***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Peripheral arterial disease ( PAD ) of the lower limbs is a cardiovascular disease highly prevalent particularly in the asymptomatic form . Its prevalence starts to be a concern in low coronary risk countries like Spain . Few studies have analyzed the relationship between ankle-brachial index ( ABI ) and cardiovascular morbi-mortality in low cardiovascular risk countries like Spain where we observe significant low incidence of ischemic heart diseases together with high prevalence of cardiovascular risk factors . The objective of this study is to determine the relationship between pathological ABI and incidence of cardiovascular events ( coronary disease , cerebrovascular disease , symptomatic aneurism of abdominal aorta , vascular surgery ) and death in the > 49 year population -based cohort in Spain ( ARTPER ) . Methods  Baseline ABI  was measured in 3,786 r and omly selected patients from 28 Primary Health Centers in Barcelona , distributed as : ABI<0.9 peripheral arterial disease ( PAD ) , ABI ≥1.4 arterial calcification ( AC ) , ABI 0.9 - 1.4 healthy ; and followed during 4 years . Results 3,307 subjects were included after excluding those with previous vascular events . Subjects with abnormal ABI were older with higher proportion of men , smokers and diabetics . 260 people presented cardiovascular events ( incidence 2,117/100,000 person-years ) and 124 died from any cause ( incidence 978/100,000 person-years ) . PAD had two-fold greater risk of coronary disease ( adjusted hazard ratio ( HR ) = 2.0 , 95 % confidence interval ( CI ) 1.3 - 3.2 ) and increased risk of vascular surgery ( HR = 5.6 , 95%CI 2.8 - 11.5 ) and mortality ( HR = 1.8 , 95%CI 1.4 - 2.5 ) . AC increased twice risk of cerebrovascular events ( HR = 1.9 , 95%CI 1.0 - 3.5 ) with no relationship with ischemic heart disease . Conclusions PAD increases coronary disease risk and AC cerebrovascular disease risk in low cardiovascular risk Mediterranean population . ABI could be a useful tool to detect patients at risk in Primary Health Care INTRODUCTION AND OBJECTIVES To estimate the prevalence of peripheral arterial disease as measured on ankle-brachial index and evaluate the associated risk , clinical , and diagnostic factors . METHODS Cross-sectional study conducted in a r and om population -based sample of 2833 individuals aged 25 to 79 years from Don Benito health area ( Badajoz ) . Peripheral arterial disease was considered for ankle-brachial index<0.90 . To identify symptomatic disease we used the Edinburgh question naire . The current screening recommendations , changes to other categories of estimated coronary risk associated with index measurements , and the association with risk factors were assessed . RESULTS The prevalence of peripheral arterial disease was 3.7 % ( 95 % confidence interval , 3.0%-4.5 % ) , 5.0 % ( 3.9%-6.3 % ) in men and 2.6 % ( 1.8%-3.5 % ) in women ( P=.001 ) . The cumulative prevalence in those aged 50 , 60 and 70 years were 6.2 % , 9.1 % , and 13.1 % respectively . The disease was symptomatic in 13.3 % ( 6.8%-19.8 % ) of cases and 29.6 % of asymptomatic patients were not detected as recommended for high-risk groups . The use of ankle-brachial index increased the number of individuals with high coronary risk by 32.7 % . Peripheral arterial disease was positively associated with age , smoking , hypercholesterolemia , sedentary lifestyle , microalbuminuria and history of cardiovascular disease , and negatively with alcohol consumption . CONCLUSIONS The use of ankle-brachial index for peripheral arterial disease diagnosis is advisable because of the low prevalence of symptomatic cases and the associated change in estimated coronary risk . Screening groups should be adapted to the Spanish population . Smoking and hypercholesterolemia are major associated risk factors OBJECTIVE A population -based point-prevalence study was conducted to determine the prevalence of peripheral arterial disease ( PAD ) in Sweden , with special attention to critical limb ischemia and sex differences . METHODS An age-st and ardized r and omly selected population sample of 8000 women and men , aged 60 to 90 years , from four different regions in Sweden was invited to participate . The sample had the same age and gender distribution as the Swedish population in this age group . Participating subjects completed question naires on medical history , present medication , and symptoms , and their ankle-brachial index ( ABI ) was measured . Subjects were analyzed for presence of PAD according to reported symptoms and an ABI<0.9 . RESULTS A total of 5080 subjects were included , giving a participation rate of 64 % . The prevalence of any PAD , asymptomatic PAD , intermittent claudication , and severe limb ischemia was , respectively , 18 % ( 95 % confidence interval [ CI ] , 16 % to 20 % ) 11 % ( 9 % to 13 % ) , 7 % ( 6.5 to 7 % ) and 1.2 % ( 1 % to 1.5 % ) . Women had a higher prevalence than men when PAD was diagnosed with ABI only ; that is , asymptomatic PAD ( 12.6 % vs 9.4 % , P=.03 ) and severe limb ischemia ( 1.5 % vs 0.8 % , P<.008 ) . The prevalence of any PAD was 7.9 % in the age group 60 to 65 years and increased to 47.2 % among the age group 85 to 90 years . Severe limb ischemia occurred in 0.3 % in the youngest age group , was highest in the age group 80 to 84 years at 3.3 % , and declined to 2.5 % among the oldest . The prevalence of PAD differed between regions ( P<.0001 ) . CONCLUSIONS PAD is common in Sweden , and almost a fifth of all elderly individuals have some stage of this disease . Women are more often afflicted than men . The prevalence of severe ischemia , as a measure of critical limb ischemia , is about 1 % the population BACKGROUND Type 2 diabetes is a major cardiovascular risk factor , and early-onset ( < 40 years ) type 2 diabetes is becoming more common . AIM To determine the prevalence of complications , and cardiovascular risk factors at diagnosis , in early-onset type 2 diabetes , and to compare these between South Asians and Europeans . DESIGN Prospect i ve study of newly-diagnosed type 2 diabetes patients aged < 40 years , attending hospital and primary care clinics 1999 - 2001 . METHODS Patients were assessed for signs of macrovascular disease , retinopathy , neuropathy and nephropathy . Cardiovascular risk factors  were also determined . RESULTS Overall , 292 patients were enrolled ( 165 South Asians ) .  Macrovascular disease was more prevalent in South Asians ( 15.7 % vs. 9.4 % , p<0.001 ) , as was microvascular disease ( 27.3 % vs. 16.5 % , p<0.001 ) , including retinopathy ( 17.5 % vs. 7.9 % , p<0.001 ) , and nephropathy ( 18.1 % vs. 7.8 % , p<0.001 ) . South Asians had trends towards greater waist : hip ratio ( 0.95 vs. 0.90 ) , and higher blood pressure ( 127/80 vs. 123/76 mmHg ) . HDL cholesterol was lower ( 1.0 vs. 1.3 mmol/l , p<0.001 ) and fasting triglycerides higher ( 1.9 vs. 1.5 mmol/l , p<0.001 ) in South Asians . Absolute CHD risk was significantly higher in South Asians ( 16.9 % vs. 13.7 % , p<0.001 ) . DISCUSSION Complications were common at diagnosis , with a quarter of all patients having evidence of at least one diabetic complication . South Asians had a higher prevalence of established macrovascular and microvascular disease , compared to Europeans , and a higher risk of CHD , predominantly because of lower HDL cholesterol and higher blood pressure OBJECTIVE To investigate the prevalence of peripheral arterial disease ( PAD ) and correlative risk factors among natural population in China . METHODS  Ankle brachial index ( ABI ) was measured by trained doctors and related data were collected in residents from Beijing , Shanghai , Changsha , Guangdong , Neimenggu , and Xinjiang selected through cluster multistage and r and om sampling method . PAD was defined as an ABI < or = 0.9 in either leg . RESULTS The  prevalence of PAD among 21 152 eligible participants was 3.08 % , the st and ardized prevalence was 3.04 % . The prevalence in males and females was 2.52 % and 3.66 % and the st and ardized prevalence was 1.84 % and 4.31 % respectively , the prevalence rate was significantly lower in males than that in females ( P < 0.01 ) . The prevalence in both males and females increased significantly in proportion to aging ( P < 0.01 ) . The prevalence in Han Chinese was significantly higher than that in non-Han Chinese ( P < 0.01 ) . Logistic regression analysis showed that older age , female gender , Han Chinese , waist circumference , smoking , lipid disorder , diabetes mellitus , coronary artery disease and a history of ischemic stroke were associated with the increased prevalence of PAD . Incidence of known PAD was 1.38 % in this cohort . CONCLUSIONS Older age , female gender , Han Chinese , waist circumference , smoking , lipid disorder , diabetes mellitus , coronary artery disease and a history of ischemic stroke were associated with the increased prevalence of PAD in natural Chinese population OBJECTIVES We examined the ability of ankle brachial index , C-reactive protein and central augmentation index to identify individuals in the general population with severe atherosclerosis , diagnosed as those with ischaemic cardiovascular disease . METHODS AND RESULTS We examined 4159 r and omly sample d individuals from the Danish general population , of which 250 had severe atherosclerosis . After adjustment for gender and age , individuals with ankle brachial index of 0.71 - 0.90 and < 0.70 vs. 0.91 - 1.10 had odds ratios for severe atherosclerosis of 1.6 ( 95%CI:1.1 - 2.3 ) and 2.9 ( 1.9 - 4.6 ) , respectively . C-reactive protein of > 3.0 or 1.0 - 3.0 mg/L vs. < 1.0 mg/L as well as central augmentation index in quintiles did not identify individuals with severe atherosclerosis , and did not improve further the ability of ankle brachial index to identify such individuals . On a continuous scale using receiver operating characteristics curves , presence of severe atherosclerosis was predicted by ankle brachial index ( P=0.00000003 ) , C-reactive protein ( P=0.000003 ) , as well as central augmentation index ( P=0.001 ) ; these three curves did not differ . CONCLUSION Ankle brachial index < 0.9 identify individuals with severe atherosclerosis in the general population , while C-reactive protein in three groups and central augmentation index in quintiles did not . On a continuous scale , all three variables predicted severe atherosclerosis OBJECTIVES Our aim was to evaluate the possible association between homocysteine levels and peripheral arterial disease ( PAD ) in a population -based study of Japanese-Brazilians . MATERIAL S AND METHODS This cross-sectional study was derived from a population -based survey on the prevalence of diabetes and associated diseases conducted in Japanese-Brazilians . A total of 1330 male and female subjects aged > or=30 years were su bmi tted to clinical examination and laboratory procedures including homocysteine measurement . The ankle-brachial index ( ABI ) was calculated ; subjects with ABI values < 0.9 were diagnosed with PAD . The evaluable population included 1008 subjects .  Logistic regression was used taking PAD as the dependent variable . RESULTS Mean age of the population was 56.5 years and overall prevalence of PAD was 20 % . A worse cardiovascular profile was found in male patients , including significantly higher homocysteine levels ( 11.9+/-1.8 vs. 9.1+/-1.1micromol/L , p<0.001 ) . Men with PAD had higher prevalence rates of hyperhomocysteinemia compared to women ( 22.7 % vs 7.6 % ) . Univariate analysis showed an odds ratio of hyperhomoc 
    Output:
    
Blacks are vulnerable to PAD , in contrast to Asians who have lower prevalence of PAD when compared to whites .