Various behavioral and physiological pathways follow a pre-determined, 24 hour cycle known as the circadian rhythm. Metabolic homeostasis is regulated by the circadian rhythm. Time-restricted eating (TRE) is a type of intermittent fasting based on the circadian rhythm. In this study, we aim to analyze systemically the effects of TRE on body weight, body composition, and other metabolic parameters. We reviewed articles from PubMed, EMBASE, and the Cochrane Library to identify clinical trials that compared TRE to a regular diet. We included 19 studies for meta-analysis. Participants following TRE showed significantly reduced body weight (mean difference (MD), −0.90; 95% confidence interval (CI): −1.71 to −0.10) and fat mass (MD: −1.58, 95% CI: −2.64 to −0.51), while preserving fat-free mass (MD, −0.24; 95% CI: −1.15 to 0.67). TRE also showed beneficial effects on cardiometabolic parameters such as blood pressure (systolic BP, MD, −3.07; 95% CI: −5.76 to −0.37), fasting glucose concentration (MD, −2.96; 95% CI, −5.60 to −0.33), and cholesterol profiles (triglycerides, MD: −11.60, 95% CI: −23.30 to −0.27). In conclusion, TRE is a promising therapeutic strategy for controlling weight and improving metabolic dysfunctions in those who are overweight or obese. Further large-scale clinical trials are needed to confirm these findings and the usefulness of TRE.

Previous studies have shown that angiopoietin-like protein 8 (ANGPTL8), also called as betatrophin, acts together with ANGPTL3 to regulate lipid metabolism, glucose metabolism, and energy homeostasis. Moreover, ANGPTL8 promotes proliferation of pancreatic β-cells and induces insulin secretion. However, there are no previous longitudinal studies in humans. We analyzed the age- and sex-matched data of 240 normal weight and overweight Korean children from the Korean Metabolic disorders and Obesity Study in Elementary School children (K-MOSES), a prospective observational cohort study. At baseline, ANGPTL8 concentrations were positively associated with triglycerides (TG) (r = 0.168, P = 0.010), whereas ANGPTL3 levels were associated with fasting insulin (r = 0.248, P < 0.001) and the homeostasis model assessment of insulin resistance (HOMA-IR) (r = 0.197, P = 0.002). Although both ANGPTL8 and ANGPTL3 levels did not differ between children with normal weight and children with overweight, ANGPTL8 levels were increased in males compared to females (341.2 [267.4–436.5] vs. 270.2 [213.9–378.8] pg/ml, P = 0.001). In particular, there was no significant inter-relationship between circulating ANGPTL8 and ANGPTL3 concentrations in Korean boys and girls (r = −0.073, P = 0.265). Multivariate analysis showed that baseline ANGPTL8 concentrations were independently associated with future changes of serum TG levels in Korean children after adjusting for confounding factors after a 3 year follow-up period (r = −0.165, P = 0.016). This longitudinal study demonstrated for the first time that baseline ANGPTL8 levels were associated with baseline and future changes in TG levels in Korean children.

The association of metabolic syndrome (MetS) with the development of Parkinson disease (PD) is currently unclear. We sought to determine whether MetS and its components are associated with the risk of incident PD using large-scale cohort data for the whole South Korean population. Health checkup data of 17,163,560 individuals aged ≥40 years provided by the National Health Insurance Service (NHIS) of South Korea between January 1, 2009, and December 31, 2012, were included, and participants were followed up until December 31, 2015. The mean follow-up duration was 5.3 years. The hazard ratio (HR) and 95% confidence interval (CI) of PD were estimated using a Cox proportional hazards model adjusted for potential confounders. We identified 44,205 incident PD cases during follow-up. Individuals with MetS (n = 5,848,508) showed an increased risk of PD development compared with individuals without MetS (n = 11,315,052), even after adjusting for potential confounders including age, sex, smoking, alcohol consumption, physical activity, income, body mass index, estimated glomerular filtration rate, and history of stroke (model 3; HR, 95% CI: 1.24, 1.21–1.27). Each MetS component was positively associated with PD risk (HR, 95% CI: 1.13, 1.10–1.16 for abdominal obesity; 1.13, 1.10–1.15 for hypertriglyceridemia; 1.23, 1.20–1.25 for low high-density lipoprotein cholesterol; 1.05, 1.03–1.08 for high blood pressure; 1.21, 1.18–1.23 for hyperglycemia). PD incidence positively correlated with the number of MetS components (log-rank p < 0.001), and we observed a gradual increase in the HR for incident PD with increasing number of components (p < 0.001). A significant interaction between age and MetS on the risk of incident PD was observed (p for interaction < 0.001), and people aged ≥65 years old with MetS showed the highest HR of incident PD of all subgroups compared to those <65 years old without MetS (reference subgroup). Limitations of this study include the possibilities of misdiagnosis of PD and reverse causality. Our population-based large-scale cohort study suggests that MetS and its components may be risk factors of PD development.

Moon S, et al. Endocrinol Metab. 2018 Dec;33(4):473-484. https://doi.org/10.3803/EnM.2018.33.4.473

Although liver enzymes, such as γ-glutamyltransferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), have recently been suggested as risk factors for cardiovascular diseases (CVD), impact on mortality after myocardial infarction (MI) or ischemic stroke (IS) was not previously examined. Using a population-based, nationwide cohort database, we explored the implication of GGT and aminotransferases on the development of CVD and all-cause mortality during a median 9.1 years of follow-up. Among 16,624,006 Korean adults, both GGT and aminotransferases exhibited a positive relationship with MI, IS, and mortality in a multivariate adjusted model. ALT and AST showed U-shaped associations with mortality, whereas GGT showed a positive linear relationship with mortality. The risk of 1-year mortality after MI or IS was significantly higher in the highest quartile of GGT compared to the lowest quartile (HR, 1.46; 95% CI, 1.40-1.52). The implication of GGT on MI, IS, and mortality persisted regardless of traditional cardiovascular risk parameters. This study demonstrated the unique pattern of association of ALT, AST, and GGT with the development of CVD and all-cause mortality in the Korean population. In particular, GGT showed the most robust linear relationship with mortality before and after cardiovascular events independent of risk factors.