Evidence for a relationship between body mass and energy metabolism in the human brain

Cerebral energy metabolism has been suggested to have an important function in body weight regulation. We therefore examined whether there is a relationship between body mass and adenosine triphosphate (ATP) metabolism in the human brain. On the basis of our earlier findings indicating a neuroprotective preferential energy supply of the brain, as compared with peripheral muscle on experimentally induced hypoglycemia, we examined whether this physiological response is preserved also in low-weight and obese participants. We included 45 healthy male subjects with a body mass index (BMI) ranging from 17 to 44 kg/m(2). Each participant underwent a hypoglycemic glucose-clamp intervention, and the ATP metabolism, that is, the content of high-energy phosphates phosphocreatine (PCr) and ATP, was measured repeatedly by (31)phosphor magnetic resonance spectroscopy ((31)P-MRS) in the cerebral cortex and skeletal muscle. Results show an inverse correlation between BMI and high-energy phosphate content in the brain (P<0.01), whereas there was no such relationship found between skeletal muscle and BMI. The hypoglycemic clamp intervention did not affect the ATP metabolism in both tissues. Our data show an inverse correlation between BMI and cerebral high-energy phosphate content in healthy humans, suggesting a close relationship between energetic supply of the brain and body weight regulation.

Incidence and impact of childhood and adolescent injuries: a population-based study

BACKGROUND

The study of disabilities, use of health services, and absenteeism of parents among 0- to 17-year-old residents of Jerusalem (n = 432) hospitalized for unintentional injuries.

METHODS

Telephone interviews with parents, 6 months after hospitalization. Disabilities among 4 to 17 year olds were measured by a 25-item scale derived from the International Classification of Impairments, Disabilities, and Handicaps and by limitations of activities.

RESULTS

Six months after the injury, limitations ranged from 8.3% (daily activities) to 19.4% (sport activities). About one in three presented at least one disability in the 25-item scale. All disabilities were present in higher proportions among adolescents. The more severe injuries whether to the head or other parts of the body presented higher percentages of disabilities. Burns and traffic crashes were associated with higher proportions of disabilities than other causes and with more frequent work absenteeism by their parents.

CONCLUSION

A relatively large proportion of children remain with long-term disabilities irrespective of cause and body part injured. Because the sequelae of injuries is multifaceted, rehabilitation should include coordination between health and other services.

The development of disability scales for childhood and adolescent injuries

Scales for the study of injury-induced disabilities among 0-17 year olds were developed. Telephone interviews were conducted among parents of injured children (n = 432) 6 months after hospitalization in the three main hospitals of Jerusalem, about disabilities immediately following and 6 months after the injury. The scale for 4-17 year olds included 25 items derived from the International Classification of Disabilities, Impairments and Handicaps. Factor analysis revealed three dimensions of disability: personal care and daily activities; motor activities; and communication and sensory activities. The scale and the derived subscales on personal care and daily activities, and on motor activities showed high Cronbach's alpha, especially for disabilities immediately after the injury. The scale or subscales are easy to use, related to everyday activities performed by children in all cultures, are not related to the characteristics of the respondents, and have high consistency-reliability and construct validity. They may be used to assess the prevalence of disabilities in population studies.

The changes of IGF binding proteins after rhGH administration to patients totally dependent on parenteral nutrition

The objective was to study the effect of recombinant human growth hormone (rhGH) administration to patients with chronic malnutrition maintained on total parenteral nutrition (TPN) on the levels of insulin-like growth factor-I (IGF-I) and IGF binding proteins (IGFBPs) during a double-blind trial. After 1 week of TPN the patients were randomized into group I (placebo) or group II (rhGH). Samples were collected on the first day (start of the TPN) to measure basal values, the seventh day to study the effect of TPN and the 10th, 14th and 21st days to evaluate the rhGH effect. Basal laboratory evaluation, nutritional status and glucose tolerance were assessed using standard laboratory techniques. Radioimmunoassays were used to analyse IGF-I, free IGF-I (fIGF-I) and IGFBP1-3. Electrophoresis with Western ligand blotting and Western immunoblotting was applied to find the pattern of IGFBPs. TPN had no effect on the circulating IGF-I concentration and the pattern of IGFBPs present in the studied groups of patients. The rhGH administration led to significant increases of IGF-I, total IGFBP-3, glycosylated IGFBP-3 (39, 42 kDa) and the 29 kDa fragment of IGFBP-3 and the decrease of IGFBP-2 during the trial (P<0.05). The mean levels of IGFBP-1, fIGF-I and the parameters of nutritional status in group II during the trial were not significantly influenced by rhGH. However, it has been found that IGFBP-1 and fIGF-I levels were correlated with the levels of the weekly nitrogen balance of each patient in group II at the end of the trial. In spite of the significant changes of IGF-I, IGFBP-2, total IGFBP-3 and IGFBP-3 (29 kDa proteolytic fragment) after rhGH administration to patients with malnutrition, maintained on parenteral nutrition, the increase of nitrogen balance was seen only in patients who decreased their IGFBP-1 and increased bioavailable IGF-I as reflected by measurement of fIGF-I. The levels of IGFBP-1 may provide a useful marker of IGF-I bioavailability in monitoring the efficiency of the rhGH therapy in malnourished patients.

[Can normalization of vascular cytoadhesive activity be explained by the anti-atherosclerosis effect of growth hormone?]

BACKGROUND

The increased mortality caused by premature atherosclerosis has been shown among patients with hypopituitarism receiving conventional hormone treatment but with unsubstituted growth hormone deficiency. This experience belongs among the most important arguments in favour of replacement with growth hormone. The mechanisms of the antiatherogenic effect of growth hormone are poorly understood. The protective effect of growth hormone on the vascular endothel and its intervention in the clotting process, which have not been yet elucidated, may be the causative factors.

METHODS AND RESULTS

The endothelial damage as given by measuring of circulating soluble cytoadhesive molecules sE-selectin, sP-selectin and intercellular adhesive molecule 1 (ICAM 1) was measured in 15 adult panhypopituitaric patients before and after 1 year treatment with recombinant human growth hormone. The blood levels of all of these cytoadhesive molecules decreased significantly (p < 0.01) during the treatment. None of the concomitantly followed coagulation tests (prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin III, von Willebrand's factor and D-dimer) was significantly changed during the treatment. The tendency to decrease (p = 0.054) was observed with antithrombin III.

CONCLUSIONS

The decrease of circulating cytoadhesive molecules in blood during the treatment of growth hormone gives evidence for its protective effect, either direct or mediated, on the vascular endothel. These findings could bring an explantation for the premature atherosclerotic changes in hypopituitarism and antiatherogenic effect of growth hormone.