (median, 8.8 years), 1,815 patients (17.8%) developed MACEs. After adjusting for traditional cardiovascular risk factors, each 1-SD increase in remnant-C was associated with a 7% higher MACE risk (hazard ratio [HR] 1.07, 95% CI 1.02–1.12, P = 0.004). In the fully adjusted model, the visit-to-visit remnant-C variability calculated using logSD (HR 1.41, 95% CI 1.18–1.69, P < 0.001) and logARV (HR 1.45, 95% CI 1.22–1.73, P < 0.001) was associated with MACEs. Residual lipid risk (remnant-C ≥31 mg/dL) recognized individuals at a higher MACE risk, regardless of LDL-C concentrations. Within each LDL-C subgroup (>100 or ≤100 mg/dL), high baseline remnant-C was associated with a higher MACE risk (HR 1.37, 95% CI 1.09–1.73, P = 0.007; HR 1.22, 95% CI 1.04–1.41, P = 0.015, respectively). CONCLUSIONS: Remnant-C levels were associated with MACEs in patients with type 2 diabetes independent of LDL-C, and visit-to-visit remnant-C variability helped identify those with higher cardiovascular risk.

Objective: PCSK9 (proprotein convertase subtilisin/kexin type 9) plays a critical role in cholesterol metabolism via the PCSK9–LDLR (low-density lipoprotein receptor) axis in the liver; however, evidence indicates that PCSK9 directly contributes to the pathogenesis of various diseases through mechanisms independent of its LDL-cholesterol regulation. The objective of this study was to determine how PCSK9 directly acts on vascular smooth muscle cells (SMCs), contributing to degenerative vascular disease. Approach and Results: We first examined the effects of PCSK9 on cultured human aortic SMCs. Overexpression of PCSK9 downregulated the expression of ApoER2 (apolipoprotein E receptor 2), a known target of PCSK9. Treatment with soluble recombinant human ApoER2 or the DNA synthesis inhibitor, hydroxyurea, inhibited PCSK9-induced polyploidization and other cellular responses of human SMCs. Treatment with antibodies against ApoER2 resulted in similar effects to those observed with PCSK9 overexpression. Inducible, SMC-specific knockout of Pcsk9 accelerated neointima formation in mouse carotid arteries and reduced age-related arterial stiffness. PCSK9 was expressed in SMCs of human atherosclerotic lesions and abundant in the “shoulder” regions of vulnerable atherosclerotic plaques. PCSK9 was also expressed in SMCs of abdominal aortic aneurysm, which was inversely related to the expression of smooth muscle α-actin. Conclusions: Our findings demonstrate that PCSK9 inhibits proliferation and induces polyploidization, senescence, and apoptosis, which may be relevant to various degenerative vascular diseases.

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) clinically reduce atherosclerosis and lower blood pressure. However, their impact on endothelial dysfunction in type 2 diabetes (T2D) remains unclear. In this study, we investigated the protective effect and underlying mechanism of the SGLT2 inhibitor dapagliflozin in diabetes. Vascular reactivity was measured to assess the vasoprotective effect of dapagliflozin in a mouse model of high glucose (HG)-induced T2D. Pulse wave velocity was measured to quantify arterial stiffness. Protein expression was assessed by western blotting and immunofluorescence, oxidative stress was evaluated using dihydroethidium, nitric oxide was evaluated using the Griess reaction, and cellular senescence was assessed based on senescence-associated beta-galactosidase (SA‐β‐gal) activity and the expression of senescence markers. Furthermore, the endothelial nitric oxide synthase (eNOS) acetylation status was determined and eNOS interactions with SIRT1 were evaluated by coimmunoprecipitation assays. Dapagliflozin protected against impaired endothelium-dependent vasorelaxation and improved arterial stiffness in the mouse model of T2D; mouse aortas had significantly reduced levels of senescence activity and senescence-associated inflammatory factors. HG-induced increases in senescence activity, protein marker levels, and oxidative stress in vitro were all ameliorated by dapagliflozin. The decreases in eNOS phosphorylation and nitric oxide (NO) production in senescent endothelial cells were restored by dapagliflozin. SIRT1 expression was reduced in HG-induced senescent endothelial cells, and dapagliflozin restored SIRT1 expression. SIRT1 inhibition diminished the antisenescence effects of dapagliflozin. Coimmunoprecipitation showed that SIRT1 was physically associated with eNOS, suggesting that the effects of dapagliflozin are dependent on SIRT1 activation. These findings indicate that dapagliflozin protects against endothelial cell senescence by regulating SIRT1 signaling in diabetic mice.

Diabetic vascular aging is driven by macrophage senescence, which propagates senescence-associated secretory phenotypes (SASP), exacerbating vascular dysfunction. This study utilized a type 2 diabetes mellitus (T2DM) mouse model induced by streptozotocin injection and a high-fat diet to investigate the role of STING in macrophage senescence. Vascular aging markers and senescent macrophages were assessed in vivo, while in vitro, high glucose treatment induced macrophage senescence, enhancing senescence in co-cultured vascular smooth muscle cells. Mechanistic studies revealed that STING activation inhibits autophagy by phosphorylating ULK1 at S757, accelerating senescence. Pharmacological modulation showed that the STING inhibitor H-151 alleviates, while the agonist DMXAA enhances, senescence. These findings highlight the STING-autophagy axis as a critical driver of macrophage senescence, offering insights into the molecular mechanisms of diabetic vascular aging and identifying potential therapeutic targets to mitigate vascular complications in diabetes.

Background: The association between metabolic syndrome and the development of heart failure (HF) with preserved ejection fraction (HFpEF) has not been completely clarified.Aim: To evaluate the association between metabolic syndrome and the risk of HF hospitalization for patients with HFpEF.Methods: Patient data were obtained from the American cohort of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial database. Data for the primary outcome (hospitalization for HF) and secondary outcomes (all-cause mortality, cardiovascular mortality, and all-cause hospitalization) were collected, and hazard ratios (HRs) for the patients with and without metabolic syndrome were analyzed by applying a multivariable Cox proportional hazard model.Results: Among the 1,548 total participants, 1,197 had metabolic syndrome. The patients with metabolic syndrome exhibited worse heart function and a lower quality of life than those without metabolic syndrome. During the 3.3 years of follow-up, 351 patients were hospitalized for HF. After a multivariable adjustment, the risk of hospitalization for HF and all-cause hospitalization (adjusted HR = 1.42, 95% CI: 1.01–2.00; p = 0.042 and adjusted HR = 1.27; 95% CI: 1.04–1.54; p = 0.017, respectively) were independently associated with HFpEF for the patients with metabolic syndrome. In addition, the risks of HF hospitalization and all-cause hospitalization among 267 propensity score-matched patients were higher for patients with metabolic syndrome (HR = 1.53, 95% CI = 1.05–2.23, and p = 0.025 and HR = 1.34, 95% CI = 1.08–1.67, and p = 0.009, respectively).Conclusion: The risks of HF hospitalization and all-cause hospitalization were higher for patients with HFpEF having metabolic syndrome than for those without metabolic syndrome.