Vascular characteristics in young women-Effect of extensive endurance training or a sedentary lifestyle.

AIM: To explore whether high-level endurance training in early age has an influence on the arterial wall properties in young women. METHODS: Forty-seven athletes (ATH) and 52 controls (CTR), all 17-25 years of age, were further divided into runners (RUN), whole-body endurance athletes (WBA), sedentary controls (SC) and normally active controls (AC). Two-dimensional ultrasound scanning of the carotid arteries was conducted to determine local common carotid artery (CCA) geometry and wall distensibility. Pulse waves were recorded with a tonometer to determine regional pulse wave velocity (PWV) and pulse pressure waveform. RESULTS: Carotid-radial PWV was lower in WBA than in RUN (P < .05), indicating higher arterial distensibility along the arm. Mean arterial pressure was lower in ATH than in CTR and in RUN than in WBA (P < .05). Synthesized aortic augmentation index (AI@75) was lower among ATH than among CTR (-12.8 ± 1.6 vs -2.6 ± 1.2%, P < .001) and in WBA than in RUN (-16.4 ± 2.5 vs -10.7 ± 2.0%, P < .05), suggesting a diminished return of reflection waves to the aorta during systole. Carotid-femoral PWV and intima-media thickness (IMT), lumen diameter and radial distensibility of the CCA were similar in ATH and CTR. CONCLUSION: Elastic artery distensibility and carotid artery IMT are not different in young women with extensive endurance training over several years and in those with sedentary lifestyle. On the other hand, our data suggest that long-term endurance training is associated with potentially favourable peripheral artery adaptation, especially in sports where upper body work is added. This adaptation, if persisting later in life, could contribute to lower cardiovascular risk.

The impact of using sagittal abdominal diameter to predict major cardiovascular events in European patients with type 2 diabetes.

BACKGROUND AND AIMS: Obesity is associated with diabetes type 2 and one of the most important risk factors for cardiovascular disease. We explored if sagittal abdominal diameter (SAD) is a better predictor of major cardiovascular events than waist circumference (WC) and body mass index (BMI) in type 2 diabetes. METHODS AND RESULTS: The CARDIPP study consists of a cohort of patients with type 2 diabetes. In this study we used data from 635 participants with no previous myocardial infarction or stroke, with a mean follow-up time of 7.1 years. SAD, WC and BMI were measured at baseline and the end-point was first cardiovascular event, measured as a composite of ICD-10 codes for acute myocardial infarction, stroke or cardiovascular mortality. SAD was significantly higher in the major cardiovascular event group compared to participants that did not suffer a major cardiovascular event during follow-up (p < 0.001). SAD >25 cm was the only anthropometric measurement that remained associated with major cardiovascular events when adjusted for modifiable and non-modifiable factors (hazard ratio 2.81, 95% confidence interval 1.37-5.76, p = 0.005). CONCLUSION: SAD with the cut off level of >25 cm, if confirmed in larger studies, may be used as a more independent risk-assessment tool compared with WC in clinical practice, to identify persons with type 2 diabetes at high cardiovascular risk. ClinicalTrials.gov: NCT01049737.

Association between serum 25(OH)D3 and cardiovascular morbidity and mortality in people with Type 2 diabetes: a community-based cohort study.

AIM: We aimed to explore the association between vitamin D and cardiovascular morbidity and mortality in people with Type 2 diabetes recruited from a community-based study because there is limited and inconsistent research of this group. METHODS: A prospective community-based cohort study among people aged 55-66 years with Type 2 diabetes as part of The Cardiovascular Risk in Type 2 Diabetes - A Prospective Study in Primary Care (CARDIPP). We analysed serum 25-hydroxyvitamin D3 [25(OH)D3 ] at baseline. Cox regression analyses were used to calculate hazard ratios (HR) for the first myocardial infarction, stroke or cardiovascular mortality according to 25(OH)D3 . RESULTS: We examined 698 people with a mean follow-up of 7.3 years. Serum 25(OH)D3 was inversely associated with the risk of cardiovascular morbidity and mortality: HR 0.98 [95% confidence interval (CI) 0.96 to 0.99, P = 0.001]. Compared with the fourth quartile (Q4) [25(OH)D3 > 61.8 nmol/l], HR (with 95% CI) was 3.46 (1.60 to 7.47) in Q1 [25(OH)D3 < 35.5 nmol/l] (P = 0.002); 2.26 (1.01 to 5.06) in Q2 [25(OH)D3 35.5-47.5 nmol/l] (P = 0.047); and 1.62 (0.70 to 3.76) in Q3 [25(OH)D3 47.5-61.8 nmol/l] (P = 0.26) when adjusting for age, sex and season. The results remained significant after adjusting also for cardiovascular risk factors, physiological variables including parathyroid hormone and previous cardiovascular disease (P = 0.027). CONCLUSIONS: Low 25(OH)D3 is associated with an increased risk of cardiovascular morbidity and mortality in people with Type 2 diabetes independent of parathyroid hormone. Vitamin D could be considered as a prognostic factor. Future studies are needed to explore whether vitamin D deficiency is a modifiable risk factor in Type 2 diabetes.

Prediction of Post-interventional Outcome in Great Saphenous Vein Incompetence: The Role of Venous Plethysmography with Selective Superficial Vein Occlusion.

OBJECTIVE/BACKGROUND: To evaluate whether the outcome of radiofrequency ablation (RFA) treatment of great saphenous vein (GSV) incompetence may be predicted using strain-gauge plethysmography (SGP) with selective occlusion of the superficial venous system. METHODS: Seventeen patients (20 limbs) underwent endovenous RFA treatment for GSV incompetence (Clinical Etiology Anatomy Pathophysiology classification C2-C5; "C-group"). Duplex ultrasound (DUS) and SGP were performed with selective occlusion of superficial veins before and after RFA. Selective superficial occlusion was validated, in a control group (C-group) of 12 patients (14 legs), by ascending phlebography. In the RFA group, the time taken to reach 50% and 90% (T50, T90) of maximum venous volume was measured, as well as relative maximal reflux rates (%EV/min). The methodological error and coefficient of variation (CV) were assessed. RESULTS: Nineteen of 20 legs had complete post-operative GSV obliteration using DUS, and refilling times were improved after RFA (T50 11 ± 3 vs. 19 ± 3 s; p < .001; T90 27 ± 5 vs. 47 ± 6 s; p < .001). With SGP, the methodological error and CV for T50 were 4 s and 16%, respectively. Equivalence between pre-operative superficial occlusion and post-operative baseline measurements was achieved in 15 of 17 legs for T50, and 12 of 17 for T90 (three of the 20 legs were excluded due to treatment failure [n = 1], and untreated perforating veins [n = 2]). Mean differences (95% confidence interval) were within the equivalence ranges (T50 1 [-1 to 3] seconds; T90 -3 [-11 to 4] seconds). In the C-group superficial vein occlusion was possible in 12 of 14 legs. The remaining patient (two legs) showed incomplete superficial vein occlusion at ankle level (lipodermatosclerosis) and complete superficial vein occlusion at calf level. CONCLUSION: SGP with standardized superficial venous occlusion seems to be a reliable method for identifying venous reflux and may be useful in predicting the results of successful RFA treatment.

The association between endostatin and kidney disease and mortality in patients with type 2 diabetes.

AIM: Circulating endostatin, a biologically active derivate of collagen XVIII, is considered to be a marker of kidney disease and a risk factor for its related mortality. However, less is known of the role of endostatin in diabetes and the development of diabetic nephropathy. For this reason, our study investigated the associations between circulating endostatin and the prevalence and progression of kidney disease, and its mortality risk in patients with type 2 diabetes (T2D). METHODS: This was a cohort study of 607 patients with T2D (mean age: 61 years, 44% women). Estimated glomerular filtration rate (eGFR), calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation, was used to assess the patients' kidney function decline and mortality. RESULTS: Of the total study cohort, 20 patients declined by ≥20% in eGFR over 4 years, and 44 died during the follow-up (mean duration: 6.7 years). At baseline, participants with diabetic nephropathy (defined as eGFR<60mL/min/1.73m2) and/or microalbuminuria [defined as a urinary albumin-to-creatinine ratio (ACR)>3g/mol] had higher median levels of endostatin than those without nephropathy (62.7µg/L vs 57.4µg/L, respectively; P=0.031). In longitudinal analyses adjusted for age, gender, baseline eGFR and ACR, higher endostatin levels were associated with a higher risk of decline (≥20% in eGFR, OR per 1 SD increase: 1.73, 95% CI: 1.13-2.65) and a higher risk of mortality (HR per 1 SD increase: 1.57, 95% CI: 1.19-2.07). CONCLUSION: In patients with T2D, circulating endostatin levels can predict the progression of kidney disease and mortality independently of established kidney disease markers. The clinical usefulness of endostatin as a risk marker in such patients merits further studies.

Pedometer-determined physical activity level and change in arterial stiffness in Type 2 diabetes over 4 years.

AIM: To explore prospectively the correlation between the level of pedometer-determined physical activity at the start of the study and the change in pulse wave velocity from baseline to 4 years later in people with Type 2 diabetes. METHODS: We analysed data from 135 men and 53 women with Type 2 diabetes, aged 54-66 years. Physical activity was measured with waist-mounted pedometers on 3 consecutive days and the numbers of steps/day at baseline were classified into four groups: <5000 steps/day, 5000-7499 steps/day, 7500-9999 steps/day and ≥10 000 steps/day. Pulse wave velocity was measured using applanation tonometry over the carotid and femoral arteries at baseline and after 4 years. RESULTS: The mean (±sd; range) number of steps/day was 8022 (±3765; 956-20 921). The participants with the lowest level of physical activity had a more pronounced increase in the change in pulse wave velocity compared with the participants with the highest. When change in pulse wave velocity was analysed as a continuous variable and adjusted for sex, age, diabetes duration, HbA1c , BMI, systolic blood pressure, pulse wave velocity at baseline, ß-blocker use, statin use, unemployment, smoking and diabetes medication, the number of steps/day at baseline was significantly associated with a less steep increase in change in pulse wave velocity (P=0.005). Every 1000 extra steps at baseline corresponded to a lower increase in change in pulse wave velocity of 0.103 m/s. CONCLUSIONS: We found that a high level of pedometer-determined physical activity was associated with a slower progression of arterial stiffness over 4 years in middle-aged people with Type 2 diabetes.

No benefit of screening for abdominal aortic aneurysm among 70- instead of 65-year-old men.

AIM: Screening 65-year-old men for abdominal aortic aneurysm (AAA) reduces mortality from ruptured AAA (rAAA). Lower than expected prevalence of AAA is now found, why screening at a higher age and rescreening has been discussed. Our aim was to determine if screening at 70 years of age, instead of 65, increases clinical effectiveness. METHODS: Seven thousand nine hundred fifty-one and 5623 previously un-screened 65- and 70-year old men were invited to ultrasound screening. RESULTS: The attendance rate was 85.7% and 84.0%, P<0.01, for the 65- and 70-year old men respectively. The screening-detected prevalence did not differ, being 1.9% and 2.3%, P=0.15, respectively, probably due to the fact that 23.5% and 37.4% of all known AAA among 65- and 70-year-old men, were detected by other means prior to screening, P<0.01. However, the total known prevalence differed between the age-groups, being at least 2.1% and 3.0% respectively, P<0.001. CONCLUSION: The screening-detected AAA-prevalence did not differ between 65- and 70-year-old men, due to the greater number of AAA known prior to screening among 70- compared to 65-year-old men. Screening men at 70 instead of 65 years of age would not result in detection of substantially more previously unknown AAA, thus not preventing rAAA and consequently not more saved life-years. Further, data also indicates that it is questionable if re-screening the 65-year-old male population after five years would generate any important clinical effect.

Predictive markers of abdominal aortic stiffness measured by echo-tracking in subjects with varying insulin sensitivity.

Arterial stiffness is influenced by advancing age and vascular disease and is an independent risk factor for cardiovascular events and death. Using ultrasound measurements, arterial stiffness in a specific arterial segment can be assessed. The aim of this observational study was to explore the prospective and cross-sectional associations between arterial stiffness measured by ultrasound locally in the abdominal aorta and cardiovascular risk factors/markers including insulin resistance measured by the homeostatic model assessment-insulin resistance (HOMA-IR), lipids and abdominal obesity. This study includes 335 subjects from Malmö, Sweden, examined in 1991-1994 and again at follow-up in 1998-2000 (mean age 64 years, 42% men). Ultrasound measurement of the abdominal aorta was performed at follow-up investigation. In the female subgroup, there was a positive association between HOMA-IR at baseline and abdominal aortic stiffness at follow-up (ß = 0.18, P = 0.03) and a negative association between high-density lipoprotein and aortic stiffness (ß = -0.23, P = 0.005), independently of classical cardiovascular risk factors. These associations were not found among men. The results suggest a greater or different role of impaired glucose metabolism in the pathophysiology of arterial stiffness in women than in men.

Microalbuminuria, but not reduced eGFR, is associated with cardiovascular subclinical organ damage in type 2 diabetes.

AIM: This study explored the association between reduced estimated glomerular filtration rate (eGFR) and microalbuminuria vs. subclinical organ damage in patients with type 2 diabetes. METHODS: Data from middle-aged patients with type 2 diabetes (n=706) treated in primary care were analyzed for microalbuminura, defined as a urinary albumin/creatinine ratio (uACR)≥3.0mmol/mol, and reduced eGFR, defined as<60mL/min/1.73m(2), in relation to blood pressure, pulse wave velocity (PWV), left ventricular mass index (LVMI), and carotid intima-media thickness (IMT) and lumen diameter (LD). RESULTS: Patients with microalbuminuria had significantly higher 24-h ambulatory systolic blood pressure (ASBP) compared with subjects with uACR<3mg/mmol: 137 vs. 128mmHg (P<0.001). There were no differences in ASBP in patients with eGFR<60mL/min/1.73m(2). However, patients with vs. without microalbuminuria had increased PWV (11.4 vs. 10.1m/s; P<0.001), LVMI (134.4 vs. 118.6g/m(2); P<0.001), LD (7.01±0.93 vs. 6.46±0.74mm; P<0.001) and IMT (0.78 vs. 0.74mm; P=0.047), respectively. The associations between uACR vs. PWV and LVMI were more robust after adjusting for age, diabetes duration, ASBP, HbA1c, LDL-cholesterol, and antihypertensive and lipid-lowering therapy compared with uACR vs. IMT. There were no statistically significant differences in PWV, LVMI or IMT between patients with reduced (<60mL/min/1.73m(2)) vs. normal eGFR. CONCLUSION: Levels of urinary albumin excretion, but not reduced eGFR, were associated with increased arterial stiffness, left ventricular mass and atherosclerosis in patients with type 2 diabetes.

Abdominal obesity and low-grade systemic inflammation as markers of subclinical organ damage in type 2 diabetes.

AIM: This study aimed to explore the associations between abdominal obesity, inflammatory markers and subclinical organ damage in 740 middle-aged patients with type 2 diabetes. METHODS: Waist circumference (WC) and sagittal abdominal diameter (SAD) were measured, and blood samples were analyzed for C-reactive protein (CRP) and IL-6. Carotid intima-media thickness (IMT) was evaluated by ultrasonography, and aortic pulse wave velocity (PWV) measured with applanation tonometry. RESULTS: Abdominal obesity as determined by SAD and WC was significantly correlated with IL-6 (WC: r=0.27, P<0.001; SAD: r=031, P<0.001), CRP (WC: r=0.29, P<0.001; SAD: r=0.29, P<0.001), IMT (WC: r=0.09, P=0.013; SAD: r=0.11, P=0.003) and PWV (WC: r=0.18, P<0.001; SAD: r=0.21, P<0.001). In multiple linear regressions with IMT and PWV as dependent variables, and age, gender, statin use, systolic blood pressure (SBP), body mass index (BMI), CRP and HbA1c as independent variables, both SAD and WC remained associated with IMT and PWV. On stepwise linear regression and entering both SAD and WC, the association between SAD and PWV was stronger than the association between WC and PWV. CONCLUSION: Both SAD and WC are feasible measures of obesity, and both provide information on inflammation, atherosclerosis and arterial stiffness in type 2 diabetes, while SAD appears to be slightly more robustly associated with subclinical organ damage than WC.

Lower prevalence than expected when screening 70-year-old men for abdominal aortic aneurysm.

BACKGROUND: Screening 65-year-old men for abdominal aortic aneurysms (AAA) is a cost-effective method to reduce the mortality from ruptured AAA. However, contemporary results show a lower than expected prevalence of AAA, thus questioning the benefit of screening. Since the prevalence increases with age, a possible way to enhance the benefit of screening might be to screen older men. Our aim was to determine the contemporary screening-detected prevalence among 70-year-old men. METHODS: A total of 5,623 unscreened 70-year-old men were invited to ultrasound screening. Uni- and multivariable analyses were used to assess the risk factors for AAA. RESULTS: The attendance rate was 84.0%. The prevalence of previously unknown AAAs was 2.3%. When adding the 64 men with an already known AAA to the screening-detected ones, the total prevalence in the population was at least 3.0%, and the previously discovered AAAs constituted 37.4% of the total prevalence. "Ex smoker" and "Current smoker" were the most important risk factors. CONCLUSIONS: When screening 70-year-old men for AAA, the prevalence was less than half that expected, despite a high attendance rate. Smoking was the strongest risk factor. Almost 40% of the men with AAAs were already known from other means than screening.

Cardiovascular function in adulthood following intrauterine growth restriction with abnormal fetal blood flow.

OBJECTIVES: To examine whether intrauterine growth restriction (IUGR) is associated with increased cardiovascular risk later in life. METHODS: We examined 19 young adults (aged 22-25 years) who were born at term after IUGR, along with 18 controls. All had been examined previously with fetal Doppler, and in the present follow-up with echocardiography, carotid echo-tracking ultrasound, applanation tonometry, blood pressure and laser Doppler, in order to characterize their cardiac and vascular geometry and/or function. RESULTS: The diameter of the ascending aorta and the left ventricular diameter were smaller in the IUGR group, but only ascending aortic diameter remained significantly smaller after adjustment for body surface area (P < 0.05). The aortic pressure augmentation index was higher in the IUGR group (P < 0.05). The common carotid artery diameter, intima-media thickness and distensibility as well as left ventricular mass and function were similar in the two groups. IUGR status was found to be an independent predictor of ascending aortic diameter. CONCLUSIONS: IUGR due to placental dysfunction seems to contribute to the higher systolic blood pressure augmentation and the smaller aortic dimensions that are observed in adults more than 20 years later, with possible negative consequences for future left ventricular performance due to increased aortic impedance.

Subject-specific aortic wall shear stress estimations using semi-automatic segmentation.

Atherosclerosis development is strongly believed to be influenced by hemodynamic forces such as wall shear stress (WSS). To estimate such an entity in-vivo in humans, image-based computational fluid dynamics (CFD) is a useful tool. In this study, we use a combination of magnetic resonance imaging (MRI) and CFD to estimate WSS. In such method, a number of steps are included. One important step is the interpretation of images into 3D models, named segmentation. The choice of segmentation method can influence the resulting WSS distribution in the human aorta. This is studied by comparing WSS results gained from the use of two different segmentation approaches: manual and semi-automatic, where the manual approach is considered to be the reference method. The investigation is performed on a group of eight healthy male volunteers. The different segmentation methods give slightly different geometrical depictions of the human aorta (difference in the mean thoracic Aorta lumen diameter were 0·7% P< 0·86). However, there is a very good agreement between the resulting WSS distribution for the two segmentation approaches. The small differences in WSS between the methods increase in the late systole and early diastolic cardiac cycle time point indicating that the WSS is more sensitive to local geometric differences in these parts of the cardiac cycle (correlation coefficient is 0·96 at peak systole and 0·68 at early diastole). We can conclude that the results show that the semi-automatic segmentation method can be used in future to estimate relevant aortic WSS.

Pedometer-determined physical activity is linked to low systemic inflammation and low arterial stiffness in Type 2 diabetes.

AIMS: The aim of this study was to explore the association between pedometer-determined physical activity versus measures of obesity, inflammatory markers and arterial stiffness in people with Type 2 diabetes. METHODS: We analysed data from 224 men and 103 women with Type 2 diabetes, aged 54-66 years. Physical activity was measured with waist-mounted pedometers during three consecutive days and the number of steps/day were calculated and classified in four groups: < 5000 steps/day, 5000-7499 steps/day, 7500-9999 steps/day and ≥ 10000 steps/day. Blood samples were analysed for lipids, HbA(1c), inflammatory markers including C-reactive protein and interleukin-6. Nurses measured blood pressure and anthropometrics. Aortic pulse wave velocity was measured with applanation tonometry over the carotid and femoral arteries. RESULTS: Mean steps/day was 7683 ± 3883 (median 7222, interquartile range 4869-10,343). There were no differences in age, diabetes duration, blood pressure, lipids or glycaemic control between the four groups of pedometer-determined physical activity. Subjects with higher steps/day had lower BMI (28.8 vs. 31.5 kg/m(2), P < 0.001), waist circumference (101.7 vs. 108.0 cm, P < 0.001), lower levels of C-reactive protein (1.6 vs. 2.6 mg/l, P = 0.007), lower levels of interleukin-6 (1.9 vs. 3.8 pg ml, P < 0.001) and lower pulse wave velocity (10.2 vs. 11.0 m/s, P = 0.009) compared with less physically active people. CONCLUSIONS: We conclude that physical activity measured with pedometer was associated not only with less abdominal obesity, but also with decreased systemic low-grade inflammation as well as with low arterial stiffness, in people with Type 2 diabetes.

Diameter and compliance of the greater saphenous vein - effect of age and nitroglycerine.

OBJECTIVES: The greater saphenous vein (GSV) is commonly used in autologous vein graft surgery. GSV diameter has proven to influence graft patency, and furthermore venous compliance might be of importance. The purpose of the study was to evaluate the effect of age on GSV diameter and compliance, and to evaluate the effect of nitroglycerine (NTG). METHODS: The diameter and compliance of the GSV, with and without NTG, were examined with B-mode ultrasound in 12 elderly (70·3 ± 1·2 year) and 15 young (25·1 ± 0·6 year) men. The GSV diameter at the thigh and calf level was measured at rest, after 6 min of venous stasis (60 mmHg) and after NTG administration. Pressure-area curves during a linear venous pressure decrease were produced. Venous compliance was calculated using the quadratic regression equation (area) = ß(0) + ß(1) (cuff pressure) + ß(2) (cuff pressure)(2) . RESULTS: GVS diameter between the groups showed significant lower diameter in elderly compared to young men (P<0·05). Venous occlusion increased GSV diameter in elderly men (P<0·01) as well as young men (P<0·001). NTG increased GSV diameter in elderly men (P<0·01) with an equal trend in young men. During venous occlusion, after administration of NTG, GSV diameter increased further in both elderly (P<0·01) and young men (P<0·001). GSV compliance was decreased in elderly (ß(1) , 0·037 ± 0019, ß(2,) -0·000064 ± 00017) versus young men (ß(1) , 0·128 ± 0·013, ß(2) , -0·00010 ± 000018) [P<0·001 (ß(1) ), P<0·02 (ß(2) )]. CONCLUSIONS: Baseline GSV diameter as well as GSV compliance is decreased in elderly men compared to the young subjects. As reduced GSV diameter as well as reduced compliance is related to decreased graft patency, these findings might be of importance for the uses of GSV as graft material in cardiovascular bypass surgery. The clinical value has to be clarified in future studies.

Impaired abdominal aortic wall integrity in elderly men carrying the angiotensin-converting enzyme D allele.

OBJECTIVE: A polymorphism in the angiotensin-converting-enzyme gene (ACE I/D) has been associated with abdominal aortic aneurysm and a link between aortic aneurysm and aortic stiffness has been suggested. This study aimed to explore the links between ACE I/D polymorphism, circulating ACE and abdominal aortic wall integrity as reflected by abdominal aortic wall stiffness. MATERIAL: A total of 212 men and 194 women, aged 70-88 years, were studied. METHODS: Mechanical properties of the abdominal aorta were determined using the Wall Track System, ACE genotype using the polymerase chain reaction (PCR) and circulating ACE level by enzyme-linked immunosorbent assay (ELISA). RESULTS: In men, pulsatile diameter change differed between genotypes (II 0.70, ID 0.55 and DD 0.60 mm, P = 0.048), whereas a tendency was seen for distensibility coefficient (DC) (II 10.38, ID 7.68 and ID 8.79, P = 0.058). Using a dominant model (II vs. ID/DD), men carrying the ACE D allele had lower pulsatile diameter change (P = 0.014) and DC (P = 0.017) than II carriers. Multiple regression analyses showed additional associations between the D allele and increased stiffness ß, and reduced compliance coefficient. CONCLUSION: Men carrying the ACE D allele have stiffer abdominal aortas compared with II carriers. Deranged abdominal aortic stiffness indicates impaired vessel wall integrity, which, along with other local predisposing factors, may be important in aneurysmal disease.

In vivo estimation of the contribution of elastin and collagen to the mechanical properties in the human abdominal aorta: effect of age and sex.

The mechanical properties of the aorta affect cardiac function and are related to cardiovascular morbidity/mortality. This study was designed to evaluate the isotropic (mainly elastin, elastin(iso)) and anisotropic (mainly collagen, collagen(ani)) material parameters within the human aorta in vivo. Thirty healthy men and women in three different age categories (23-30, 41-54, and 67-72 yr) were included. A novel mechanical model was used to identify the mechanical properties and the strain field with aid of simultaneously recorded pressure and radius in the abdominal aorta. The magnitudes of the material parameters relating to both the stiffness of elastin(iso) and collagen(ani) were in agreement with earlier in vitro studies. The load-bearing fraction attributed to collagen(ani) oscillated from 10 to 30% between diastolic and systolic pressures during the cardiac cycle. With age, stiffness of elastin(iso) increased in men, despite the decrease in elastin content that has been found due to elastolysis. Furthermore, an increase in stiffness of collagen(ani) at high physiological pressure was found. This might be due to increased glycation, as well as changed isoforms of collagen in the aortic wall with age. A marked sex difference was observed, with a much less age-related effect, both on elastin(iso) and collagen(ani) stiffness in women. Possible factors of importance could be the effect of sex hormones, as well as differing collagen isoforms, between the sexes.

Carotid intima-media thickness and apolipoprotein B/apolipoprotein A-I ratio in middle-aged patients with Type 2 diabetes.

AIMS: To explore the association between carotid intima-media thickness (IMT) and the apolipoprotein B (apoB)/apolipoprotein A-I (apoA-I) ratio compared with conventional lipids in middle-aged patients with Type 2 diabetes. METHODS: We analysed data from 247 patients with Type 2 diabetes, aged 55-66 years, in the Cardiovascular Risk factors in Patients with Diabetes-a Prospective study in Primary care (CARDIPP-1) study. Primary care nurses measured blood pressure and anthropometric characteristics. Blood samples were taken for laboratory analyses. The carotid IMT was determined by ultrasonography at the University Hospital in Linköping and at the County Hospital Ryhov, Jönköping, Sweden. RESULTS: The ApoB/apoA-I ratio (r = 0.207, P = 0.001), apoB (r = 0.166, P = 0.009) and non-high-density lipoprotein cholesterol (non-HDL-c) (r = 0.129, P = 0.046) correlated with IMT. Conventional lipids, high-sensitivity C-reactive protein (hsCRP), glycated haemoglobin (HbA(1c)) and systolic blood pressure were not significantly correlated to IMT. A stepwise logistic regression analysis was conducted with IMT as the dependent variable and the apoB/apoA-I ratio, HbA(1c), hsCRP, low-density lipoprotein cholesterol (LDL-c), total cholesterol, non-HDL-c and treatment with statins as independent variables. Following adjustment for age and gender, only the apoB/apoA-I ratio remained significantly associated with IMT (odds ratio 4.3, 95% confidence intervals 1.7-10.8, P = 0.002). CONCLUSIONS: We conclude that there was a significant association between the apoB/apoA-I ratio and IMT in middle-aged patients with Type 2 diabetes. The association was independent of conventional lipids, hsCRP, glycaemic control and use of statins.

Masked nocturnal hypertension--a novel marker of risk in type 2 diabetes.

AIMS/HYPOTHESIS: This study was designed to evaluate the prevalence of masked nocturnal hypertension (MNHT) and its impact on arterial stiffness and central blood pressure in patients with type 2 diabetes. METHODS: Middle-aged patients (n = 414) with type 2 diabetes underwent clinic and ambulatory BP measurements and applanation tonometry. RESULTS: MNHT (clinic BP < 130/80 mmHg and night-time BP > or = 120/70 mmHg) was found in 7.2% of patients (n = 30). Compared with patients with both clinical and nocturnal normotension (n = 70), patients with MNHT had higher aortic pulse wave velocity (PWV) (10.2 +/- 1.8 m/s vs 9.4 +/- 1.7 m/s; p = 0.03) and higher central BP (117.6 +/- 13.9/74.0 +/- 9.1 mmHg vs 110.4 +/- 16.4/69.7 +/- 9.6 mmHg, p = 0.04). In patients with clinical normotension, night-time systolic BP correlated significantly with PWV. CONCLUSIONS/INTERPRETATION: Thirty per cent of patients with clinical normotension had nocturnal hypertension. This was accompanied by increased arterial stiffness and higher central BP. We conclude that in clinically normotensive patients with type 2 diabetes, ambulatory BP measurement may help clinicians to identify patients with increased cardiovascular risk.

Association of genetic variation on chromosome 9p21.3 and arterial stiffness.

OBJECTIVES: Genome wide association studies have consistently reported associations between a region on chromosome 9p21.3 and a broad range of vascular diseases, such as coronary artery disease (CAD), aortic and intracranial aneurysms and type-2 diabetes (T2D). However, clear associations with intermediate phenotypes have not been described so far. To shed light on a possible influence of this chromosomal region on arterial wall integrity, we analysed associations between single nucleotide polymorphisms (SNPs) and degree of stiffness of the abdominal aorta in elderly individuals. METHODS AND RESULTS: A total of 400 subjects, 212 men and 188 women, aged 70-88 years were included. Arterial stiffness was examined at the midpoint between the renal arteries and the aortic bifurcation. Two CAD- and aneurysm-associated SNPs (rs10757274 and rs2891168) and one T2D-associated SNP (rs1081161) within the 9p21.3 region were genotyped. Aortic compliance and distensibility coefficients were higher in carriers of the rs10757274G and rs2891168G alleles in men reflecting a decrease in aortic stiffness. Adjustment for age and mean arterial pressure had no effect on these associations. The two SNPs were not associated with intima-media thickness or lumen diameter of the abdominal aorta. There were no associations between the rs10811661 SNP and any measure of aortic stiffness. CONCLUSIONS: Impaired mechanical properties of the arterial wall may explain the association between chromosome 9p21.3 polymorphisms and vascular disease.