Ghrelin and Insulin Secretion in Humans: Not a Tale of Two Hormones?

Failure of pancreatic β-cells to secrete adequate amounts of insulin is a fundamental defect in type 1 and type 2 diabetes, and the search for innovative strategies to improve β-cell mass and function is a major priority in diabetes research. Ghrelin, a 28-amino acid peptide hormone predominantly secreted by the stomach, was identified as ligand of the growth hormone secretagogue receptor type-1a (GHSR-1a) (1). The Ser3-octanoylated ghrelin form (acylated ghrelin [AG]) also was soon recognized to act as a hypothalamic orexigenic signal (2) and to modulate tissue pathways and functions as a potential contributor to metabolic adaptation to low nutrient availability. Experimental AG administration commonly causes weight gain and hyperglycemia by enhancing food intake, fat deposition, and hepatic gluconeogenesis (3–5). A more comprehensive understanding of the metabolic impact of ghrelin has been recently allowed by the increasing appreciation of the independent, and generally more favorable, effects of its unacylated form (UAG), which does not increase food intake or circulating glucose in vivo (3,4,6). Although no specific UAG receptor has been yet identified, UAG coadministration may counteract the glucogenic effects of AG as well as AG-induced hyperglycemia (3,4,7), and positive or negative associations have been respectively reported in humans between AG or UAG and markers of whole-body insulin resistance (8). Modulating the AG–UAG balance by inhibiting the acylating enzyme ghrelin O-acyltransferase (9) or by

High-Fat Diet with Acyl-Ghrelin Treatment Leads to Weight Gain with Low Inflammation, High Oxidative Capacity and Normal Triglycerides in Rat Muscle

Obesity is associated with muscle lipid accumulation. Experimental models suggest that inflammatory cytokines, low mitochondrial oxidative capacity and paradoxically high insulin signaling activation favor this alteration. The gastric orexigenic hormone acylated ghrelin (A-Ghr) has antiinflammatory effects in vitro and it lowers muscle triglycerides while modulating mitochondrial oxidative capacity in lean rodents. We tested the hypothesis that A-Ghr treatment in high-fat feeding results in a model of weight gain characterized by low muscle inflammation and triglycerides with high muscle mitochondrial oxidative capacity. A-Ghr at a non-orexigenic dose (HFG: twice-daily 200-µg s.c.) or saline (HF) were administered for 4 days to rats fed a high-fat diet for one month. Compared to lean control (C) HF had higher body weight and plasma free fatty acids (FFA), and HFG partially prevented FFA elevation (P<0.05). HFG also had the lowest muscle inflammation (nuclear NFkB, tissue TNF-alpha) with mitochondrial enzyme activities higher than C (P<0.05 vs C, P = NS vs HF). Under these conditions HFG prevented the HF-associated muscle triglyceride accumulation (P<0.05). The above effects were independent of changes in redox state (total-oxidized glutathione, glutathione peroxidase activity) and were not associated with changes in phosphorylation of AKT and selected AKT targets. Ghrelin administration following high-fat feeding results in a novel model of weight gain with low inflammation, high mitochondrial enzyme activities and normalized triglycerides in skeletal muscle. These effects are independent of changes in tissue redox state and insulin signaling, and they suggest a potential positive metabolic impact of ghrelin in fat-induced obesity

evidence for acute stimulation of fibrinogen production by glucagon in humans

Fibrinogen, an acute-phase protein, and glucagon, a stress hormone, are often elevated in many conditions of physical and metabolic stress, including uncontrolled diabetes. However, the possible mechanisms for this association are poorly known. We have studied the acute effects of selective hyperglucagonemia (raised from ∼200 to ∼350 pg/ml for 3 h) on fibrinogen fractional secretion rate (FSR) in eight normal subjects during infusion of somatostatin and replacement doses of insulin, glucagon, and growth hormone. Fibrinogen FSR was evaluated by precursor-product relationships using either Phe ( n = 8) or Leu ( n = 2) tracers. Hyperglucagonemia did not change either plasma Phe or Tyr specific activity. After hyperglucagonemia, fibrinogen FSR increased by ∼65% (from 12.9 ± 3.6 to 21.5 ± 6.1% per day, P < 0.025) using plasma Phe specific activity as the precursor pool. FSR increased by ∼80% (from 16.6 ± 4.8 to 29.4 ± 8.8% per day, P < 0.025) if plasma Phe specific activity was corrected for the ketoisocaproate/Leu enrichment (or specific activity) ratio to obtain an approximate estimate of intrahepatic Phe specific activity. FSR increased by ∼60% when using plasma Tyr specific activity as precursor pool ( n = 8) ( P < 0.05), as well as when using the Leu tracer precursorproduct relationship ( n = 2). In conclusion, selective hyperglucagonemia for ∼3 h acutely stimulated fibrinogen FSR using a Phe tracer method. Thus, glucagon may be involved in the increase of fibrinogen concentration and FSR observed under stressed or pathologic conditions

Pédiatrie [News in paediatrics]

Every pediatrician will be confronted with newborns oryoung infants with skin lesions in proximity of the vertebral column. It is important not to miss a spinal dysraphism because of the risk of meningeal infection or of the possible presence of a tethered cord. A practical algorithm is presented. Non-accidental injury in young infants and toddlers is not rare but difficult to detect. Bruises and fractures are highly suspicious for non-accidental injury and should trigger specific investigations. Emergency departments and hospitals are switching from hypotonic to isotonic solutions as maintenance infusions of children. They reduce the risk of hyponatremia without increasing that of hypernatremia, and they should be used preferentially in the majority of pediatric clinical settings

PG-SGA SF in nutrition assessment and survival prediction for elderly patients with cancer

Background: This study was sought to report the prevalence of malnutrition in elderly patients with cancer. Validate the predictive value of the nutritional assessment tool (Patient-Generated Subjective Global Assessment Short Form, PG-SGA SF) for clinical outcomes and assist the therapeutic decision. Methods: This is a secondary analysis of a multicentric, observational cohort study. Elderly patients with cancer older than 65 years were enrolled after the first admission. Nutritional status was identified using the PG-SGA SF. Results: Of the 2724 elderly patients included in the analysis, 65.27% of patients were male (n = 1778); the mean age was 71.00 ± 5.36 years. 31.5% of patients were considered malnourished according to PG-SGA SF. In multivariate analysis, malnutrition(PG-SGA SF &gt; 5) was significantly associated with worse OS (HR: 1.47,95%CI:1.29–1.68), affects the quality of life, and was related to more frequent nutrition impact symptoms. During a median follow-up of 4.5 years, 1176 death occurred. The mortality risk was 41.10% for malnutrition during the first 12 months and led to a rate of 323.98 events per-1000-patient-years. All nutritional assessment tools were correlated with each other (PG-SGA SF vs. PG-SGA: r = 0.98; PG-SGA SF vs. GLIM[Global Leadership Initiative on Malnutrition]: r = 0.48, all P &lt; 0.05). PG-SGA SF and PG-SGA performed similarly to predict mortality but better than GLIM. PG-SGA SF improves the predictive ability of the TNM classification system for mortality in elderly patients with cancer, including distinguishing patients’ prognoses and directing immunotherapy. Conclusions: The nutritional status as measured by PG-SGA SF which is a prognostic factor for OS in elderly cancer patients and could improve the prognostic model of TNM

Treating hyperglycemia improves skeletal muscle protein metabolism in cancer patients after major surgery

Objective: Cancer and surgical stress interact to aggravate insulin resistance, protein catabolism, and glutamine depletion in skeletal muscle. We compared the effects of insulin-mediated euglycemia and moderate hyperglycemia on kinetics of protein and selected amino acids in skeletal muscle of female cancer patients after major surgery. Design: In each patient, a 24-hr period of insulin-mediated tight euglycemia (mean blood glucose, 5.8 0.4 mmol/L) preceded or followed a 24-hr control period of moderate hyperglycemia (mean blood glucose, 9.6 0.6 mmol/L) on the first and second day after surgery, in randomized order, according to a crossover experimental design. Setting: Intensive care unit, cancer ospital. Patients: Cancer patients after abdominal radical surgery combined with intraoperative radiation therapy. Interventions: Intensive (57 +/- 11 units/24 hrs) and conventional (25 +/- 5 units/24 hrs) insulin treatment during total parenteral nutrition. Measurements and Main Results: Muscle metabolism was assessed at the end of each 24-hr period of euglycemia and of hyperglycemia by leg arteriovenous catheterization with stable isotopic tracers. We found that euglycemia as compared with hyperglycemia was associated with higher (p < .05) fractional glucose uptake (16% +/- 4% vs. 9% +/- 3%); higher (p < .05) muscle protein synthesis and neutral net protein balance (-3 +/- 3 vs. -11 +/-3 nmol phenylalanine·100 (mL-1)·(min-1), respectively); lower (-52% +/- 12%, p < .01) muscle nonprotein leucine disposal (an index of leucine oxidation) and higher (p < .05) plasma leucine concentrations; and higher (3.6 +/- 1.7 times, p < .01) net de novo muscle glutamine synthesis and plasma glutamine concentrations (p < .05). Euglycemia was associated with higher (23% +/- 7%, p < .05) plasma concentrations of arginine but did not affect either arginine release from muscle or plasma concentration and muscle flux of asymmetrical dimethylarginine. Rate of muscle proteolysis correlated (p < .05) with muscle release of asymmetrical dimethylarginine. Conclusions: Treating hyperglycemia improves skeletal muscle protein and amino acid metabolism in cancer patients after major surgery

The Conceptual Definition of Sarcopenia: Delphi Consensus from the Global Leadership Initiative in Sarcopenia (GLIS)

\ua9 2024 The Author(s).Importance: Sarcopenia, the age-related loss of muscle mass and strength/function, is an important clinical condition. However, no international consensus on the definition exists. Objective: The Global Leadership Initiative in Sarcopenia (GLIS) aimed to address this by establishing the global conceptual definition of sarcopenia. Design: The GLIS steering committee was formed in 2019-21 with representatives from all relevant scientific societies worldwide. During this time, the steering committee developed a set of statements on the topic and invited members from these societies to participate in a two-phase International Delphi Study. Between 2022 and 2023, participants ranked their agreement with a set of statements using an online survey tool (SurveyMonkey). Statements were categorised based on predefined thresholds: strong agreement (&gt;80%), moderate agreement (70-80%) and low agreement (&lt;70%). Statements with strong agreement were accepted, statements with low agreement were rejected and those with moderate agreement were reintroduced until consensus was reached. Results: 107 participants (mean age: 54 \ub1 12 years [1 missing age], 64% men) from 29 countries across 7 continents/regions completed the Delphi survey. Twenty statements were found to have a strong agreement. These included; 6 statements on \u27general aspects of sarcopenia\u27 (strongest agreement: the prevalence of sarcopenia increases with age (98.3%)), 3 statements on \u27components of sarcopenia\u27 (muscle mass (89.4%), muscle strength (93.1%) and muscle-specific strength (80.8%) should all be a part of the conceptual definition of sarcopenia)) and 11 statements on \u27outcomes of sarcopenia\u27 (strongest agreement: sarcopenia increases the risk of impaired physical performance (97.9%)). A key finding of the Delphi survey was that muscle mass, muscle strength and muscle-specific strength were all accepted as \u27components of sarcopenia\u27, whereas impaired physical performance was accepted as an \u27outcome\u27 rather than a \u27component\u27 of sarcopenia. Conclusion and relevance: The GLIS has created the first global conceptual definition of sarcopenia, which will now serve to develop an operational definition for clinical and research settings

High Rate of Large Deletions in Caenorhabditis briggsae Mitochondrial Genome Mutation Processes

Mitochondrial DNA (mtDNA) mutations underlie a variety of human genetic disorders and are associated with the aging process. mtDNA polymorphisms are widely used in a variety of evolutionary applications. Although mtDNA mutation spectra are known to differ between distantly related model organisms, the extent to which mtDNA mutation processes vary between more closely related species and within species remains enigmatic. We analyzed mtDNA divergence in two sets of 250-generation Caenorhabditis briggsae mutation-accumulation (MA) lines, each derived from a different natural isolate progenitor: strain HK104 from Okayama, Japan, and strain PB800 from Ohio, United States. Both sets of C. briggsae MA lines accumulated numerous large heteroplasmic mtDNA deletions, whereas only one similar event was observed in a previous analysis of Caenorhabditis elegans MA line mtDNA. Homopolymer length change mutations were frequent in both sets of C. briggsae MA lines and occurred in both intergenic and protein-coding gene regions. The spectrum of C. briggsae mtDNA base substitution mutations differed from the spectrum previously observed in C. elegans. In C. briggsae, the HK104 MA lines experienced many different base substitution types, whereas the PB800 lines displayed only C:G → T:A transitions, although the difference was not significant. Over half of the mtDNA base substitutions detected in the C. briggsae MA lines were in a heteroplasmic state, whereas all those previously characterized in C. elegans MA line mtDNA were fixed changes, indicating a narrower mtDNA bottleneck in C. elegans as compared with C. briggsae. Our results show that C. briggsae mtDNA is highly susceptible to large deletions and that the mitochondrial mutation process varies between Caenorhabditis nematode species

Diabetes Mellitus Is Associated with Shortened Activated Partial Thromboplastin Time and Increased Fibrinogen Values

OBJECTIVE: This study was designed to examine the relationship between shortened activated partial thromboplastin time (APTT) and increased fibrinogen values with diabetes mellitus. METHODS: APTT, prothrombin time (PT), fibrinogen, fasting plasma glucose (FPG) and glycosylated hemoglobin A1c (HbA1c) levels were measured in 1,300 patients. Patients were divided into three groups according to their HbA1c and FPG levels. RESULTS: When participants were grouped according to their HbA1c levels, we found significantly shorter APTT values (26.9±5.6 s) and increased fibrinogen levels (3.1, 1.9-6.3 g/L) in the diabetes group when compared with the other two groups. When participants were grouped according to their FPG levels, we found significantly shorter APTT values (26.9±6.2 s) and increased fibrinogen levels (3.1, 1.8-6.2 g/L) in the diabetes group when compared with the euglycemic group. CONCLUSIONS: Shorter APTT and increased fibrinogen levels might be useful hemostatic markers in patients with diabetes and in patients at high risk for diabetes