Protein and vitamin B6 intake are associated with liver steatosis assessed by transient elastography, especially in obese individuals

BACKGROUND/AIMS

Although the detrimental effects of several dietary components on the promotion of nonalcoholic fatty liver disease are well known, no studies have assessed the role of dietary vitamin B6. Moreover, studies on the associations between dietary components or body composition indices and liver steatosis assessed by transient elastography are rare. Our aim was to identify the nutritional factors and anthropometric parameters associated with liver steatosis.

METHODS

In this cross-sectional study, we enrolled 168 individuals (35% obese) who underwent a liver steatosis assessment by Controlled Attenuation Parameter measurement and nutritional assessment.

RESULTS

Tertiles of vitamin B6 intake were positively associated with hepatic steatosis (B=1.89, P=0.026, confidence interval [CI] 0.03-0.80) as well as with triglycerides, glucose, alanine aminotransferase (ALT), and body mass index . In obese individuals, after multivariable analysis, the Controlled Attenuation Parameter score was still associated with triglycerides, ALT, and total protein intake (B=0.56, P=0.01, CI 0.10-1.02). Participants in tertile I (low intake) had a lower Controlled Attenuation Parameter than those in tertile III (P=0.01).

CONCLUSIONS

We found a positive association between hepatic steatosis or Controlled Attenuation Parameter score and vitamin B6/total protein intake, probably related to the high intake of meat. Vitamin B6 might have a pathogenic role related to the increase of hepatic steatosis.

Effects of acute physical exercise on oxidative stress and inflammatory status in young, sedentary obese subjects

Circulating oxidative stress and pro-inflammatory markers change after regular physical exercise; however, how a short session of acute physical activity affects the inflammatory status and redox balance in sedentary individuals is still unclear. Aim of this study is to assess antioxidant and inflammatory parameters, both at rest and after acute exercise, in sedentary young men with or without obesity. Thirty sedentary male volunteers, aged 20–45 (mean age 32 ± 7 years), were recruited, divided into 3 groups (normal weight: BMI < 25 kg/m²; overweight to moderate obesity: 25–35 kg/m²; severe obesity: 35–40 kg/m²), and their blood samples collected before and after a 20-min run at ~ 70% of their VO_2max for the measurement of Glutathione Reductase, Glutathione Peroxidase, Superoxide Dismutase, Total Antioxidant Status (TAS) and cytokines (IL-2, IL-4, IL-6, IL-8, IL-10, IL-1α, IL-1β, TNFα, MCP-1, VEGF, IFNγ, EGF). Inter-group comparisons demonstrated significantly higher Glutathione Reductase activity in severely obese subjects in the post-exercise period (P = 0.036), and higher EGF levels in normal weight individuals, either before (P = 0.003) and after exercise (P = 0.05). Intra-group comparisons showed that the acute exercise stress induced a significant increase in Glutathione Reductase activity in severely obese subjects only (P = 0.007), a significant decrease in MCP-1 in the normal weight group (P = 0.02), and a decrease in EGF levels in all groups (normal weight: P = 0.025, overweight/moderate obesity: P = 0.04, severe obesity: P = 0.018). Altogether, these findings suggest that in sedentary individuals with different ranges of BMI, Glutathione Reductase and distinct cytokines are differentially involved into the adaptive metabolic changes and redox responses induced by physical exercise. Therefore, these biomarkers may have the potential to identify individuals at higher risk for developing diseases pathophysiologically linked to oxidative stress.

Is hand-grip another culprit for the risk of fractures in HIV-positive patients?

Risk of bone fractures in patients with HIV infection is greater than in the general population, particularly in those co-infected with hepatitis viruses. We compared bone mineral density (BMD) and muscular strength, measured by hand grip test (HG), in HIV mono-infected and co-infected patients. T-score values were lower in HIV patients co-infected with hepatitis viruses vs. mono-infected individuals. Since no significant correlations between HG and T-scores were found, we hypothesize that these factors belong, at least in part, to independent pathways, so both should be taken into account as risks for fragility fractures. Larger prospective studies are needed to confirm this hypothesis.

High Vegetable Fats Intake Is Associated with High Resting Energy Expenditure in Vegetarians

It has been demonstrated that a vegetarian diet may be effective in reducing body weight, however, the underlying mechanisms are not entirely clear. We investigated whether there is a difference in resting energy expenditure between 26 vegetarians and 26 non-vegetarians and the correlation between some nutritional factors and inflammatory markers with resting energy expenditure. In this cross-sectional study, vegetarians and non-vegetarians were matched by age, body mass index and gender. All underwent instrumental examinations to assess the difference in body composition, nutrient intake and resting energy expenditure. Biochemical analyses and 12 different cytokines and growth factors were measured as an index of inflammatory state. A higher resting energy expenditure was found in vegetarians than in non-vegetarians (p = 0.008). Furthermore, a higher energy from diet, fibre, vegetable fats intake and interleukin-β (IL-1β) was found between the groups. In the univariate and multivariable analysis, resting energy expenditure was associated with vegetarian diet, free-fat mass and vegetable fats (p < 0.001; Slope in statistic (B) = 4.8; β = 0.42). After adjustment for cytokines, log10 interleukin-10 (IL-10) still correlated with resting energy expenditure (p = 0.02). Resting energy expenditure was positively correlated with a specific component of the vegetarian's diet, i.e., vegetable fats. Furthermore, we showed that IL-10 was positively associated with resting energy expenditure in this population.