Diabetes News
Impaired microvascular properties in uncomplicated type 1 diabetes identified by Doppler ultrasound of the ocular circulation
Objective: Quantification of Doppler flow velocity waveforms has been shown to predict adverse cardiovascular outcomes and identify altered downstream haemodynamics and vascular damage in a number of organ beds. We employed novel techniques to quantify Doppler flow velocity waveforms from the retro bulbar circulation.
Methods and results: In total, 39 patients with uncomplicated Type 1 diabetes mellitus, and no other significant cardiovascular risk factors were compared with 30 control subjects. Flow velocity waveforms were captured from the ophthalmic artery (OA), central retinal artery (CRA) and the common carotid artery. The flow velocity profiles were analysed in the time domain to calculate the resistive index (RI), and time-frequency domain using novel discrete wavelet transform methods for comparison. Analysis of flow waveforms from the OA and CRA identified specific frequency band differences between groups, occurring independently of potential haemodynamic or metabolic confounding influences. No changes were identified in the calculated RI from any arterial site.
Conclusion: Novel analysis of the arterial flow velocity waveforms recorded from the retro bulbar circulation identified quantifiable differences in Doppler flow velocity waveform morphology in patients with diabetes prior to the development of overt retinopathy. The technique may be useful as an additional marker of cardiovascular risk.
The Radioprotective 105/MD-1 Complex Contributes to Diet-Induced Obesity and Adipose Tissue Inflammation
Recent accumulating evidence suggests that innate immunity is associated with obesity-induced chronic inflammation and metabolic disorders. Here, we show that a Toll-like receptor (TLR) protein, radioprotective 105 (RP105)/myeloid differentiation protein (MD)-1 complex, contributes to high-fat diet (HFD)-induced obesity, adipose tissue inflammation, and insulin resistance. An HFD dramatically increased RP105 mRNA and protein expression in stromal vascular fraction of epididymal white adipose tissue (eWAT) in wild-type (WT) mice. RP105 mRNA expression also was significantly increased in the visceral adipose tissue of obese human subjects relative to nonobese subjects. The RP105/MD-1 complex was expressed by most adipose tissue macrophages (ATMs). An HFD increased RP105/MD-1 expression on the M1 subset of ATMs that accumulate in eWAT. Macrophages also acquired this characteristic in coculture with 3T3-L1 adipocytes. RP105 knockout (KO) and MD-1 KO mice had less HFD-induced adipose tissue inflammation, hepatic steatosis, and insulin resistance compared with wild-type (WT) and TLR4 KO mice. Finally, the saturated fatty acids, palmitic and stearic acids, are endogenous ligands for TLR4, but they did not activate RP105/MD-1. Thus, the RP105/MD-1 complex is a major mediator of adipose tissue inflammation independent of TLR4 signaling and may represent a novel therapeutic target for obesity-associated metabolic disorders.
Effects of Diet Soda on Gut Hormones in Youths With Diabetes
OBJECTIVE
In patients with type 2 diabetes, but not type 1 diabetes, abnormal secretion of incretins in response to oral nutrients has been described. In healthy youths, we recently reported accentuated glucagon-like peptide 1 (GLP-1) secretion in response to a diet soda sweetened with sucralose and acesulfame-K. In this study, we examined the effect of diet soda on gut hormones in youths with diabetes.
RESEARCH DESIGN AND METHODS
Subjects aged 12–25 years with type 1 diabetes (n = 9) or type 2 diabetes (n = 10), or healthy control participants (n = 25) drank 240 mL cola-flavored caffeine-free diet soda or carbonated water, followed by a 75-g glucose load, in a randomized, cross-over design. Glucose, C-peptide, GLP-1, glucose-dependent insulinotropic peptide (GIP), and peptide Tyr-Tyr (PYY) were measured for 180 min. Glucose and GLP-1 have previously been reported for the healthy control subjects.
RESULTS
GLP-1 area under the curve (AUC) was 43% higher after ingestion of diet soda versus carbonated water in individuals with type 1 diabetes (P = 0.020), similar to control subjects (34% higher, P = 0.029), but was unaffected by diet soda in patients with type 2 diabetes (P = 0.92). Glucose, C-peptide, GIP, and PYY AUC were not statistically different between the two conditions in any group.
CONCLUSIONS
Ingestion of diet soda before a glucose load augmented GLP-1 secretion in type 1 diabetic and control subjects but not type 2 diabetic subjects. GIP and PYY secretion were not affected by diet soda. The clinical significance of this increased GLP-1 secretion, and its absence in youths with type 2 diabetes, needs to be determined.
Liraglutide Treatment in a Patient With HIV and Uncontrolled Insulin-Treated Type 2 Diabetes
Detection of myocardial microvascular disease using contrast echocardiography during adenosine stress in type 2 diabetes mellitus: Prospective comparison with single-photon emission computed tomography
Purrpose: To evaluate myocardial microvascular disease in patients with type 2 diabetes mellitus (DM) using myocardial contrast echocardiography (MCE) and to report on its diagnostic accuracy using single photon emission tomography (SPECT) as reference test.
Methods: We prospectively enrolled 79 patients (25 DM; 66±11 years) who underwent simultaneous SPECT and MCE with contrast agent during adenosine stress. MCE and SPECT were visually analyzed using 17 segments. Quantitative MCE parameters were derived from replenishment curves. Microbubble velocity (β min–1), absolute myocardial blood flow (MBF ml/min/g), and reserve values were calculated. Diagnostic accuracy and area under curve (AUC) was reported.
Results: Patients with DM had higher BMI vs non DM (33±7 vs 28±5kg/m2 P=0 .007), with more prior myocardial infarction (40 vs 15% P=.01). Visual MCE was abnormal in 40 (51%) patients (60% in DM vs 46% in non DM P=0.04). SPECT was abnormal in 38 (48%) patients [60% in DM vs 42% non DM, P=0.01]. Reserve parameters were lower in DM vs. non DM patients: (β 1.77±1.12 vs 2.20±1.4, P<0.001 and MBF 2.86± 2.62 vs. 3.67±2.84, P<0.001). DM patients without CAD on SPECT had significantly lower β, and MBF reserve compared to non DM patients without CAD. Compared to SPECT, β reserve cutoff 1.6 had AUC 0.817, sensitivity 81%, and specificity 66% while MBF reserve cutoff 1.9 had AUC 0.760, sensitivity 79%, and specificity 63% in DM patients.
Conclusion: Diabetes is associated with myocardial microvascular abnormalities as evidenced by abnormal myocardial perfusion on visual and quantitative MCE.
Building muscle without heavy weights
Weight training at a lower intensity but with more repetitions may be as effective for building muscle as lifting heavy weights, says a new opinion piece. Issues and Events
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