Biomarkers Of Metabolic Health Research Articles

Effects of single bout of very high-intensity exercise on metabolic health biomarkers in overweight/obese sedentary men

This study aimed to investigate the effects of a single session of sprint interval training (SIT) and a single extended sprint (ES), matched for total work, on metabolic health biomarkers. Ten overweight/obese men aged 26.9±6.2years participated. Following a pre-trial incremental exercise test and SIT familiarization, each participant undertook three 2-day trials in randomized order. On Day 1 participants either undertook no exercise (CON), four maximal 30-s sprints, with 4.5min recovery between each (SIT), or a single maximal extended sprint (ES) matched with SIT for work done. On Day 2, participants had a fasting blood sample taken, undertook an oral glucose tolerance test to determine insulin sensitivity index (ISI), and had blood pressure measured. Total work done during exercise did not differ between SIT and ES (61.7±2.9 vs. 61.3±2.8kJ; p=0.741). Mean power was higher in SIT than ES (518±21 vs. 306±16W, p<0.0005), resulting in a shorter high-intensity exercise duration in SIT (120±0 vs. 198±10s, p<0.0005). ISI was 44.6% higher following ES than CON (9.4±2.1 vs. 6.5±1.3; p=0.022), but did not differ significantly between SIT and CON (6.6±0.9 vs. 6.5±1.3; p=0.208). However, on the day following exercise fat oxidation in the fasted state was increased by 63% and 38%, compared to CON, in SIT and ES, respectively (p<0.05 for both), with a concomitant reduction in carbohydrate oxidation (p<0.05). A single ES, which may represent a more time-efficient alternative to SIT, can increase insulin sensitivity and increase fat oxidation in overweight overweight/obese sedentary men.

Role of General Control Nonderepressible 2 (GCN2) kinase in mediating responses to dietary methionine restriction

Restriction of dietary methionine from normal levels (0.86%) to 0.17% produces a coordinated series of biochemical and physiological responses that improve biomarkers of metabolic health, limit fat accretion, and enhance insulin sensitivity. GCN2 kinase serves as a sensor to detect reductions in essential amino acids and initiates integrated behavioral and transcriptional responses that mediate metabolic adaptation. The role of GCN2 in mediating the responses to dietary methionine restriction (MR) was assessed using GCN2−/− mice. Dietary MR for 8 wks produced a comparable reduction in hepatic triglyceride and increase in food consumption in wild type (WT) and GCN2−/− mice, while the normal diet‐induced increase in plasma adiponectin was actually enhanced in GCN2 nulls. The transcriptional responses produced by dietary MR in brown adipose tissue did not differ between WT and GCN2 null mice. In contrast, the diet‐induced increase in energy expenditure and reductions in fasting insulin and hepatic SCD‐1 expression observed in WT mice were partially compromised in GCN2 nulls, and the normal reductions in adiposity, plasma leptin and glucose were absent in GCN2−/− mice. The present findings suggest that GCN2 is an important component of the nutrient sensing mechanism(s) linking restriction of dietary methionine to the metabolic adaptations produced by the diet. Work supported by NIH: 2 P20 RR021945 (TWG), 2 U24 DK076169 (TWG), 1 F32 DK088513 (EPP), 1 RO1 HD070487 (TGA).Grant Funding Source: NIH

Global LINE-1 DNA methylation is associated with blood glycaemic and lipid profiles

Background Patterns of DNA methylation change with age and these changes are believed to be associated with the development of common complex diseases. The hypothesis that Long Interspersed Nucleotide Element 1 (LINE-1) DNA methylation (an index of global DNA methylation) is associated with biomarkers of metabolic health was investigated in this study.Methods Global LINE-1 DNA methylation was quantified by pyrosequencing in blood-derived DNA samples from 228 individuals, aged 49–51 years, from the Newcastle Thousand Families Study (NTFS). Associations between log-transformed LINE-1 DNA methylation levels and anthropometric and blood biochemical measurements, including triglycerides, total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, fasting glucose and insulin secretion and resistance were examined.Results Linear regression, after adjustment for sex, demonstrated positive associations between log-transformed LINE-1 DNA methylation and fasting glucose {coefficient 2.80 [95% confidence interval (CI) 0.39–5.22]}, total cholesterol [4.76 (95% CI 1.43–8.10)], triglycerides [3.83 (95% CI 1.30–6.37)] and LDL-cholesterol [5.38 (95% CI 2.12–8.64)] concentrations. A negative association was observed between log-transformed LINE-1 methylation and both HDL cholesterol concentration [−1.43 (95% CI −2.38 to −0.48)] and HDL:LDL ratio [−1.06 (95% CI −1.76 to −0.36)]. These coefficients reflect the millimoles per litre change in biochemical measurements per unit increase in log-transformed LINE-1 methylation.Conclusions These novel associations between global LINE-1 DNA methylation and blood glycaemic and lipid profiles highlight a potential role for epigenetic biomarkers as predictors of metabolic disease and may be relevant to future diagnosis, prevention and treatment of this group of disorders. Further work is required to establish the role of confounding and reverse causation in the observed associations.

Effects of a high-protein, low-carbohydrate v. high-protein, moderate-carbohydrate weight-loss diet on antioxidant status, endothelial markers and plasma indices of the cardiometabolic profile

There are concerns that weight-loss (WL) diets based on very low carbohydrate (LC) intake have a negative impact on antioxidant status and biomarkers of cardiovascular and metabolic health. Obese men (n 16) participated in a randomised, cross-over design diet trial, with food provided daily, at approximately 8.3 MJ/d (approximately 70 % of energy maintenance requirements). They were provided with two high-protein diets (30 % of energy), each for a 4-week period, involving a LC (4 % carbohydrate) and a moderate carbohydrate (MC, 35 % carbohydrate) content. Body weight was measured daily, and weekly blood samples were collected. On average, subjects lost 6.75 and 4.32 kg of weight on the LC and MC diets, respectively (P < 0.001, SED 0.350). Although the LC and MC diets were associated with a small reduction in plasma concentrations of retinol, vitamin E (α-tocopherol) and β-cryptoxanthin (P < 0.005), these were still above the values indicative of deficiency. Interestingly, plasma vitamin C concentrations increased on consumption of the LC diet (P < 0.05). Plasma markers of insulin resistance (P < 0.001), lipaemia and inflammation (P < 0.05, TNF-α and IL-10) improved similarly on both diets. There was no change in other cardiovascular markers with WL. The present data suggest that a LC WL diet does not impair plasma indices of cardiometabolic health, at least within 4 weeks, in otherwise healthy obese subjects. In general, improvements in metabolic health associated with WL were similar between the LC and MC diets. Antioxidant supplements may be warranted if LC WL diets are consumed for a prolonged period.

Progress and future directions on physical activity research among youth.

There is strong evidence to support the benefits of regular physical activity for children and adolescents (heretofore referred to as "youth"). Evidence includes improved cardiorespiratory fitness, muscular fitness, bone health, body composition, and cardiovascular and metabolic health biomarkers. Importantly, physical inactivity is a modifiable risk factor for lifestyle-related chronic diseases and conditions and may track through adulthood. Because of the potential benefits and modifiable nature of the behavior, the "2008 Physical Activity Guidelines for Americans" recommends 1 hour or more of daily physical activity for youth. Most of the time should be spent in either moderate-or vigorous-intensity aerobic activities and should also include muscle and bone strengthening activities. The 2010 World Health Organization "Global Recommendations for Physical Activity and Health" supports similar guidelines for youth.

Too much sitting: a novel and important predictor of chronic disease risk?

Research on physical activity and health has pointed clearly to increasing the time that adults spend doing moderate to vigorous intensity activities: 30 minutes a day is generally recommended. However,...

Shared care in paediatric heart transplantation

<h3>Objective</h3> To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. <h3>Design</h3> 60 Danish adults at...