Relations of pulse wave velocity to waist circumference independent of hip circumference

Metabolic syndrome is related to vascular structural alterations but not to functional ones both in hypertensives and healthy subjects

BACKGROUND AND AIMS

Metabolic Syndrome (MS) has been related to an impairment in arterial structural and functional properties with heterogeneous results. In this paper we focused on the effects of MS on arterial carotid-femoral PWV and common carotid IMT in two different populations, one of hypertensive patients and one of healthy controls.

METHODS AND RESULTS

We enrolled 816 consecutive HT and 536 healthy controls. Vascular structural (IMT) and functional (PWV) properties were evaluated. NCEP-ATP-III criteria were used for diagnosis of MS. MS was diagnosed in 26.9% and 6.9% in hypertensive and control subjects, respectively. PWV was similar in controls with and without MS (7.7 ± 1.9 vs 7.6 ± 1.1 m/s, p = 0.69), while IMT was higher in controls with than those without MS (0.64 ± 0.18 vs 0.57 ± 0.13 mm, p = 0.02). Hypertensives with MS were older (57.9 ± 12.2 vs 52.7 ± 14.1 years, p < 0.001) and showed higher PWV (9.0 ± 2.3 vs 8.4 ± 2.1 m/s, p = 0.001) and IMT (0.72 ± 0.22 vs 0.65 ± 0.17 mm, p < 0.001) than those without MS, however at the age-adjusted analysis only the difference in IMT was confirmed (p = 0.007). Regression models showed that MS was an independent determinant of IMT in both controls (β = 0.08, p = 0.03) and hypertensives (β = 0.08, p = 0.01), but not of PWV either in controls (β = 0.006, p = 0.886 and β = 0.04, p = 0.19, respectively).

CONCLUSIONS

the main finding of our work is that MS is a significant determinant of IMT while this is not the case for PWV. This result have been confirmed both in hypertensive subjects and in healthy controls.

Effect of carbohydrate restriction-induced weight loss on aortic pulse wave velocity in overweight men and women

Increased aortic stiffness, measured by carotid-to-femoral pulse wave velocity (PWV), is an independent predictor of cardiovascular disease, and past data have shown that low-fat and low-energy diets, fed for 8–24 weeks, lower PWV. The purpose of this study was to determine whether a reduction in PWV would be achieved by dietary carbohydrate (CHO) restriction, shown to bring about weight loss over a shorter timeframe. Men (n = 10, age: 41.8 ± 10.2 years, BMI: 34.2 ± 3.0 kg/m2 (mean ± SD)) and women (n = 10, age: 38.6 ± 6.1 years, BMI: 33.5 ± 3.8 kg/m2) with characteristics of insulin resistance and the metabolic syndrome consumed a structured, CHO-restricted diet for 4 weeks (energy deficit, 645 kcal/day). For the whole group, subjects lost 5.4% ± 0.5% (P < 0.001) of body weight and experienced significant reductions in blood pressure (6%–8%), plasma insulin (34%), and triglycerides (34%). PWV was reduced by 6% ± 2% (7.1 ± 0.2 m/s to 6.7 ± 0.2 m/s, P = 0.008) and surprisingly, in women, it fell significantly (from 7.2 ± 0.3 m/s to 6.3 ± 0.3 m/s, P = 0.028), while no changes were observed in men (7.2 ± 0.3 vs. 7.0 ± 0.3 m/s, P = 0.144). This is the first study to demonstrate that weight loss can improve PWV in as little as 4 weeks and that dietary CHO restriction may be an effective treatment for reducing aortic stiffness in women. Future studies are needed to establish the mechanisms by which dietary CHO restriction may confer more cardiovascular benefits to women than to men.

Changes in truncal obesity and fat distribution predict arterial health

BACKGROUND

Truncal obesity is associated with metabolic syndrome and cardiovascular risk. Although vascular health is influenced by weight, it is not known whether changes in fat distribution modulate arterial function.

OBJECTIVE

We assessed how changes in truncal (android) fat at 1 year affect arterial stiffness and endothelial function.

METHODS

We recruited 711 healthy volunteers (235 males, age 48 ± 11 years) into the Emory Predictive Health Study; 498 returned at 1 year. Measurements included anthropometric and chemistry panels, fat mass using dual-energy X-ray absorptiometry, arterial stiffness indices (pulse wave velocity [PWV], augmentation index [AIx], and subendocardial viability ratio [SEVR]; Sphygmocor), flow-mediated dilation (FMD), and reactive hyperemia index (Endo-PAT).

RESULTS

At baseline, measures of body mass correlated with PWV, AIx, SEVR, and FMD. In a multivariable analysis including body mass index (BMI) and traditional risk factors, BMI remained an independent predictor of PWV, AIx, SEVR, and FMD. In a model including BMI and measures of fat distribution, android fat remained an independent predictor of PWV (β = 0.31, P = .004), AIx (β = 0.24, P = .008), and SEVR (β = -0.41, P < .001). The 1-year change in android fat correlated negatively with change in SEVR (β = -0.13, P = .005) and FMD (β = -0.13, P = .006) after adjustment for change in gynoid fat.

CONCLUSION

In addition to BMI, android fat is a determinant of arterial stiffness, independent of traditional risk factors. Changes in android fat over time are associated with simultaneous changes in vascular function, indicating fat distribution's effect on vascular health.

Effects of Short-Term Exenatide Treatment on Regional Fat Distribution, Glycated Hemoglobin Levels, and Aortic Pulse Wave Velocity of Obese Type 2 Diabetes Mellitus Patients

BACKGROUND

Most type 2 diabetes mellitus patients are obese and have obesity related vascular complications. Exenatide treatment is well known for both decreasing glycated hemoglobin levels and reduction in body weight. So, this study aimed to determine the effects of exenatide on body composition, glycated hemoglobin levels, and vascular stiffness in obese type 2 diabetes mellitus patients.

METHODS

For 1 month, 32 obese type 2 diabetes mellitus patients were administered 5 μg of exenatide twice daily. The dosage was then increased to 10 μg. Patients' height, body weight, glycated hemoglobin levels, lipid profile, pulse wave velocity (PWV), body mass index, fat mass, and muscle mass were measured by using Inbody at baseline and after 3 months of treatment.

RESULTS

After 3 months of treatment, glycated hemoglobin levels decreased significantly (P=0.007). Triglyceride, total cholesterol, and low density lipoprotein levels decreased, while aspartate aminotransferase and alanine aminotransferase levels were no change. Body weight, and fat mass decreased significantly (P=0.002 and P=0.001, respectively), while interestingly, muscle mass did not decrease (P=0.289). In addition to, Waist-to-hip ratio and aortic PWV decreased significantly (P=0.006 and P=0.001, respectively).

CONCLUSION

Effects of short term exenatide use in obese type 2 diabetes mellitus with cardiometabolic high risk patients not only reduced body weight without muscle mass loss, body fat mass, and glycated hemoglobin levels but also improved aortic PWV in accordance with waist to hip ratio.

The role of abnormal metabolic conditions on arterial stiffness in healthy subjects with no drug treatment

BACKGROUND

Subjects with abnormal metabolic conditions had increased risk for cardiovascular disease. We investigated the role of abnormal metabolic conditions on arterial stiffness in healthy subjects with no drug treatment.

METHODS

A total 601 subjects (age 48.7 ± 11.8 years, male 46.2 %, hypertension 19.1 %) were enrolled. Major cardiovascular risk factors, metabolic conditions and parameters (pre-diabetes, diabetes mellitus, metabolic syndrome, fasting blood sugar (FBS), glycated hemoglobin), lipid profiles, hsCRP, and brachial ankle pulse wave velocity (baPWV) were measured.

RESULTS

Subjects with metabolic syndrome (n = 200) had higher baPWV than in subjects without metabolic syndrome (n = 401) even after adjustments for age, sex and presence of hypertension (1435.9 ± 212.2 vs. 1336.5 ± 225.0 cm/sec, p < 0.001). The differences of baPWV among normal FBS, prediabetes and diabetes mellitus groups are significant (P for trend = 0.036) by multivariate analysis (adjustments for age, sex, office systolic blood pressure). Subjects with diabetes mellitus (n = 30) had higher baPWV than in subjects with normal FBS (n = 384, 1525 ± 267.1 vs. 1341.5 ± 224.1 cm/sec, P = 0.016 adjustments for age, sex, office systolic blood pressure). BaPWV in subjects with prediabetes (n = 187) was slightly higher, but not statistically significant than in subjects with normal FBS (P = 0.377). Of interest, FBS was one of the independent predictors for increased baPWV (β = 0.809, 95 % CI 0.222-1.397, p = 0.007) by multivariate analysis.

CONCLUSIONS

Subjects with abnormal metabolic conditions have increased arterial stiffness independent of age and BP which may contribute to the development of cardiovascular disease.

Overall and abdominal obesity indicators had different association with central arterial stiffness and hemodynamics independent of age, sex, blood pressure, glucose, and lipids in Chinese community-dwelling adults

Objective

Limited large sample studies have specially compared overall and abdominal obesity in relation to central arterial stiffness and hemodynamics in community-dwelling adults, especially in the People’s Republic of China. This study aimed to compare the relationship between an overall obesity indicator (body mass index [BMI]), an abdominal obesity index (waist circumference [WC]), and central arterial stiffness and hemodynamics, independent of age, sex, blood pressure, glucose, and lipids, in Chinese community-dwelling adults.

Methods

For 2,624 adults in this study, anthropometric indices, such as BMI and WC, were measured. Central arterial stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV). Central hemodynamics was represented by central pulse pressure (cPP).

Results

Both overall and abdominally obese adults were older, with significantly higher cfPWV, cPP, peripheral pulse pressure (pPP), fasting blood glucose (FBG), and low-density lipoprotein-cholesterol (LDL-C), and significantly lower high-density lipoprotein-cholesterol (HDL-C). After adjusting for age and sex, both the overall and abdominally obese individuals had independently higher pPP, FBG, and LDL-C levels, and lower HDL-C level. The overall obese individuals had independently higher cPP, but not cfPWV, after adjusting for age and sex, while the abdominally obese individuals had independently higher cfPWV, but not cPP. After adjusting for age, sex, pPP, FBG, LDL-C, and HDL-C, WC, but not BMI, was independently correlated with cfPWV, and BMI, but not WC, was independently associated with cPP. Age, sex, pPP, FBG, and HDL-C levels have independent association with cfPWV. Age, sex, pPP, but not FBG and HDL-C levels, have independent association with cPP.

Conclusion

The abdominal obesity index (WC), rather than the overall obesity indicator (BMI), was related to central arterial stiffness, independent of age, sex, blood pressure, glucose and lipids, while the overall obesity indicator (BMI), rather than the abdominal obesity indicator (WC), was independently correlated with central hemodynamics. Age, sex, and blood pressure were independently associated with central arterial stiffness and hemodynamics, but blood glucose and lipids were independently associated with central arterial stiffness, rather than hemodynamics.

Prevalence and determinants of hyperlipidemia in moderate altitude areas of the Yunnan-Kweichow plateau in Southwestern China

The objective of the current study was to determine the prevalence and determinants of hyperlipidemia among the populations living at moderate altitude on the Yunnan-Kweichow Plateau in Southwestern China. We randomly recruited 1415 people for this study. These subjects underwent a physical examination and a comprehensive questionnaire regarding their daily habits and diets. Furthermore, blood samples from the participants were collected for assessing the lipid profile. We found that 49.3% of participants (95% CI: 46.7-51.9%) suffered from hyperlipidemia. The prevalence in men was significantly higher than that in women (53.6% vs. 44.7%, p<0.01). The prevalence of hypercholesterolemia was 23.3% and of hypertriglyceridemia was 34.1%. Low HDL-C showed a prevalence of 17.5% and high LDL-C of 9.0%. The prevalence of hyperlipidemia also increased with age, as did the prevalence of high TC, TG, and LDL-C. Hyperlipidemic subjects tended to be older and have a higher BMI and WHR than the normolipidemic subjects in the study cohort (p<0.05). The hyperlipidemic subjects, both men and women, tended to dine out often and consume more animal-based foods and alcohol. In addition, the hyperlipidemic men in our cohort consumed more salted food then their normolipidemic counterparts (p<0.01). Normolipidemic subjects of both sexes were also found to prefer a vegetarian diet (p<0.01). Age, alcohol consumption, a preference for meat and animal products, regular dining out, and BMI were found to be the main determinants of hyperlipidemia in women, whereas a prevalence of salted food was observed to be related to hyperlipidemia in men from the Yunnan-Kweichow Plateau subpopulation under study (p<0.05). The average daily energy, and protein and fat intakes of the sampled subjects were also higher than the levels set by the Chinese Recommendation Nutrient Intakes (RNI), while hyperlipidemic subjects had an even higher average daily intake of total fat, cholesterol, and lower dietary fiber compared with the normolipidemic subjects in the study group (p<0.05). In conclusion, this study reveals a higher prevalence of hyperlipidemia, hypercholesterolemia, hypertriglyceridemia, increased BMI and WHR values in men, as well as a slightly higher prevalence of low HDL-C and high LDL-C in women from Yunnan-Kweichow Plateau. The incidence of hyperlipidemia also increased with age, as did the prevalence of an abnormal TC, TG, LDL-C, and WHR in our study cohort. A high BMI, and less healthy living habits and dietary preferences thus play significant roles in the onset of hyperlipidemia.

Abdominal obesity vs general obesity for identifying arterial stiffness, subclinical atherosclerosis and wave reflection in healthy, diabetics and hypertensive

Background

Our aim was to analyze the relationship between abdominal obesity and general obesity, with subclinical atherosclerosis, arterial stiffness and wave reflection in healthy, diabetics and hypertensive subjects.

Methods

A cross-sectional descriptive study was made of 305 individuals (diabetics 32.8%, hypertensive subjects 37.0% and healthy individuals 30.2%). Measurements: Body mass index (BMI), waist circumference (WC), body fat percentage (BFP) and waist/height ratio (WHtR). Arterial stiffness was assessed according to pulse wave velocity (PWV), intima-media thickness of the common carotid artery (C-IMT), augmentation index (central and peripheral), ankle-brachial index (ABI), and central and peripheral pulse pressure.

Results

WC and WHtR showed a positive correlation to PWV and C-IMT in the studied groups. After adjusting for age, gender, high sensitivity c-reactive protein, serum glucose and the presence of diabetes, hypertension, smoking, dyslipidemia, antidiabetic drugs, lipid-lowering drugs, and atherosclerotic plaques, it was seen that for every 0.1 point increase in WHtR, and for every cm increase in WC, the PWV increased 0.041 and 0.029 m/sec, and C-IMT increased 0.001 mm and 0.001 mm, respectively.

Conclusions

The measures of abdominal obesity (WHtR and WC) correlates better than BMI and BFP with arterial stiffness evaluated by PWV, and with subclinical atherosclerosis evaluated by C-IMT, independently of the presence of diabetes or hypertension.

Trial Registration

Clinical Trials.gov Identifier: NCT01325064