Clinical research and methodology. The paradigm of fatty liver and atherosclerosis behind the chicken or the egg dilemma

Non-alcoholic fatty liver disease and Atherosclerosis at a crossroad: The overlap of a theory of change and bioinformatics

Atherosclerosis (ATH) and non-alcoholic fatty liver disease (NAFLD) are medical conditions that straddle a communal epidemiology, underlying mechanism and a clinical syndrome that has protean manifestations, touching every organ in the body. These twin partners, ATH and NAFLD, are seemingly straightforward and relatively simple topics when considered alone, but their interdependence calls for more thought. The study of the mutual relationship of NAFLD and ATH should involve big data analytics approaches, given that they encompass a constellation of diseases and are related to several recognized risk factors and health determinants and calls to an explicit theory of change, to justify intervention. Research studies on the “association between aortic stiffness and liver steatosis in morbidly obese patients”, published recently, sparsely hypothesize new mechanisms of disease, claiming the “long shadow of NAFLD” as a risk factor, if not as a causative factor of arterial stiffness and ATH. This statement is probably overreaching the argument and harmful for the scientific credence of this area of medicine. Despite the verification that NAFLD and cardiovascular disease are strongly interrelated, current evidence is that NAFLD may be a useful indicator for flagging early arteriosclerosis, and not a likely causative factor. Greater sustainable contribution by precision medicine tools, by validated bioinformatics approaches, is needed for substantiating conjectures, assumptions and inferences related to the management of big data and addressed to intervention for behavioral changes within an explicit theory of change.

Nonalcoholic fatty liver disease and advanced fibrosis are associated with left ventricular diastolic dysfunction

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) may be associated with a wide spectrum of cardiac abnormalities, which share many metabolic risk factors. This study aimed to evaluate whether NAFLD is associated with left ventricular (LV) diastolic dysfunction independent of other classical risk factors.

METHODS

A total of 3300 subjects (mean age, 54.1 years; 62.9% men), who underwent echocardiography and hepatic ultrasonography, were enrolled. LV diastolic dysfunction was diagnosed and graded using conventional and Doppler echocardiographic assessments. NAFLD was diagnosed by ultrasonographic findings without any evidence of significant alcohol consumption or viral hepatitis, other liver diseases, or medication provoking fatty liver. Advanced fibrosis was defined as having intermediate-high probability for advanced fibrosis using the NAFLD fibrosis score.

RESULTS

The prevalence of LV diastolic dysfunction was 35.1%. NAFLD had a higher prevalence and severity of LV diastolic dysfunction. The prevalence rates of LV diastolic dysfunction were significantly increased according to the NAFLD fibrosis grade (30.4% for no-NAFLD, 35.2% for NAFLD without advanced fibrosis and 57.4% for NAFLD with advanced fibrosis, p < 0.001). Multivariable analysis showed that NAFLD was associated with a 29% increase in the risk of diastolic dysfunction compared with controls (odds ratio [OR] 1.29; 95% confidence interval [CI] 1.07-1.60). There was significant interaction between obesity (BMI < 25 kg/m2vs. ≥ 25 kg/m2) and advanced fibrosis for LV diastolic dysfunction. A significant, incrementally increased risk of diastolic dysfunction according to the fibrosis grade was more pronounced in the non-obese population [adjusted OR (95% CI), 1.40 (1.06-1.84) for NAFLD without advanced fibrosis, 1.44 (0.95-2.17) for NAFLD with advanced fibrosis vs. no NAFLD, P for trend = 0.022] compared with the obese population (p for trend = 0.081), independent of other well-defined risk factors.

CONCLUSIONS

NAFLD was associated with increased risk for LV diastolic dysfunction. In addition, an incrementally increased risk for LV diastolic dysfunction according to fibrosis grade was prominent in the non-obese population.

Neglected features of lifestyle: Their relevance in non-alcoholic fatty liver disease

AIM

To investigated in non-alcoholic-fatty-liver-disease (NAFLD), with ultrasound (US)-detected fatty liver, and in a group of non-alcoholic and otherwise healthy subjects, relationship of neglected features of lifestyle with NAFLD and obesity.

METHODS

Five hundred and thirty-two NAFLD and 667 non-NAFLD healthy subjects, age 21-60 years were studied. Severity of liver steatosis was assessed by US bright liver score. The adherence to mediterranean diet score (AMDS) was assessed on the basis of a 1-wk recall computerized questionnaire which included a detailed physical activity reports (Baecke questionnaire). The western dietary profile score, as a simplified paradigm of unhealthy diet, a questionnaire quantifying sun exposure score and a sleep habits questionnaires provided a further comprehensive lifestyle assessment.

RESULTS

Body mass index (BMI), insulin resistance (HOMA), and triglycerides, poorer adherence to a mediterranean diet profile, sedentary habits, minor sun exposure and use of “western diet” foods are greater in NAFLD. Multiple linear regression analysis, weighted by years of age, displays BMI, HOMA and AMDS as the most powerful independent predictors of fatty liver severity; however, also the physical activity score, the western diet habit and the sun exposure score are acting inside the model with significant independent effects.

CONCLUSION

Articulated clinical intervention, according to our results, are justified in NAFLD and can be pursued addressing by focused intervention nutritional profile, physical exercise mainly in open-air subsets for enhancing sun exposure and healthier sleep duration and rhythm.

Integration of suboptimal health status and endothelial dysfunction as a new aspect for risk evaluation of cardiovascular disease

BACKGROUND

Suboptimal health status (SHS) is recognized as a subclinical, reversible stage of chronic disease. Association has been confirmed between SHS and cardiovascular risk factors, indicating that SHS may contribute to the development of cardiovascular disease. This study explored integrated risk assessment of cardiovascular disease by combining SHS questionnaire-25 (SHSQ-25) and indicators of endothelial dysfunction.

METHODS

A community-based cross-sectional study was conducted in a sample of 459 residents of Samara, Russia, who had no history of clinical diagnosed disease and did not receive any treatment in the last 2 weeks. The SHS score was derived from the data collected in the SHSQ-25. Blood pressure, body mass index, and glucose and lipid levels (total cholesterol, low density lipoprotein, cholesterol and triglycerides) were measured by physical examination and laboratory performance. The relationship between SHS and endothelial dysfunction was examined using Pearson's correlation linear regression analysis. Cluster analysis was performed to identify systemic patterns arising from exposure to a variety of risk factors.

RESULTS

Significant correlations were observed between index of endothelial function and the overall performance of SHS (r = -0.31, p < 0.05), and individual scales of the questionnaire SHSQ-25: fatigue (r = -0.36, p < 0.05), mental (r = -0.29, p < 0.05), and the cardiovascular system (r = -0.36). Based on cluster analysis, all subjects were grouped into five clusters: (1) optimal health status, (2) SHS at low risk of disease states, (3) SHS with a high risk of non-cardiac pathologies profile, (4) SHS of low risk of cardiovascular disease, and (5) SHS with high risk of cardiovascular disease.

CONCLUSIONS

SHS is associated with endothelial dysfunction. Integration of suboptimal health status and endothelial dysfunction provides a novel tool to allow people to get a more holistic picture of both subjective and objective health measures, and also can be applied to routine screening for risks of cardiovascular diseases.