Predictions of energy intake and energy allowance of patients with Duchenne muscular dystrophy and their validity.

Patients with Duchenne muscular dystrophy are so malnourished that energy supplementation is crucial. Their degree of energy deficiency was assessed as difference between their energy intake and their energy allowance, which were deduced from easily measured parameters. A significant, negative relationship was found between the basal metabolic rate (BMR) (Y, %, BMR/standard BMR) and body weight (X, %, body weight/standard body weight) in the patients, from which the formula for the BMR was deduced to be Y = -1.116X + 174.5 (n = 202, r = -0.72, p less than 0.001). Thus, it is possible to estimate the energy allowance for individual patients by a factorial procedure from the presumed BMR and a factor for physical activity. In addition, their energy intake was calculated from a constant protein-energy % (14.6%) in their diet and nitrogen intake which was deduced from a significant positive correlation between their nitrogen intake (Y, mg/kg/day) and their nitrogen excretion in 24 h urine samples (X, mg/kg/day). This correlation conformed to the equation Y = 1.053X + 32.4 (n = 267, r = +0.76, p less than 0.001). The validities of the above predictions for energy intake and allowance were examined by plotting the degree of energy deficiency (% ratio of presumed intake/presumed allowance) against the concentrations of retinal binding protein, prealbumin and transferrin in the serum, because rapid turnover proteins are sensitive to energy deficiency. Significant positive correlations were obtained with both variables, suggesting that these predictions were valid.     

进行性肌营养不良合并中枢神经系统感染1例

进行性肌营养不良(progressive muscular dystrophy,PMD)是一组原发于肌肉组织的遗传性、进行性肌纤维变性疾病,主要临床表现为进行性加重的肌肉萎缩和无力,主要累及肢体和头面部肌肉,少数累及心肌.遗传方式主要为常染色体显性、隐性和X连锁隐性遗传.进行性肌营养不良的诊断主要依据症状、体征、家族史、肌酸激酶及肌电图检查,肌肉活组织检查及基因检测予以确诊.关于进行性肌营养不良症患者合并中枢神经系统感染报道较少,本文报道1例进行性肌营养不良合并中枢神经系统感染的诊治经过.     

Postabsorptive and insulin-stimulated energy and protein metabolism in patients with myotonic dystrophy type 1

BACKGROUND: Exaggerated insulin resistance was described as the major metabolic abnormality in myotonic dystrophy type 1 (DM1). We reported recently that the severity of the impairment in insulin-stimulated glucose metabolism in these patients was overestimated. OBJECTIVE: The aim was to dissect out insulin action with respect to whole-body energy homeostasis and glucose, protein, and lipid metabolism in patients with DM1 to assess the relevance of insulin resistance to the heterogeneous clinical manifestations of this syndrome. DESIGN: Ten nondiabetic patients with DM1 and 10 matched healthy control subjects were studied by means of 1) dual-energy X-ray absorptiometry; 2) a euglycemic-hyperinsulinemic clamp (40 mU. m(-2). min(-1)) combined with a primed, continuous infusion of [6,6-d(2)]glucose and [1-(13)C]leucine; 3) indirect calorimetry; and 4) localized (1)H magnetic resonance spectroscopy of the calf muscles. RESULTS: Patients with DM1 had less lean body mass, greater fat mass, and greater intramyocellular lipid contents than did healthy control subjects. Energy expenditure and glucose and lipid metabolism did not differ significantly between the groups. In contrast, markers of proteolysis were higher in DM1 patients in the postabsorptive and insulin-stimulated conditions and were associated with lower plasma concentrations of insulin-like growth factor 1 (P < 0.03) and higher plasma concentrations of tumor necrosis factor alpha receptor 2 (P = 0.04). CONCLUSIONS: Despite greater body fat and intramyocellular lipid contents in patients with DM1, insulin sensitivity was not significantly different between patients and control subjects. In contrast, the loss of lean body mass in patients with DM1 was associated with abnormal postabsorptive and insulin-stimulated regulation of protein breakdown. Lower plasma insulin-like growth factor 1 concentrations and higher tumor necrosis factor system activity might be involved in the muscle wasting of DM1.     

Body composition and energy expenditure in Duchenne muscular dystrophy

OBJECTIVE: To investigate the relationship between resting energy expenditure (REE) and body composition in Duchenne Muscular Dystrophy (DMD). DESIGN: An observational study. SETTING: University Research Centre. SUBJECTS: Nine Duchenne children (age range 6-12 y), mean relative weight 128%, agreed to undergo the investigation and all of them completed the study; INTERVENTIONS: Assessment of body composition (total body fat and skeletal muscle mass) by magnetic resonance imaging and resting energy expenditure by indirect calorimetry. MAIN OUTCOME MEASURES: Fat mass (FM; kg and percentage weight), fat-free mass (FFM; kg and percentage weight), muscle mass (kg and percentage weight), resting energy expenditure (kJ/kg body weight and kJ/kg fat-free mass). RESULTS:: In Duchenne children fat mass averages 32% and total skeletal muscle mass 20% of body weight. Resting energy expenditure per kg of body weight falls within the normal range for children of the same age range, while when expressed per kg of FFM is significantly higher than reference values. No relationship was found between REE and total skeletal muscle mass. CONCLUSIONS: Our results do not demonstrate a low REE in DMD boys; on the contrary REE per kg of FFM is higher than normal, probably due to the altered FFM composition. We suggest that the development of obesity in DMD children is not primarily due to a low REE but to other causes such as a reduction in physical activity and or overfeeding.     

18 years experience with mechanical ventilation in patients with Duchenne muscular dystrophy

OBJECTIVE: To find out which patients with Duchenne muscular dystrophy are eligible for starting home mechanical ventilation and what the survival rate is. DESIGN: Retrospective. METHOD: In 48 patients with Duchenne muscular dystrophy who were treated with home ventilation from 1987, the results were assessed in the follow-up visit in February 2005. Initially, ventilation was only given through a tracheotomy (TPPV), but after starting up a multidisciplinary neuromuscular consultation, non-invasive ventilation (NIPPV) was offered in an earlier stage of the disease. The following data were derived from the outpatient medical record: indication for ventilation, vital capacity (VC), arterial blood gas values, duration of ventilation up to February 2005, survival and causes of death. RESULTS: 15 patients died. The 5-year survival rate was 75% from the start of mechanical ventilation and 67% (18/27) of the patients were still living at home at the time of the follow-up visit. The most important causes of death were cardiomyopathy (5/15) and tracheal bleeding (3/15). The group of patients who started ventilation before 1995 (n = 17) had a significantly smaller VC than the group (n = 31) who started after the neuromuscular consultation was set up. The PaCO2 during daytime was significantly higher in the group that started ventilation before 1995 compared to the group that started later. CONCLUSION: Home mechanical ventilation can be implemented effectively in patients with Duchenne dystrophy, with a 5-year survival of 75%.     

Protein and energy metabolism in starvation reconsidered

Current concepts of the metabolic changes during starvation have been heavily influenced by recent studies on grossly obese subjects undergoing therapeutic fasting. It has been suggested that during prolonged starvation the central nervous system develops the ability to utilize ketone bodies, and that the consequent reduction in gluconeogenesis leads to an adaptive sparing of protein catabolism. However, our analysis of classical studies on starvation shows that during prolonged starvation in normal subjects the fraction of total energy expenditure derived from protein (the P ratio) remained unchanged. Although urinary nitrogen was reduced during the progress of the fast, we conclude that this is secondary to the general reduction in metabolic rate, rather than to a specific sparing of protein.     

Professional activity of Emery-Dreifuss muscular dystrophy patients in Poland

Objectives

Emery-Dreifuss muscular dystrophy (EDMD) is a very rare genetic disorder affecting skeletal and heart muscles. The aim of this study was to identify factors which might influence the ability to work in EDMD patients in Poland.

Material and Methods

The study included 24 patients suffering from either of the two EDMD forms: 17 with emerinopathy (EDMD1; EDMD caused by mutations in the emerin gene) and 7 with laminopathy (EDMD2; EDMD caused by the lamin A/C gene mutations). After clinical evaluation of EDMD course, study participants were questioned about their education, current and former employment, and disability certificates and pensions.

Results

54% of the study participants were employed, and 90% of them had job position corresponding to their education. Undertaking work did not correlate with the level of physical performance or disease complication, but it revealed statistically significant correlation with a higher level of education (p = 0.015). Only 23% of professionally active patients were employed in a sheltered workplace. Disability certificate was granted to all EDMD2 and to 90% of EDMD1 patients. All EDMD2 and 50% of EDMD1 patients received a disability pension, which reflects more severe course of EDMD2.

Conclusions

Higher level of education increased the chance of employment, even if significant disability was present. Therefore, I hypothesize that advice on education and job counseling should be applied as early as possible after the diagnosis of EDMD.     

Protein metabolism in adult patients with phenylketonuria

OBJECTIVE: Protein intake recommendations in phenylketonuria (PKU) are frequently the subject of discussion. For healthy adults, the recommended daily allowance (RDA) is 0.8 g.kg(-1).d(-1), which is generally lower than that observed in the general Western population. We investigated whether whole-body protein metabolism in patients with PKU is comparable to that of healthy controls at a RDA rate of protein intake. METHODS: Six adult patients with well-controlled PKU and six healthy subjects of comparable age, height, and weight were studied using a primed continuous infusion of [1-(13)C]-valine for 8 h after an overnight fast before and during frequent meals. Normal protein was given to controls, whereas patients with PKU received a combination of an amino acid mixture and natural protein. RESULTS: No significant differences were observed between patients with PKU and controls in preprandial and prandial rates of valine appearance and oxidation and protein breakdown, protein synthesis, and net protein balance. Feeding resulted in a significant (P < 0.01) decrease in protein breakdown (PKU: 94 +/- 15 micromol.kg(-1).h(-1) preprandial to 49 +/- 10 micromol.kg(-1).h(-1) prandial; controls: 97 +/- 10 micromol.kg(-1).h(-1) preprandial to 55 +/- 10 micromol.kg(-1).h(-1) prandial), whereas no effects were observed in protein synthesis (PKU: 77 +/- 10 micromol.kg(-1).h(-1) preprandial to 73 +/- 7 micromol.kg(-1).h(-1) prandial; controls: 76 +/- 8 micromol.kg(-1).h(-1) preprandial to 71 +/- 5 micromol.kg(-1).h(-1) prandial). Net protein balance increased from negative prandial to positive preprandial values (PKU: -17 +/- 6 micromol.kg(-1).h(-1) preprandial to +23 +/- 8 micromol.kg(-1).h(-1) prandial; controls: -21 +/- 4 micromol.kg(-1).h(-1) preprandial to +16 +/- 9 micromol.kg(-1).h(-1) prandial). CONCLUSION: Whole-body protein metabolism in adult patients with PKU is fully comparable to that in healthy controls at the RDA level of protein intake.     

Protein and energy metabolism with biosynthetic human growth hormone in patients on full intravenous nutritional support

Our objective was to examine the effect of biosynthetic human growth hormone (BSHGH) on protein and energy metabolism in patients on full intravenous nutrition (IVN). Fifteen patients who had been established on IVN were allocated at random to receive either BSHGH (0.1 mg/kg/day) or placebo daily for 7 days. All patients received the same feeding regimen which contaminated 14 gN, 1000 kcal of glucose and 1000 kcal of fat (Intralipid) daily. The mean nitrogen balance for days 4 to 7 was significantly more positive with BSHGH (7.0 +/- 0.6 gN/day) than with placebo (4.4 +/- 0.7 gN/day). The BSHGH group were lighter (53 +/- 4.6 kg body weight) than controls (68 +/- 5.1 kg), but the difference was not significant. Resting energy expenditure (expressed as percentage of day 1) increased throughout the study in patients receiving BSHGH (day 7, 120.8 +/- 5.5%), whereas in patients receiving placebo it remained stable (day 7, 98.9 +/- 2.7%). The nonprotein respiratory quotients were similar for BSHGH (mean days 4-7, 0.94 +/- 0.04) and placebo (mean days 4-7, 0.93 +/- 0.01) (p greater than 0.05). This study demonstrates more positive nitrogen balance, which may in part be due to different substrate loads, and an increase in energy expenditure in patients receiving BSHGH.