The development of an EU-wide nutrition and physical activity expert knowledge base to support a personalised mobile application across various EU population groups.

A healthy lifestyle comprising regular physical activity and an adequate diet is imperative for the prevention of non-communicable diseases such as hypertension and some cancers. Advances in information computer technology offer the opportunity to provide personalised lifestyle advice directly to the individual through devices such as smartphones or tablets. The overall aim of the PROTEIN project (Wilson-Barnes et al., 2021) was to develop a smartphone application that could provide tailored and dynamic nutrition and physical activity advice directly to the individual in real time. However, to create this mobile health (m-health) smartphone application, a knowledge base of reference ranges for macro-/micronutrient intake, anthropometry, biochemical, physiological and sleep parameters was required to underpin the parameters of the recommender systems. Therefore, the principal aim of this emerging research paper is to describe the process by which experts in nutrition and physiology from the PROTEIN consortium collaborated to develop the nutritional and physical activity requirements, based upon existing recommendations, for 10 separate population groups living within the EU including, but not limited to healthy adults, adults with type 2 diabetes mellitus, cardiovascular disease, excess weight, obesity and iron deficiency anaemia. A secondary aim is to describe the development of a library of 24-h meal plans appropriate for the same groups and also encompassing various dietary preferences and allergies. Overall, the consortium devised an extensive nutrition and physical activity knowledge base that is pertinent to 10 separate EU user groups, is available in 7 different languages and is practically implemented via a library of culturally appropriate, 24-h meal plans.

Correction to: Identification of an intracellular metabolic signature impairing beta cell function in the rat beta cell line INS-1E and human islets.

As part of an institutional investigation by University of Bremen, the work carried out by Kathrin Maedler's laboratory has been reviewed.

Novel adipokines: methodological utility in human obesity research.

BACKGROUND: Adipokines could pose a link between adiposity, systemic inflammation and metabolic disease risk. However, it is unclear whether representative biomarkers are methodologically suitable for use in human obesity research. METHODS: We assessed the intra-individual reproducibility of selected adipokines in a sample of 207, apparently healthy, participants with available biosample collections over a 4-month period. Concentrations of the following adipokines were measured at each sampling time point: fatty-acid binding protein-4 (FABP-4), lipocalin-2, monocyte chemoattractant protein 1 (MCP-1), procalcitonin, progranulin, vaspin and visfatin/Nampt. We calculated intraclass correlation coefficients (ICC) and examined Bland-Altman plots. RESULTS: The analyses suggested an overall good to excellent biomarker reproducibility over 4 months: FABP-4: ICC=0.73 (95% confidence interval: 0.65, 0.78), lipocalin-2: 0.64 (0.55, 0.71), MCP-1: 0.85 (0.81; 0.89), procalcitonin: 0.78 (0.72, 0.83), progranulin: 0.59 (0.50, 0.68) and vaspin: 0.86 (0.82, 0.89). A good agreement of the repeated measurements was further supported by the Bland-Altman plots. No substantial differences in biomarker performance according to adiposity status could be observed. Reliability of visfatin/Nampt could not be assessed due to a high number of measurements below the lower limit of detection. CONCLUSION: Results suggest that single measurements of the evaluated adipokines could be used in population-based studies aimed to assess links between obesity, inflammation and metabolic diseases.

Fetuin A is a Predictor of Liver Fat in Preoperative Patients with Nonalcoholic Fatty Liver Disease.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) are frequent comorbidities in perioperative patients. However, the predictive role of the hepatokine fetuin A was not evaluated in this collective. OBJECTIVE: To study fetuin A as predictor of NAFLD/NASH in preoperative patients. METHODS: 58 subjects were included. Fetuin A was studied in patients undergoing open abdominal surgery and in a subset with acute liver failure. Blood and liver specimens were sampled. NAFLD was histologically evaluated. Liver fat was additionally analyzed by an enzymatic approach, circulating fetuin A by enzyme linked-immunosorbent assay, fetuin A mRNA by reverse-transcription PCR. RESULTS: Univariate correlation studies linked fetuin A to liver steatosis (r = 0.40, p = .029) and hepatocellular ballooning degeneration (r = 0.34, p = .026). Compared to non-NAFLD subjects fetuin A was increased in NAFLD (p = .009) and in NASH (p = .029). However, when corrected for main confounders by linear modeling, fetuin A remained related to hepatic steatosis, but not to ballooning degeneration or other NAFLD features. In support of this, biochemically analyzed liver lipids correlated with fetuin A in plasma (r = 0.34, p = .033) and with hepatic fetuin A mRNA (r = 0.54, p < .001). In addition, plasma fetuin A was related to hepatic mRNA (r = 0.32, p = .036), while circulating levels were reduced by 64% with acute liver failure (p < .001), confirming the liver as main fetuin A source. CONCLUSION: Fetuin A is suggested as noninvasive biomarker of hepatic steatosis in preoperative settings.

Regulation of the clock gene expression in human adipose tissue by weight loss.

BACKGROUND: The circadian clock coordinates numerous metabolic processes to adapt physiological responses to light-dark and feeding regimens and is itself regulated by metabolic cues. The implication of the circadian clock in the regulation of energy balance and body weight is widely studied in rodents but not in humans. Here we investigated (1) whether the expression of clock genes in human adipose tissue is changed by weight loss and (2) whether these alterations are associated with metabolic parameters. SUBJECTS/METHODS: Subcutaneous adipose tissue (SAT) samples were collected before and after 8 weeks of weight loss on an 800 kcal per day hypocaloric diet (plus 200 g per day vegetables) at the same time of the day. Fifty overweight subjects who lost at least 8% weight after 8 weeks were selected for the study. The expression of 10 clock genes and key metabolic and inflammatory genes in adipose tissue was determined by quantitative real-time PCR. RESULTS: The expression of core clock genes PER2 and NR1D1 was increased after the weight loss. Correlations of PERIOD expression with body mass index (BMI) and serum total, high-density lipoprotein and low-density lipoprotein (LDL) cholesterol levels and of NR1D1 expression with total and LDL cholesterol were found that became non-significant after correction for multiple testing. Clock gene expression levels and their weight loss-induced changes tightly correlated with each other and with genes involved in fat metabolism (FASN, CPT1A, LPL, PPARG, PGC1A, ADIPOQ), energy metabolism (SIRT1), autophagy (LC3A, LC3B) and inflammatory response (NFKB1, NFKBIA, NLRP3, EMR1). CONCLUSION: Clock gene expression in human SAT is regulated by body weight changes and associated with BMI, serum cholesterol levels and the expression of metabolic and inflammatory genes. Our data confirm the tight crosstalk between molecular clock and metabolic and inflammatory pathways involved in adapting adipose tissue metabolism to changes of the energy intake in humans.

Continuous glucose monitoring in people with diabetes: the randomized controlled Glucose Level Awareness in Diabetes Study (GLADIS).

AIMS: To investigate the best glucose monitoring strategy for maintaining euglycaemia by comparing self-monitoring of blood glucose with continuous glucose monitoring, with or without an alarm function. METHODS: A 100-day, randomized controlled study was conducted at four European centres, enrolling 160 patients with Type 1 or Type 2 diabetes, on multiple daily insulin injections or continuous subcutaneous insulin infusion. Participants were randomized to continuous glucose monitoring without alarms (n = 48), continuous glucose monitoring with alarms (n = 49) or self-monitoring of blood glucose (n = 48). RESULTS: Time spent outside the glucose target during days 80-100 was 9.9 h/day for the continuous glucose monitoring without alarms group, 9.7 h/day for the continuous glucose monitoring with alarms group and 10.6 h/day for the self-monitoring of blood glucose group (P = 0.18 and 0.08 compared with continuous glucose monitoring without and with alarms, respectively).The continuous glucose monitoring with alarms group spent less time in hypoglycaemia compared with the self-monitoring of blood glucose group (1.0 h/day and 1.6 h/day, respectively; 95% CI -1.2 to -0.1; P = 0.030). Among those treated with continuous subcutaneous insulin infusion, time spent outside the glucose target was significantly different when comparing continuous glucose monitoring without alarms and self-monitoring of blood glucose (-1.9 h/day; 95% CI -3.8 to 0.0; P = 0.0461) and when comparing continuous glucose monitoring with alarms and self-monitoring of blood glucose (-2.4 h/day; 95% CI -4.1 to -0.5; P = 0.0134). There was no difference in HbA1c reduction from baseline in the three groups; however, the proportion of participants with a reduction of ≥ 6 mmol/mol (≥ 0.5%) was higher in the continuous glucose monitoring without alarms (27%) and continuous glucose monitoring with alarms groups (25%) than in the self-monitoring of blood glucose group (10.6%). CONCLUSIONS: This study shows that the use of continuous glucose monitoring reduces time spent outside glucose targets compared with self-monitoring of blood glucose, especially among users of insulin pumps.

Chemerin and prediction of Diabetes mellitus type 2.

OBJECTIVE: Insulin resistance and subclinical inflammation are characteristics in the development of type 2 diabetes mellitus (T2DM). The adipokine chemerin has been associated with both factors. The aim of this study was to analyse whether chemerin predicts T2DM. DESIGN: Blood samples of 440 participants of the Metabolic-Syndrome Berlin-Potsdam (MesyBepo) follow-up study without diabetes at baseline were available for chemerin measurement. Mean follow-up of participants was 5·3 years. Glucose metabolism was analysed using oral glucose tolerance test including insulin measurements. Chemerin was measured using a commercially available ELISA. RESULTS: Thirty-five individuals developed T2DM during follow-up. Chemerin predicted incident T2DM (Chemerin 1. Tertile: reference, 2. Tertile: OR 2·33 [0·68-7·95]; Chemerin 3. Tertile: OR 3·42 [1·01-11·58] after adjustment for age, sex, BMI, follow-up time, HbA1c, HOMA-IR and WHR). In a secondary analysis, chemerin also predicted worsening of fasting glucose and HbA1c (adjusted for age, sex, BMI, time of follow-up, WHR, HDL cholesterol and triglycerides). CONCLUSIONS: Our data suggest that chemerin is a weak predictor of T2DM.

Effect of a high-protein diet on maintenance of blood pressure levels achieved after initial weight loss: the DiOGenes randomized study.

Randomized trials have shown significant blood pressure (BP) reductions after increased protein compared with carbohydrate intake, but the effect on BP maintenance after initial weight loss is unclear. We examined the effect of a high-protein diet on the maintenance of reduced BP after weight loss in 420 overweight adults from the Diet, Obesity and Genes study. After an 8-week weight-loss period (>8% BW), subjects (42±6 years) were randomized to either a high-protein diet (23-28 en% protein) or a lower-protein control diet (10-15 en% protein) for 26 weeks. BMI after weight loss was 30.3±4.3 kg m(-2), BP was 118/73 mm Hg and 28 subjects (6.5%) used antihypertensive agents. Systolic BP during 26 weeks of weight maintenance dietary intervention increased in both treatment groups, but it was 2.2 mm Hg less (95% CI: -4.6 to 0.2 mm Hg, P=0.08) in the high-protein group than in the lower-protein control group. In 191 (pre)hypertensive subjects (baseline systolic BP⩾120 mm Hg), a larger difference was observed (-4.2 mm Hg (-7.7, -0.7), P=0.02). The effect was attenuated after adjustment for initial BP (-3.4 mm Hg (-6.9, -0.03), P=0.048), and after additional adjustment for weight change (-2.7 mm Hg (-6.1, 0.4), P=0.11). Adjustment for 24-h urinary excretion of sodium and potassium did not change the results. Diastolic BP yielded similar results. These findings suggest that a BP reduction after weight loss is better maintained when the intake of protein is increased at the expense of carbohydrates. This effect is partly mediated by body weight.

[Circadian clocks and energy metabolism: implications for health]. / Zirkadiane Uhren und Energiestoffwechsel: Implikationen für die Gesundheit.

On behavioural as well as physiological levels our daily life is regulated by the circadian clock - endogenous oscillators present in the hypothalamus and in peripheral tissues - which is believed to have evolved as an adaptation to Earth rotation around the Sun and its consequent 24 h dark-light cycle. Accumulative evidence suggests that the circadian clock plays a pivotal role for energy metabolism and energy homeostasis: many hormones, enzymes and transport systems involved in the regulation of energy metabolism have been shown to display circadian rhythms in their expression, secretion and/or activity patterns. The energy metabolism, in turn, can impact on the circadian clock - a process that is called entrainment. Thus, the circadian clock and energy metabolism are intimately intertwined. So far this interplay and its implications for health have not been understood very well. For health maintenance, however, it seems to be crucial to avoid any desynchronisation between the circadian clock and energy metabolism. Form a clinical point of view this might be important for the treatment of obesity and associated disorders and may lead to new life-style approaches.

Preferential deposition of visceral adipose tissue occurs due to physical inactivity.

We hypothesised that strict inactivity (bed rest) would lead to regional differences in fat deposition. Twenty-four male subjects underwent 60 d bed rest and remained inactive (n = 9), performed resistance exercise plus whole-body vibration (RVE; n = 7) or resistance exercise only (RE; n = 8). Fat mass was assessed via dual X-ray absorptiometry. In the inactive subjects, fat deposition differed between body regions (P = 0.0005) with android region visceral adipose tissue increasing the most (+29% at the end of bed rest), followed by remainder of the trunk (from chin to the iliac crest; +10%) and the arms and legs (both +7%). Insulin sensitivity reduced in the inactive subjects at the end of bed rest (P = 0.036). RE did not have a significant impact on regional fat mass changes (P ⩾ 0.055). In RVE, increases in visceral adipose tissue (-14%; P = 0.028 vs inactive subjects) and in the arms (arms -8%, P = 0.011 vs inactive) were not seen. We conclude that inactivity leads to a preferential increase in visceral adipose tissue.

Plasma adiponectin in heart failure with and without cachexia: catabolic signal linking catabolism, symptomatic status, and prognosis.

BACKGROUND AND AIMS: Adiponectin (ADPN) as an adipose tissue hormone contributes to regulation of energy metabolism and body composition and is associated with cardiovascular risk profile parameters. Cardiac cachexia may develop as a result of severe catabolic derangement in chronic heart failure (CHF). We aimed to determinate an abnormal ADPN regulation as a link between catabolic signalling, symptomatic deterioration and poor prognosis. METHODS AND RESULTS: We measured plasma ADPN in 111 CHF patients (age 65 ± 11, 90% male, left ventricular ejection fraction (LVEF) 36 ± 11%, peak oxygen consumption (peakVO2) 18.1 ± 5.7 l/kg*min, body mass index (BMI) 27 ± 4 kg/m(2), all mean ± standard deviation) and 36 healthy controls of similar age and BMI. Body composition was assessed by dual energy X-ray absorptiometry, insulin sensitivity was evaluated by homoeostasis model assessment, exercise capacity by spiroergometry. Plasma ADPN did not differ between CHF vs. controls (13.5 ± 11.0 vs. 10.5 ± 5.3 mg/l, p > 0.4), but increased stepwise with NYHA functional class (I/II/III: 5.7 ± 1.4/10.7 ± 8.3/19.2 ± 14.0 mg/l, ANOVA p < 0.01). Furthermore, ADPN correlated with VO2 at anaerobic threshold (r = -0.34, p < 0.05). ADPN was highest in cachectic patients (cCHF, 16%) vs. non-cachectic (ncCHF) (18.7 ± 15.0 vs. 12.5 ± 9.9 mg/l; p < 0.05). ADPN indicated mortality risk independently of established prognosticators (HR: 1.04 95% CI: 1.02-1.07; p < 0.0001). ADPN above the mean (13.5 mg/l) was associated with a 3.4 times higher mortality risk in CHF vs. patients with ADPN levels below the mean. CONCLUSION: Circulating ADPN is abnormally regulated in CHF. ADPN may be involved in impaired metabolic signalling linking disease progression, tissue wasting, and poor outcome in CHF.

Elevated hepatic chemerin mRNA expression in human non-alcoholic fatty liver disease.

OBJECTIVE: Adipose tissue-derived factors link non-alcoholic fatty liver disease (NAFLD) with obesity, which has also been reported for circulating chemerin. On the other hand, hepatic chemerin and chemokine-like receptor 1 (CMKLR1) mRNA expression has not yet been studied in an extensively characterized patient collective. DESIGN: This study was cross-sectional and experimental in design. METHODS: Liver tissue samples were harvested from 47 subjects and histologically examined according to the NAFLD activity score (NAS). The concentrations of chemerin and CMKLR1 were measured using semi-quantitative real-time PCR, and the concentration of serum chemerin was measured using ELISA. To evaluate potential effects of chemerin and CMKLR1, cultured primary human hepatocytes (PHHs) were exposed to selected metabolites known to play a role in NAFLD (insulin, glucagon, palmitoic acid, and interleukin-6 (IL6)). RESULTS: Chemerin and CMKLR1 mRNA levels were elevated in the human liver. Their expression was correlated with the NAS (R(2)=0.543; P<0.001 and R(2)=0.355; P=0.014 respectively) and was significantly elevated in patients with definite non-alcoholic steatohepatitis (NASH) (P<0.05 respectively). Linear regression analysis confirmed an independent association of liver fibrosis, steatosis, inflammation, and hepatocyte ballooning with hepatic chemerin mRNA expression (P<0.05 respectively). The expression of hepatic chemerin and CMKLR1 was correlated with the measures of obesity (P<0.05). The incubation of PHHs with IL6 significantly increased the expression of CMKLR1 mRNA (P=0.027), while that of chemerin remained unaffected (P>0.05). None of the other metabolites showed an influence (P>0.05). CONCLUSION: This is the first study to show that chemerin mRNA expression is significantly elevated in the liver of NASH patients and that CMKLR1 expression is upregulated in liver inflammation, whereby IL6 could play a causal role.

The impact of insulin-independent, glucagon-induced suppression of total ghrelin on satiety in obesity and type 1 diabetes mellitus.

AIMS/HYPOTHESIS: The mechanisms underlying glucagon-induced satiety are incompletely understood. The glucagon-induced reduction in total ghrelin exerted at the hypothalamo-pituitary level might be responsible for this effect. Here we investigated glucagon-suppressive effects on circulating total and acyl-ghrelin, both in obesity and in type 1 diabetes mellitus (T1DM), with respect to the role of glucagon in appetite control. We further aimed to identify a possible mechanistic impact of changes in endogenous insulin. METHODS: In our prospective, double-blinded, placebo-controlled study, we investigated the endocrine and metabolic responses to intramuscular glucagon administration in 13 patients with T1DM (6 males, 7 females; body mass index [BMI] 24.8 ± 0.95 kg/m(2)), 11 obese participants (OP; 5 males, 6 females; BMI 34.4 ± 1.7 kg/m(2)), and 13 healthy lean participants (LP; 6 males, 7 females; BMI 21.7 ± 0.6 kg/m(2)). RESULTS: As compared with placebo, glucagon significantly increased satiety index in T1DM and in LP (P < .001) but failed to induce satiety in OP (P = .152). Total ghrelin significantly decreased after glucagon administration in all study groups (P < .01). Similarly, acyl-ghrelin significantly decreased in LP (P < .01). However, acyl-ghrelin concentrations showed no change in OP (P = .248) and even increased substantially in T1DM (P < .01). Changes in acyl-ghrelin correlated positively with changes in nonesterified fatty acid concentrations in all groups (r = 0.31-0.43; P < .01). CONCLUSIONS/INTERPRETATION: Glucagon-induced satiety was preserved in T1DM but not in obesity. This effect was unrelated to changes in total or acylated ghrelin and was independent of endogenous insulin release. In contrast to the insulin-independent glucagon-induced suppression of total ghrelin, glucagon- and/or insulin-induced modification of lipolysis may determine changes in acylated ghrelin.

Experience and acceptability of diets of varying protein content and glycemic index in an obese cohort: results from the Diogenes trial.

BACKGROUND/OBJECTIVES: To investigate acceptability and tolerability of diets of different protein and glycemic index (GI) content aimed at weight maintenance following a phase of rapid weight loss, as part of a large pan-European dietary intervention trial. SUBJECTS/METHODS: The Diogenes study (www.diogenes-eu.org) consisted of an initial 8-week rapid weight-loss phase (800-1000 kcal/day), followed by a 6-month weight maintenance intervention with five different diets varying in protein and GI content. Measurement of a range of outcomes relating to experience of the Diogenes diets in terms of acceptability, experience and mood were recorded via end of day questionnaires throughout the study. RESULTS: Weight change during the initial weight loss phase weakly, but positively correlated with acceptability of the programme (r range=-0.08 to 0.2, P 0.05, n=685 on four of five dimensions). Success at weight maintenance positively correlated with acceptance of the programme (r range=-0.21 to -0.34, P<0.001, n=540 for all five dimensions). The diets with higher protein content were more acceptable than the low protein (LP) diets, however, no differences between the high vs low GI diets were found concerning acceptability and tolerability. CONCLUSIONS: Results suggest that moderately high protein diets, compared with LP diets, are more acceptable diets for weight control in overweight individuals.

Glucagon increases circulating fibroblast growth factor 21 independently of endogenous insulin levels: a novel mechanism of glucagon-stimulated lipolysis?

AIMS/HYPOTHESIS: Glucagon reduces body weight by modifying food intake, glucose/lipid metabolism and energy expenditure. All these physiological processes are also controlled by fibroblast growth factor 21 (FGF-21), a circulating hepatokine that improves the metabolic profile in obesity and type 2 diabetes. Animal experiments have suggested a possible interaction between glucagon and FGF-21 however, the metabolic consequences of this crosstalk are not understood. METHODS: The effects of exogenous glucagon on plasma FGF-21 levels and lipolysis were evaluated in healthy volunteers and humans with type 1 diabetes, as well as in rodents with streptozotocin (STZ)-induced insulinopenic diabetes. In vitro, the role of glucagon on FGF-21 secretion and lipolysis was studied using isolated primary rat hepatocytes and adipocytes. Fgf-21 expression in differentiated rat pre-adipocytes was suppressed by small interfering RNA and released FGF-21 was immunoneutralised by polyclonal antibodies. RESULTS: Glucagon induced lipolysis in healthy human volunteers, patients with type 1 diabetes, mice and rats with STZ-induced insulinopenic diabetes, and in adipocytes isolated from diabetic and non-diabetic animals. In addition, glucagon increased circulating FGF-21 in healthy humans and rodents, as well as in patients with type 1 diabetes, and insulinopenic rodents. Glucagon stimulated FGF-21 secretion from isolated primary hepatocytes and adipocytes derived from animals with insulinopenic diabetes. Furthermore, FGF-21 stimulated lipolysis in primary adipocytes isolated from non-diabetic and diabetic rats. Reduction of Fgf-21 expression (by approximately 66%) or immunoneutralisation of released FGF-21 markedly attenuated glucagon-stimulated lipolysis in adipocytes. CONCLUSIONS/INTERPRETATION: These results indicate that glucagon increases circulating FGF-21 independently of endogenous insulin levels. FGF-21 participates in glucagon-induced stimulation of lipolysis.

Fatty acid composition of adipose tissue triglycerides after weight loss and weight maintenance: the DIOGENES study.

Fatty acid composition of adipose tissue changes with weight loss. Palmitoleic acid as a possible marker of endogenous lipogenesis or its functions as a lipokine are under debate. Objective was to assess the predictive role of adipose triglycerides fatty acids in weight maintenance in participants of the DIOGENES dietary intervention study. After an 8-week low calorie diet (LCD) subjects with > 8 % weight loss were randomized to 5 ad libitum weight maintenance diets for 6 months: low protein (P)/low glycemic index (GI) (LP/LGI), low P/high GI (LP/HGI), high P/low GI (HP/LGI), high P/high GI (HP/HGI), and a control diet. Fatty acid composition in adipose tissue triglycerides was determined by gas chromatography in 195 subjects before the LCD (baseline), after LCD and weight maintenance. Weight change after the maintenance phase was positively correlated with baseline adipose palmitoleic (16:1n-7), myristoleic (14:1n-5) and trans-palmitoleic acid (16:1n-7t). Negative correlation was found with baseline oleic acid (18:1n-9). Lower baseline monounsaturated fatty acids (14:1n-5, 16:1n-7 and trans 16:1n-7) in adipose tissue triglycerides predict better weight maintenance. Lower oleic acid predicts lower weight decrease. These findings suggest a specific role of monounsaturated fatty acids in weight management and as weight change predictors.