Pulse Pressure as a Risk Factor for Peripheral Vascular Disease in Type 2 Diabetic Patients

Incidence of Peripheral Arterial Disease and Its Association with Pulse Pressure: A Prospective Cohort Study

BACKGROUND

The association of pulse pressure and peripheral arterial disease (PAD) has seldom been examined using a prospective design. This study aimed to investigate the association of pulse pressure with PAD incidence in an elderly general population.

METHODS

We utilized data from a cohort conducted in Beijing with additionally 2-year follow-up time. PAD was defined as an ankle brachial index value <0.9 in either leg. Cox proportional hazard regression model was used to quantify the magnitude of pulse pressure on PAD incidence.

RESULTS

During a 2-year follow-up time, 357 of 4,201 (8.5%) participants developed PAD with 105 (6.9%) men and 252 (9.4%) women, respectively. After adjusting for baseline age, sex, body mass index, hypertension, diabetes, total cholesterol, and high-density lipoprotein cholesterol, and smoking, the hazard ratio and 95% confidence interval for people with pulse pressure greater than 60 mmHg was 2.20 (1.53, 3.15) compared with those whose pulse pressure was less than 40 mmHg. A linear trend was observed for the association of pulse pressure with PAD.

CONCLUSION

Higher pulse pressure was associated with higher PAD incidence.

Peripheral Arterial Disease and Its Association With Arsenic Exposure and Metabolism in the Strong Heart Study

At high levels, inorganic arsenic exposure is linked to peripheral arterial disease (PAD) and cardiovascular disease. To our knowledge, no prior study has evaluated the association between low-to-moderate arsenic exposure and incident PAD by ankle brachial index (ABI). We evaluated this relationship in the Strong Heart Study, a large population-based cohort study of American Indian communities. A total of 2,977 and 2,966 PAD-free participants who were aged 45-74 years in 1989-1991 were reexamined in 1993-1995 and 1997-1999, respectively, for incident PAD defined as either ABI <0.9 or ABI >1.4. A total of 286 and 206 incident PAD cases were identified for ABI <0.9 and ABI >1.4, respectively. The sum of inorganic and methylated urinary arsenic species (∑As) at baseline was used as a biomarker of long-term exposure. Comparing the highest tertile of ∑As with the lowest, the adjusted hazard ratios were 0.57 (95% confidence interval (CI): 0.32, 1.01) for ABI <0.9 and 2.24 (95% CI: 1.01, 4.32) for ABI >1.4. Increased arsenic methylation (as percent dimethylarsinate) was associated with a 2-fold increased risk of ABI >1.4 (hazard ratio = 2.04, 95% CI: 1.02, 3.41). Long-term low-to-moderate ∑As and increased arsenic methylation were associated with ABI >1.4 but not with ABI <0.9. Further studies are needed to clarify whether diabetes and enhanced arsenic metabolism increase susceptibility to the vasculotoxic effects of arsenic exposure.

The Relationship Between High Pulse Pressure and Low Ankle-Brachial Index. Potential Utility in Screening for Peripheral Artery Disease in Population-Based Studies

INTRODUCTION

The ankle-brachial index (ABI) is a reliable screening procedure for peripheral artery disease detection. However, ABI testing is time-consuming and requires trained personnel, which may preclude its routine use in population-based surveys. Preliminary data suggest a relationship between ABI values and pulse pressure (PP) levels.

AIM

To assess whether PP calculation might help to detect persons who need ABI screening in population-based studies.

METHODS

All Atahualpa residents aged ≥60 years were identified during a door-to-door survey and invited to undergo ABI testing. Non-consented persons and those with ABI ≥1.4 were excluded. Using generalized linear and logistic regression models adjusted for demographics and cardiovascular risk factors, as well as receiver operator characteristics curve analysis, we evaluated the association between PP values and ABI, as well as the reliability of PP to identify candidates for ABI testing.

RESULTS

Out of 239 participants (mean age 70 ± 8 years, 62 % women), 46 (19 %) had an ABI ≤0.9 and 136 (57 %) had PP >65 mmHg, with a negative relationship between them (R = -0.386, p < 0.0001). A PP >65 mmHg was associated with an ABI ≤ 0.9 in the logistic regression model (OR 3.46, 95 % CI 1.07-11.2, p = 0.038). Continuous PP levels also correlated negatively with ABI (β -0.0014, 95 % CI -0.0024 to -0.0004, p = 0.005). The sensitivity of a PP >65 mmHg to predict a low ABI was 85 %, and the specificity was 50 %. In contrast, the sensitivity of blood pressure ≥140/90 mmHg was 27 % and the specificity was 10 %. The area under the curve for the predictive value of a PP >65 mmHg was 0.673 (95 % CI 0.609-0.736), and that of a blood pressure ≥140/90 mmHg was 0.371 (95 % CI 0.30-0.443), with a significant difference between them (p < 0.0001).

CONCLUSIONS

PP calculation may be a simple tool to detect candidates for ABI testing in population-based studies.

Prevalence of low ankle brachial index and its association with pulse pressure in an elderly Chinese population: a cross-sectional study

Background

We investigated the prevalence of low ankle brachial index (ABI) and the association of low ABI with pulse pressure among elderly community residents in China.

Methods

This population-based cross-sectional study was conducted in Beijing and recruited 2982 participants who were aged 60 years or older in 2007. Low ABI was defined as an ABI value less than 0.9 in either leg. Participants with or without stroke or coronary heart disease (CHD) were analyzed separately. The association between pulse pressure and low ABI was examined by using multiple logistic regression models.

Results

The prevalence of low ABI was 5.65% (4.24% among men and 6.52% among women; P = 0.0221) among participants without stroke or CHD and 10.91% (13.07% among men and 9.49% among women; P = 0.1328) among those with stroke or CHD. After adjusting for confounders, the odds ratio (95% CI) for each 5-mm Hg increase in pulse pressure was 1.19 (1.07, 1.33) and 1.10 (1.02, 1.20) for men and women, respectively, among participants without stroke or CHD and 1.17 (1.03, 1.34) and 1.15 (1.02, 1.30) for men and women with stroke or CHD. When pulse pressure was classified into quartiles and the lowest quartile was used as reference, the association between pulse pressure and low ABI remained positive in men and women.

Conclusions

Low ABI was prevalent among elderly Chinese, and pulse pressure was positively associated with low ABI.

Risk factors related to low ankle-brachial index measured by traditional and modified definition in hypertensive elderly patients

Peripheral arterial disease (PAD) increases with age and ankle-brachial index (ABI) ≤ 0.9 is a noninvasive marker of PAD. The purpose of this study was to identify risk factors related to a low ABI in the elderly using two different methods of ABI calculation (traditional and modified definition using lower instead of higher ankle pressure). A cross-sectional study was carried out with 65 hypertensive patients aged 65 years or older. PAD was present in 18% of individuals by current ABI definition and in 32% by modified method. Diabetes, cardiovascular diseases, metabolic syndrome, higher levels of systolic blood pressure and pulse pressure, elevated risk by Framingham Risk Score (FRS), and a higher number of total and antihypertensive drugs in use were associated with low ABI by both definitions. Smoking and LDL-cholesterol were associated with low ABI only by the modified definition. Low ABI by the modified definition detected 9 new cases of PAD but cardiovascular risk had not been considered high in 3 patients when calculated by FRS. In conclusion, given that a simple modification of ABI calculation would be able to identify more patients at high risk, it should be considered for cardiovascular risk prediction in all elderly hypertensive outpatients.

Distribution of ankle—brachial index and the risk factors of peripheral artery disease in a multi-ethnic Asian population

Peripheral artery disease (PAD) is a manifestation of systemic atherosclerosis and is associated with increased cardiovascular morbidity and mortality. We describe the prevalence and risk factors of PAD in a multi-ethnic Asian population (Chinese, Malays and Indians) in Singapore. The Singapore Prospective Study Program recruited 4132 individuals between 2004 and 2006 in which the ankle—brachial index (ABI) was measured using the Smartdop™ 20EX bi-directional blood flow detector. PAD was defined as ≤ 0.9 and a high ABI > 1.4, with ABI 1.11—1.20 as reference. The mean age (SD) of individuals in the study was 49.9 (11.8) years, with 51.8% females. PAD was present in 4.3% of the population and a high ABI (> 1.4) was rare. Malays and Indians had a higher risk (especially in females). Compared to those with an ABI between 1.11 and 1.20, those with PAD were more likely to be of Malay and Indian ethnicity, female sex, with higher systolic blood pressure and pulse pressure, with increased prevalence of diabetes mellitus, hypertension, albuminuria and renal impairment, and with a past history of stroke. In conclusion, in this large multi-ethnic Asian population, we document the distribution and risk factor associations for PAD. PAD shows an ethnic distribution similar to that of coronary artery disease in Singapore, with differences in sex distribution. Apart from traditional vascular risk factors, pulse pressure, renal impairment and a past history of stroke are important determinants of PAD.

Relationships Between Vascular Indexes and Atherosclerotic Risk Factors in Patients With Type 2 Diabetes Mellitus

The relationships of cardio-ankle vascular index, (a new indicator of arterial stiffness), common carotid artery intima-media thickness, and ankle-brachial pressure index with atherosclerotic risk factors were compared in patients with type 2 diabetes. There were significant correlations between each pair of the above vascular indexes. Both cardio-ankle vascular index and intima-media thickness showed significant correlations with age, systolic blood pressure, pulse pressure, and serum total cholesterol. Ankle-brachial pressure index showed a significant negative correlation with pulse pressure but not with systolic blood pressure and total cholesterol. Logistic regression analysis showed that cardio-ankle vascular index and intima-media thickness were associated with systolic blood pressure and pulse pressure independently of age. These results suggest that there are significant associations among the 3 vascular indexes and that systolic blood pressure and pulse pressure are major, age-independent determinants of cardio-ankle vascular index and common carotid artery intima-media thickness in patients with diabetes.

Non-traditional cardiovascular risk factors contribute to peripheral arterial disease in patients with type 2 diabetes

OBJECTIVE

This study evaluated the prevalence of peripheral arterial disease (PAD) in type 2 diabetes and its association with traditional and non-traditional cardiovascular (CV) risk factors.

SUBJECTS AND METHODS

In 1610 type 2 diabetics PAD was defined as ankle-brachial pressure index (ABPI)<0.9.

RESULTS

PAD prevalence was 17%, increased with age, diabetes duration, HbA 1c levels, previous CV events. There were no significant differences in the prevalence of traditional CV risk factors between patients with and without PAD. PAD patients had higher levels of fibrinogen (10.88+/-2.32 versus 10.2+/-2.23micromol/L; p<0.0001), uric acid (327.1+/-89.2 versus 315.2+/-83.3micromol/L, p<0.01), pulse pressure (70+/-18 versus 60+/-16mm Hg, p<0.0001), higher rate of microalbuminuria (21.3% versus 13.7%; p<0.05) and lower glomerular filtration rate (GFR, 80.7+/-24 versus 89.9+/-22 ml/min/1.73 m2; p<0.001) than those without. In age-gender-adjusted analysis, smoking (OR 1.5; CI: 1.07-2.2), HbA 1c (OR 1.45; CI: 1.07-2.08), high pulse pressure (OR 2.81; CI: 1.63-4.82), reduced GFR (OR 2.16; CI: 1.4-3.3), microalbuminuria (OR 1.62; CI: 1.11-2.36), high fibrinogen levels (OR 2.03; CI: 1.34-3.07) were associated with PAD. In multivariate analysis age, male sex, smoking, high pulse pressure, low GFR, high fibrinogen levels, previous CV events were independent risk factors for PAD.

CONCLUSIONS

PAD prevalence is high in Type 2 diabetic patients. Non-traditional cardiovascular risk factors may be involved in the development of this complication.

Can we improve cardiovascular risk prediction beyond risk equations in the physician's office?

BACKGROUND AND OBJECTIVES

Beyond a global estimation of the cardiovascular risk through the assessment of major risk factors and their integration in dedicated risk scales or equations, the use of specific markers provides additive prognostic information at an individual level, including predisposing factors, which are not included in the risk equations as well as the individual susceptibility to their long-term exposure. However, the majority of these markers require specific devices and skills, which are not widely available in primary care.

METHODS

Some clinical and/or "low-cost" parameters are shown to be valuable risk markers, and their use could refine the risk estimation in a physician's office. Several epidemiologic studies suggest the heart rate, the pulse pressure and the ankle-brachial index are effective cardiovascular risk markers. The arms systolic pressure asymmetry could also be a useful marker of risk.

RESULTS AND CONCLUSIONS

Through a general review, the authors evaluate the potential of these clinical markers, including their use in combination for more accurate risk determination.

Importance of arterial pulse pressure as a predictor of coronary heart disease risk in PROCAM

AIMS

To investigate pulse pressure (PP) as an independent predictor of coronary heart disease (CHD) risk.

METHODS AND RESULTS

On the basis of a 10-year follow-up of 5389 men aged 35-65 at recruitment into PROCAM, we used a proportional hazards model to calculate the effect of systolic blood pressure (SBP), diastolic blood pressure (DBP), and PP on CHD risk after correcting for age, high-density lipoprotein cholesterol, LDL cholesterol, triglycerides, smoking, diabetes, and family history of premature CHD. Increases of 10 mmHg in DBP, SBP, and PP were associated with an increased CHD hazard ratio (HR) of approximately 10%. When the group was divided into the age groups <50, 50-59, and >59 years, this relationship was seen in the age group 50-59 years for DBP, SBP, and PP and in men aged > or =60 for PP only (25% increase in HR). Overall, CHD risk in men with PP > or =70 mmHg was more three times that of men with PP <50 mmHg. This increased risk was not apparent at age <50 years, was greatest at age >60 years, and was also present in men who were normotensive at recruitment (SBP < or =160 mmHg, DBP < or =95 mmHg).

CONCLUSION

In older European men, increased PP is an important independent determinant of coronary risk, even among those initially considered normotensive.