Double-blind Randomized Controlled Study of Linoleic Acid Supplementation for 1 Year in Patients With Cystic Fibrosis - Influence on Clinical Status and Metabolism
Phase: NA
Conditions: Cystic Fibrosis
Sponsor: Karolinska Institutet

  Project plan 20241110 (rev)  
 
 
Double-blind randomized controlled study 
of linoleic acid supplementation for 1 year 
in patients with cystic fibrosis. 
 –Influence on clinical status and 
metabolism. 
-NETwork study of LA supplementation 
in CF patients (NETLACF) 
 
The study is registered at ClinTrial.gov ID #NCT04531410 
 
 
Funding: European Society of Pediatric Gastroenterology 
and Nutrition; Swedish CF Association; Heart-Lung 
Foundation; Erica Lederhausen´s Foundation. 
The supplement was generously provided by AAK Ltd, 
Karlshamn/Copenhagen, Sweden/Denmark. 
 
 

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Six center study 
 
1. Sweden, Stockholm 
Birgitta Strandvik1 MD, PhD, Project coordinator, Senior advisor 
Craig Wheelock2, PhD, Biochemist 
 
2. Poland, Poznan 
Jaroslaw Walkowiak3 MD, PhD Principal investigator 
Sławomira Drzymała-Czyż3 RD, PhD 
 
3. Italy, Milan 
Carla Colombo4 MD PhD Principal investigator 
Gianfranco Alicandro4 MSc 
Nadia Faelli4 MD 
Arianna Biffi4 RN Local coordinator 
Anna Bulfamante4 RD, Dietician 
 
4. Norway, Oslo. 
Egil Bakkeheim5 MD, Principal investigator 
 Christien Sachs-Olsen5, Local coordinator 
 Magnhild  Kolsgaard5, RD, PhD, Dietician 
 
Department of Biosciences and Nutrition1 and  Department of Medical Biochemistry and 
Biophysic2, Karolinska Institutet, Stockholm, .   
Department of Pediatric Gastroenterology and Metabolic Diseases3, Poznan University of 
Medical Sciences, Poznan, Poland. 
Cystic Fibrosis Center University of Milan4, Fondazione IRCCS Ca´Granda Opsedale 
Maggiore Policlinico, Milan Ital.,  
Norwegian Center for Cystic Fibrosis5, Oslo University, Oslo, Norway.  
 
 
 

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Summary:  
Undernutrition is a common problem in patients with cystic fibrosis (CF) despite 
international consensus that the patients shall be given 120-200% of energy 
recommendations. Studies imply that one problem might be that the patients are 
not compensated for the essential fatty acid deficiency (linoleic acid, LA), which is 
well known in these patients. This deficiency is shown not to be due to fat 
malabsorption, but associated to an increased turnover of archidonic acid, a 
transformation product of LA. This abnormality is related to mutations associated 
with a more severe clinical phenotype. The most common and typical symptom of 
LA deficiency is poor growth. Studies in animals have further indicated that many of 
the symptoms in CF are related to the deficiency. A series of recent prospective 
studies from Wisconsin corroborate the importance of LA for growth. In Sweden LA 
has been supplemented to most patients since the late 70´, and the condition of 
patients have been among the leading in the world regarding growth, pulmonary 
function and survival. Short-term studies have shown better effect of LA 
supplementation compared to similar supply of energy without including extra LA. 
There are few long-term studies, performed before the gene was identified, giving 
very heterogeneous patient groups in regard to genotype, but some positive results 
on growth and physiology. It´s of interest that modern personalized extremely 
expensive therapy with correctors and potentiators for Cystic Fibrosis 
Transmembrane Conductance Regulator may influence lipid metabolism. LA might 
thus tentatively be a cheap adjuvant to this modern therapy, but this has to be 
specially studied.  
The benefit for the patients would be great if the expected positive effect can be 
proved in the planned study. The treatment will be cheap and without adverse 
effects. From socioeconomic point of view is would be a great advantage.  

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AIM 
 To investigate the impact of long-term supplementation of fatty acids on clinical 
status and metabolism in patients with cystic fibrosis (CF). 
DESIGN 
A double-blind controlled randomized study of supplementation of linoleic acid (LA) 
compared to oleic acid (OA), and with long-chain omega 3 fatty acid (DHA) for one 
year to patients with CF. 
 
BACKGROUND 
CF is a systemic disease with major clinical symptoms from the gastrointestinal 
tract, predominantly pancreatic insuffficency and hepatobiliary disease, and from 
the lungs. Although survival has increased during the latest decades it is still a fatal 
disease with a high therapeutic burden and high percentage of impaired growth 
despite recommendations of very high energy intake, also in early infancy (Shoff et 
al 2006; Munck et al. 2018). Underweight is common both in children and adults 
with CF (NACFF Patient Register, ECFS Patient Registry). 
It has been known for more than 50 years that patients with CF have low levels of 
the essential fatty acid linoleic acid (18:2w6, LA) and also that the long-chain 
polyunsaturated  fatty acid (LCPUFA) docosahexaenoic acid (22:6w3, DHA) may be 
decreased in plasma and tissues (Kuo et al.1962, Underwood et al.1972, Freedman 
et al 2004). After 1975, when a newborn temporarily recovered in pancreatic 

5 
 
function after Intralipid® administration (Elliott et al.1975), some short-term trials 
with LA or high energy diets including LA have been performed showing a positive 
association to growth (van Egmont et al 1996, Steinkamp et al 2000) and pulmonary 
function (Chase et al 1979, Mischler et al 1986, Walkowiak J 2007, Maqbool et al 
2008, Hjelte et al 2008,  Lai et al. 2009). A few long-term studies have indicated 
beneficial effect of intravenous linoleic acid supplementation (Chase et al 1979, 
Kusoffsky 1983, Strandvik et al 1989, Strandvik et al 1994). In comparison, exclusive 
high energy intake does not have the same effect (van Egmont et al 1996, 
Steinkamp et al 2000, Aldámeiz-Echevarria et al 2013, Munck et al 2018). One study 
combining omega-6 and omega-3 fatty acids showed marked improvement in 
several parameters, compared to supplementation with only omega-3 fatty acids, 
which rarely gives any clinical benefit  (Oliveira et al. 2010, Oliver et al. 2011, 
Alicandro G et al. 2013). In a small long-term controlled supplementation study 
performed before the gene was identified, improvement was seen in renal, liver 
and bile acid parameters (Strandvik et al.1989, Strandvik et al. 1994). Long-term 
treatment increased LA in many organs (Mischler et al 1986). Very long-term 
treatment with omega-6 rich oils and Intralipid● have resulted in exceptionally good 
clinical conditions regarding growth, bone mineral density, pulmonary function, 
reduction of pulmonary exacerbations and low clinical infectious status in a 
relatively large patient cohort, i.e. most of the Swedish patients with CF, compared 
with other international centers (Strandvik 1988; Strandvik 2006, Gronowitz et 
al.2004 ). The role of LA in these observations are supported by studies finding 
better growth and lung function in patients with higher LA concentrations in serum 

6 
 
(Maqbool et al 2008). However, there is a lack of long-term randomized controlled 
studies. Other treatment modalities, such as increased physical activity from early 
age, also introduced in the Swedish patients in the late 80´s (Blomqvist et al.1988), 
have probably also a large impact on the good clinical status of the Swedish 
patients.  
   It was shown more than 30 years ago that the LA deficiency was not due to 
malabsorption, but probably to an increased release of arachidonic acid (20:4w6, 
AA), causing an increased metabolism of LA, resulting in LA deficiency (Carlstedt-
Duke et al. 1986, Strandvik et al 1988) and increase of eicosanoid metabolites 
(Strandvik Seybert 1996, Jabr et al 2013). Many studies in animals and cells have 
confirmed the hypothesis of high turnover (for review see Strandvik 2010). A 
hypothesis with an algorithm was formed to explain the mechanisms for the 
different symptoms (Strandvik 1989, Strandvik 1992) supported in later studies. 
From studies of newborns diagnosed by neonatal screening, it has been shown that 
80% of patients with meconium ileus have markers of LA deficiency, high Mead acid 
and EFA index (T/T ratio), and similar markers were increased in around 50 % of 
patients without meconium ileus (Lai et al 2000). A relative improvement occurred 
during infancy, but again the markers deteriorate in late toddler age to prepuberty 
(Lai et al 2000), which coincides with the dip in growth in the patients as illustrated 
in both the European and North American CF patient registers. The Wisconsin CF 
Neonatal Screening Group have followed their patients in a series of papers and 
showed that intake of LA up to 2 years of age resulted in higher plasma LA 
concentrations with an OR of 7.46 for maintaining high LA if intake was > 5% of total 

7 
 
energy intake and both high energy and LA concentration increased the possibility 
to recover in weight to 2 years of age (OR 30.6, p=0.002). They conclude that 
“maintaining normal plasma LA for a prolonged period in addition to sustaining a 
high energy intake may be important in facilitating adequate weight gain” (Shoff et 
al 2006).  These early ”responders” also required lower energy intake to maintain 
adequate growth (Lai et al 2009), which is similar to our observation that patient 
who received regular LA supplementation had normal weight without increasing the 
energy intake (Kindstedt-Arfwidson et al 1988). In a follow up study the Wisconsin 
group found that the early response in growth was associated with better growth 
and lung function up to 12 years of age and in this paper they also included patients 
with meconium ileus, who initially had a more severe LA deficiency and they were 
also later much worse off (Sanders et al. 2018). They summarize that “Further 
studies are needed to identify optimal CF interventions that can maximize the 
chance for achieving early growth recovery” (Sanders et al 2018).  
People with CF have low IGF-1 concentrations (Switzer et al 2009; Rogan et al 2010; 
Bessich et al 2013), and the low IGF-I concentrations correlates with lean body mass 
(Sermet-Gaudelus et al 2003), which usually is  low in patients with CF, except in the 
LA supplied Swedish population (Gronowitz et al. 2008). In transgenic CF rats low 
IGF-1 levels correlated with impaired growth and bone content (Stalvey et al 2017). 
Studies have shown that low LA concentrations are associated with low IGF-1 levels 
in infants (Kjellberg et al 2018) and in animals (Korotkova et al 2004 and 2005). 
Other factors for poor growth might be an increased caloric demand, and it has 
been shown that severe CF phenotype is associated with an increased basic 

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metabolic turn-over (O´Rawe et al 1992). In rats with essential fatty acid deficiency 
an increased basal respiration has been reported (Rafael et al 1984). Furthermore, 
the increased intestinal permeability, which relates to membrane phospholipid 
layers, is correlated to the clinically more severe phenotypes in patients with CF 
(Hallberg et al 1997). 
   The cause of the low DHA is not clear, but the improvement of DHA by LA 
supplementation suggests that it might not be of primary importance (Farrell et al 
1985, Strandvik et al 2001) and maybe associated with a high phospholipid turn-
over (Bhura-Bandali et al. 2000, Strandvik 2010, Rogiers et al1984). However, long-
term studies in CF mice and a recent paper suggest that the ratio between AA/DHA 
in blood cell tissues is related to the liver disease in CF, suggesting that the 
concentrations of polyunsaturated fatty acids (PUFA) might contribute to the 
unexplained liver affection in many of the patients (Lindblad et al. 1999; Beharry et 
al. 2007; van Biervliet et al 2010; Jörgensen et al. 2012, Drzymala-Cryz et al, 2017). 
Because one study of transgenic CF mice showed low DHA associated with 
morphological changes in ileum and pancrease (Freedman et al 1999), although 
later not confirmed in a long-time study (Beharry et al 2007), many clinical trials 
with supplementation of omega-3 LCPUFA started, but mainly failed to show clinical 
improvement despite marked increase of omega-3 fatty acids in plasma (van 
Biervliet et al. 2008, Oliver et al. 2011, Alicandro et al. 2013). One study with regular 
intravenous supplementation of omega-3 for 3 months even showed negative 
impact on the patients (Durieu et al. 2007). As mentioned above one study showed 

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marked clinical improvement by a combination of omega-3 and omega-6 
supplementation (Oliveira et al. 2010).    
It is well known that low LA concentrations are associated with high AA 
concentration, while supplementation with LA decreases the AA concentration (Liou 
et al. 2007, Friesen et al 2010, Bjermo H et al 2012, Wheelock & Strandvik 2020). In 
healthy individuals no increase of inflammatory markers have been reported with 
omega-6 supplementation (Bjermo et al 2012, Johnson GH & Fritsche K  2012). This 
is of  importance since the release of AA is the rate-limiting step for eicosanoid 
production, which is increased in CF (Strandvik a Seybert 1996, Chase & Dupont 
1978, Jabr et al 2013). In one study of 10 months supplementation of LA in CF 
patients prostaglandin F2α poduction decreased (Chase & Dupont 1978). Ivacaftor 
did not influence LA concentration but decreased AA concentration in plasma and 
decreased PGE-M in urine  in the GOAL study for patients with G551D mutations ( 
O´Connor & Siegmiller 2016).  These studies show that both LA and CFTR modulators 
might influence lipid metabolism and decrease inflammatory mediators. Despite this 
fact, the lack of good randomized clinical studies have made many centers hesitate 
to supply LA because it’s a substrate for AA and thereby also for the pro-
inflammatory lipid mediators. High AA concentrations have been found in bronchial 
secretions in CF (Gilljam et al 1986) and was confirmed in a recent study of sputum 
from CF patients (Yang J,  et al 2012) 
 In a recent double-blind randomized trial high AA concentration in plasma was 
associated with low NO in the airways of CF patients (Keen et al. 2010). Low NO can 
contribute to pseudomonas colonization, which is considered a threat for 

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progression of the pulmonary damage. Furthermore many studies have shown that 
OA increases compensatory when LA decreases (Christophe et al  1994), and it was 
shown in Toronto, (contributing to their persistent use of high fat diet when rest of 
the world prescribed low fat diet to CF) that high OA stimulated the growth of 
Staphylococcus aureus, the first colonizer of the airways in patients with CF ( 
Campbell et al.1983). Similar imbalance of LA and OA was also found to impair the 
oxygen pressure influencing the hemoglobin oxygenation which would be a factor 
increasing the airway pathology in CF (Campbell et al 1976). Thus, it seems 
important to increase LA concentration and reduce AA concentration in the patients 
with CF also from reported pulmonary associations (Wheelock & Strandvik 2020). 
Many studies have shown that the pulmonary symptoms are the most affected 
persistent problem in the neonatally screened patients despite their high caloric 
diet, and improved early growth is associated with better pulmonary function up to 
12 years of age (Sanders et al 2018).  
   It is also important that the hyperactivity of the epithelial sodium channel (ENaC), 
which is shown to contribute to the pulmonary symptoms, seem to be normalized 
by LA supplementation, as notified in sweat glands and kidneys (Strandvik 2021), 
and which might be an effect of the protein-lipid interaction. In recent studies the 
interaction of modulators and phospholipids have been shown (Liessi et al.2020; 
Kopp et al.2018 . 
The recent discovery of the importance of the long-chain PUFA of the omega-3 
series for the normal inflammatory response by transformation to prosolving 
specialized  markers (SPM),  the anti- inflammatory lipoxines (Rogeiero et al. 2012) 

11 
 
may indicate that supply of omega-3 fatty acids might be important as a general 
treatment for CF patients with their chronic airway inflammation. Further 
improvement might therefore be expected with a combined supplementation, 
especially since the long-chain omega-3 fatty acids inhibit delta-6 desaturase and 
thereby may further reduce the transformation of LA to AA (Hagve et al 1988).  
 
WORKING PLAN  
Patients and Eligibility. 
Patients with CF, carrying 2 severe mutations referred to Class I and II, i.e. 
mutations associated with more severe LA deficiency and more severe clinical 
symptoms, (like delF508, 394delTT) are included after informed consent.  The 
reason for including only those with clinically more severe phenotype is that those 
have pancreatic insufficiency and also other symptoms more expressively related to 
genotype (see above). Exclusion criteria will be pregnancy and transplantation and 
age above 15 and below 5 years (due to pulmonary function tests) and severe liver 
disease (cirrhosis, portal hypertension). The patients shall not have taken any lipid 
supplements for 2 months before inclusion and not be treated with any modulators 
(like Orkambi, Trikafta).  
The patients will keep to their ordinary treatment of PERT and vitamins and that for 
the pulmonary symptoms and infections. No special dietary recommendations will 
be given, but PERT might be increased, when the supplement is given and that shall 
be registered. Number of pulmonary exacerbations and type of treatment, including 
antibiotics, are registered and also compared with the year before the study. 
Sample size 
A sample of 84 patients (42 per group) will ensure that a two-sided test with α 
=0.05 has 80% power to detect a 0.5 mean difference in 1-year change in weight-

12 
 
for-age Z-score, assuming a pooled standard deviation of 0.8. This last figure has 
been obtained from a previous intervention study on cystic fibrosis patients 
(Alicandro et al. 2013). Since we expect a withdrawal rate of close to 10%, we 
planned to enroll 90 patients (45 per groups). The patients and caregivers will be 
informed by oral and written information and included after informed consent. The 
study is approved by local Ethic Committées and by the one at Karolinska Institutet 
and the study is performed according to the Helsinki Declaration. 
 
          Design  
         The study is designed as a double-blind randomized clinical trial 
         The patients will be randomized to either  
• treatment A: linoleic acid (12 g for children 5-15 years) + 600 mg algeal DHA 
• treatment B:, oleic acid (12 g for children 5-15 years) + 600 mg  algeal DHA  
The fatty acids will be given daily for 12 months, in vials containing an emulsion of 
totally 20 ml ( provided by AKK Company, Karlshamn, Sweden and Copenhagen 
Denmark, packed by WinterMedic, Odense, Denmark), which can be mixed with  
milk, juice, sour cream, porridge or any similar feeding at breakfast time. Some 
extra enzymes may be added. 
The treatment will last 12 months, starting and ending at time of the yearly check 
up of the patients. Half the number of patients will be randomly allocated to receive 
either treatment A or B. An independent researcher (not involved in the study) will 
generate the allocation sequence at each center. This will reduce small differences 
in local treatment policy. The vials with supplementation will only be coded (black 
or white capsula) so neither patient nor caregivers or staff in charge will be 
informed by the type of supplementation.  
 
Primary Outcome 

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• BMI Z-score, weight-Z-score  
Secondary outcomes 
• Height Z-score 
• FEV1 (% of predicted) and oxygen saturation 
• Exacerbations and infectious parameters compared to year before. 
• Plasma phospholipid fatty acid profile. 
• Plasma concentration of IGF-I 
 
Explanatory outcomes 
• Bone mineral density 
• Lean body mass and fat mass.  
• Liver function tests  
• Lipid mediators (like eicosanoids and docosanoids)  
• Cytokines 
• 8-iso-prostane 
• Sweat sodium and chloride concentrations 
• Renal sodium excretion 
• Resting energy expenditure  
• Intestinal function (fecal calprotectin and fat absorption coefficient) 
• Oral glucose tolerance with insulin determination. 
        
METHODS 
Patients will be screened for enrollment and will be allocated to one of the treatment at 
baseline visit. Follow-up visits will be scheduled at 6 and 12 months after treatment 
allocation.  Some measures, like fat absorption coefficient and calprotectin and resting 
energy expenditure, exhaled NO and ergometer test will not be performed in all patients 
due to limited capacity at some centres. The study procedures are summarized in table 1. 

14 
 
Table 1. Outline of study procedures 
 
Baseline visit: 
Screening and 
allocation 
+6 months 
+12 months 
Anthropometry 
X 
X 
X 
DXA 
X 
 
X 
FFQ 
X 
X 
X 
24-h dietary recall 
X 
X 
X 
Pulmonary function 
X 
 
X 
Blood sample 
X 
X 
X 
F-Calprotectin 
X 
 
X 
Urine sample 
X 
 
X 
Ergometer test with 
oxygen saturation 
X 
 
X 
Oral glucose tolerance 
X 
 
X 
Indirect calorimetry 
X 
 
X 
Sweat test 
X 
 
X 
Compliance to treatment 
X 
X 
X 
CF Questionnaire  
X 
X 
X 
 
1. Anthropometry. 

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Height and weight are controlled with the same equipment for each patient at 
respective centre and at each scheduled visit (baseline, 6 and 12 months after 
allocation). Z-scores of weight, height and BMI will be computed using WHO as 
growth standard. DXA is performed at start and after 12 months period for 
determination of bone mineral content and density, lean body mass and fat mass. 
1. Food registration. 
• Food frequency questionnaire (FFQ) will be performed at startand each 
scheduled visit, mainly used for calculation of energy intake and intake of 
fat and fatty acids (validated questionnaire Eriksson S et al. 2010). Since 
the products are different in different countries the FFQ form can only  
suggest type of products to be evaluated, complemented by the local 
dietician. The reason to include these registrations is to individually make 
a comparison with intake at start and end of study possible, checking that 
not major changes have occurred in diet, which can influence the results. 
• 24-hour recall will be performed at start, 6 months and 12 months after 
allocation as a complement to FFQ for portion size, type of products etc. 
3. Pulmonary function. 
•  Routine pulmonary function (FEV1) at each clinical visit  
•   Full spirometry at start and end of treatment 
•  Exhaled NO (if available) 
•  Ergometer test at start and end  
• Oxygen saturation (ear-tip). 
   
4. Biochemistry. 
• Routine blood biochemistry (fasting) at start and end of treatment period, 
including Hb, platelets, white blood cell count and differential count, ASAT, ALAT, 
alkaline phosphatase, GGT, PK, total and conjugated bilirubin, bile acids, 
cholesterol, lipoproteins, triglycerides, urea, creatinine, glomerulus filtration rate. 
Ig-G. CRP, sedimentation rate. 

16 
 
• 1 ml serum/plasma for later analyses ( to freezer divided in 4 tubes for 
later analyses of lipid mediators at KI). 
• 0,5 ml for IGF-I analysis (to freezer for later analysis in Sweden) 
• 0.5 ml plasma for cytokines (to freezer for sending to Stockholm for 
analyses (OLINK, Uppsala, Sweden). 
• 0.5 ml plasma for analyses of phospholipid fatty acids (to free8zer for later 
analysis in Poznan or Stockholm). 
• Urine sample for routine tests, incl sodium and creatinine concentrations. 
5.   Intestinal function 
• F-Calprotectin at start and after12 months (in freezer for later analyses at 
one center) 
• Fat absorption at start and 12 months. Three day dietary recording and 
feces 
Sampling. Mixture in local laboratory with freezing of an aliquote for later 
                transport to Poznan  
     6.  Metabolic tests 
• Urine sample for 8-isoprostane and lipid mediators as eicosanoids, 
docosanoids and linoleic acid metabolites (directly to freezer -80 each 
sample in 2 x 8 ml and in  4 x 2 ml) for later analyses in Stockholm. 
• Indirect calorimetry at start and after 12 months (if available in the 
hospital). 
• Sweat test at start and after 12 months. Both sodium and chloride 
analyses. 
• Oral glucose tolerance test. 
 
7.Quality of life. 
Quality of life will be assessed through the CF Questionnaire Revised (CFQ), a 
disease-specific tool that measures health-related quality of life in patients with 

17 
 
CF. There are different versions of the questionnarie: two for children over 6 
years, one to be completed by the child and one to be completed by parent (CFQ 
Child and CFQ-Parent, respectively).  
8.  Compliance with the treatment 
Compliance with the treatment will be evaluated by monthly contact with the 
study coordinator of respective centre, when not used vials will be registered and 
new supplied. The patients are asked to make a dairy over the daily intake also 
reported monthly to the coordinator. Extent of physical activity shall be notified. 
 
9. Statistics 
           All data will be collected in identical Excel files and analysed in one center at end  
           study.  
The main analysis will be carried out on the intention-to-treat population defined as 
all randomized patients. We will also conduct a secondary analysis on the per-
protocol population excluding patients not receiving the allocated treatment for 
more than 2 months. 
Between-treatment differences in the primary outcome across time points will be 
evaluated by fitting random intercept linear mixed-effects models. Mixed effects 
model can account for intra-correlated repeated measures on the same subjects 
and accommodate missing data due to dropouts. The models will include the z-
score of BMI as response variable, treatment, time and time x treatment interaction 
as independent variables. The model coefficients for the time x treatment 
interaction will be considered an estimate of the treatment effect on changes in the 
study outcome. Time will be included in the model as categorical variable with the 
following categories: baseline (pre-treatment), +6 months and +12 months from 
treatment allocation. 

18 
 
Seondary and explanatory outcomes will be compared across treatment groups 
using the paired t-test for normally distributed variables, otherwise the non-
parametric Wilcoxon signed-rank test for dependent samples will be used. 
A stratified analysis by sex will be performed. 
 
   RISK-BENEFIT 
There will be no adverse effects to expect of this treatment , since the control group 
will have the same treatment as offered generally to patients, i.e. extra calories. The 
extra LA will not exceed the general intake in US (Choque et al 2014). Both groups 
get similar amount of omega-3 fatty acids; dose in agreement with general 
recommendations.  The extra burden of investigations is small since the patients 
always have more extensive investigations at the yearly checkup.   
IMPORTANCE 
If clinical status is improved the patients in both groups will be asked for the 
possibility to continue with Group A therapy for one further year (requires new 
ethical applications). Furthermore, good result would indicate a multicenter study 
for treatment from diagnosis in countries with neonatal screening, which would be 
extremely important since many of the symptoms start early and especially the 
supply of high caloric diet gives many problems in patients and parents, and 
unsatisfying results, It can also have the potential to be a cheap complement to 
modern expensive drug treatment. 
A special benefit for individuals and society would be if this simple, cheap and non 
hazardous treatment can reduce the enormous costs of the modern drug 
treatment, which is further not always available.  
 
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