Various types of fasting diet and possible benefits in nonalcoholic fatty liver: Mechanism of actions and literature update

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of chronic liver injury, affecting around one-fourth of the general population across the world. Several important pathophysiological mechanisms underlying NAFLD include oxidative stress, inflammation, liver fibrosis, and apoptosis. Currently, therapeutic approaches are not ideal for managing NAFLD, thus new approaches and treatments are still needed. Over the last two decades, various fasting protocols have been explored to reduce body weight and improve metabolic disorders. In this review, we provide updated literature that supports fasting regimens for subjects with NAFLD and describes underlying mechanisms of action. We suggest that fasting regimens may modulate NAFLD via several mechanisms, including changes in gut microbiota, hepatic arginase, hepatic autophagy, inflammatory responses, liver functional enzymes and hepatic steatosis, fibroblast growth factors signaling, white adipose tissue browning, adipokines, circadian rhythms, lipid profiles, and body composition.

Effect of exercise intervention on clinical parameters in patients with non-alcoholic fatty liver disease and type 2 diabetes mellitus: a meta-analysis of randomized controlled trials

The effect of exercise on clinical parameters in patients with non-alcoholic fatty liver disease (NAFLD) combined with type 2 diabetes mellitus (T2DM) is unknown. In this meta-analysis, we identified and evaluated the effect of exercise on clinical parameters (BMI, ALT, lipid metabolism, glucose metabolism) in patients with NAFLD combined with T2DM. We conducted a comprehensive search of Medline, Embase, Web of Science, Cochrane Database of Systematic Reviews, and CNKI in December 2022. Data from relevant randomized controlled trials were collected according to inclusion and exclusion criteria. 6 eligible studies with 238 subjects were finally included. We used Review Manager 5.3 for meta-analysis. The study found that exercise improved BMI, ALT, TC, LDL-C, HbA1c, and HOMA-IR, TG, but did not significantly improve HDL-C. Subgroup analysis showed that high-intensity interval training significantly improved BMI (SMD: -0.43, 95% CI: -0.80, -0.06), ALT (SMD: -4.63, 95% CI: -8.42, -0.83), TC (SMD: -0.94, 95% CI: -1.82, -0.07), LDL-C (SMD: -0. 87, 95% CI: -1.26, -0.49), HbA1c (SMD: -1.12, 95% CI: -1.75, -0.48), HOMA-IR (SMD: -0.59, 95% CI: -0.94, -0.25); moderate-intensity continuous training improved ALT (SMD: -3.96, 95% CI: -7.71, -0.21), TG (SMD: -1.59, 95% CI: -2.58, -0.61), HbA1c (SMD: -0.71, 95% CI: -1.37, -0.05), HOMA-IR (SMD: -1.73, 95% CI: -3.40, -0. 06), and to some extent HDL-C levels (SMD: 0.53, 95% CI: 0.04, 1.02); resistance training improved LDL-C (SMD: -2.06, 95% CI: -3.14, -0.98). In conclusion, exercise improved indicators in patients with NAFLD combined with T2DM, but the improvement indicators varied by type of exercise.

Effects of eight-week high-intensity interval training on some metabolic, hormonal and cardiovascular indices in women with PCOS: a randomized controlled trail

BACKGROUND

Studies have revealed that high-intensity interval training (HIIT) has beneficial effect on hormonal, cardiovascular indices in women with polycystic ovary syndrome (PCOS). There, however, is still no comprehensive data on the type, intensity and duration of training for these women.

OBJECTIVE

The current study aimed to investigate the effects of high-intensity interval training (HIIT) on metabolic, hormonal and cardiovascular indices in women with PCOS compared to a control group.

METHODS

In a randomized controlled study, 28 patients (age: 23.8 ± 5.3 years, weight: 82.4 ± 9.7 kg, BMI: 30.33 ± 3.99 kg/m²) were divided into two groups including HIIT (n = 14) and the control (n = 14). The training protocol was performed with 100-110 maximum aerobic velocity (MAV), 4-6 sets, 4 laps, 3 sessions per week for eight weeks. Anthropometric indices, aerobic performance, insulin resistance and sensitivity, lipid profiles, testosterone, cortisol and hs-CRP were evaluated.

RESULTS

The HIIT intervention decreased BMI, waist to hip ratio (WHR), visceral fat, insulin, insulin resistance, low density lipoprotein (LDL), atherogenic index, cholesterol and cortisol (P < 0.05). All variables remained unchanged in the control group (P > 0.05). Except for VAI, FBG, HDL, TG and AIP, the rest of the variables in the training and control groups show a significant difference (P < 0.05).

CONCLUSION

The results of the present study indicate that eight weeks of HIIT has beneficial effects on anthropometric, insulin sensitivity, fat profile, and inflammatory and cardiovascular indices in PCOS patients. It seems that the intensity of HIIT (100-110 MAV) is a determining factor in creating optimal adaptations in PCOS patients.

TRAIL REGISTRATION

IRCT20130812014333N143. Registration date: 22/03/2020. URL: https://en.irct.ir/trial/46295 .