JIMD Short Report #002 (2006) Online DOI 10.1007/s10545-006-0227-x
S H O RT R E P O RT
Dietary intervention and oxidative phosphorylation capacity Eva Morava · Richard Rodenburg · Heidi Zweers van Essen · Maaike De Vries · Jan Smeitink
Received: 2 September 2005 / Accepted: 7 February 2006 C SSIEM and Springer 2006
Summary Secondary deterioration of mitochondrial function has been reported in patients with anorexia and cancerrelated malnutrition. Inadequate nutrition, failure to thrive and feeding problems are also common symptoms in children with primary oxidative phosphorylation defects. As a standard intervention protocol we advise an age-appropriate diet and energy intake in our patients diagnosed with a mitochondrial dysfunction. By comparing the results of the first and the second samples from a group of children who underwent repeated muscle biopsies, we observed biochemical improvement in the mitochondrial function in 7 out of 10 patients following dietary advice and intervention. We suggest evaluating the nutritional state by interpretation of the skeletal muscle biochemistry in patients with a suspected oxidative phosphorylation defect. Since an insufficient dietary intake could play a role in secondary mitochondrial dysfunction, nutritional intervention should be performed prior to the biopsy. On the other hand, our data suggest that optimizing the nutritional and energy intake might also improve the utilization of the residual mitochondrial energy-generating capacity in patients with primary oxidative phosphorylation defects.
Communicating editor: Garry Brown Competing interests: None declared E. Morava () · R. Rodenburg · M. De Vries · J. Smeitink Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Mitochondrial Disorders, Nijmegen, The Netherlands e-mail:
[email protected] H. Z. van Essen Department of Dietetics, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Mitochondrial Disorders, Nijmegen, The Netherlands
Introduction Secondary deterioration of mitochondrial function has been described in conditions with extreme malnutrition, as in anorexia nervosa or in severe end-stage cancer. Anorexia (Essen et al 1981; Morton et al 1998) or cancer-related cachexia (Ushmorov et al 1999) alters the normal endocrine regulation and might lead to an increase of inhibitory mechanisms, causing further decline in cell growth and energy production. Inadequate nutrition, failure to thrive and feeding problems are also common symptoms in children with oxidative phosphorylation defects (Smeitink 2003). Malnutrition, including decreased energy and vitamin intake, might lead to further deterioration of the clinical condition and could cause a secondary worsening in the already insufficient ATP production of the mitochondria. Optimizing the nutritional intake leads to the restitution of the nutrition-related secondary dysfunction in the oxidative phosphorylation system and might also increase the cellular energy-generating capacity (Morava et al 2005). In certain genetic disorders, high-energy diet or other nutritional interventions are unsuccessful because of an inherited predisposition for growth delay due to malabsorption, or a deficient capacity to intensify metabolism or cell replication. The clinical and biochemical effects of malnutrition and that of optimal feeding and high energy intake in patients with a disorder of oxidative phosphorylation have not yet been studied.
Patients and methods Children with a suspected disorder of the oxidative phosphorylation participated in a diagnostic protocol of multiple Springer
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Table 1 Clinical features of our patients at the time of the first muscle biopsy
a Patient 6: 11778G>A mtDNA mutation. b Features changed by the time of the second biopsy. c Clinical score (Wolf and Smeitink 2002): probable mitochondrial disorder 5–7, definite mitochondrial disorder 8–12 (indicated by bold type).
Patient Feature
1
2
3
4
5
6a
7
8
9
10
Muscle weakness Exercise intolerance MR/loss of skills Seizures Extrapyramidal/pyramidal signs Ataxia Cardiomyopathy Optic atrophy Hearing loss Abnormal MRI Hypothyroidism FTT Lactic acidaemia High serum alanine Organic aciduria Clinical scorec Clinical scorec (repeated biopsy)
+ + − − + − + − − − − + + − − 6 6
+ + + − − − + + − − − + + + − 8 8
+ + + + −b − − − − + − + + + − 8 8
+ + + − − + − − − − − + + − − 6 5
+ + + − − + − + − + − +b +b +b − 8 5
+ + + + + − − −b − + − +b − − − 7 7
+ + + + − − − − − − + − + − − 6 6
+ + − − − − − − − −b − +b + − − 5 3
+ + + − + + − − − − − + + + − 8 8
+ + + + + − − − − + − − + − − 7 7
investigations including laboratory measurements, ECG, chest radiography, EEG, visual evoked potentials (VEP), acoustic evoked potentials (BAEP), sensory evoked potentials (SEP) and a cranial MRI. A severity assessment (Table 1) was based on the clinical symptoms, metabolic alterations and abnormal neuroimaging features using the mitochondrial diagnostic score (Wolf and Smeitink 2002). With a score higher than 5, an open muscle biopsy was performed under general anaesthesia. ATP production from pyruvate oxidation and the activities of the mitochondrial complexes I–V were measured in a fresh muscle sample according to methods described previously (Janssen et al 2003; Smeitink et al 2001). As a standard intervention protocol, all patients were advised to follow an age-appropriate diet including the energy intake and other nutrients, vitamins and minerals. The children received regular physiotherapy as well. During the follow-up period, in 10 patients with comparable clinical and biochemical signs of mitochondrial dysfunction without a known genetic causation (Tables 1 and 2), a second muscle biopsy was performed after informed consent, either because of a significant change in the clinical picture or because of a striking discrepancy between the severity of the biochemical results and the phenotype. All the children studied had a significantly decreased ATP production from pyruvate oxidation shown by the first biopsy. Four patients presented additionally with decreased activity of the enzyme complexes I, III and IV or PDHc in muscle, not expressed in cultured fibroblasts (Table 1). We retrospectively analysed the clinical, nutritional and biochemical data and repeated the evaluations at the time of the second biopsy.
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Dietary consultation was requested for all patients diagnosed with a mitochondrial dysfunction. Calculation of the nutritional and energy intakes was based on the 3day intake form, and the diet was adjusted to the ageappropriate (and not the weight-appropriate) requirements according to the suggestions of the Dutch Health Committee (Gezondheidsraad 2001) and the WHO (Table 3). We used the term ‘inappropriate nutrition’ if the patient did not receive the age-appropriate energy, nutritional and vitamin intake, according to the national health standards (Gezondheidsraad 2001). In such a case the patient received subsequent supplementation. Two children with mitochondrial enzyme complex deficiencies (patients 1 and 2) were treated with high-dose beta-carotene and alpha-tocopherol. The patient with mild PDHc deficiency was treated with thiamin for a test period; because blood thiamine levels were normal and given the lack of clinical and biochemical effects, the therapy was stopped after 3 months. There was no change in medication between the time of the first and second biopsy. None of the children received co-enzyme Q 10 , riboflavin, creatine monohydrate or other nutraceutical products that could influence mitochondrial function. Dietary intervention was different in each patient according to the clinical situation and the presence of gastroesophageal reflux, eating disorder or malabsorption. In each child we used the appropriate intervention to reach the ageappropriate intake. If this was not possible, we started tube feeding and forced enteral feeding. In three patients nutritional counselling was sufficient; two children received total gastric formula feeding; and two received night-feeding (tube feeding) with a formula to provide the required energy
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intake and to achieve an increase in the weight and height ratios.
12 28 21 17 12 28 13 16 1 year 4 year 2 years 4 years 1 year 3 year 1/2 year 1/2 year –2SD –2SD –3SD –2SD –1SD –1SD –2SD –1SD – Night feeding Tube feeding + + Night feeding + Tube feeding 3 4 5 6c 7 8 9 10
W/H: weight for height; CS, citrate synthase. a Age appropriate diet initiated at the time of the first biopsy. b Tocopherol and beta-carotene supplementation from the time of the first biopsy. c Patient 6: 11778G>A (Leber) mutation.
–3SD 0–1SD 0SD 0SD 0SD +1SD 0–1SD 0SD
2 years 6 years 4 years 10 years 7 years 5 years 15 years 3 years
14 53 23 38 49 48 50 38
CI:22, CIII:14, CIV:65 CI:0, CIII:72 CIV:18 Normal Normal Normal Normal Normal Normal Normal Normal 5 6 3 years 2 years –3SD –3SD
CI:70, CIII:0, CIV:90 CI:67, CIII:N CIV:37 Normal CI 82 PDHc 76 Normal Normal Normal Normal Normal 1 year 1 year 2 –2SD –2SD – – 1b 2b
W/H Patient
Normo-caloric dieta
Age at at biopsy 1
4 4
W/H Complex activity in % of lowest controls ATP production (nmol/h per mU CS)
Table 2 Growth parameters, diet and biochemical features in our patients at the time of the two biopsies
Age at biopsy 2
ATP production (nmol/h per mU CS)
Complex activity in % of lowest controls
Results All children had inappropriate nutrition with decreased energy intake; seven children (patients 1–6 and 9) had a weight-for-height index below 2 standard deviations and three children (patients 7, 8 and 10) had a weight-for-height index below 1 standard deviation (by a length below 1 SD) compared to the age- and sex-matched growth centile curve. In three patients (patients 1–3) no significant biochemical improvement was detected in the second biopsy. Following dietary advice and intervention (Table 2) seven children (patients 4–10) had an improvement in the growth parameters. In the second biopsy increases in the ATP production and/or the enzyme activities were detected in all these patients compared to the first evaluation. Patient 5 still had decreased ATP production but had normal PDHc activity in the repeat biopsy. In four patients (patients 4, 7–9) the biochemical evaluation revealed normal ATP production and mitochondrial enzyme complex activities. The mitochondrial clinical diagnostic score (Wolf and Smeitink 2002) of the patients was between 5 and 8 at the time of the first biopsy (Table 1). At the time of the second biopsy, disease progression was observed in patient 3 (appearance of extrapyramidal symptoms), with an increase in the clinical score. In the patient group with the improved growth parameters, patient 6 developed optic atrophy and patient 8 developed cystic pontic lesions. There was an improvement of the lactic acidaemia in patients 5 and 8. At the time of the second biopsy, three patients had a lower total clinical score (patients 4, 5 and 8). In two cases there was an objective improvement in the exercise tolerance (patients 4 and 8). The parents reported positive changes such as increased alertness and activity and better concentration (patients 4, 8 and 10). No hypoglycaemia occurred in the patient population (patients 4 and 10 had previous recurrent episodes of hypoglycaemia). Two children with severe hypotonia learned to walk at the ages of 4 and 7 years respectively. The clinical diagnostic score (Wolf and Smeitink 2002) of the patients was between 3 and 8 at the time of the second biopsy (Table 1). Mitochondrial DNA sequence analysis revealed the 11778G > A (Leber) mutation in patient 6. Patient 7 was subsequently diagnosed with a chromosome aberration (46,XY,dup(17)(q21-q22)). Patient 5 was diagnosed with Joubert syndrome (Morava 2005). Discussion A change in the mitochondrial oxidative phosphorylation capacity measured in a fresh muscle biopsy might occur as a Springer
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Table 3 Age-appropriate energy intake suggested in our patients during dietary intervention
result of many different clinical and environmental factors— muscle exercise and activity, diet, vitamin and cofactor levels, spontaneous partial restitution of a decreased activity, different age, a different sampling site or a change or in the ratio of heteroplasmy of the mutation in the muscle sample. Technical problems are less likely as the underlying cause given the high accuracy of the ATP production and enzyme activity measurements. In our study group, in 7 out of 10 children with mitochondrial dysfunction the biochemical results of the second biopsy were significantly different from those of the first muscle samples. In four patients, all biochemical parameters normalized at the time of the second biopsy. We concluded that in most cases the age-appropriate nutrition, and the conversion of a catabolic phase to an anabolic period, could be responsible for the improvement in ATP production. The observation of total restitution of the mitochondrial function in patient 7, diagnosed with a chromosome alteration, and the significant improvement observed in the child with Joubert syndrome are suggestive of a secondary mitochondrial dysfunction responding to adequate diet in two severely retarded patients with feeding problems. The measurement of a significant increase in the ATP production in the second biopsy in the other patients with a high clinical/biochemical score for a disorder of oxidative phosphorylation might also lead us to the conclusion that the previously detected low energy production occurred at least in part due to malnutrition and/or a low substrate intake. An almost normal ATP production was measured in the repeated biopsy in the patient carrying the 11778G>A mtDNA mutation. In this type of mutation, in view of the highly tissuespecific expression, the previously measured mitochondrial dysfunction in muscle could also be due to a catabolic stage. We therefore suggest evaluating the nutritional state by the interpretation of the skeletal muscle biochemistry in patients with a suspected oxidative phosphorylation defect. Since an insufficient dietary intake could play a role in secondary mitochondrial dysfunction, nutritional intervention should be performed prior to the biopsy. The intervention was unsuccessful in the patients with the most pronounced biochemical abnormalities, which could be due to the severe primarymitochondrial dysfunction with
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Age
Boys (kJ/day) [kcal/day])
Girls (kcal/day [kcal/day])
0–6 months 6–12 months 1–3 years 4–8 years 9–13 years 14–18 years
2090 [500] 3560 [850] 5020 [1200] 7200 [1720] 10 590 [2530] 14 020 [3350]
2090 [500] 3560 [850] 4710 [1125] 6485 [1550] 9500 [2270] 10 460 [2500]
an energy transduction defect. This observation might help us to further differentiate these patients from those with secondary disorders. However, in patients 4 and 8, with the presence of clinical features compatible with a primary mitochondrial disease, not only biochemical improvement but also a significant clinical improvement was detected on forced nasogastric (night) tube-feeding. Our data suggests that optimizing the nutritional and energy intake might improve the utilization of the residual mitochondrial energygenerating capacity. On the basis of our observations, we suggest the administration of an age-appropriate energy and dietary intake in patients diagnosed with mitochondrial dysfunction. Acknowledgements The authors were supported by the European Community’s Sixth Framework Programme for Research, Priority 1 ‘Life sciences, genomics and biotechnology for health’, contract number LSHM-CT-2004–503116.
References Essen B, Fohlin L, Thoren C, Saltin B (1981) Skeletal muscle fibre types and sizes in anorexia nervosa patients. Clin Physiol 1: 395–403. Gezondheidsraad (2001) Voedingsnormen: energie, eiwitten, vetten en verteerbare koolhydraten 19: 12. Janssen AJ, Smeitink JA, van den Heuvel LP (2003) Some practical aspects of providing a diagnostic service for respiratory chain defects. Ann Clin Biochem 40: 3–8. Morava E, Dinopoulos A, Kroes HY, et al (2005) Mitochondrial dysfunction in a patient with Joubert syndrome. Neuropediatrics 36: 214–217. Morton J, McLoughlin DM, Whiting S, Russell GF (1999) Carnitine levels in patients with skeletal myopathy due to anorexia nervosa before and after refeeding. Int J Eat Disord 26: 341– 344. Smeitink JA (2003) Mitochondrial disorders: clinical presentation and diagnostic dilemmas. J Inherit Metab Dis 26: 199–207. Smeitink J, Sengers R, Trijbels F, van den Heuvel L (2001) Human NADH: ubiquinone oxidoreductase. J Bioenerg Biomembr 33: 259–266. Ushmorov A, Hack V, Droge W (1999) Differential reconstitution of mitochondrial respiratory chain activity and plasma redox state by cysteine and ornithine in a model of cancer cachexia. Cancer Res 59: 3527–3534. Wolf NI, Smeitink JA (2002) Mitochondrial disorders: a proposal for consensus diagnostic criteria in infants and children. Neurology 59: 1402–1405.
