Risk factors for premature peripheral vascular disease: results for the National Health and Nutritional Survey, 1999-2002

The Role of the Coagulation System in Peripheral Arterial Disease: Interactions with the Arterial Wall and Its Vascular Microenvironment and Implications for Rational Therapies

Peripheral artery disease (PAD) is a clinical manifestation of atherosclerotic disease with a large-scale impact on the economy and global health. Despite the role played by platelets in the process of atherogenesis being well recognized, evidence has been increasing on the contribution of the coagulation system to the atherosclerosis formation and PAD development, with important repercussions for the therapeutic approach. Histopathological analysis and some clinical studies conducted on atherosclerotic plaques testify to the existence of different types of plaques. Likely, the role of coagulation in each specific type of plaque can be an important determinant in the histopathological composition of atherosclerosis and in its future stability. In this review, we analyze the molecular contribution of inflammation and the coagulation system on PAD pathogenesis, focusing on molecular similarities and differences between atherogenesis in PAD and coronary artery disease (CAD) and discussing the possible implications for current therapeutic strategies and future perspectives accounting for molecular inflammatory and coagulation targets. Understanding the role of cross-talking between coagulation and inflammation in atherosclerosis genesis and progression could help in choosing the right patients for future dual pathway inhibition strategies, where an antiplatelet agent is combined with an anticoagulant, whose role, despite pathophysiological premises and trials' results, is still under debate.

Major adverse limb events among patients with premature peripheral artery disease compared with those at the common age undergoing revascularization in the Vascular Quality Initiative

OBJECTIVES

Premature peripheral artery disease (PAD), defined as ≤ 50 years of age, is associated with poor outcomes following lower extremity revascularization (LER). However, the specific characteristics and outcomes of this group of patients compared to those at the common age undergoing revascularization have not been examined. The aim of this study is to compare patients with early versus late onset premature PAD undergoing LER focusing on major adverse limb events (MALEs).

METHODS

All LER procedures (open and endovascular) in the Vascular Quality Initiative (VQI) were reviewed. A histogram of patient age at the time of initial LER (no prior LER) was used to define the common age, which included all patients within one standard deviation of the mean. Characteristics and outcomes of patients with premature PAD were compared to patients treated at the common age of presentation undergoing LER.

RESULTS

A histogram of all patients undergoing LER was used to define 60 to 80 years as the common age. Patients with premature PAD were more likely to be female, African American, and Hispanic compared to patients at the common age. Patients with premature PAD were also more likely to have insulin-dependent diabetes, be current smokers, on dialysis, and be treated for claudication. Patients with premature PAD were less likely to have Transatlantic Intersociety Consensus (TASC II) C or D disease and were less likely to be on antiplatelets and statins. These differences were more pronounced in patients with chronic limb-threatening ischemia (CLTI). Cox proportional hazards regression demonstrated that premature PAD was independently associated with major adverse limb events (MALEs) at one-year for patients with claudication (HR:1.7, 95% CI:1.4-2.0) and CLTI (HR:1.3, 95% CI:1.2-1.5) compared to patients 60 to 80 years of age.

CONCLUSION

Patients with premature PAD have significant differences in characteristics compared to patients treated at the common age. Vascular providers should emphasize medical therapy prior to LER given the lower rates of medical optimization and worse one-year MALEs in patients with premature PAD.

Outcomes of bypass and endovascular interventions for advanced femoropopliteal disease in patients with premature peripheral artery disease

OBJECTIVE

Patients with premature peripheral artery disease (PAD), defined as age ≤50 years at presentation, have had poor outcomes with open and endovascular lower extremity revascularization. It is unclear whether either strategy is associated with better outcomes because comparative studies have been limited to case series in this patient population. The aim of the present study was to compare the outcomes of patients with premature PAD who had undergone bypass or endovascular revascularization for advanced femoropopliteal disease. Our hypothesis was that open bypass would provide superior long-term outcomes compared with endovascular intervention for patients with premature advanced femoropopliteal PAD.

METHODS

All the patients with premature PAD who had undergone isolated femoropopliteal lower extremity revascularization and included in the Vascular Quality Initiative infrainguinal bypass and peripheral vascular intervention files were reviewed from 2003 through 2019. Propensity score matching (1:1) was performed between patients who had undergone femoropopliteal bypass and endovascular interventions for isolated femoropopliteal Trans-Atlantic Classification System C or D lesions. The 1-year outcomes, including reintervention, patency, major amputation, and mortality, were analyzed.

RESULTS

Of the 2538 included patients, 902 had undergone isolated femoropopliteal endovascular intervention and 1636 had undergone femoropopliteal bypass. The endovascular intervention group were more likely to have diabetes (68.9% vs 54.0%; P < .001), coronary artery disease (31.0% vs 23.0%; P < .001), renal failure requiring dialysis (14.2% vs 7.2%; P < .001), and claudication (45.1% vs 36.6%; P < .001) compared with the bypass group. After propensity score matching, 466 patients were in each group with no significant differences in the baseline characteristics. Perioperative morbidity was higher with femoropopliteal bypass compared with endovascular intervention (12.0% vs 7.9%; P = .038); however, the rates of major amputation and mortality were not different. At 1 year, patients who had undergone femoropopliteal bypass were less likely to require reintervention (17.0% vs 25.2%; P = .012). However, no differences were found in major amputation (7.7% vs 7.9%; P = .928) or mortality (5.2% vs 5.2%; P = 1.00). Propensity score matching was also performed between femoropopliteal bypass with the great saphenous vein and isolated femoropopliteal endovascular interventions, and the outcomes were similar.

CONCLUSIONS

For patients with premature PAD and advanced femoropopliteal disease, bypass surgery decreased the reintervention rate at 1 year but was associated with increased perioperative morbidity and hospital length of stay compared with endovascular therapy. No differences were found in major amputation or mortality between the two strategies.

Premature Atherosclerotic Cardiovascular Disease: What Have We Learned Recently?

PURPOSE OF REVIEW

In contrast to patients with non-premature atherosclerotic cardiovascular disease (ASCVD), patients with premature ASCVD have not observed a similar decline in cardiovascular mortality and recurrent adverse events. We sought to review the underlying risk factors, potential gaps in medical management, associated outcomes, and tools for risk prognostication among patients with premature ASCVD.

RECENT FINDINGS

In addition to traditional cardiovascular risk factors (i.e., diabetes, familial hypercholesterolemia), non-traditional risk factors such as chronic inflammatory conditions, recreational drug use, genetics, and pregnancy-related complications play a key role in development and progression of premature ASCVD. Patients with premature ASCVD, and especially women, receive less optimal medical management as compared to their non-premature counterparts. There is an increasing prevalence of cardiovascular risk factors among young adults. Hence, this population remains at an elevated risk for premature ASCVD and subsequent adverse cardiovascular events. Future studies evaluating different risk assessment tools and focusing on young patients across all three major domains of ASCVD are needed.

Premature atherosclerotic peripheral artery disease: An underrecognized and undertreated disorder with a rising global prevalence

Premature atherosclerotic peripheral artery disease (PAD) of the lower extremities is characterized by disease diagnosis before the age of 50 years. The global prevalence of premature PAD has increased, and the disease is often underdiagnosed given heterogenous patient symptoms. Traditional cardiovascular risk factors like smoking, diabetes, hypertension, and hyperlipidemia as well as non-traditional risk factors like elevated lipoprotein(a), family history of PAD, hypercoagulability, and systemic inflammation are associated with premature PAD. Patients with premature PAD tend to have an aggressive vascular disease process, a high burden of cardiovascular risk factors, and other concomitant atherosclerotic vascular diseases like coronary artery disease. Prevention of cardiovascular events, improvement of symptoms and functional status, and prevention of adverse limb events are the main goals of patient management. In this review, we discuss the epidemiology, risk factors, clinical evaluation, and management of patients with premature PAD.

Nationwide Trends in Prevalent Cardiovascular Risk Factors and Diseases in Young Adults: Differences by Sex and Race and In-Hospital Outcomes

OBJECTIVES

Prevalence and trends in all cardiovascular disease (CVD) risk factors among young adults (18-39 years) have not been evaluated on a large scale stratified by sex and race. The aim of this study was to establish the prevalence and temporal trend of CVD risk factors in US inpatients younger than 40 years of age from 2007 through 2014 with racial and sex-based distinctions. In addition, the impact of these risk factors on inpatient outcomes and healthcare resource utilization was explored.

METHODS

A cross-sectional nationwide analysis of all hospitalizations, comorbidities, and complications among young adults from 2007 to 2014 was performed. The primary outcomes were frequency, trends, and race- and sex-based differences in coexisting CVD risk factors. Coprimary outcomes were trends in all-cause mortality, acute myocardial infarction, arrhythmia, stroke, and venous thromboembolism in young adults with CVD risk factors. Secondary outcomes were demographics and resource utilization in young adults with versus without CVD risk factors.

RESULTS

Of 63 million hospitalizations (mean 30.5 [standard deviation 5.9] years), 27% had at least one coexisting CVD risk factor. From 2007 to 2014, admission frequency with CVD risk factors increased from 42.8% to 55.1% in males and from 16.2% to 24.6% in females. Admissions with CVD risk were higher in male (41.4% vs 15.9%) and white (58.4% vs 53.8%) or African American (22.6% vs 15.9%) patients compared with those without CVD risk. Young adults in the Midwest (23.9% vs 21.1%) and South (40.8% vs 37.9%) documented comparatively higher hospitalizations rates with CVD risk. Young adults with CVD risk had higher all-cause in-hospital mortality (0.4% vs. 0.3%) with a higher average length of stay (4.3 vs 3.2 days) and charges per admission ($30,074 vs $20,124).

CONCLUSIONS

Despite modern advances in screening, management, and interventional measures for CVD, rising trends in CVD risk factors across all sex and race/ethnic groups call for attention by preventive cardiologists.

The effects of dietary flaxseed on cardiac arrhythmias and claudication in patients with peripheral arterial disease

Patients with peripheral artery disease (PAD) are at increased risk for cardiovascular events, and higher susceptibility for cardiac arrhythmias may be involved. The objectives of this double-blinded randomized controlled FLAX-PAD trial were to determine whether daily consumption of a diet supplemented with 30 g of milled flaxseed (or placebo) over 1 year by PAD patients has effects on the prevalence of cardiac arrhythmias and exercise capacity. Cardiac arrhythmias were assessed on a cardiac stress test and at rest. At baseline, the PAD patients had a high incidence of cardiac arrhythmias (48% in the flaxseed group and 32% in the placebo group). After 1 year, the presence of cardiac arrhythmias in the flaxseed group decreased by 2% and increased by 12% in the placebo group (P > 0.05). Electrocardiographic variables (P, PR, QRS, QT, and QTc) did not change in either group during the trial. Patients from both groups improved initial and absolute claudication distances but the intergroup difference was also not statistically significant. In summary, the prevalence of cardiac arrhythmias and physical capacity trended in a positive direction for patients ingesting flaxseed but either a larger sample size or a longer intervention with flaxseed may be required to show statistically significant differences.

Hypercoagulability predicts worse outcomes in young patients undergoing lower extremity revascularization

OBJECTIVE

Although we know that young patients with peripheral artery disease (PAD) have worse outcomes than older patients, there is a scarcity of information about the incidence of hypercoagulability in this population. Our aim was to analyze outcomes of young patients diagnosed with a hypercoagulable state (unusual tendency toward thrombosis) after lower extremity revascularization compared with similar patients without hypercoagulability.

METHODS

All patients 50 years of age or younger undergoing an initial procedure for lower extremity PAD from 2000 to 2015 at the Cleveland Clinic were retrospectively analyzed. Patients with a hypercoagulability panel were included and classified into groups as hypercoagulable positive (HP) or hypercoagulable negative (HN). Demographics, preoperative risk factors, form of presentation, level of disease, and type of intervention were analyzed in addition to perioperative complications, early failure, and length of stay. Primary outcomes were limb loss and primary, primary assisted, and secondary patencies. Outcomes were analyzed and Kaplan-Meier curves generated.

RESULTS

Ninety-one patients were included for a total of 118 limbs. Mean follow-up was 32 months; 55% of patients had a hypercoagulable disorder, with 59% having lupus anticoagulant and 32% hyperhomocysteinemia. In the HP group, 71% were men; 49% were men in the HN group. Patients overall had a high prevalence of smoking (86%), hypertension (36%), and hyperlipidemia (33%). Acute limb ischemia was the most common form of presentation for both groups (50% HP, 38% HN). The aortoiliac segment was the most commonly affected (38% HP, 50% HN). The most frequent operation in the HN group was endarterectomy or bypass (32%); in the HP group, it was an endovascular intervention (29%). Perioperative occlusion or failure was 18% in the HN group vs 30% in the HP group (P > .05). Primary patency, primary assisted patency, and secondary patency at 36 months were all better for the HN group (no statistical significance) in all treatment groups. Major amputation at 36 months was significantly worse for the HP group (40% vs 10% in the HN group; P < .005). There was no difference in perioperative complications or length of stay.

CONCLUSIONS

Young patients undergoing lower extremity revascularization for PAD have worse outcomes when associated with hypercoagulability. There are trends to decreased patency of revascularization in these patients, with significantly more major amputations. No clear differences between modalities of treatment were demonstrated.

Peripheral Atheromatous Arterial Disease in the Young: Risk Factors, Clinical Features, and Prognosis From the COPART Cohort

We describe the cardiovascular risk factors, clinical presentation, and prognosis in a comparative study of patients with peripheral artery disease (PAD) from the Cohorte des Patients ARTériopathes (COPART) cohort, which includes patients hospitalized for PAD in France. Among the 2514 patients included in the cohort, 189 had PAD before or at the age of 50 years and 2325 had it after. Young patients with PAD had diabetes less frequently (34% vs 46%, P < .001), were more frequent active smokers (58% vs 23%, P < 0.001), had lower high-density lipoprotein cholesterol (HDL-C; 41 ± 14 vs 44 ± 15 mg/dL, P = .026), and had a less frequent family and personal history of coronary heart disease. In a subset of 59 patients whose lipoprotein (a) (Lp(a)) was measured, the Lp(a) levels were higher in the young patients than in the older ones (89.7 mg/dL [9.7-151.3] vs 19.9 mg/dL [3.0-207.9], P = .004). Survival and amputation-free survival was 2.2 times higher (1.5-3.2, P < .001) in the young after 1 year. The onset of PAD before 50 years was associated with active smoking, low HDL-C, high Lp(a), and lower mortality.

Biomarkers and Genetics in Peripheral Artery Disease

BACKGROUND

Peripheral artery disease (PAD) is highly prevalent and there is considerable diversity in the initial clinical manifestation and disease progression among individuals. Currently, there is no ideal biomarker to screen for PAD, to risk stratify patients with PAD, or to monitor therapeutic response to revascularization procedures. Advances in human genetics have markedly enhanced the ability to develop novel diagnostic and therapeutic approaches across a host of human diseases, but such developments in the field of PAD are lagging.

CONTENT

In this article, we will discuss the epidemiology, traditional risk factors for, and clinical presentations of PAD. We will discuss the possible role of genetic factors and gene-environment interactions in the development and/or progression of PAD. We will further explore future avenues through which genetic advances can be used to better our understanding of the pathophysiology of PAD and potentially find newer therapeutic targets. We will discuss the potential role of biomarkers in identifying patients at risk for PAD and for risk stratifying patients with PAD, and novel approaches to identification of reliable biomarkers in PAD.

SUMMARY

The exponential growth of genetic tools and newer technologies provides opportunities to investigate and identify newer pathways in the development and progression of PAD, and thereby in the identification of newer biomarkers and therapies.

Periodontal disease and atherosclerosis

Atherosclerotic disease (AD) is one of the most important causes of morbidity and mortality in the world. It expresses inflammatory markers such as C-reactive protein (CRP) and can provoke arterial wall thickening, which can be evaluated using Doppler ultrasound. Risk factors associated with AD include diabetes mellitus, systemic arterial hypertension, dyslipidemia and smoking. More recently, periodontal disease (PD) has been identified as a factor related to AD. Periodontal disease has a high prevalence in the global population and the inflammatory process and bacterial activity at the periodontium appear to increase the risk of AD. Encouraging good oral hygiene can reduce expression of inflammatory markers of AD. A review of literature on PD, AD and inflammatory markers and the interrelationships between the two diseases was conducted using data published in articles indexed on the PUBMED, SCIELO and BIREME databases.

Novel risk factors for premature peripheral arterial occlusive disease in non-diabetic patients: a case-control study

Background

This study aimed to determine the prevalence of genetic and environmental vascular risk factors in non diabetic patients with premature peripheral arterial disease, either peripheral arterial occlusive disease or thromboangiitis obliterans, the two main entities of peripheral arterial disease, and to established whether some of them are specifically associated with one or another of the premature peripheral arterial disease subgroups.

Methods and Results

This study included 113 non diabetic patients with premature peripheral arterial disease (diagnosis <45-year old) presenting either a peripheral arterial occlusive disease (N = 64) or a thromboangiitis obliterans (N = 49), and 241 controls matched for age and gender. Both patient groups demonstrated common traits including cigarette smoking, low physical activity, decreased levels of HDL-cholesterol, apolipoprotein A–I, pyridoxal 5′-phosphate (active form of B6 vitamin) and zinc. Premature peripheral arterial occlusive disease was characterized by the presence of a family history of peripheral arterial and carotid artery diseases (OR 2.3 and 5.8 respectively, 95% CI), high lipoprotein (a) levels above 300 mg/L (OR 2.3, 95% CI), the presence of the factor V Leiden (OR 5.1, 95% CI) and the glycoprotein Ia^{807T,837T,873A} allele (OR 2.3, 95% CI). In thromboangiitis obliterans group, more patients were regular consumers of cannabis (OR 3.5, 95% CI) and higher levels in plasma copper has been shown (OR 6.5, 95% CI).

Conclusions

According to our results from a non exhaustive list of study parameters, we might hypothesize for 1) a genetic basis for premature peripheral arterial occlusive disease development and 2) the prevalence of environmental factors in the development of thromboangiitis obliterans (tobacco and cannabis). Moreover, for the first time, we demonstrated that the 807T/837T/873A allele of platelet glycoprotein Ia may confer an additional risk for development of peripheral atherosclerosis in premature peripheral arterial occlusive disease.

Prevalence of low ankle brachial index and relationship with cardiovascular risk factors in a Western urban population in Turkey

We determined the prevalence of peripheral arterial disease (PAD) and associated risk factors in an urban population age ≥30 years in Turkey and assessed the impact of incorporating ankle brachial index (ABI) measurement with coronary heart disease risk calculations to the risk reclassification of individuals. The sample was drawn from 4600 participants of Balcova Heart Study. The prevalence of low ABI (<0.9) was 6.3%. Current smoking (odds ratio [OR]: 5.07, 95% confidence interval [CI]: 1.85-13.88), cardiovascular disease history (OR: 6.83, 95% CI: 3.00-15.53), hypertension (OR: 2.58, 95% CI: 1.06-6.33), diabetes (OR: 3.25, 95% CI: 1.51-6.98), and high waist circumference (OR: 2.24, 95% CI: 1.02-4.94) were positively associated with prevalent PAD. When ABI measurement was taken into account, 3.5% of low or intermediate risk patients were reclassified as high risk. Screening individuals who have one of these risk factors with ABI can help reclassifying individuals toward the high-risk category.

Substantial adverse association of visual and vascular comorbidities on visual disability in multiple sclerosis

Background: Visual comorbidities are common in multiple sclerosis (MS) but the impact of visual comorbidities on visual disability is unknown.

Objective: We assessed the impact of visual and vascular comorbidities on severity of visual disability in MS.

Methods: In 2006, we queried participants of the North American Research Committee on Multiple Sclerosis (NARCOMS) about cataracts, glaucoma, uveitis, hypertension, hypercholesterolemia, heart disease, diabetes and peripheral vascular disease. We assessed visual disability using the Vision subscale of Performance Scales. Using Cox regression, we investigated whether visual or vascular comorbidities affected the time between MS symptom onset and the development of mild, moderate and severe visual disability.

Results: Of 8983 respondents, 1415 (15.9%) reported a visual comorbidity while 4745 (52.8%) reported a vascular comorbidity. The median (interquartile range) visual score was 1 (0–2). In a multivariable Cox model the risk of mild visual disability was higher among participants with vascular (hazard ratio [HR] 1.45; 95% confidence interval [CI]: 1.39–1.51) and visual comorbidities (HR 1.47; 95% CI: 1.37–1.59). Vascular and visual comorbidities were similarly associated with increased risks of moderate and severe visual disability.

Conclusions: Visual and vascular comorbidities are associated with progression of visual disability in MS. Clinicians hearing reports of worsening visual symptoms in MS patients should consider visual comorbidities as contributing factors. Further study of these issues using objective, systematic neuro-ophthalmologic evaluations is warranted.

Prevalence of CKD and comorbid illness in elderly patients in the United States: results from the Kidney Early Evaluation Program (KEEP)

BACKGROUND

Elderly individuals with chronic kidney disease (CKD) have high rates of comorbid conditions, including cardiovascular disease and its risk factors, and CKD-related complications. In individuals aged > or = 65 years, we sought to describe the prevalence of CKD determined from laboratory test results in the Kidney Early Evaluation Program (KEEP; n = 27,017) and National Health and Nutrition Examination Survey (NHANES) 1999-2006 (n = 5,538) and the prevalence of diagnosed CKD determined from billing codes in the Medicare 5% sample (n = 1,236,946). In all 3 data sources, we also explored comorbid conditions and CKD-related complications.

METHODS

CKD was identified as decreased estimated glomerular filtration rate (<60 mL/min/1.73 m(2)) or increased albumin-creatinine ratio in KEEP and NHANES; CKD was identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes in Medicare. Investigated comorbid conditions included diabetes, hypertension, high cholesterol level, coronary artery disease, congestive heart failure, cerebrovascular disease, peripheral vascular disease, and cancer, and CKD-related complications included anemia, hypocalcemia, hyperphosphatemia, and hyperparathyroidism.

RESULTS

The prevalence of CKD was approximately 44% in both KEEP and NHANES participants, and the prevalence of diagnosed CKD was 7% in Medicare beneficiaries. In all 3 data sets, the prevalence of CKD or diagnosed CKD was higher in participants aged > or = 80 years and those with comorbid conditions. For KEEP and NHANES participants, the prevalence of most comorbid conditions and CKD complications increased with decreasing estimated glomerular filtration rate. For participants with CKD stages 3-5, a total of 29.2% (95% CI, 27.8-30.6) in KEEP and 19.9% (95% CI, 17.0-23.1) in NHANES had anemia, 0.7% (95% CI, 0.4-0.9) and 0.6% (95% CI, 0.3-1.3) had hypocalcemia, 5.4% (95% CI, 4.7-6.1) and 6.4% (95% CI, 5.1-8.0) had hyperphosphatemia, and 52.0% (95% CI, 50.4-53.6) and 30.0% (95% CI, 25.9-34.3) had hyperparathyroidism, respectively.

CONCLUSIONS

CKD is common in the elderly population and is associated with high frequencies of concomitant comorbid conditions and biochemical abnormalities. Because CKD is not commonly diagnosed, greater emphasis on physician education may be beneficial.

Novel markers of peripheral arterial disease

Peripheral arterial disease (PAD), a relatively common manifestation of atherosclerotic vascular disease, is associated with significant morbidity and mortality. Although conventional risk factors contribute to the onset and progression of PAD, the role of 'novel' biomarkers in pathways of inflammation, thrombosis, lipoprotein metabolism, and oxidative stress in determining susceptibility to PAD is being increasingly recognized. Validation of novel risk factors for PAD may allow earlier detection, an improved understanding of disease etiology and progression, and the development of new therapies. In this review, we discuss available evidence for associations between novel circulating markers and several aspects of PAD including disease susceptibility, progression, functional limitation, and adverse outcomes.

Fibrinogen kinetics and protein turnover in hypertension: Effects of insulin

BACKGROUND AND AIM

Hyperfibrinogenemia, a cardiovascular risk factor, is frequent in hypertension and largely unexplained. In this study, we measured fibrinogen production and whole-body protein turnover under both basal and hyperinsulinemic states, in hypertensive [H] and control [C] subjects, using a leucine stable isotope tracer and precursor-product relationships.

METHODS AND RESULTS

Since hypertension is often a feature of the "metabolic", insulin resistance syndrome, which in turn affects both fibrinogen kinetics and whole-body protein turnover, we selected hypertensive subjects without the metabolic syndrome. Following basal measurements, an euglycemic, approximately euaminoacidemic, hyperinsulinemic clamp was performed, with plasma insulin raised to 700-900 pmol/L. In H, rates of the fractional and absolute synthesis (FSR and ASR, respectively) of fibrinogen were 30%-40% greater (p<0.05 or less) than in C in both states, whereas leucine turnover was normal. Hyperinsulinemia did not modify fibrinogen synthesis in either group with respect to baseline, whereas it suppressed leucine appearance from endogenous proteolysis by approximately 40% to same extent in both groups. Amino acid clearance was similar in both the H and C subjects. In H, the insulin-mediated glucose disposal (M) was approximately 25% lower, (although insignificantly) than in controls, showing no overall insulin resistance. There was an inverse correlation between M and fibrinogen FSR during the clamp.

CONCLUSIONS

In essential hypertension fibrinogen production is increased, is not further stimulated by insulin, and is inversely related to insulin sensitivity at high-physiological insulin concentrations. Amino acid disposal and basal as well as insulin-responsive protein degradation rates are instead normal.

Peripheral vascular disease-related procedures in dialysis patients: predictors and prognosis

BACKGROUND AND OBJECTIVES

Peripheral vascular disease (PVD) is prevalent among dialysis patients, and many dialysis patients undergo PVD-related procedures. We aimed to examine the risk factors for and prognosis after such procedures in the dialysis setting.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a national prospective cohort study of 1041 incident dialysis patients, we examined the factors that are associated with PVD procedures (lower extremity amputations and bypasses) after the start of dialysis. Adjusted risk for PVD procedures of various factors was estimated using multivariable Cox proportional hazards models. Incidence rates of subsequent cardiovascular events, infectious hospitalizations, PVD- and cardiovascular disease-related mortality, and all-cause mortality were compared for those with and without a PVD procedure.

RESULTS

Overall, 217 (21%) patients underwent a PVD procedure after the start of dialysis. For those without diabetes, only PVD history (relative hazard [RH] 2.9; 95% confidence interval [CI] 1.3 to 6.6) and increased fibrinogen (RH 1.2; 95% CI 1.0 to 1.5) predicted PVD procedures. For those with diabetes, increased serum phosphate (RH 1.2; 95% CI 1.1 to 1.4), along with decreased albumin, increased C-reactive protein and fibrinogen, and lower SBP, was associated with risk for PVD procedures. Of those who had a procedure compared with those who did not, 68 versus 30% experienced a subsequent cardiovascular event, 85 versus 66% an infectious hospitalization, 11 versus 2% a PVD-related death, and 81 versus 59% all-cause death (mean follow-up 3.0 yr).

CONCLUSIONS

Prognosis after PVD procedures is poor, and providers should be aware that risk factors for PVD procedures may differ by diabetes status.

What's new in lower-extremity arterial disease? WOCN's 2008 clinical practice guideline

Lower-extremity arterial disease (LEAD) affects 8 to 10 million people in the United States, resulting in pain, tissue loss, infection, limb loss, and an impaired quality of life. LEAD is underdiagnosed, undertreated, and often unrecognized. The purpose of this article is to provide a summary of the recommendations from the 2008 evidence-based, clinical practice guideline, Guideline for the Management of Patients With Lower-Extremity Arterial Disease, recently released from the Wound, Ostomy and Continence Nurses Society. This article presents an overview of the process used to develop the guideline, a discussion of risks for LEAD, and specific recommendations for assessment, interventions, patient education, and risk-reduction strategies.

A case of polyarteritis nodosa presenting initially as peripheral vascular disease

Polyarteritis nodosa is a rare necrotizing vasculitis that can be progressive and fatal, and its initial presenting symptom may be leg claudication due to peripheral vascular ischemia. To date, there have been fewer than ten case reports of polyarteritis nodosa presenting as peripheral vascular disease. We report a case of a 38-year-old man initially diagnosed to have premature peripheral vascular disease who presented 1 year later with symptoms consistent with giant cell arteritis and subsequently developed bowel ischemia leading to a fatal outcome. Based on the autopsy and the patient's clinical course, the final diagnosis was polyarteritis nodosa. This case illustrates the challenges in diagnosing polyarteritis nodosa and the importance of considering vasculitis in young patients presenting with atypical presentations of diseases such as peripheral vascular disease or giant cell arteritis.

The effects of increasing obesity on outcomes of vascular surgery

The aim of this study was to determine whether vascular patients are becoming progressively more obese and whether morbid obesity affects outcomes from vascular surgery. Data for the index vascular procedures of infrainguinal bypass, carotid endarterectomy, and abdominal aortic aneurysm (AAA) repair were collected in a computer database for 1996-2006. Body mass index (BMI) was stratified into <18.5 kg/m2 as underweight, >35 kg/m2 as morbidly obese, and other as control (18.5 < BMI < 35). The data were analyzed with respect to operation duration, length of stay, complication rates, and mortality rates. Results were adjusted for potential confounding variables, including mode of admission, diabetes, cardiac history, renal function, and smoking. A total of 1,317 patients were reviewed, and 1,105 cases were deemed suitable for analysis. The incidence of morbid obesity increased in a linear manner from 1.3% to 9% over the 10-year period. The operation duration was longer for morbidly obese subjects compared with normals. This was only statistically significant for AAA repair category, with a mean operating time of 158.4 +/- 65.5 min for patients with BMI <35 kg/m2 vs. 189.8 +/- 92.2 min for morbidly obese patients (p < 0.014). Infection rates were consistently higher in the morbidly obese group; however, this reached a statistically significant rate among AAA repair cases (43.5% [n = 16] vs. 34.8% [n = 159], p < 0.004). There were no significant differences in other complications, graft failure, length of stay, or mortality. Vascular patients are becoming progressively more obese. Procedures performed on morbidly obese subjects take longer, and these patients have higher rates of infectious complications. This is mainly attributable to AAA. This did not translate into poorer final outcomes in this study, although significant differences might emerge from a larger sample.

Elevated serum alkaline phosphatase and peripheral arterial disease in the United States National Health and Nutrition Examination Survey 1999-2004

BACKGROUND

Alkaline phosphatase (ALP) is elevated in peripheral arterial disease (PAD). We therefore examined the relationship of PAD with ALP and other liver enzymes in the United States National Health and Nutrition Examination Survey 1999-2004.

METHODS

The analysis included 5995 men and non-pregnant women aged >or=40 years with no missing data in variables of interest. PAD was defined as ankle-brachial blood pressure index (ABI) <0.90 in either leg.

RESULTS

Serum alkaline phosphatase (ALP) level was associated significantly with lower ABI after adjustment for confounding factors (p=0.019). No significant association of ABI with other liver enzymes was found. Serum ALP level increased with increasing age, body mass index, C-reactive protein, monocyte count, serum uric acid, lead, cadmium, and prevalence of hypercholesterolemia, diabetes, smoking, non-alcohol drinking, and cardiovascular diseases after adjusting for age, sex, race/ethnicity, and survey years (p<0.02). The highest quartile of serum ALP was associated with an odds ratio of 1.89 (95% confidence interval [CI]: 1.25-2.85) for PAD after adjustment for confounding factors (p for trend=0.023). In subjects with normal kidney function (glomerular filtration rate >90 ml/min/1.73 m(2)), the odds ratio increased to 4.22 (95% CI 1.45-12.35) (p=0.010).

CONCLUSION

Elevated serum ALP is correlated with PAD, independent of other traditional cardiovascular risk factors.

[Thrombophilias and peripheral arterial occlusive disease]

Peripheral arterial occlusive disease is a frequent disease due to the classical vascular risk factors such as smoking, diabetes mellitus, dyslipidemia, and hypertension. Despite these risk factors, many thrombophilias (physiological inhibitors defects, Factor V Leiden and 20210A prothrombin gene variant, antiphospholipid antibodies, mild hyperhomocysteinemia 15-30micromol/l) can be evoked in some clinical forms of peripheral arterial occlusive disease. This paper provides a synthesis of the published data about this topic. Screening for these thrombophilias is justified in patients with venous thromboembolic disease, or signs of antiphospholipid syndrome and possibly in different situations such as premature atheroma of lower limbs, chronic ischaemia, evolutive disease despite adapted treatment and revascularisation failures without evident technical explanation. Except for the antiphospholipid syndrome, there is currently no consensus for systematic screening of thrombophilia and treatment in patients with peripheral arterial occlusive disease.

Prevalence of risk factors for diabetic foot complications

Background

Foot complications are common in diabetic patients and are considered one of the most expensive diabetes (DM) complications to treat. The aim of this study was to determine the prevalence and risk factors for foot complications among diabetic patients in Al-Ain district, United Arab Emirates (UAE).

Methods

The study was part of a general cross-sectional survey carried out to assess the prevalence of DM complications in Al-Ain district, UAE. A sample of 513 diabetic patients with a mean age of 53 years (SD: ± 13) were randomly selected during 2003/2004. All completed an interviewer-administered questionnaire and underwent medical assessment including foot examination and assessment of presence of peripheral neuropathy (PN) and peripheral vascular disease (PVD).

Results

Forty nine percent of the study populations were diagnosed to have DM without presenting with symptoms of diabetes and 35% had hypertension. The majority (86%) had type 2 DM. Of the total sample, 39% (95% CI: 35.1-43.7%) had PN and 12% (95% CI: 8.8–14.4%) had PVD. There were no cases of amputation and only one case had previous history of lower extremity ulceration. Significant risk factors for PN and PVD were: male gender, poor level of education, UAE nationality, increased duration of diabetes, type 2 DM, presence of hypertension and microalbuminuria (MA).

Conclusion

Despite the low prevalence of foot ulceration and amputation among the study population, nevertheless, a substantial proportion had potential risk factors for foot complications.

Peripheral Arterial Disease: A Guide for Nephrologists

Cardiovascular disease is a major source of morbidity and mortality for patients with chronic kidney disease (CKD). Peripheral arterial disease (PAD) is a strong predictor of coronary artery disease and a risk factor for mortality in the general population. This is of particular interest to nephrologists because the risk for PAD is increased in CKD. Often, PAD is overlooked as a source of morbidity and as a cardiovascular risk factor in this population. This review serves as an overview of the epidemiology, screening, diagnosis, and treatment of PAD with an emphasis on CKD.

Normality of upper and lower peripheral pulse transit time of normotensive and hypertensive children

OBJECTIVES

The ankle-brachial index (ABI) is known to be indicative of sub-clinical peripheral arterial diseases that are correlated with cardiovascular disease risk factors like atherosclerosis or ischemic extremity. Due to its occluding measurement nature, this may not be appealing to less cooperative patients when multiple prolonged screening is required. A simple and non-intrusive approach termed pulse transit time ratio (PTTR) has recently shown to be potential surrogate marker for the prolonged ABI measurement. Other studies have also suggested that subjects with hypertension have stiffer arterial wall and thereby can confound transit time related parameters. Thus, it becomes important to understand the PTTR normality and difference of hypertensive children when compared to those measured from normotensive children.

METHODS

About 55 normotensive (39 male; aged 8.4 +/- 2.3 yr) and 4 hypertensive (4 male; aged 5-10 yr) Caucasian children were recruited from the same geographical location. A customized device was used to compute pulse transit time related measurements. Since the PTTR approach produced a delta value that was similar to that of ABI, possible inter-subject physiologic differences had limited confounding effects on the derived PTTR parameter.

RESULTS

The obtained transit time measurements from the hypertensive children had lower pulse transit time value when compared to their normotensive counterparts. However, the statistical analysis indicated that they had insignificant PTTR difference (p > 0.01) from those seen in the normotensive children.

CONCLUSIONS

The findings herein suggest that stiffer arterial wall may have confounding effects on the derived transit time related measurements but it is limited on the PTTR parameter. Similar to the ABI approach, PTTR may be only confounded by abnormal local changes in either of the measured peripheral arterial wall. Hence, the PTTR technique shows promise to be an ABI marker from this perspective.