Insulin resistance, postprandial GLP-1 and adaptive immunity are the main predictors of NAFLD in a homogeneous population at high cardiovascular risk.

BACKGROUND AND AIMS: The role of the different factors associated with fatty liver is still poorly defined. We evaluated the relationships between liver fat content (LF) and metabolic, inflammatory and nutritional factors in a homogeneous cohort of individuals at high cardio-metabolic risk. METHODS AND RESULTS: In 70 individuals with high waist circumference and at least one more criterion for metabolic syndrome enrolled in a nutritional intervention study, LF was evaluated at baseline by hepatic/renal echo intensity ratio (H/R), together with dietary habits (7-day dietary record), insulin sensitivity and ß-cell function (fasting and OGTT-derived indices), fasting and postprandial plasma GLP-1 and lipoproteins, and plasma inflammatory markers. H/R correlated positively with fasting and OGTT plasma glucose and insulin concentrations, HOMA-IR and ß-cell function, and IL-4, IL-17, IFN-γ, TNF-α, FGF and GCSF plasma concentrations (p < 0.05 for all), and negatively with insulin sensitivity (OGIS), dietary, polyphenols and fiber (p < 0.05 for all). By multiple stepwise regression analysis, the best predictors of H/R were OGIS (ß = -0.352 p = 0.001), postprandial GLP-1 (ß = -0.344; p = 0.001), HDL-cholesterol (ß = -0.323; p = 0.002) and IFN-γ (ß = 0.205; p = 0.036). CONCLUSION: A comprehensive evaluation of factors associated with liver fat, in a homogeneous population at high cardio-metabolic risk, indicated a pathogenic combination of the same pathways underlying the atherosclerotic process, namely whole body insulin sensitivity and inflammation. The higher predictive value of postprandial variables suggests that liver fat is essentially a postprandial phenomenon, with a relevant role possibly played by GLP-1. REGISTRATION NUMBER FOR CLINICAL TRIALS: NCT01154478.

Contrast-enhanced ultrasound evaluation of peripheral microcirculation in diabetic patients: effects of cigarette smoking.

PURPOSE: Cigarette smoking and diabetes mellitus predisposes to vascular disease. Our study aimed to evaluate the chronic effects of cigarette smoking on peripheral microcirculation assessed with contrast-enhanced ultrasound (CEUS) in diabetic patients. MATERIALS AND METHODS: The study population comprised ten smoker (7/3 M/W, age 42-76 years) and 16 nonsmoker (8/8 men/women, age 47-80 years) diabetic patients. The ankle-brachial index (ABI) was determined, and colour Doppler ultrasound (CDUS) of the lower legs was performed to determine the presence of peripheral arteriopathy disease (PAD). Microvascular blood flow in the gastrocnemius muscle was evaluated with CEUS. RESULTS: No differences were observed in ABI and CDUS examination between smokers and nonsmokers. Smoking had a significant effect on microcirculatory function. Timeto-peak (TTP), arrival time in tissue (ATt) and artery/ tissue transit time (A/Ttt) were significantly prolonged in smokers (TTP 43.76 ± 9.38 s vs. 34.12 ± 6.8 s, p=0.011, ATt 28.9 ± 7.5s vs. 22.4 ± 6.4 s, p=0.017 and A/Ttt 6.81 ± 4.52 s vs. 3.25 ± 3.27 s, p=0.02), with no significant differences between patients with and without PAD. CONCLUSIONS: The long-term exposure to cigarette smoke affects microcirculatory function. Contrast imaging is a noninvasive technique that can document these effects.