Crosstalk between dietary patterns,obesity and nonalcoholic fatty liver disease

The prevalence of nonalcoholic fatty liver disease(NAFLD)is rising worldwide,paralleling the epidemic of obesity.The liver is a key organ for the metabolism of proteins,fats and carbohydrates.Various types of fats and carbohydrates in isocaloric diets differently influence fat accumulation in the liver parenchyma.Therefore,nutrition can manage hepatic and cardiometabolic complications of NAFLD.Even moderately reduced caloric intake,which leads to a weight loss of 5%-10%of initial body weight,is effective in improving liver steatosis and surrogate markers of liver disease status.Among dietary patterns,the Mediterranean diet mostly prevents the onset of NAFLD.Furthermore,this diet is also the most recommended for the treatment of NAFLD patients.However,clinical trials based on the dietary interventions in NAFLD patients are sparse.Since there are only a few studies examining dietary interventions in clinically advanced stages of NAFLD,such as active and fibrotic steatohepatitis,the optimal diet for patients in these stages of the disease must still be determined.In this narrative review,we aimed to critically summarize the associations between different dietary patterns,obesity and prevention/risk for NAFLD,to describe specific dietary interventions’impacts on liver steatosis in adults with NAFLD and to provide an updated overview of dietary recommendations that clinicians potentially need to apply in their daily practice.

Preparatory training attenuates drastic response of the insulin-like growth factor binding protein 1 at the point of maximal oxygen consumption in handball players

Background:Intensive exercise changes physiological need for glucose and several biochemical pathways responsible for its metabolism response.Among them are those which involve insulin,insulin-like growth factor(IGF-1),and IGF-binding proteins(IGFBPs).Different types and degrees of exercise,as well as an athlete's fitness,may induce a range of responses regarding concentrations and time needed for the alteration.The idea of the work was to find out whether and how insulin/IGF axis responds to additional physical activity in the already trained subjects and if so,is the adaptation potentially beneficial from the aspect of metabolic control.Methods:The effect of 4-week intensive training on campus(preparatory training) on the levels of insulin,IGF-1,and IGFBPs during maximal progressive exercise test(MPET) on a treadmill was compared to the results obtained during MPET conducted after a regular training season of a female elite handball team(n = 17,age:17 ± 1 years,height:171 ± 8 cm,weight:65 ± 8 kg,body mass index:22 ± 1 kg/m^2 at the beginning of the study;there were no significant changes at the end).Serum samples were obtained from players immediately before the test(basal),at the end of the test after reaching the point of maximal oxygen consumption(VO_(2max)),and after recovery.Results:The concentration of insulin decreased at VO_(2max),but remained higher in players after preparatory training(12.2 ± 2.5 m U/L vs.8.9 ± 4.4 m U/L,p = 0.049).The level of IGFBP-1 decreased in players at VO_(2max) in either case of training,but it remained much higher in tests performed after the preparatory regime than before(p = 0.029).Concentrations of IGF-1,IGFBP-2,-3,and-4 did not change significantly.Conclusion:The inverse relation between insulin and IGFBP-1 was lost during MPET,as these 2 molecules changed in the same direction.The results obtained suggest less severe stress-induced depression of insulin and IGFBP-1 after preparatory training.But another metabolic mechanism cannot be excluded,and that is potentially impaired insulin sensitivity resulting in higher level of IGFBP-1.

Liver disease and COVID-19:The link with oxidative stress,antioxidants and nutrition

Varying degrees of liver injuries have been reported in patients infected with the severe acute respiratory syndrome-coronavirus-2(SARS-CoV-2).In general,oxidative stress is actively involved in initiation and progression of liver damage.The liver metabolizes various compounds that produce free radicals.Maintaining the oxidative/antioxidative balance is important in coronavirus disease 2019(COVID-19)patients.Antioxidant vitamins,essential trace elements and food compounds,such as polyphenols,appear to be promising agents,with effects in oxidative burst.Deficiency of these nutrients suppresses immune function and increases susceptibility to COVID-19.Daily micronutrient intake is necessary to support anti-inflammatory and antioxidative effects but for immune function may be higher than current recommended dietary intake.Antioxidant supplements(β-carotene,vitamin A,vitamin C,vitamin E,and selenium)could have a potential role in patients with liver damage.Available evidence suggests that supplementing the diet with a combination of micronutrients may help to optimize immune function and reduce the risk of infection.Clinical trials based on the associations of diet and SARS-CoV-2 infection are lacking.Unfortunately,it is not possible to definitively determine the dose,route of administration and best timing to intervene with antioxidants in COVID-19 patients because clinical trials are still ongoing.Until then,hopefully,this review will enable clinicians to understand the impact of micronutrient dietary intake and liver status assessment in COVID-19 patients.