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Increased aortic stiffness is closely associated with central obesity whereas mesenteric fat is the key adipose tissue in central obesity. We investigated the associations of mesenteric fat thickness with aortic stiffness, with comparison to conventional obesity measures. We used ultrasound to measure mesenteric, pre-peritoneal and subcutaneous fat thickness, carotid intima-media thickness (CIMT) and carotid-femoral pulse wave velocity (c-f PWV), an index of central aortic stiffness. Anthropometric indexes, blood pressure, fasting plasma glucose and lipid profile were measured. One hundred forty-seven healthy volunteers (age [mean ± standard deviation]: 43.2 ± 13.3 y; 41.5% men) were assessed. On univariate analysis, mesenteric, preperitoneal and subcutaneous fat thickness, body mass index (BMI), waist circumference (WC), waist/hip ratio (WHR) and waist/height ratio (WHtR) were associated with c-f PWV with or without adjustment for age. The mesenteric fat thickness had the highest correlation coefficient (r = 0.48, p0.001) with c-f PWV among all the investigated obesity indexes. Using multiple linear regression analysis, only mesenteric fat thickness remained to be an independent determinant of c-f PWV after adjustments for other abdominal fat thickness, anthropometric and metabolic indexes and CIMT. In conclusion, mesenteric fat thickness is an independent risk factor for aortic stiffness and has a stronger association with aortic stiffness compared with conventional obesity indexes.

To compare the extent to which visceral adiposity, as measured by mesenteric fat thickness, contribute to cardiometabolic risk, especially insulin resistance, in women with PCOS and healthy control.This is a cross-sectional study with a total of 190 women with PCOS fulfilling the Rotterdam diagnostic criteria. Women without PCOS were recruited from a previous study, which comprised 416 healthy women controls with normal glucose tolerance. All subjects underwent OGTT, biochemical assessment, and sonographic assessment with measurements of mesenteric, preperitoneal and subcutaneous fat thickness.Mesenteric fat thickness was strongly correlated to cardiometabolic traits including blood pressure, fasting and 2-h glucose, triglycerides, HOMA-IR; and was negatively correlated to HDL-C in both cohorts (all p0.01). In PCOS, positive correlation was observed between mesenteric fat thickness and free androgen index (p0.01). Compared with controls, the regression line between mesenteric fat and HOMA-IR is much steeper in PCOS (p0.01).Women with PCOS remain more insulin resistant compared to controls at any given degree of visceral adiposity.

The augmented velocity index (Avi) is a new Doppler index associated with arterial stiffness. We examined associations of renal Avi with blood pressure (BP), aortic stiffness and carotid intima-media thickness (IMT), and compared its performance with that of resistive index (RI). One hundred forty-seven volunteers were recruited. Renal Avi had significant positive correlations with systolic BP (r = 0.37, p0.001), diastolic BP (r = 0.2, p = 0.016), mean arterial pressure (r = 0.29, p0.001), pulse pressure (r = 0.31, p0.001), carotid-femoral pulse wave velocity (r = 0.49, p0.001) and carotid IMT (r = 0.23, p = 0.005). RI correlated positively with pulse pressure (r = 0.3, p0.001) only. After adjustments for co-variables, the associations remained similar. Patients with abnormal BP values (≥130/80 mm Hg), IMT and aortic stiffness (≥1 standard deviation of mean value) had higher Avi than those with normal values, but not RI. In conclusion, renal Avi had stronger associations with BP, arterial stiffness and carotid IMT than RI in apparently healthy volunteers, and was significantly increased in abnormal patients.

Augmented Velocity Index (Avi) is a new Doppler index developed to quantify velocity changes at the late systolic peak. We examined its reliability, association with arterial stiffness and cardiovascular risk factors. The Avi is calculated as (late systolic peak velocity - early systolic peak velocity)/(highest peak systolic velocity - end-diastolic velocity). Fifty volunteers (mean age ± standard deviation: 43.5 ± 14.2 y, men: 52%) without known medical illnesses or drug use were recruited. Carotid Doppler waveforms with measurements of Avi were recorded. Carotid pressure waveforms were obtained by applanation tonometry for measurement of the Augmentation Index (AI). Clinical measurements including body mass index (BMI) and blood pressure (BP) were assessed, and fasting blood was taken for measurement of glycemia and lipid profile. Another 15 volunteers (age range: 22-60 y, men: 33.3%) were recruited to study the reliability of Avi measurement. The results revealed that carotid Avi closely correlated with the index of arterial stiffness, AI (r = 0.76, p0.001) on Pearson correlation. On multiple linear regression analysis, Avi remained a significant independent determinant of AI after adjustments for clinical variables. The Avi had significant associations with cardiovascular risk factors (age, BMI, total cholesterol, low-density lipoprotein cholesterol, systolic and diastolic BP). The intra-class correlation coefficients for inter-observer and intra-observer reliability of Avi measurements were 0.93 (95% confidence interval [CI]: 0.8-0.98) and 0.97 (95% CI: 0.92-0.99) respectively. In conclusion, the Avi is a reproducible new Doppler index, independently associated with arterial stiffness in terms of the AI, which initially correlated with cardiovascular risk factors.

An intermediate phenotype of a disease is a trait in the path of pathogenesis from genetic predisposition to disease manifestation. Identifying intermediate phenotypes with high heritability is helpful in delineating the genetics of a disorder. In this study, we aimed to examine various traits with regards to obesity, cardiovascular risk and upper airway structure to identify potential intermediate phenotypes of childhood obstructive sleep apnea (OSA). Children aged between 6 and 18 years and their parents and siblings were recruited. All subjects underwent anthropometric measurements, cardiovascular risk assessment, sonographic measurement of lateral parapharyngeal wall (LPW) thickness, X-ray cephalometry and overnight polysomnography. A total of 34 phenotypes were examined. One hundred and one families consisting of 127 children (46 overweight) and 198 adults (84 overweight) were recruited. Heritability of obstructive apnea-hypopnea index (OAHI) was significant in overweight (h2 = 0.54) but not normal-weight individuals (h2 = 0.12). LPW thickness (h2 = 0.68) and resting blood pressure (h2 = 0.36 and 0.43 for systolic blood pressure [SBP] and diastolic blood pressure [DBP], respectively) were significantly heritable and associated with OAHI. Moreover, these traits were found to have shared genetic variance with OAHI in the overweight subgroup. Hyoid bone position also had significant heritability (h2 = 0.55) and association with OAHI but genetic correlation with OSA severity was not demonstrated. These findings suggest that LPW thickness and resting blood pressure are possible intermediate phenotypes of OSA independent of body mass index, especially in overweight patients. Identifying genes relevant to these phenotypes may help to elucidate the genetic susceptibility of OSA.

STUDY OBJECTIVES: Adenotonsillar hypertrophy is the major cause of obstructive sleep apnea (OSA) in prepubertal children, but children without enlarged lymphoid tissues may still suffer from OSA. This study aimed to identify other potential anatomic features associated with childhood OSA. METHODS: This prospective study took place between January 2010 and April 2014. Prepubertal children suspected to have OSA, aged 6 to 11 years, were recruited. They underwent anthropometric measurements, nocturnal polysomnography, tonsil size evaluation, x-ray cephalometry, and sonographic measurement of lateral parapharyngeal wall (LPW) thickness. Linear regression analyses were used to test for the association between anatomic measurements and OSA severity. Logistic regression analyses were used to identify potential anatomic markers for different cutoffs (obstructive apneahypopnea index (OAHI) ≥ 1 and ≥ 5 events/h) for OSA. RESULTS: Forty-seven children with OSA (20 with moderate to severe disease) and 43 children for the control group were recruited. Sonographic measurement of LPW thickness and position of hyoid bone taken from x-ray cephalometry were risk factors associated with OSA. Linear regression analyses found that these two phenotypes were associated with OAHI. Multivariate models adjusted for age, sex, body mass index, z score, and tonsil size revealed that lower position of hyoid bone was independently associated with higher risk for OSA, whereas both lower position of hyoid bone and greater LPW thickness were associated with higher OAHI and also a higher risk for moderate to severe OSA. CONCLUSIONS: Position of hyoid bone and LPW thickness are anatomical markers of childhood OSA independent of obesity and tonsil size. Screening tools may include cephalometry and sonographic measurement of LPW to allow better delineation of OSA risk. CITATION: Au CT, Chan KC, Liu KH, Chu WC, Wing YK, Li AM. Potential anatomic markers of obstructive sleep apnea in prepubertal children. J Clin Sleep Med. 2018;14(12):1979–1986.

Background Polycystic ovary syndrome (PCOS) is associated with increased metabolic risk, though data on long-term follow-up of cardiometabolic traits are limited. We postulated that Chinese women with PCOS would have higher risk of incident diabetes and cardiometabolic abnormalities than those without PCOS during long-term follow-up. Methods and findings One hundred ninety-nine Chinese women with PCOS diagnosed by the Rotterdam criteria and with a mean age of 41.2 years (SD = 6.4) completed a follow-up evaluation after an average of 10.6 ± 1.3 years. Two hundred twenty-five women without PCOS (mean age: 54.1 ± 6.7 years) who underwent baseline and follow-up evaluation over the same period were used for comparison. Progression of glycaemic status of women both with and without PCOS was assessed by using 75-g oral glucose tolerance test (OGTT) screening with the adoption of 2009 American Diabetes Association diagnostic criteria. The frequency of impaired glucose regulation, hypertension, and hyperlipidaemia of women with PCOS at follow-up has increased from 31.7% (95% CI 25.2%–38.1%) to 47.2% (95% CI 40.3%–54.2%), 16.1% (95% CI 11.0%–21.2%) to 34.7% (95% CI 28.1%–41.3%), and 52.3% (95% CI 45.3%–59.2%) to 64.3% (95% CI 57.7%–71.0%), respectively. The cumulative incidence of diabetes mellitus (DM) in follow-up women with PCOS is 26.1% (95% CI 20.0%–32.2%), almost double that in the cohort of women without PCOS (p < 0.001). Age-standardised incidence of diabetes among women with PCOS was 22.12 per 1,000 person-years (95% CI 10.86–33.37) compared with the local female population incidence rate of 8.76 per 1,000 person-years (95% CI 8.72–8.80) and 10.09 per 1,000 person-years (95% CI 4.92–15.26, p < 0.001) for women without PCOS in our study. Incidence rate for women with PCOS aged 30–39 years was 20.56 per 1,000 person-years (95% CI 12.57–31.87), which is approximately 10-fold higher than that of the age-matched general female population in Hong Kong (1.88 per 1,000 person-years, [95% CI 1.85–1.92]). The incidence rate of type 2 DM (T2DM) of both normal-weight and overweight women with PCOS was around double that of corresponding control groups (normal weight: 8.96 [95% CI 3.92–17.72] versus 4.86 per 1,000 person-years [95% CI 2.13–9.62], p > 0.05; overweight/obese: 28.64 [95% CI 19.55–40.60] versus 14.1 per 1,000 person-years [95% CI 8.20–22.76], p < 0.05). Logistic regression analysis identified that baseline waist-to-hip ratio (odds ratio [OR] = 1.71 [95% CI 1.08–2.69], p < 0.05) and elevated triglyceride (OR = 6.63 [95% CI 1.23–35.69], p < 0.05) are associated with the progression to T2DM in PCOS. Limitations of this study include moderate sample size with limited number of incident diabetes during follow-up period and potential selection bias. Conclusions High risk of diabetes and increased cardiovascular disease risk factors among Chinese women with PCOS are highlighted in this long-term follow-up study. Diabetes onset was, on average, 10 years earlier among women with PCOS than in women without PCOS., Ronald Ching Wan Ma and colleagues reveal the higher incidence of diabetes and CVD in Chinese women with polycystic ovary syndrome., Author summary Why was this study done? Besides reproductive abnormality, it is known that women with polycystic ovary syndrome (PCOS) are at high risk of metabolic complications, such as insulin resistance (IR), impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM). The majority of the accessible longitudinal studies regarding the progression of T2DM in women with PCOS are from the United States, Australia, and Europe. Previous studies have mainly relied on self-report of diabetes status or linkage through national patient registries, which might underestimate the prevalence and incident rate of T2DM in women with PCOS. What did the researchers do and find? During 2016–2017, we prospectively investigated the progression of glycaemic status among 199 Chinese women with PCOS and compared the data with those of 242 women without PCOS by using oral glucose tolerance test (OGTT) for comprehensive glycaemic status screening. We found that the age-standardised incidence rate of T2DM among women with PCOS was around 2.5-fold higher compared with the local female population incidence rate. We noted that the incidence rate of T2DM of both normal-weight and overweight women with PCOS was around double that of respective control groups. This is a key controversial area in international literature and differs from data on individuals of European descent. Diabetes onset was, on average, 10 years earlier among women with PCOS than in women without PCOS. Chinese women with PCOS were at 6-fold higher risk of developing T2DM compared with those without PCOS. High waist-to-hip ratio (WHR), elevated triglyceride, and presence of hyperandrogenism are associated with the progression to T2DM in PCOS. What do these findings mean? This study highlighted the risk of diabetes and metabolic abnormalities in women with PCOS. The study has shed some light on the potential burden of young-onset diabetes associated with PCOS. This work has already been considered in the recent international guidelines, suggesting the clinical relevance of this work. Our data provide useful insights that universal screening should be considered in all Chinese adult women with PCOS. Our data suggested WHR, elevated triglyceride, and hyperandrogenism are associated with the progression to T2DM in PCOS, although we were unable to explore relationships with IR. Therefore, further research is clearly warranted.

Background and objective Mesenteric fat thickness (MFT) was associated with metabolic syndrome (MetS) and obstructive sleep apnoea (OSA) in separate studies. This study aimed to assess whether the association of MFT with MetS was independent of OSA in subjects with suspected OSA. Methods Two hundred forty-two subjects (men: 181; women: 61) with suspected OSA underwent ultrasound examinations for measurements of mesenteric, subcutaneous and preperitoneal fat thicknesses after overnight polysomnography. Anthropometric measurements and metabolic risk profile were assessed. Results Two hundred twenty-one (91%) subjects were confirmed to have OSA with Apnoea–Hypopnoea Index (AHI) >5/h. MFT had significant correlation (P

Background and objective Mesenteric fat is a type of intraperitoneal adipose tissue draining into portal circulation. The objective of this study was to investigate the relationships between mesenteric fat thickness and obstructive sleep apnoea (OSA) in patients with suspected OSA. Methods One hundred forty-nine subjects (men: 114; women: 35) with suspected OSA underwent ultrasound examinations of mesenteric, preperitoneal and subcutaneous fat thickness after overnight polysomnography. Body mass index (BMI) and neck circumference were recorded. Results The subjects with OSA (n = 130, apnoea/hypopnoea index (AHI) >5/h) had greater neck circumference, higher BMI, and greater mesenteric and preperitoneal fat thickness than those without OSA (n = 19, AHI ≤ 5/h). There was positive correlation of AHI with mesenteric (r = 0.43, P

Background. Increased renal arterial resistance is associated with various types of chronic renal parenchymal diseases. A resistance index (RI) > 0.8 predicts deterioration in renal function in diabetic subjects. However, the association between renal RI and other diabetic complications has not been investigated. In this study, we examined the association between intrarenal arterial RI and diabetic complications in Chinese type 2 diabetic subjects. Methods. Three hundred and eighty-seven Chinese type 2 diabetic patients were recruited from a structured assessment programme to evaluate their risk factors and complications as a part of the quality improvement programme at the Prince of Wales Hospital. All subjects underwent ultrasound examinations for the assessment of intrarenal arterial RI of both kidneys. Clinical and biochemical parameters, including diabetes-related microvascular complications (nephropathy, retinopathy and sensory neuropathy) and macrovascular diseases, were examined. Results. The mean RI of patients with any microvascular complications (0.70 ± 0.09 versus 0.65 ± 0.06) such as nephropathy (0.71 ± 0.09 versus 0.66 ± 0.06), retinopathy (0.71 ± 0.08 versus 0.67 ± 0.08) and sensory neuropathy (0.75 ± 0.07 versus 0.68 ± 0.08) and with any macrovascular complications (0.71 ± 0.09 versus 0.68 ± 0.08) was higher than those without (P < 0.05). On multivariate analysis, after controlling for confounding variables, an RI ≥0.75 was associated with microvascular complications, nephropathy, retinopathy and sensory neuropathy, with odds ratio of 4.02 [95% confidence interval (CI) 1.72–9.4], 4.99 (2.61–9.56), 2.78 (1.52–5.09) and 5.74 (1.8–18.3), respectively. The association of RI with macrovascular complications was not significant in multivariate analysis. Conclusion. Increased intrarenal arterial resistance was independently associated with an increased risk of microvascular complications including diabetic nephropathy, diabetic retinopathy and diabetic sensory neuropathy in Chinese type 2 diabetic patients.

Visceral fat is believed to be important in the pathogenesis of metabolic syndrome and fatty liver. In this study, we examined the relationship between mesenteric fat thickness and other sonographic indices of adiposity and the presence of fatty liver among subjects with polycystic ovary syndrome (PCOS).A total of 117 Chinese subjects with PCOS were evaluated (mean age, 28.6 ± 6.5 yr; mean body mass index, 24.3 ± 5.3 kg/m(2)). Anthropometric measurements and metabolic risk profile, including a standard oral glucose tolerance test, were assessed in all subjects. All subjects underwent an ultrasound examination for measurement of thickness of mesenteric, preperitoneal, and sc fat as well as evaluation for fatty liver.Forty-six (39.3%) of the subjects had fatty liver. PCOS subjects with fatty liver had higher body mass index, waist circumference, waist-hip ratio, and systolic blood pressure; a more unfavorable lipid profile with higher triglyceride; lower high-density lipoprotein cholesterol; higher fasting glucose and insulin; higher 2-h glucose during oral glucose tolerance test; lower SHBG; and higher alanine aminotransferase. Subjects with fatty liver had increased thickness of preperitoneal, mesenteric, and sc fat, as well as increased carotid intima-media thickness. Abdominal fat thickness showed moderate correlation to alanine aminotransferase as well as fasting insulin. On multivariate logistic regression, fasting insulin and mesenteric fat thickness were identified as independent predictors of fatty liver among subjects with PCOS.Fatty liver is present in a significant proportion of Chinese patients with PCOS. Sonographic measurement of mesenteric fat is an independent determinant of fatty liver among subjects with PCOS and identifies subjects at increased cardiovascular risk.

Mesenteric fat is drained by the portal circulation and has been suggested to be a key component in obesity-related health risk, notably the metabolic syndrome. There are increasing epidemiological and experimental data showing that fatty liver is another component of this multifaceted syndrome. Given their intimate anatomical and physiological relationships, we hypothesized that mesenteric fat thickness may be independently associated with the risk of fatty liver. To test this hypothesis, we examined the predictive role of various fat deposits including mesenteric fat thickness, and various metabolic variables on the risk of fatty liver. A total of 291 Chinese subjects (134 men and 157 women with a mean BMI of 23.7 kg/m2, range: 16.5–33.4 kg/m2) underwent ultrasound examination for measurement of mesenteric, subcutaneous and preperitoneal fat thickness, and for diagnosis of fatty liver. Body mass index, waist circumference, and waist–hip ratio were recorded. Blood pressure was measured. Fasting plasma glucose, insulin resistance, high-density lipoprotein cholesterol (HDL-C), triglycerides, low-density lipoprotein cholesterol (LDL-C), liver enzymes were determined by common methods. The subjects with fatty liver had greater abdominal fat thickness and higher anthropometric indexes than those without fatty liver. The subjects with fatty liver also showed higher blood pressure, worse lipid and glycaemic profile compared with those without fatty liver. Using multiple logistic regression analysis, mesenteric fat thickness was a risk factor of fatty liver, independent of body mass index, age, sex, insulin resistance, fasting plasma glucose, lipid and blood pressure. The odds ratio was 1.5 (95% confidence interval: 1.27–1.77) for every 1 mm increase in the mesenteric fat thickness. Measurement of preperitoneal and subcutaneous fat deposits did not show significant associations with fatty liver. Mesenteric fat thickness measured on ultrasound is an independent determinant of fatty liver.

Carotid intima-media thickness (IMT) is an established surrogate marker for atherosclerosis. We have previously reported that abdominal fat, notably mesenteric fat, was a major explanatory variable for multiple cardiovascular risk factors. Given the intimate relationships between visceral fat, cardiovascular risk factors and atherosclerosis, we hypothesize that there are independent relationships between mesenteric fat and carotid IMT. Two hundred and eighty-two Chinese subjects (M: 129, F: 153; mean body mass index (BMI): 23.8 kg/m(2); age range: 20-68 years) were recruited. Maximum carotid IMT as well as maximum mesenteric, preperitoneal and subcutaneous fat thickness were measured by carotid and abdominal ultrasound examinations, respectively. Obesity index and conventional cardiovascular risk factors were assessed by physical examination and blood taking. On univariate analysis, mesenteric but not preperitoneal fat thickness was the major correlate with carotid IMT in both men and women. There was also a weak correlation between carotid IMT and subcutaneous fat thickness in women. On multivariate analysis, mesenteric fat thickness was an independent determinant of carotid IMT after adjustment for subcutaneous and preperitoneal fat thickness, age, gender, blood pressure, insulin resistance, lipid and glycaemic parameters. The association of mesenteric fat thickness with carotid IMT appeared stronger in women than in men, which however was not confirmed on multivariate analysis. In conclusion, mesenteric fat thickness measured on ultrasound showed significant association with carotid IMT, lending further support to the linking role of portal adipose tissue in obesity-related atherosclerosis. Effect of gender on the relationships of mesenteric fat with atherosclerosis risk require further elucidation. Measurement of mesenteric fat thickness may be a useful indicator of regional fat distribution in the assessment of cardiovascular risks.

OBJECTIVE: Visceral fat, notably mesenteric fat, which is drained by the portal circulation, plays a critical role in the pathogenesis of metabolic syndrome through increased production of free fatty acids, cytokines and vasoactive peptides. We hypothesize that mesenteric fat thickness as measured by ultrasound scan could explain most of the obesity-related health risk. We explored the relationships between cardiovascular risk factors and abdominal fat as determined by sonographic measurements of thickness of mesenteric, preperitoneal and subcutaneous fat deposits, total abdominal and visceral fat measurement by magnetic resonance imaging (MRI) and anthropometric indexes. DESIGN: A cross-sectional study. SUBJECTS: Subjects included 18 healthy men and 19 women (age: 27–61 y, BMI: 19–33.4 kg/m2). MEASUREMENTS: The maximum thickness of mesenteric, preperitoneal and subcutaneous fat was measured by abdominal ultrasound examination. MRI examinations of whole abdomen and pelvis were performed and the amount of total abdominal and visceral fat was quantified. The body mass index, waist circumference and waist–hip ratio were recorded. Cardiovascular risk factors were assessed by physical examination and blood taking. RESULTS: Men had more adverse cardiovascular risk profile, higher visceral fat volume and thicker mesenteric fat deposits than women. Among all the investigated obesity indexes, the mesenteric fat thickness showed the highest correlations with total cholesterol, LDL-C, triglycerides, fasting plasma glucose, HbA1c and systolic blood pressure in men, and with triglycerides and HbA1c in women. On stepwise multiple regression analysis with different obesity indexes as independent variables, 30–65% of the variances of triglycerides, total cholesterol, LDL-C and HbA1c in men, and triglycerides in women were explained by the mesenteric fat thickness. CONCLUSION: Compared with sonographic measurement of subcutaneous and preperitoneal fat thickness, MRI measurement of total abdominal and visceral fat and anthropometric indexes, sonographic measurement of mesenteric fat thickness showed better associations with some of the cardiovascular risk factors. It may potentially be a useful tool to evaluate regional distribution of obesity in the assessment of cardiovascular risk.

Shear wave elastography (SWE) is a new technique which provides quantitative assessment of soft tissue stiffness. The aim of this study was to assess the reliability of SWE stiffness measurements and its usefulness in evaluating post-irradiation neck fibrosis.50 subjects (25 patients with previous radiotherapy to the neck and 25 sex and age-matched controls) were recruited for comparison of SWE stiffness measurements (Aixplorer, Supersonic Imagine). 30 subjects (16 healthy individuals and 14 post-irradiated patients) were recruited for a reliability study of SWE stiffness measurements. SWE stiffness measurements of the sternocleidomastoid muscle and the overlying subcutaneous tissues of the neck were made. The cross-sectional area and thickness of the sternocleidomastoid muscle and the overlying subcutaneous tissue thickness of the neck were also measured. The post-irradiation duration of the patients was recorded.The intraclass correlation coefficients for the intraoperator and interoperator reliability of deep and subcutaneous tissue SWE stiffness ranged from 0.90-0.99 and 0.77-0.94, respectively. The SWE stiffness measurements (mean +/- SD) of deep and subcutaneous tissues were significantly higher in the post-irradiated patients (64.6 ± 46.8 kPa and 63.9 ± 53.1 kPa, respectively) than the sex and age-matched controls (19.9 ± 7.8 kPa and 15.3 ± 8.37 respectively) (p0.001). The SWE stiffness increased with increasing post-irradiation therapy duration in the Kruskal Wallis test (p0.001) and correlated with muscle atrophy and subcutaneous tissue thinning (p0.01).SWE is a reliable technique and may potentially be an objective and specific tool in quantifying deep and subcutaneous tissue stiffness, which in turn reflects the severity of neck fibrosis.

Introduction: Contemporary studies indicate that the incidence of deep vein thrombosis (DVT) is increasing in the Asian population. The present study aims to evaluate the incidence of postoperative DVT in Chinese patients undergoing surgery for colorectal ­malignancies. Methods: Fifty-one consecutive patients with carcinoma of the rectum or sigmoid colon scheduled for resection were included in the study. None of the study subjects were given any form of DVT prophylaxis. Serial duplex ultrasound of both lower limbs were examined in the preoperative and postoperative periods. Results: Three patients were excluded from the study because of the presence of DVT noted preoperatively. A total of 20/48 (41.7%) patients developed asymptomatic calf vein thrombosis. One out of 20 patients required anticoagulation because of thrombus propagation. None of the subjects showed signs or symptoms of DVT or pulmonary embolism. A total of 7/20 thrombi resolved completely at 4 weeks after operation. Only old age and smoking were identified as being associated with a higher incidence of DVT. Disseminated disease, type of operation, duration of operation and postoperative complications did not appear to be risk factors for DVT. Conclusion: A high incidence of asymptomatic calf vein thrombosis occurred after colorectal surgery for malignancies in Chinese. The majority did not progress even without anticoagulation.

BACKGROUND Radiation-induced carotid stenosis in patients with head and neck tumors can cause significant mortality and morbidity. This study examined the incidence of stenosis in the extracranial carotid arteries of nasopharyngeal carcinoma patients after radiotherapy. METHODS The extracranial carotid arteries of 71 (53 male and 18 female; mean age of 53.6 years) postradiation patients with nasopharyngeal carcinoma were examined with color Doppler ultrasound. The distribution of the arterial stenosis and the degree of stenosis were documented. The results were compared with the control group, which comprised 51 newly diagnosed nasopharyngeal carcinoma patients (35 male and 16 female, mean age of 48.8 years) before radiotherapy. Incidences of risk factors for arterial stenosis such as hypertension, smoking, and hypercholesterolemia also were studied in these two groups. RESULTS There was no significant difference in the incidence of risk factors between the two groups. Arterial stenosis was, however, more common in the postradiation group than the preradiation group (56 of 71 vs. 11 of 51). The common/internal carotid arteries (CCA/ICA) were most commonly involved (55 of 71 vs. 11 of 51; P 50% reduction of luminal diameter) was only found in the postradiation group (21 of 71 in CCA/ICA, 11 of 71 in ECA, 4 of 71 in VA). CONCLUSIONS This study showed that radiation could cause significant carotid stenosis. Ultrasound examinations for these patients therefore are necessary for early detection and possible intervention of this late radiation-induced complication. Cancer 2001;92:2357–63. © 2001 American Cancer Society.

Background Carotid artery stenosis is a late complication of radiotherapy to the neck region. This complication has, however, a significant impact with increased risk of stroke causing mortality and morbidity. Clinicians' awareness of this complication and early detection is therefore important. Methods Eighty patients with nasopharyngeal carcinoma (NPC) who had received radiotherapy were recruited for color Doppler ultrasonography of the carotid arteries. fifty-eight patients with newly diagnosed NPC who had never received any radiotherapy were recruited as controls. All patients with significant carotid stenosis were referred to the neurology clinic for further assessment. Results Twenty-four patients were found to have more than 50% diameter reduction in the extracranial carotid artery. Clinical assessment by a neurologist showed 9 of 24 patients had a history of transient ischemic attack, amaurosis fugax, or stroke. Seven of these patients had clinically detectable neck bruit. Conclusions Clinicians attending to patients after radiotherapy for head and neck cancers should be aware of this long-term complication of radiotherapy. A detailed clinical history and incorporation of auscultation of carotid arteries in routine follow-up of postradiotherapy patients are recommended. © 2001 John Wiley & Sons, Inc. Head Neck 23: 780–784, 2001.

Mesenteric fat is a type of intraperitoneal adipose tissue draining into portal circulation. The objective of this study was to investigate the relationships between mesenteric fat thickness and obstructive sleep apnoea (OSA) in patients with suspected OSA.One hundred forty-nine subjects (men: 114; women: 35) with suspected OSA underwent ultrasound examinations of mesenteric, preperitoneal and subcutaneous fat thickness after overnight polysomnography. Body mass index (BMI) and neck circumference were recorded.The subjects with OSA (n = 130, apnoea/hypopnoea index (AHI)5/h) had greater neck circumference, higher BMI, and greater mesenteric and preperitoneal fat thickness than those without OSA (n = 19, AHI ≤ 5/h). There was positive correlation of AHI with mesenteric (r = 0.43, P 0.001) and preperitoneal fat thickness (r = 0.3, P 0.001), whereas no significant association was observed between AHI and subcutaneous fat thickness (r = 0.09, P = 0.27). On multivariate logistic regression, after adjustments for gender, age, BMI, neck circumference, and preperitoneal and subcutaneous fat thickness, the mesenteric fat thickness had a positive association with the presence of moderate OSA and severe OSA, with odds ratios of 7.18 and 7.45 for every 1 cm increase in mesenteric fat thickness when AHI was defined as ≥15/h and AHI ≥ 30/h, respectively.Mesenteric fat thickness is associated with increased risk of OSA, independent of other abdominal fat thickness, BMI and neck circumference. Sonographic measurement is potentially a useful tool for further evaluating the complex association of visceral fat, metabolic syndrome and OSA.

To examine the sensitivity of ultrasonography (US) compared with conventional radiography in detection of lower limb (thigh) medial arterial calcification (MAC) in type 2 diabetic patients and evaluate its association with diabetes-related complications.The study was approved by the local research ethics committee, and informed written consent was obtained. US was performed in 289 patients with type 2 diabetes mellitus, and MAC severity was assigned a score from 0 to 8. Among the patients, 263 underwent radiographic examinations. All subjects underwent clinical evaluation to detect the presence of diabetes-related complications.US helped detect MAC in more subjects compared with radiography (65.8% vs 12.2%). US helped detect MAC from mild (scores 1-4) to severe (scores 5-8) degrees, while mild degree of MAC was poorly demonstrated with radiography. The incidence of nephropathy, retinopathy, sensory neuropathy, and macrovascular complications increased with the severity of MAC (based on US scoring). With univariate analysis, the presence of MAC was associated with nephropathy (P.001), retinopathy (P.001), sensory neuropathy (P=.004), and macrovascular complications (P.001). After adjustment for potential confounders, the presence of severe MAC was associated with nephropathy, retinopathy, and macrovascular complications, with the odds ratios of 3.4 (95% confidence interval [CI]: 1.53, 7.43; P=.003), 2.6 (95% CI: 1.22, 5.32; P=.013), and 3.8 (95% CI: 1.37, 10.6; P=.01), respectively.In type 2 diabetic Chinese patients, US was more sensitive than conventional radiography in the detection of MAC, particularly when the MAC was mild. The presence of severe MAC was associated with diabetic nephropathy, retinopathy, and macrovascular complications. US detection of MAC was a potential early marker to identify diabetes-related complications.

Renal dysfunction can be evaluated by increased intra-renal arterial resistance index (RI). We evaluated 113 Chinese men with type 2 diabetes on their RI. Results suggest that RI is associated with chronic kidney disease and subclinical arteriosclerosis. RI may help monitoring the deterioration of intra-renal hemodynamics.

Summary Aims Sonographic measurement of mesenteric fat thickness (MFT) is a novel, accurate and simple tool to evaluate regional distribution of obesity. We used MFT to determine the optimal waist circumference (WC) values and associated risk factors for cardiovascular disease (CVD). Methods 282 healthy Chinese (age 41.8±7.4 years, BMI 23.8±3.3kg/m 2 ) was assessed. High MFT was defined as mean+1 SD of the cohort. We compared the CVD risks including fatty liver amongst subjects with normal waist, central pre-obesity and central obesity. Results WC of 84.6cm in men and 75.7cm in women were the optimal cutoff values to predict high MFT with ROC analysis. Using WC cutoff values ≥85–90cm and ≥90cm to define central pre-obesity and obesity in men (≥75–80cm and ≥80cm in women), both central obesity and pre-obesity had higher MFT and CVD risk than those with normal waist. The frequencies of fatty liver in these 3 categories were 15.9%, 56.7% and 96.7% in men and 6.9%. 17.9% and 63.2% in women ( p Conclusion In addition to central obesity, "central pre-obesity" identifies subjects who harbor high CVD risks, fatty liver and excess visceral fat.

OBJECTIVE—Mesenteric fat, a reflection of visceral adiposity, may play an important role in the pathogenesis of metabolic syndrome and cardiovascular diseases (CVD). In this study, we examined the independent relationship between mesenteric fat thickness and metabolic syndrome and defined its optimal cutoff value to identify high-risk subjects for metabolic syndrome and CVD. RESEARCH DESIGN AND METHODS—A total of 290 Chinese subjects had an ultrasound examination for measurements of thickness of mesenteric, preperitoneal, and subcutaneous fat as well as carotid intima-media thickness (IMT). Anthropometric measurements and metabolic risk profile were assessed by physical examination and blood taking. RESULTS—Twenty (6.9%) subjects had metabolic syndrome according to the National Cholesterol Education Panel Adult Treatment Panel III criteria with Asian definitions for central obesity (waist circumference >80 cm in women and >90 cm in men). Mesenteric fat thickness had significant correlations (P < 0.05) with various metabolic variables. On multivariate regression, mesenteric fat thickness was an independent determinant of all components of metabolic syndrome after adjustment for age, sex, homeostasis model assessment of insulin resistance, and other fat deposits. The odds ratio of metabolic syndrome was increased by 1.35 (95% CI 1.10–1.66)-fold for every 1-mm increase in mesenteric fat thickness. On receiver-operating characteristic curve analysis, mesenteric fat thickness of ≥10 mm was the optimal cutoff value to identify metabolic syndrome, with sensitivity of 70% and specificity of 75%. Subjects with mesenteric fat thickness ≥10 mm had higher carotid IMT than those with thickness CONCLUSIONS—Mesenteric fat thickness was an independent determinant of metabolic syndrome and identified subjects with increased carotid IMT.

AIM: Intima-media thickness (IMT) has been shown to be useful in the evaluation and monitoring of carotid artery atherosclerosis in patients at risk of cardiovascular events. In this study, we aimed to examine the IMT in patients with nasopharyngeal carcinoma (NPC) who received irradiation to the carotid arteries during radiotherapy, and compared them with a control group. MATERIALS AND METHODS: Fifty-one NPC patients (aged between 39 and 69 years) and a group of 51 age-and sex-matched controls were studied by ultrasound. The IMT at the far wall of the common carotid artery was measured three times and the average value taken in each subject. The IMT of both groups were compared. Risk factors for IMT thickness, including hypertension, smoking, hyperglycaemia, hypercholesterolaemia, history of cerebrovascular accidents and cardiovascular disease, were also studied. RESULTS: The mean carotid IMT of patients in the NPC group (2.2+/−1.5 mm) was statistically greater than that in normal controls (0.7+/−0.15 mm) (P < 0.05). There was no statistically significant difference between the IMT in the right and left common carotid arteries within each group of patients. CONCLUSION: The findings suggest that patients with irradiation have increased arterial IMT. As they are asymptomatic the clinical relevance is not clear. So, N. M. C. etal. (2002) Clinical Radiology57, 600–603.

Patients with end-stage renal disease (ESRD) are at increased risk for tissue calcifications as a result of deranged mineral metabolism. We tested the hypothesis that valvular calcification is a marker of atherosclerosis in patients with ESRD.Echocardiography was performed in 92 patients undergoing peritoneal dialysis with no background atherosclerotic vascular complications to detect valvular calcification. We used B-mode ultrasonography to determine carotid artery intima-media thickness and the presence of plaque and calcification.Compared with patients without valvular calcification (n=66), those with valvular calcification (n=26) had higher C-reactive protein levels (P=.01) and greater mean +/- SE carotid intima-media thickness (1.12 +/- 0.06 vs 0.88 +/- 0.04 mm; P=.003). Carotid artery calcification was present unilaterally and bilaterally in 4 patients (15%) and 17 patients (65%) with valvular calcification vs 11 (17%) and 14 (21%) without, respectively (P.001). Carotid artery plaque was present unilaterally and bilaterally in 11 patients (12%) and 16 patients (65%) with valvular calcification vs 3 (17%) and 17 (24%) without, respectively (P=.001). Using multiple logistic regression analysis, every 1-mm increase in carotid intima-media thickness was independently associated with a 6.51-fold (95% confidence interval, 1.58-26.73; P=.009) increased risk of valvular calcification, and calcification and plaque in the carotid arteries were associated with a 7.18-fold (95% confidence interval, 2.39-21.51; P.001) and a 5.00-fold (95% confidence interval, 1.77-14.13; P=.002) increased risk of valvular calcification, respectively.The associations among valvular calcification, inflammation, carotid atherosclerosis, and arterial calcification suggest that valvular calcification is a marker of atherosclerosis and arterial calcification in patients with ESRD.

OBSTRUCTIVE SLEEP APNEA (OSA) IS A COMMON FORM OF SLEEP-DISORDERED BREATHING CHARACTERIZED BY REPETITIVE EPISODES OF PARTIAL OR COMPLETE upper airway obstruction causing sleep fragmentation and symptoms.1 OSA syndrome is equally common among the middle-aged male Caucasian and Asian populations, with a prevalence of at least 4%.2–4 Most patients with OSA have an anatomically small upper airway with augmented pharyngeal dilator muscle activation maintaining airway patency awake but not asleep.5 Obesity is the most important risk factor in the pathogenesis of OSA in middle-aged adults.6 Craniofacial abnormality also plays an important role in OSA, especially in Asian populations. Although Asian patients with OSA are generally less obese than their Caucasian counterparts, craniofacial abnormalities such as a low hyoid bone and retro-position of the maxilla or mandible are common predisposing factors for OSA in Asian populations.7,8 Fat deposits in the tongue and soft tissues surrounding the upper airspace may narrow the airway during wakefulness.9 It has been suggested that thickness of the lateral parapharyngeal muscular walls demonstrated on magnetic resonance imaging (MRI) rather than enlargement of parapharyngeal fat pads was the predominant anatomic factor causing airway narrowing in apneic subjects.10 However MRI is an expensive imaging modality that is not readily available in most clinical settings. Ultrasound is a simple imaging technique that can demonstrate part of the anatomic structures surrounding the upper airway, and the thickness of the lateral parapharyngeal wall (LPW) can be measured in an oblique coronal plane close to the imaging plane on MRI. The aims of this study were to explore the potential role of ultrasound imaging in the evaluation of the upper airway in subjects with suspected OSA by comparing measurements of the LPW thickness based on ultrasound and MRI. In addition, we investigated if there was any association between the LPW thickness based on sonographic measurement and the severity of OSA.