phosphocreatine and Weight-Loss

Seizures and neurologic involvement have been reported in patients infected with Shiga toxin (Stx) producing

Topics: Amygdala; Animals; Brain; Calcium-Binding Proteins; Cell Culture Techniques; Cerebral Cortex; Disease Models, Animal; DNA-Binding Proteins; Endothelial Cells; Erythrocytes; Escherichia coli; Hemolytic-Uremic Syndrome; Hippocampus; Humans; Kidney; Magnetic Resonance Imaging; Male; Mice; Microfilament Proteins; Microglia; Nervous System; Phosphocreatine; Rabbits; Repressor Proteins; Shiga Toxin; Shiga Toxin 2; Spectrum Analysis; Thalamus; Toxicity Tests; Tumor Necrosis Factor-alpha; Weight Gain; Weight Loss

A reduced myocardial phosphocreatine/adenosine triphosphate (PCr/ATP) ratio is linked to both diastolic dysfunction and heart failure. Although obesity is well known to cause diastolic dysfunction a link to impaired cardiac energetics has only recently been established. We assessed whether or not long-term weight loss in obesity, which is known to reduce mortality, is accompanied by both improved cardiac energetics and diastolic function. Normal weight (BMI 22 ± 2; n = 18) and obese subjects (BMI 34 ± 4; n = 13) underwent cine-MRI (1.5 Tesla) to determine left ventricular diastolic function using volume-time curve analysis, and (31)P-MR spectroscopy (3 Tesla) to assess cardiac energetics (PCr/ATP ratio). Obese subjects (n = 13) underwent repeat assessment after 1 year of supervised weight loss. Obesity, in the absence of identifiable cardiovascular risk factors, was associated with significantly impaired myocardial high energy phosphate metabolism (PCr/ATP ratio, normal; 2.03 ± 0.27 vs. obese; 1.58 ± 0.47, p = 0.002) and significantly lower peak diastolic filling rate (normal; 4.8 ± 0.8 vs. obese; 3.8 ± 0.7 EDV/s, p = 0.01). Weight loss (on average 9 kg, 55% excess weight) over 1 year resulted in a 24% increase in PCr/ATP ratio (p = 0.01) and an 18% improvement in peak diastolic filling rate (p = 0.01). Myocardial PCr/ATP ratio remained positively correlated with peak diastolic filling rate after weight loss (r = 0.63, p = 0.02). In obesity, weight loss improves impaired cardiac energetics and myocardial relaxation. Improved myocardial energetics appear to play a key role in diastolic functional recovery accompanying weight loss.

Topics: Adenosine Triphosphate; Adiposity; Adult; Body Mass Index; Diastole; Energy Metabolism; Humans; Magnetic Resonance Imaging, Cine; Magnetic Resonance Spectroscopy; Middle Aged; Myocardium; Obesity; Phosphocreatine; Recovery of Function; Time Factors; Treatment Outcome; Ventricular Function, Left; Weight Loss

To investigate whether 31 P-MR spectroscopy can detect reduced concentrations of high-energy phosphates, like PCr and NTP, caused by decreased metabolic activity in the brain of patients with anorexia nervosa (AN) and, furthermore, whether any impairment of the cerebral membrane metabolism can be derived from the spectra.. 10 female patients, age range 12 - 20 years and mean BMI (body mass index) of 14.8 +/- 1.6 kg/m 2, with clinically diagnosed AN (ICD-10, F50.0) and 10 healthy control subjects, age range 12 - 21 years and mean BMI 19.0 +/- 2.1 kg/m 2, without nutritional disturbances: were investigated. 31P-MR spectroscopy was performed with a 1.5 T MRI unit using single volume selection in the frontal/prefrontal region of brain. Relative metabolic concentrations were quantified by normalizing the peak areas of the metabolites with the total area of the complete phosphorous spectrum, P tot, as well as with the peak area of beta-NTP.. Significant differences between the two groups were observed for the metabolic ratios PDE/P tot, PDE/beta-NTP and alpha-NTP/P tot which were lower in the patient group except for alpha-NTP/P tot. These ratios also revealed a statistically significant correlation with the BMI (r PDE/Ptot = 0.747, r PDE/beta-NTP = 0.57, r alpha-NTP/Ptot = -0.56; p

Topics: Adolescent; Adult; Anorexia Nervosa; Body Mass Index; Brain; Child; Confidence Intervals; Data Interpretation, Statistical; Energy Metabolism; Esters; Female; Fourier Analysis; Frontal Lobe; Humans; Magnetic Resonance Spectroscopy; Models, Theoretical; Phosphates; Phosphocreatine; Polyphosphates; Software; Weight Loss

The use of magnetic resonance spectroscopy (MRS) to monitor cellular bioenergetics during weight loss may provide novel insights regarding metabolic functioning.. Changes were noted in 18 sedentary, moderately overweight women following a 7-week program consisting of a low-fat, 422-428 MJ/day (1010-1025 kcal/day) diet, a progressive walking program, a vitamin-mineral-fortified, isolated-protein meal supplement drink and a weekly group meeting. Mitochondrial energy production and utilization were assessed by measuring the concentrations of inorganic phosphate (Pi) and phosphocreatine (PCr) through magnetic resonance spectroscopy. Anthropometric changes were also monitored.. Dietary analysis of subjects' pre-intervention food records showed intakes of numerous vitamins and minerals below 100% of the Recommended Dietary Allowances (RDA), most commonly for folic acid, vitamin E, magnesium, iron and zinc. Relative to pre-intervention levels, final measurements showed that all women lost body weight, ranging from 2.6 to 10.0 kg. Body mass index declined in all subjects, from 0.55 to 3.86 kg/m2. All subjects lost fat mass, ranging from 0.9 to 10.4 kg. Seventeen of 18 women showed a decline in their percentage of body fat, ranging from 2.3 to 10.1%. Twelve of 18 subjects showed an increase of 0.1-3.5 kg of fat-free mass, with half of these values increasing by > 1.0 kg. No changes from baseline levels were found in the Pi/PCr ratio over 7 weeks under resting, exercise or recovery conditions, suggesting a preservation in muscle energy function over the course of the study while the subjects were losing fat mass and total body weight.. The possible metabolic advantage associated with a program that employs moderate energy restriction, repletion of vitamin and mineral intakes to RDA levels, and a regular aerobic exercise program is proposed.

Topics: Adipose Tissue; Adult; Anthropometry; Body Composition; Diet, Reducing; Energy Metabolism; Exercise; Female; Food, Formulated; Humans; Magnetic Resonance Spectroscopy; Mitochondria, Muscle; Obesity; Phosphates; Phosphocreatine; Phosphorus; Weight Loss