Mesenteric fat thickness is associated with increased risk of obstructive sleep apnoea.

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 < 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. CONCLUSIONS: 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.

Intrarenal arterial resistance is associated with microvascular complications in Chinese type 2 diabetic patients.

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.

US assessment of medial arterial calcification: a sensitive marker of diabetes-related microvascular and macrovascular complications.

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.