Ankle-brachial index predicts change over time in functional status in the San Diego Population Study

A machine learning algorithm for peripheral artery disease prognosis using biomarker data

Peripheral artery disease (PAD) biomarkers have been studied in isolation; however, an algorithm that considers a protein panel to inform PAD prognosis may improve predictive accuracy. Biomarker-based prediction models were developed and evaluated using a model development (n = 270) and prospective validation cohort (n = 277). Plasma concentrations of 37 proteins were measured at baseline and the patients were followed for 2 years. The primary outcome was 2-year major adverse limb event (MALE; composite of vascular intervention or major amputation). Of the 37 proteins tested, 6 were differentially expressed in patients with vs. without PAD (ADAMTS13, ICAM-1, ANGPTL3, Alpha 1-microglobulin, GDF15, and endostatin). Using 10-fold cross-validation, we developed a random forest machine learning model that accurately predicts 2-year MALE in a prospective validation cohort of PAD patients using a 6-protein panel (AUROC 0.84). This algorithm can support PAD risk stratification, informing clinical decisions on further vascular evaluation and management.

Angiogenesis-related proteins as biomarkers for peripheral artery disease

Background

Angiogenesis plays an important role in peripheral artery disease (PAD) and angiogenesis-related proteins may act as prognostic biomarkers. This study assesses the potential for angiogenesis-related proteins to predict adverse events associated with PAD.

Methods

This was a case-control study. Patients with PAD (n = 250) and without PAD (n = 125) provided blood samples and were followed prospectively for three years. Concentrations of 17 angiogenesis-related proteins were measured in plasma. The incidence of major adverse limb event (MALE), defined as a composite of major amputation or vascular intervention, was the primary outcome. Worsening PAD status, defined as a drop in ankle brachial index ≥ 0.15, was the secondary outcome. Multivariable regression adjusted for baseline characteristics was conducted to determine the prognostication value of angiogenesis-related proteins in predicting MALE.

Findings

Relative to patients without PAD, 8 proteins related to angiogenesis were expressed differentially in PAD patients. Worsening PAD status and MALE were observed in 52 (14%) and 83 (22%) patients, respectively. Hepatocyte growth factor (HGF) was the most reliable predictor of MALE (adjusted HR 0.79, 95% CI 0.15-0.86). Compared to individuals with high HGF, patients with low HGF had a decreased three-year freedom from MALE [66% vs 88%, p = 0.001], major amputation [93% vs 98%, p = 0.023], vascular intervention [68% vs 88%, p = 0.001], and worsening PAD status [81% vs 91%, p = 0.006].

Interpretation

Measuring plasma levels of HGF in individuals with PAD can assist in identifying patients at elevated risk of adverse events related to PAD who may benefit from additional evaluation or treatment.

Fatty acid binding protein 4 has prognostic value in peripheral artery disease

OBJECTIVE

Peripheral artery disease (PAD) remains undertreated, despite its association with major amputation and mortality. This is partly due to a lack of available disease biomarkers. The intracellular protein fatty acid binding protein 4 (FABP4) is implicated in diabetes, obesity, and metabolic syndrome. Given that these risk factors are strong contributors to vascular disease, we assessed the prognostic ability of FABP4 in predicting PAD-related adverse limb events.

METHODS

This was a prospective case-control study with 3 years of follow-up. Baseline serum FABP4 concentrations were measured in patients with PAD (n = 569) and without PAD (n = 279). The primary outcome was major adverse limb event (MALE; defined as a composite of vascular intervention or major amputation). The secondary outcome was worsening PAD status (drop in ankle-brachial index ≥0.15). Kaplan-Meier and Cox proportional hazards analyses adjusted for baseline characteristics were conducted to assess the ability of FABP4 to predict MALE and worsening PAD status.

RESULTS

Patients with PAD were older and more likely to have cardiovascular risk factors compared with those without PAD. Over the study period, MALE and worsening PAD status occurred in 162 (19%) and 92 (11%) patients, respectively. Higher FABP4 levels were significantly associated with 3-year MALE (unadjusted hazard ratio [HR], 1.19; 95% confidence interval [CI], 1.04-1.27; adjusted HR, 1.18; 95% CI, 1.03-1.27; P = .022) and worsening PAD status (unadjusted HR, 1.18; 95% CI, 1.13-1.31; adjusted HR, 1.17; 95% CI, 1.12-1.28; P < .001). Three-year Kaplan-Meier survival analysis demonstrated that patients with high FABP4 levels had a decreased freedom from MALE (75% vs 88%; log rank = 22.6; P < .001), vascular intervention (77% vs 89%; log rank = 20.8; P < .001), and worsening PAD status (87% vs 91%; log rank = 6.16; P = .013).

CONCLUSIONS

Individuals with higher serum concentrations of FABP4 are more likely to develop PAD-related adverse limb events. FABP4 has prognostic value in risk-stratifying patients for further vascular evaluation and management.

The prognostic capability of inflammatory proteins in predicting peripheral artery disease related adverse events

Background

Levels of inflammatory proteins and their prognostic potential have been inadequately studied in patients with peripheral artery disease (PAD). In this study, we quantified and assessed the ability of inflammatory proteins in predicting PAD-related adverse events.

Methods

In this prospective case-control study, blood samples were collected from patients without PAD (n = 202) and patients with PAD (n = 275). The PAD cohort was stratified by disease severity based on ankle brachial index (ABI): mild (n = 49), moderate (n = 164), and severe (n = 62). Patients were followed for 2 years. Plasma concentrations of 5 inflammatory proteins were measured: Alpha-2-Macroglobulin (A2M), Fetuin A, Alpha-1-Acid Glycoprotein (AGP), Serum Amyloid P component (SAP), and Adipsin. The primary outcome of our study was major adverse limb event (MALE), defined as the need for vascular intervention (open or endovascular revascularization) or major amputation. The secondary outcome was worsening PAD status, defined as a drop in ABI greater than or equal to 0.15 over the study period. Multivariable logistic regression was performed to assess the prognostic value of inflammatory proteins in predicting MALE, adjusting for confounding variables.

Results

Compared to patients without PAD, three inflammatory proteins were differentially expressed in patients with PAD (AGP, Fetuin A, and SAP). The primary outcome (MALE) and secondary outcome (worsening PAD) status were noted in 69 (25%) and 60 (22%) patients, respectively. PAD-related adverse events occurred more frequently in severe PAD patients. Based on our data, the inflammatory protein AGP was the most reliable predictor of primary and secondary outcomes. On multivariable analysis, there was a significant association between AGP and MALE in all PAD disease states [mild: adjusted HR 1.13 (95% CI 1.05-1.47), moderate: adjusted HR 1.23 (95% CI 1.16-1.73), severe: adjusted HR 1.37 (95% CI 1.25-1.85)]. High levels of AGP were associated with lower 2-year MALE-free survival in all PAD disease states [mild (64% vs. 100%, p = 0.02), moderate (64% vs. 85%, p = 0.02), severe (55% vs. 88%, p = 0.02), all PAD (62% vs. 88%, p = 0.01)].

Conclusion

Levels of inflammatory protein AGP may help in risk stratifying PAD patients at high risk of MALE and worsening PAD status and subsequently facilitate further vascular evaluation and initiation of aggressive medical/surgical management.

Urinary Cystatin C Has Prognostic Value in Peripheral Artery Disease

Despite its association with adverse outcomes, peripheral artery disease (PAD) remains undertreated. Cystatin C is elevated in patients with renal disease and may be a marker of cardiovascular disease. We examined the prognostic ability of urinary Cystatin C (uCystatinC) in predicting adverse PAD-related events. In this prospective case-control study, urine samples were collected from patients with PAD (n = 121) and without PAD (n = 77). The cohort was followed for 2 years. uCystatinC was normalized to urinary creatinine (uCr) (uCystatinC/uCr; μg/g). The primary outcome was major adverse limb event (MALE; composite of vascular intervention (open or endovascular) or major limb amputation). The secondary outcome was worsening PAD status (drop in ABI ≥ 0.15). Multivariable Cox regression and Kaplan–Meier analyses were performed to assess the prognostic value of uCystatinC/uCr with regards to predicting MALE and worsening PAD status. Our analysis demonstrated that patients with PAD had significantly higher median [IQR] uCystatinC/uCr levels (24.9 μg/g [14.2–32.9] vs. 20.9 μg/g [11.1–27.8], p = 0.018). Worsening PAD status and MALE were observed in 39 (20%) and 34 (17%) patients, respectively. uCystatinC/uCr predicted worsening PAD status with a hazard ratio (HR) of 1.78 (95% CI 1.12–2.83, p = 0.015), which persisted after controlling for baseline demographic and clinical characteristics (adjusted HR 1.79 [95% CI 1.11–2.87], p = 0.017). Patients with high uCystatinC/uCr had a lower 2-year freedom from MALE (77% vs. 89%, p = 0.025) and worsening PAD status (63% vs. 87%, p = 0.001). Based on these data, higher uCystatinC/uCr levels are associated with adverse PAD-related events and have prognostic value in risk-stratifying individuals for further diagnostic vascular evaluation or aggressive medical management.

Urinary Fatty Acid Binding Protein 3 Has Prognostic Value in Peripheral Artery Disease

Background

Despite its significant association with limb loss and death, peripheral artery disease (PAD) remains underdiagnosed and undertreated. The current accepted gold-standard for PAD screening, the ankle brachial index (ABI), is limited by operator dependence, erroneous interpretation, and unreliability in patients with diabetes. Fatty acid binding protein 3 (FABP3) is an intracellular protein that becomes released into circulation and excreted into urine following skeletal muscle injury. We examined the prognostic ability of urinary FABP3 (uFABP3) in predicting adverse PAD-related events.

Methods

In this prospective case-control study, urine samples were collected from patients with PAD (n = 142) and without PAD (n = 72). The cohort was followed for 2 years. uFABP3 was normalized to urinary creatinine (uCr) (uFABP3/uCr). The primary outcome was major adverse limb event (MALE; composite of vascular intervention [open or endovascular] or major limb amputation). The secondary outcome was worsening PAD status (drop in ABI≥0.15). Cox regression analyses with multivariable adjustment for baseline demographic and clinical variables were performed to assess the prognostic value of uFABP3/uCr with regards to predicting MALE and worsening PAD status.

Results

Patients with PAD had significantly higher median [IQR] uFABP3/uCr levels (3.46 [2.45–6.90] vs. 2.61 [1.98–4.62], p = 0.001). MALE and worsening PAD status were observed in 21 (10%) and 28 (14%) patients, respectively. uFABP3/uCr predicted MALE and worsening PAD status with adjusted hazard ratios (HR) of 1.28 (1.16–1.41, p = 0.001) and 1.16 (1.02–1.27, p = 0.021), respectively. Patients with high uFABP3/uCr had a lower 2-year freedom from MALE (86 vs. 96%, p = 0.047) and worsening PAD status (78 vs. 99%, p = 0.001). There was good discriminatory ability for uFABP3/uCr in predicting the primary outcome of MALE, with an area under the receiver operating characteristics curve (AUROC) of 0.78.

Conclusions

Measuring uFABP3/uCr levels in patients with PAD can help identify those at high risk of adverse PAD-related events. This study highlights the prognostic value of uFABP3 in risk-stratifying individuals for further diagnostic vascular evaluation or aggressive medical management.

Urinary neutrophil gelatinase-associated lipocalin (NGAL) can potentially predict vascular complications and reliably risk stratify patients with peripheral arterial disease

Neutrophil gelatinase-associated lipocalin (NGAL) is expressed in atherosclerotic plaques and implicated in the development of cardiovascular diseases. Peripheral arterial disease (PAD) is an atherosclerotic disease that often results in major cardiovascular events. This study aimed to prospectively examine the potential of urine NGAL (uNGAL) in predicting worsening PAD status and major adverse limb events (MALE). Baseline urine NGAL (uNGAL) and urine creatinine (uCr) concentrations were measured in PAD (n = 121) and non-PAD (n = 77) patients. Levels of uNGAL were normalized for urine creatinine (uNGAL/uCr). Outcomes included worsening PAD status, which was defined as a drop in ankle brachial index (ABI) > 0.15, and major adverse limb events (MALE), which was defined as a need for surgical revascularization or amputations. PAD patients had 2.30-fold higher levels of uNGAL/uCr [median (IQR) 31.8 (17.0–62.5) μg/g] in comparison to non-PAD patients [median (IQR) 73.3 (37.5–154.7) μg/g] (P = 0.011). Multivariate cox analysis showed that uNGAL/uCr levels were independently associated with predicting worsening PAD status and MALE outcomes. Cumulative survival analysis, over follow up period, demonstrated a direct correlation between elevated uNGAL/uCr levels and PAD disease progression and MALE outcomes. These data demonstrate an association between elevated uNGAL/uCr levels and worsening PAD disease status and MALE outcomes, indicating its potential for risk-stratification of PAD patients.

Pilot screening program for lower extremities atherosclerotic disease in a population of central Greece

BACKGROUND

Screening program in lower extremity atherosclerotic disease (LEAD) has not been widely implemented from health systems. The aim of this study was to assess the incidence of LEAD in Greece though a pilot LEAD screening program.

METHODS

Males >60 years old without known diagnosis of LEAD or chronic renal disease were invited through public primary health care institutions to participate in a pilot screening program in Central Greece. Demographics, atherosclerotic risk factors and other comorbidities were recorded. LEAD was defined as ankle-brachial pressure index (ABPI) of <0.9 or >1.4.

RESULTS

Among a total of 1152 individuals (invitation acceptance 70%; 1152/1638) LEAD was detected in 13% (148); including 7% with ABPI<0.9 and 6% with ABPI>1.4. Comparing the groups with ABPI<0.9 vs. normal ABPI, abnormal ABPI was associated with older age (P=0.001), hypertension (HT) (P=0.037), smoking (P=0.002), duration of smoking (P=0.01), packs/year (P=0.002), coronary artery disease (P=0.02), chronic obstructive pulmonary disease (P=0.028) and cerebrovascular disease (P=0.001). After multivariate analysis, increased age (0.94, CI: 0.026-5.2; P=0.022), history of HT (2.4, CI: 0.44- 3.7; P=0.05) and longer duration of smoking (0.9, CI: 0.01-6.1; 0.013) were associated with ABPI <0.9. Abnormally higher ABPI (>1.4) was not associated with any factor. Among those without known CAD or CVD (96/148), 37.5% (36/96) were on statins and 21% (20/96) on antiplatelets.

CONCLUSIONS

Incidence of LEAD was 13% in a male >60 years-old population of central Greece; these individuals maybe undertreated. ABPI<0.9 was diagnosed in 7% and was associated with older age, HT and duration of smoking.

Effects of physical activity and smoking on cardio-ankle vascular index, respiratory muscle strength, and exercise performance in early normal weight adulthood: a cross-sectional study

Few studies have shown the impact of unhealthy habits on arterial stiffness, respiratory muscle strength and exercise performance in early normal weight adulthood. This study sought to determine the effects of physical activity and smoking on its parameters in normal weight male participants. Forty-eight participants were divided into four groups: physically inactive nonsmokers and smokers and physically active nonsmokers and smokers (n=12 in each group). All of the participants were measured for body composition, arterial stiffness, respiratory muscle strength and exercise performance. Two-way analysis of variance design was used to test the main and interaction effects of physical activity by group (smokers vs. nonsmokers). P-value of less than 0.05 was considered as a statistically significant difference. As a result, cardio-ankle vascular index and respiratory muscle strength were diminished in smokers and physically inactive participants, while body and visceral fat mass were increased in both those groups. Fat-free mass was lower in only physically inactive participants. This study also found the interaction effects on body fat and arterial stiffness. In conclusion, participants with healthy normal weight, but smoked and performed inappropriate physical activity, exhibited body composition imbalance, decreased respiratory muscle strength, exercise performance, and increased arterial stiffness. Therefore, smoking cessation and exercise in younger adults are appropriate ways of improving body composition, respiratory muscle strength, aerobic capacity and arterial stiffness instead of trying to control their weight by smoking.

Subclinical Cardiovascular Disease and Changes in Self-Reported Mobility: Multi-Ethnic Study of Atherosclerosis

Background

We examined associations of three markers of subclinical cardiovascular disease (intimal-medial thickening, coronary artery calcification , and ankle-brachial index) with changes in self-reported walking over time.

Methods

Data were from 6,490 Multi-Ethnic Study of Atherosclerosis participants (aged 45-84 years), free of clinical cardiovascular disease at baseline. Outcomes, assessed four times over 11 years, included self-reported walking pace (none to striding pace; score, 0-4) and total walking time (minutes/week). Linear generalized estimating equation models estimated associations of baseline intimal-medial thickening (z-scored), coronary artery calcification (Agatston units), and ankle-brachial index (ratio of ankle-to-arm systolic blood pressure) with walking pace and walking time modeled continuously in separate analyses.

Results

Median follow-up was 9.2 years (maximum, 11.4). Walking pace (estimate, -0.042 points [95% CI; -0.048, -0.036], p < 0.0001) and walking time (estimate, -4.71 minutes [95% CI: -8.54, -0.88], p = 0.016) decreased yearly. Greater baseline intimal-medial thickening related to faster decline in walking pace in multivariable analyses: walking pace score decreased 0.004 points (95% CI: -0.008, -0.001) more per year for each 1-SD higher intimal-medial thickening z-score, equivalent to an additional 10% slower yearly walking. Greater coronary artery calcification was associated with slower walking but inconsistently related to decline in walking pace. Higher ankle-brachial index was associated with faster baseline walking pace (estimate, 0.043 points [95% CI: 0.027, 0.059] per 1-SD) but unrelated to changes in walking pace. Cardiovascular disease measures were unrelated to total walking time.

Conclusions

Greater subclinical cardiovascular disease is associated with prevalent slower self-reported walking pace in middle-aged and older adults but has limited impact on changes in walking over time.

Screening for Peripheral Artery Disease Using the Ankle-Brachial Index: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Peripheral artery disease (PAD) is associated with a high risk for cardiovascular events and poor ambulatory function, even in the absence of symptoms. Screening for PAD with the ankle-brachial index (ABI) may identify patients in need of treatment to improve health outcomes.

OBJECTIVE

To systematically review evidence for the US Preventive Services Task Force on PAD screening with the ABI, the diagnostic accuracy of the test, and the benefits and harms of treatment of screen-detected PAD.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant English-language studies published between January 2012 and May 2, 2017. Surveillance continued through February 7, 2018.

STUDY SELECTION

Studies of unselected or generally asymptomatic adults with no known cardiovascular disease.

DATA EXTRACTION AND SYNTHESIS

Independent critical appraisal and data abstraction by 2 reviewers.

MAIN OUTCOMES AND MEASURES

Cardiovascular morbidity; PAD morbidity; mortality; health-related quality of life; diagnostic accuracy; and serious adverse events.

RESULTS

Five studies (N = 5864 participants) were included that examined the indirect evidence for the benefits and harms of screening and treatment of screen-detected PAD. No population-based screening trials evaluated the direct benefits or harms of PAD screening with the ABI alone. A single diagnostic accuracy study of the ABI compared with magnetic resonance angiography gold-standard imaging (n = 306) found low sensitivity (7%-34%) and high specificity (96%-100%) in a screening population. Two adequately powered trials (n = 4626) in asymptomatic populations with and without diabetes with a variably defined low ABI (≤0.95 or ≤0.99) showed no statistically significant effect of aspirin (100 mg daily) for composite CVD outcomes (adjusted hazard ratio [HR], 1.00 [95% CI, 0.81-1.23] and HR, 0.98 [95% CI, 0.76-1.26]). One trial (n = 3350) demonstrated no statistically significant increase in major bleeding events with the use of aspirin (adjusted HR, 1.71 [95% CI, 0.99- 2.97]) and no statistically significant increase in major gastrointestinal bleeding (relative risk, 1.13 [95% CI, 0.44-2.91]). Two exercise trials (n = 932) in screen-relevant populations reported no differences in quality of life, Walking Impairment Questionnaire walking distance, or symptoms at 12 and 52 weeks; no harms were reported.

CONCLUSIONS AND RELEVANCE

There was no direct evidence and limited indirect evidence on the benefits of PAD screening with the ABI in unselected or asymptomatic populations. Available studies suggest low sensitivity and lack of beneficial effect on health outcomes, but these studies have important limitations.

Fatigability and functional performance among older adults with low-normal ankle-brachial index: Cross-sectional findings from the Baltimore Longitudinal Study of Aging

BACKGROUND AND AIMS

Peripheral artery disease (PAD) is associated with poor mobility and fatigue, but the relationship between preclinical ankle-brachial index (ABI) and early markers of fatigue and functional decline has not been defined.

METHODS

570 adults, 50 and older, from the Baltimore Longitudinal Study of Aging (N = 570), with normal values of ABI (1-1.39), were classified into ABI tertiles. Perceived fatigability was assessed after a 5-min, treadmill walk (1.5 mph) using the Borg rating of perceived exertion (RPE, range 6-20). Functional evaluation included the Health, Aging and Body Composition Physical Performance Battery (HABC PPB), time to complete a 400-m corridor walk (LDCW), and VO₂ peak (ml/kg/min). High RPE and poor walking endurance (PWE) were defined as RPE≥10 and taking >5 min for the LDCW, respectively. Differences between tertiles in fatigability and functional measures were tested adjusting for demographics, behavioral characteristics, self-reported fatigue, and medical history.

RESULTS

Mean LDCW time and RPE were greater for participants in the lowest tertile compared to those in the highest; mean VO₂ peak and HABC PPB scores were lower, suggesting hierarchical associations between fatigability, functional performance, and ABI (p < 0.05 for all). Odds of PWE were greater for those in the lowest ABI tertile compared to the highest; odds of reporting high RPE were greater for those in the middle tertile.

CONCLUSIONS

Lower ABI is associated with poorer physical function and increased fatigability, suggesting that early changes in ABI may infer greater risk of functional decline, even among those who may not progress to PAD.

Femoral Artery Atherosclerosis Is Associated With Physical Function Across the Spectrum of the Ankle-Brachial Index: The San Diego Population Study

Background

The ankle‐brachial index (ABI) is inadequate to detect early‐stage atherosclerotic disease, when interventions to prevent functional decline may be the most effective. We determined associations of femoral artery atherosclerosis with physical functioning, across the spectrum of the ABI, and within the normal ABI range.

Methods and Results

In 2007–2011, 1103 multiethnic men and women participated in the San Diego Population Study, and completed all components of the summary performance score. Using Doppler ultrasound, superficial and common femoral intima media thickness and plaques were ascertained. Logistic regression was used to assess associations of femoral atherosclerosis with the summary performance score and its individual components. Models were adjusted for demographics, lifestyle factors, comorbidities, lipids, and kidney function. In adjusted models, among participants with a normal‐range ABI (1.00–1.30), the highest tertile of superficial intima media thickness was associated with lower odds of a perfect summary performance score of 12 (odds ratio=0.56 [0.36, 0.87], P=0.009), and lower odds of a 4‐m walk score of 4 (0.34 [0.16, 0.73], P=0.006) and chair rise score of 4 (0.56 [0.34, 0.94], P=0.03). Plaque presence (0.53 [0.29, 0.99], P=0.04) and greater total plaque burden (0.61 [0.43, 0.87], P=0.006) were associated with worse 4‐m walk performance in the normal‐range ABI group. Higher superficial intima media thickness was associated with lower summary performance score in all individuals (P=0.02).

Conclusions

Findings suggest that use of femoral artery atherosclerosis measures may be effective in individuals with a normal‐range ABI, especially, for example, those with diabetes mellitus or a family history of peripheral artery disease, when detection can lead to earlier intervention to prevent functional declines and improve quality of life.

Ankle-brachial index and incident diabetes mellitus: the atherosclerosis risk in communities (ARIC) study

Background

Individuals with peripheral artery disease (PAD) often have reduced physical activity, which may increase the future risk of diabetes mellitus. Although diabetes is a risk factor for PAD, whether low ankle-brachial index (ABI) predates diabetes has not been studied.

Methods

We examined the association of ABI with incident diabetes using Cox proportional hazards models in the ARIC Study. ABI was measured in 12,247 black and white participants without prevalent diabetes at baseline (1987–1989). Incident diabetes cases were identified by blood glucose levels at three subsequent visits (1990–92, 1993–95, and 1996–98) or self-reported physician diagnosis or medication use at those visits or during annual phone interview afterward through 2011.

Results

A total of 3305 participants developed diabetes during a median of 21 years of follow-up. Participants with low (≤0.90) and borderline low (0.91–1.00) ABI had 30–40% higher risk of future diabetes as compared to those with ABI of 1.10–1.20 in the demographically adjusted model. The associations were attenuated after further adjustment for other potential confounders but remained significant for ABI 0.91–1.00 (HR = 1.17, 95% CI 1.04–1.31) and marginally significant for ABI ≤ 0.90 (HR = 1.19, 0.99–1.43). Although the association was largely consistent across subgroups, a stronger association was seen in participants without hypertension, those with normal fasting glucose, and those with a history of stroke compared to their counterparts.

Conclusions

Low ABI was modestly but independently associated with increased risk of incident diabetes in the general population. Clinical attention should be paid to the glucose trajectory among people with low ABI but without diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0476-4) contains supplementary material, which is available to authorized users.