Plasma adiponectin as a predictive factor of survival after a bypass operation for peripheral arterial disease

The real-world data of lipid-lowering treatment in patients with peripheral artery disease and its association with severity of disease

BACKGROUND

The risk of coronary artery disease in peripheral arterial disease (PAD) is high, life prognosis is poor, and lipid-lowering treatment with statins has been reported to improve prognosis. In clinical practice, however, hypolipidemia is more common in patients with severe PAD and statin prescription rates appear to be low, but specific data are scarce in Japan. Therefore, we conducted this cross-sectional study in collaboration with other centers of vascular surgery to determine the rate of statin prescriptions for PAD patients in real-world practice, the rate of achievement of low-density lipoprotein (LDL) cholesterol control targets, and whether statin non-use is a determinant factor of critical limb ischemia (CLI).

METHODS

A total of 246 PAD patients (97 with CLI) from 5 sites were included in this study. Medical history and blood test data were obtained from medical records and interviews with patients, and were compared between CLI and non-CLI patients.

RESULTS

Statin prescription rate was only 34 %. The overall LDL cholesterol control target rate was 46 % of CLI cases and 51 % of non-CLI cases, according to the lipid management criteria of the Japanese Society for Atherosclerosis 2022 guidelines. Patients in the CLI group had a lower mean body mass index and lower LDL cholesterol levels than those in the non-CLI group, suggesting that these factors were responsible for the lower statin prescription rate. However, multivariate analysis revealed that statin non-use was one of the determinants of CLI.

CONCLUSIONS

Statin prescription rates for PAD patients were low in real-world practice settings in the field of vascular surgery. Since statin non-use is a determinant of CLI, there is a need to educate physicians engaged in treatment regarding lipid-lowering treatment with statins.

Clinical Implications of Low Body Mass Index on Endovascular Lower Extremity Revascularization

BACKGROUND

The epidemic of obesity and associated cardiovascular morbidity continues to grow, attracting public attention and healthcare resources. However, the impact of malnutrition and being underweight continues to be overshadowed by obesity, especially in patients with peripheral arterial disease (PAD). This study assesses the characteristics and outcomes of patients with low body mass index (BMI ≤ 18.5) compared to patients with nonobese BMI undergoing peripheral vascular interventions (PVI).

METHODS

A retrospective analysis of patients undergoing PVI due to PAD registered in the Vascular Quality Initiative database. Patients were categorized into underweight (BMI ≤ 18.5) and nonobese BMI (BMI = 18.5-30). Patients in both groups were matched 3:1 for baseline demographic characteristics, comorbidities, medications, and indications. Kaplan-Meier analysis was done for long-term outcomes.

RESULTS

A total of 337,926 patients underwent PVI, of whom 12,935 (4%) were underweight, 215,728 (64%) were nonobese, and 109,263 (32%) were obese. Underweight patients were more likely to be older, female, smokers, with chronic obstructive pulmonary disorder, and more likely to present with chronic limb-threatening ischemia than nonobese patients. After propensity matching, there were 18,047 nonobese patients and 6,031 underweight patients. There were no significant differences in matched characteristics. Perioperatively, underweight patients were more likely to require a longer hospital length of stay. Underweight patients had statistically significantly higher 30-day mortality compared to patients with nonobese BMI (3% vs. 1.6%, P < 0.001) and a higher rate of thrombotic complications. As for long-term outcomes, underweight patients had a higher rate of reintervention (20% vs. 18%, P < 0.001) and major adverse limb events (27% vs. 22%, P < 0.001). The 4-year rate of amputation-free survival was significantly lower in underweight patients (70% vs. 82%, P < 0.001), and the 2-year freedom from major amputation (90% vs. 94%, P < 0.001) showed similar trends with worse outcomes in patients who were underweight.

CONCLUSIONS

Underweight patients with PAD are disproportionally more likely to be African American, females, and smokers and suffer worse outcomes after PVI than PAD patients with nonobese BMI. When possible, increased scrutiny and optimization of nutrition and other factors contributing to low BMI should be addressed prior to PVI.

Evaluation of Perfusion Index as a Screening Tool for Developing Critical Limb Ischemia

Objective: The perfusion index (PI) is a physiological marker for evaluating the peripheral circulation. We explored the possibility of using PI as a screening tool for development of critical limb ischemia in peripheral artery disease (PAD). Method: We measured the PI in 79 limbs of 70 PAD patients. Data were analyzed to find a correlation between the PI and PAD severity. Result: The PI tended to be lower as PAD became severer. Especially, there were significant differences between the Fontaine 1 and Fontaine 4 groups in average PI and minimum PI, and between Fontaine 1 and two other groups (Fontaine 2 and Fontaine 4 groups) in maximum PI. A mild correlation was found between PI and the ankle brachial index. These data were used to calculate an average PI of 0.27 as a cut-off value for critical limb ischemia (CLI). In 65 asymptomatic PAD patients and claudication, significantly more patients with a PI value greater than the cut-off value developed CLI than those with a PI lower than the cut-off. Conclusion: The PI can be a useful tool for evaluating the development of CLI in mild PAD patients, and patients tended not to progress to CLI when their average PI was higher than 0.27. (This is a translation of Jpn J Vasc Surg 2020; 29: 103-108.).

The prognostic role of RBP-4 and adiponectin in patients with peripheral arterial disease undergoing lower limb endovascular revascularization

BACKGROUND

RBP4 is an adipokine with an established role in atherosclerosis, while adiponectin has unique anti-inflammatory properties. We investigated the association of RBP4 and adiponectin with the presence of symptomatic peripheral artery disease (PAD) and their possible prognostic role in major adverse cardiovascular events (MACE).

METHODS

We enrolled 168 consecutive patients with symptomatic, established PAD, requiring revascularization by endovascular means of any or both of their lower limbs. 88 age- and sex-matched subjects with less than 2 classical cardiovascular risk factors served as controls. Clinical parameters, glycemic and lipid profile, RBP4 and adiponectin levels were assayed. The occurrence of MACE was recorded during the 6-month follow-up and patients were assigned to MACE and non-MACE subgroups.

RESULTS

The presence of symptomatic PAD was significantly correlated with age, diabetes, hsCRP, RBP4 and low adiponectin levels (p < 0.05). After adjustment for age, RBP4 (β = 0.498, p < 0.001), and adiponectin (β = -0.288, p < 0.001) levels remained as independent predictors of PAD presence in the whole study cohort. At baseline, MACE subgroup appeared with higher RBP-4 and hsCRP serum levels than non-MACE subgroup (p < 0.001), but no differences were detected for adiponectin (p = 0.758). Serum RBP4 levels remained independent predictor of MACE (β = 0.455, p < 0.001) after adjustment for traditional cardiovascular risk factors.

CONCLUSIONS

High RBP4 and low adiponectin serum levels are independently associated with PAD presence. In addition, RBP4 is an independent predictor of MACE incidence in symptomatic PAD patients.

Sfrp5/Wnt5a and leptin/adiponectin levels in the serum and the periarterial adipose tissue of patients with peripheral arterial occlusive disease

BACKGROUND

Leptin, adiponectin, secreted frizzled-related protein 5 (Sfrp5) and wingless-type family member 5a (Wnt5a) are novel adipokines that are involved in insulin sensitivity and atherosclerosis. The aim of the present study was to investigate the serum and periarterial adipose tissue leptin/adiponectin and Sfrp5/Wnt5a levels in patients with peripheral arterial occlusive disease (PAOD).

METHODS

A total of 75 patients with PAOD and 39 control subjects were recruited. The serum concentrations of leptin, adiponectin, Sfrp5 and Wnt5a were measured by ELISAs, and the leptin, adiponectin, Sfrp5 and Wnt5a levels in the periarterial adipose tissue were observed by western blotting.

RESULTS

The serum Sfrp5 levels were significantly lower in the patients with PAOD than in the control subjects (p < 0.001) and Wnt5a levels were higher in the patients with PAOD (p < 0.001). The serum leptin levels were significantly higher in the patients with PAOD than in the control subjects (p < 0.001), and adiponectin levels were significantly lower in the patients with PAOD (p < 0.001). The serum Sfrp5 levels were associated with ABI (rs = 0.274; p = 0.018), Wnt5a (rs = -0.409; p < 0.001), adiponectin (rs = 0.244; p = 0.035) and Leptin/Adiponetin ratio (rs = -0.244; p = 0.037). The adiponectin and Sfrp5 protein levels were decreased in the periarterial adipose tissue of patients with PAOD compared with control subjects. The leptin and Wnt5a protein levels were increased in the periarterial adipose tissue of patients with PAOD compared with control subjects.

CONCLUSION

We demonstrated that the adiponectin and Sfrp5 levels in the serum and periarterial adipose tissue were significantly lower in the patients with PAOD than in the control subjects. The leptin and Wnt5a levels in the serum and periarterial adipose tissue were significantly higher in the patients with PAOD than in the control subjects.

Blood adipocytokine concentration in patients with peripheral artery disease

BACKGROUND

Inflammatory responses mediated by adipocytokines may affect both atherosclerosis development and progression, as well as the risk of in-stent restenosis. The aim of this study was to determine the relationships between blood leptin, adiponectin and tumor necrosis factor-α (TNF-α) concentrations and the 1-year outcome of superficial femoral artery (SFA) stenting.

METHODS

Blood concentrations of leptin, adiponectin and TNF-α were determined in 70 patients undergoing SFA stenting due to intermittent claudication and in 40 patients undergoing carotid artery stenting (CAS). All subjects were followed up for at least 1 year in relation to the occurrence of clinically driven target lesion revascularization (TLR) or a major adverse cardiovascular event (MACE).

RESULTS

Patients undergoing SFA stenting and CAS had similar blood adipocytokine concentrations. Patients with diabetes mellitus presented a higher leptin concentration, lower adiponectin-to-leptin ratio, and lower blood adiponectin concentration indexed to fat mass (FM) and to visceral adiposity score (VAS). In Kaplan-Meier analysis, blood concentration of TNF-α indexed to FM and to VAS was higher in patients who underwent TLR and MACE. However, in multifactorial analysis, the severity of atherosclerosis lesions in the femoropopliteal vascular region, estimated in relation to TASC-II classification, was the only predictor of TLR.

CONCLUSIONS

Circulating adipocytokines did not distinguish patients with different clinical manifestations of atherosclerosis. Higher ratios of TNF-α -to-FM and to VAS before SFA stenting were related to TLR and MACE occurrence. Dysregulation in adipocytokine secretion may be a potential mediator of a proatherogenic action of diabetes mellitus in patients with peripheral artery disease.

Multidisciplinary Treatment for Critical Limb Ischemia in Peripheral Arterial Disease

Critical limb ischemia (CLI) is a severe blockage of the arteries to the lower limbs characterized by poor prognoses for both salvage of the lower limb and patient survival. Accordingly, CLI must be diagnosed and treated appropriately from the earliest possible stage. To do so, multidisciplinary treatment not only by vascular surgeons but also by many other doctors and medical staff is necessary. Accurate diagnosis is indispensable to appropriate treatment of CLI; thus, the definitions in the recently issued new guidelines for CLI treatment are reviewed. The multidisciplinary treatment of CLI should be recognized as three elements: namely, multidisciplinary treatment to salvage the lower limb, to improve of survival prognosis, and to prevent CLI occurrence. In all of these events, team medicine administered by expert staff is indispensable. The specialist must have not only profound knowledge of his/her field of specialty but also professional skills and the ability to cooperate with other departments. A multidisciplinary treatment approach that combines the abilities of many specialists for treating severely ischemic limbs in patients with peripheral arterial disease is expected to improve both limb salvage and patient survival and should be promoted in daily clinical settings. (This is a translation of Jpn J Vasc Surg 2018; 27: 507–512.)

Cardiometabolic effects of adiponectin

Over the past two decades, adiponectin has been studied in more than eleven thousand publications. A classical adipokine, adiponectin was among the first factors secreted from adipose tissue that were found to promote metabolic function. Circulating levels of adiponectin consistently decline with increasing body mass index. Clinical and basic science studies have identified adiponectin's cardiovascular-protective actions, providing a mechanistic link to the increased incidence of cardiovascular disease in obese individuals. While progress has been made in identifying receptors essential for the metabolic actions of adiponectin (AdipoR1 and AdipoR2), few studies have examined the receptor-mediated signaling pathways in cardiovascular tissues. T-cadherin, a GPI-anchored adiponectin-binding protein, was recently identified as critical for the cardiac-protective and revascularization actions of adiponectin. Adiponectin is abundantly present on the surfaces of vascular and muscle tissues through a direct interaction with T-cadherin. Consistent with this observation, adiponectin is absent from T-cadherin-deficient tissues. Since T-cadherin lacks an intracellular domain, additional studies would further our understanding of this signaling pathway. Here, we review the diverse cardiometabolic actions of adiponectin.

High-molecular-weight and total adiponectin levels and incident symptomatic peripheral artery disease in women: a prospective investigation

BACKGROUND

Adiponectin is linked to reduced diabetes risk and may be antiatherogenic, yet clinical data show no consistent relationship with incident cardiovascular events, especially among women. To our knowledge, no prior prospective studies have evaluated adiponectin, including high-molecular-weight (HMW) adiponectin, and incident peripheral artery disease (PAD).

METHODS AND RESULTS

We evaluated the relationship of total adiponectin, HMW adiponectin, and the HMW-to-total adiponectin ratio with incident symptomatic PAD in a prospective, nested case-control study conducted within the Women's Health Study (n=110 cases, n=230 controls, frequency matched in strata defined by 5-year age categories, smoking, fasting status, and follow-up time; median cohort follow-up=13.2 years). Baseline median levels of HMW and total adiponectin were significantly lower in women developing PAD than in those remaining event free (HMW: 3.3 versus 3.8 μg/mL, P=0.0005; total: 5.6 versus 7.4 μg/mL, P<0.0001). The ratio did not differ significantly between groups. Age-adjusted PAD odds ratios (95% confidence intervals) across tertiles were 1.0, 0.66 (0.39-1.13), and 0.40 (0.22-0.74) for HMW and 1.0, 0.74 (0.43-1.25), and 0.35 (0.18-0.65) for total adiponectin (P(trend)=0.004 and 0.001, respectively). Results were similar after adjustment for traditional cardiovascular risk factors, use of postmenopausal hormone therapy, high-sensitivity C-reactive protein, soluble intercellular adhesion molecule-1, leptin, hemoglobin A(1c), and fasting insulin (adjusted odds ratio and 95% confidence interval for HMW: 1.0, 0.62 [0.29-1.34], 0.30 [0.12-0.74]; total: 1.0, 0.46 [0.22-1.00], 0.30 [0.12-0.76]; P(trend)=0.01 for both).

CONCLUSIONS

Total and HMW adiponectin are inversely associated with incident PAD among initially healthy women. These prospective data support a protective role for this adipokine in peripheral atherosclerosis development.

Effects of pioglitazone on survival and omental adipocyte function in mice with sepsis induced by cecal ligation and puncture

BACKGROUND

To examine the effects of pioglitazone, peroxisome proliferator-activated receptor-gamma (PPAR-γ), on mortality and omental adipocyte function in mice with cecal ligation and puncture (CLP).

METHODS

Male mice were assigned to receive (1) vehicle/sham-operation, (2) pioglitazone/CLP, or (3) vehicle/CLP. Pioglitazone was injected intraperitoneally for 7 d before operation. Serum and omental tissue were collected before, 24, and 48 h after CLP. Serum levels of adiponectin, cytokine, and chemokine were measured with ELISA. mRNA expressions in omental tissues were determined by RT-PCR. Survival was monitored for 7 d after CLP.

RESULTS

Survival after CLP was significantly better in the pioglitazone/CLP than in the vehicle/CLP. Serum adiponectin levels before CLP were higher in the pioglitazone/CLP than in the vehicle/CLP. Treatment with pioglitazone significantly inhibited the increases in the serum interleukin-6 and monocyte chemoattractant protein-1 (MCP-1) levels after CLP and lowered the mRNA expressions of proinflammatory cytokines, interleukin-6, and MCP-1 in omental tissue after CLP.

CONCLUSION

The anti-inflammatory effects of pioglitazone on omental adipocyte function appear to be mediated in part by PPAR-γ activation, which down-regulates the production of inflammatory mediators.

Peripheral artery disease, biomarkers, and darapladib

OBJECTIVE

Subjects with peripheral artery disease (PAD) are at increased risk of cardiovascular morbidity and mortality, perhaps in part, related to increased levels of inflammation, platelet activity, and lipids. We therefore sought to investigate the relationship between PAD and levels of inflammatory, platelet, and lipid biomarkers and the treatment effect of darapladib, a novel lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) inhibitor.

METHODS

This is a post hoc analysis of the 959 patients with coronary disease or their risk equivalent receiving atorvastatin who were randomized to receive darapladib or placebo to examine the effects of an Lp-PLA(2) inhibitor on the biomarkers of cardiovascular risk. We conducted an exploratory analysis evaluating the levels of biomarkers in subjects with PAD (n = 172) compared with those without PAD (n = 787).

RESULTS

After adjustment for age, sex, smoking, body mass index, and diabetes, subjects with PAD had greater levels of matrix metalloproteinase-9 (between group comparisons 22%, 95% confidence interval [10-31], P < .01), myeloperoxidase (12% [2-20], P = .01), interleukin-6 (13% [4-21], P = .01), adiponectin (17% [7-26], P < .01), intercellular adhesion molecule-1 (7% [2-11], P < .01), osteoprotegrin (6% [1-10], P = .02), CD40 ligand (15% [1-28], P = .04), high-sensitivity C-reactive protein (17% [1-31], P = .04), and triglycerides (11% [0.2-21], P = .05). No significant difference was detected for Lp-PLA(2) activity, P-selectin, urinary 11-dehydrothroboxane B2, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol between subjects with and without PAD. Darapladib produced highly significant inhibition of Lp-PLA(2) activity when compared with placebo at weeks 4 and 12 (P < .01) in patients with and without PAD.

CONCLUSIONS

Subjects with PAD had elevated levels of matrix metalloproteinase-9, myeloperoxidase, interleukin-6, adiponectin, intercellular adhesion molecule-1, osteoprotegrin, CD40 ligand, high-sensitivity C-reactive protein, and triglycerides compared with those without PAD. Darapladib, a novel Lp-PLA(2) inhibitor, was equally effective in reducing Lp-PLA(2) activity levels in subjects with and without PAD.

Insulin resistance, adiponectin and adverse outcomes following elective cardiac surgery: a prospective follow-up study

Background

Insulin resistance and adiponectin are markers of cardio-metabolic disease and associated with adverse cardiovascular outcomes. The present study examined whether preoperative insulin resistance or adiponectin were associated with short- and long-term adverse outcomes in non-diabetic patients undergoing elective cardiac surgery.

Methods

In a prospective study, we assessed insulin resistance and adiponectin levels from preoperative fasting blood samples in 836 patients undergoing cardiac surgery. Population-based medical registries were used for postoperative follow-up. Outcomes included all-cause death, myocardial infarction or percutaneous coronary intervention, stroke, re-exploration, renal failure, and infections. The ability of insulin resistance and adiponectin to predict clinical adverse outcomes was examined using receiver operating characteristics.

Results

Neither insulin resistance nor adiponectin were statistically significantly associated with 30-day mortality, but adiponectin was associated with an increased 31-365-day mortality (adjusted odds ratio 2.9 [95% confidence interval 1.3-6.4]) comparing the upper quartile with the three lower quartiles. Insulin resistance was a poor predictor of adverse outcomes. In contrast, the predictive accuracy of adiponectin (area under curve 0.75 [95% confidence interval 0.65-0.85]) was similar to that of the EuroSCORE (area under curve 0.75 [95% confidence interval 0.67-0.83]) and a model including adiponectin and the EuroSCORE had an area under curve of 0.78 [95% confidence interval 0.68-0.88] concerning 31-365-day mortality.

Conclusions

Elevated adiponectin levels, but not insulin resistance, were associated with increased mortality and appear to be a strong predictor of long-term mortality. Additional studies are warranted to further clarify the possible clinical role of adiponectin assessment in cardiac surgery.

Trial Registration

The Danish Data Protection Agency; reference no. 2007-41-1514.

Novel adipokines, high molecular weight adiponectin and resistin, are associated with outcomes following lower extremity revascularization with autogenous vein

OBJECTIVE

A significant portion of patients undergoing lower extremity bypass surgery (LEB) for peripheral arterial disease (PAD) will have cardiovascular or graft-related events. It has been previously demonstrated that systemic inflammation is associated with PAD and its clinical outcomes. We hypothesized that serum biomarkers of insulin resistance and inflammation would identify a subgroup at elevated risk for graft failure, limb loss, and mortality.

METHODS

This was a prospective longitudinal study of patients (n = 225) undergoing LEB using autogenous vein. Baseline blood samples were obtained prior to surgery in the fasting state. High-sensitivity C-reactive protein (hsCRP) and the adipokines resistin and high-molecular weight adiponectin (HMWA) were measured by enzyme-linked immunosorbent assay (ELISA). Median follow-up was 893 days. The major endpoints of primary patency (PP) and amputation-free survival (AFS) were examined using multivariable methods. Endpoints were screened against biomarkers and patient characteristics for univariate associations. Promising explanatory variables (P < .1) were included in multivariable Cox proportional hazard models.

RESULTS

The mean age of subjects was 67.6 years; 71.6% were male and 87.1% were Caucasian. One hundred thirty-three (59.1%) subjects underwent bypass for critical limb ischemia (CLI) and 73 (32.4%) had tissue loss. Patients with CLI and diabetes demonstrated elevated resistin and hsCRP levels. HMWA levels correlated with CLI and with a measure of insulin resistance (HOMA-IR) but not with clinical diabetes. Baseline biomarkers were higher in those presenting with tissue loss and in patients with postoperative events (mortality, limb loss). After multivariable analysis (including CLI, diabetes, age, estimated glomerular filtration rate [eGFR], adiponectin, resistin, and CRP), resistin (hazard ratio [HR] 1.75, 95% confidence interval [CI], 1.07-2.85; P = .025) and CRP (HR 2.39, 95% CI, 1.30-4.39; P = .005) were independently predictive of reduced AFS. However, only resistin maintained its significance when restricted to the diabetic cohort (HR 2.10, 95% CI, 1.10-3.99; P = .025). Higher levels of HMWA were found to be associated with primary graft patency (HR 0.73 for graft failure; 95% CI, 0.55 to 0.97; P = .031) in a multivariable model adjusting for diabetes, CRP, African-American race, CLI, high-risk conduits, and redo bypass procedures.

CONCLUSION

These findings suggest that serum biomarkers of insulin resistance and inflammation may be predictive of clinical outcomes following LEB. Improving the systemic milieu of insulin resistance and inflammation in these high-risk patients may lead to reduced morbidity and mortality.