Combining hippocampal volume metrics to better understand Alzheimer's disease progression in at-risk individuals

To date nearly all clinical trials of Alzheimer’s disease (AD) therapies have failed. These failures are, at least in part, attributable to poor endpoint choice and to inadequate recruitment criteria. Recently, focus has shifted to targeting at-risk populations in the preclinical stages of AD thus improved predictive markers for identifying individuals likely to progress to AD are crucial to help inform the sample of individuals to be recruited into clinical trials. We focus on hippocampal volume (HV) and assess the added benefit of combining HV and rate of hippocampal atrophy over time in relation to disease progression. Following the cross-validation of previously published estimates of the predictive value of HV, we consider a series of combinations of HV metrics and show that a combination of HV and rate of hippocampal atrophy characterises disease progression better than either measure individually. Furthermore, we demonstrate that the risk of disease progression associated with HV metrics does not differ significantly between clinical states. HV and rate of hippocampal atrophy should therefore be used in tandem when describing AD progression in at-risk individuals. Analyses also suggest that the effects of HV metrics are constant across the continuum of the early stages of the disease.

Home delivery service of low protein foods in inherited metabolic disorders: Does it help?

Background

In the UK, the customary method of obtaining special low protein (LP) foods was by dispensing through a pharmacist (until 2010) for patients with inherited metabolic disorders (IMD) requiring LP diets. Recently, different home delivery services have been introduced to support patient access of low protein foods, but the effectiveness of these services is unclear.

Aim

A prospective, longitudinal, observational study to examine the effectiveness and safety of patient home delivery services for LP foods over 12 months in IMD patients requiring a LP diet.

Methods

IMD patients/caregivers had the choice of 2 home delivery services (Homeward® and Vitaflo at Home®) as well as access to primary care pharmacy services. Both home delivery services provided a limited range of LP foods. Over a 12-month period, a member of the IMD dietetic team conducted 4 home visits to IMD patients on LP diets using home delivery services for low protein foods. At each visit, caregivers completed a questionnaire consisting of 20 multiple choice and open questions about their prescription experience with special LP foods. The researchers also completed stock checks, assessed 'use by dates' and adequacy of home storage for LP foods.

Results

In total, 58 patients participated in this study. Over 12 months, 95% (n = 55/58) of caregivers used their local pharmacy, 93% (n = 54/58) Homeward® and 78% (n = 45/58) Vitaflo at Home® to access LP foods. Two home delivery services were used by 41 (71%) caregivers and the remaining 17 (29%) only used one of the home delivery service companies. Each patient only stored a median of 6 (range 0-22) different LP foods at home. Overall, 45% (n = 26/58) of caregivers reported problems with their GP prescriptions. 30% (n = 16/53) of caregivers received at least one incorrect prescription when using their pharmacy (e.g. gluten-free foods instead of LP, incorrect product or incorrect product amount), 6% errors (n = 3/53) with Homeward® and 2% (n = 1/48) with Vitaflo at Home®. 49% (n = 26/53) of caregivers said they experienced delayed receipt of LP foods from their pharmacy, compared with 11% (n = 6/55) from Homeward® and 8% (n = 4/48) Vitaflo at Home®.

Conclusions

Although home delivery services for special LP foods are associated with less errors and delay compared with pharmacies, inaccuracies and inefficiencies still occur and the overall system is complex. We suggest a new, simpler, less fragmented system whereby metabolic dietitians prescribe LP foods. This is likely to result in less burden on NHS resources and ensure a better treatment delivered to IMD patients.

Growth, Protein and Energy Intake in Children with PKU Taking a Weaning Protein Substitute in the First Two Years of Life: A Case-Control Study

Growth issues have been observed in young children with phenylketonuria (PKU), but studies are conflicting. In infancy, there is an increasing trend to introduce a second-stage semi-solid weaning protein substitute (WPS) but there is concern that this may not meet energy requirements. In this longitudinal, prospective study, 20 children with PKU transitioning to a WPS, and 20 non-PKU controls were observed monthly from weaning commencement (4–6 months) to 12 m and at 15, 18 and 24 months of age for: weight, length, head circumference, body mass index (BMI), energy and macronutrient intake. Growth parameters were within normal range at all ages in both groups with no significant difference in mean z-scores except for accelerated length in the PKU group. No child with PKU had z-scores < −2 for any growth parameter at age 2 years. Total protein and energy intake in both groups were similar at all ages; however, from 12–24 months in the PKU group, the percentage of energy intake from carbohydrate increased (60%) but from fat decreased (25%) and inversely for controls (48% and 36%). In PKU, use of low volume WPS meets Phe-free protein requirements, facilitates transition to solid foods and supports normal growth. Further longitudinal study of growth, body composition and energy/nutrient intakes in early childhood are required to identify any changing trends.

The Effect of Glycomacropeptide versus Amino Acids on Phenylalanine and Tyrosine Variability over 24 Hours in Children with PKU: A Randomized Controlled Trial

Introduction: In phenylketonuria (PKU), evidence suggests that casein glycomacropeptide supplemented with rate-limiting amino acids (CGMP-AA) is associated with better protein utilisation and less blood phenylalanine (Phe) variability. Aim: To study the impact of CGMP-AA on blood Phe variability using 3 different dietary regimens in children with PKU. Methods: This was a 6-week randomised controlled cross-over study comparing CGMP-AA vs. Phe-free l-amino acids (l-AA) assessing blood Phe and tyrosine (Tyr) variability over 24 h in 19 children (7 boys) with PKU, with a median age of 10 years (6–16). Subjects were randomised to 3 dietary regimens: (1) R1, CGMP-AA and usual dietary Phe (CGMP + Phe); (2) R2, CGMP-AA − Phe content of CGMP-AA from usual diet (CGMP − Phe); and (3) R3, l-AA and usual dietary Phe. Each regimen was administered for 14 days. Over the last 48 h on days 13 and 14, blood spots were collected every 4 h at 08 h, 12 h, 16 h, 20 h, 24 h, and 04 h. Isocaloric intake and the same meal plan and protein substitute dosage at standardised times were maintained when blood spots were collected. Results: Eighteen children completed the study. Median Phe concentrations over 24 h for each group were (range) R1, 290 (30–580), R2, 220 (10–670), R3, 165 (10–640) μmol/L. R1 vs. R2 and R1 vs. R3 p < 0.0001; R2 vs. R3 p = 0.0009. There was a significant difference in median Phe at each time point between R1 vs. R2, p = 0.0027 and R1 vs. R3, p < 0.0001, but not between any time points for R2 vs. R3. Tyr was significantly higher in both R1 and R2 [70 (20–240 μmol/L] compared to R3 [60 (10–200) μmol/L]. In children < 12 years, blood Phe remained in the target range (120–360 μmol/L), over 24 h, for 75% of the time in R1, 72% in R2 and 64% in R3; for children aged ≥ 12 years, blood Phe was in target range (120–600 μmol/L) in R1 and R2 for 100% of the time, but 64% in R3. Conclusions: The residual Phe in CGMP-AA increased blood Phe concentration in children. CGMP-AA appears to give less blood Phe variability compared to l-AA, but this effect may be masked by the increased blood Phe concentrations associated with its Phe contribution. Reducing dietary Phe intake to compensate for CGMP-AA Phe content may help.

Glycomacropeptide: long-term use and impact on blood phenylalanine, growth and nutritional status in children with PKU

Abstract

In phenylketonuria, casein glycomacropeptide (CGMP) requires modification with the addition of some essential and semi essential amino acids to ensure suitability as a protein substitute. The optimal amount and ratio of additional amino acids is undefined.

Aim

A longitudinal, parallel, controlled study over 12 months evaluating a CGMP (CGMP-AA2) formulation compared with phenylalanine-free L-amino acid supplements (L-AA) on blood Phe, Tyr, Phe:Tyr ratio, biochemical nutritional status and growth in children with PKU. The CGMP-AA2 contained 36 mg Phe per 20 g protein equivalent.

Methods

Children with PKU, with a median age of 9.2 y (5-16y) were divided into 2 groups: 29 were given CGMP-AA2, 19 remained on Phe-free L-AA. The CGMP-AA2 formula gradually replaced L-AA, providing blood Phe concentrations were maintained within target range. Median blood Phe, Tyr, Phe:Tyr ratio and anthropometry, were compared within and between the two groups at baseline, 26 and 52 weeks. Nutritional biochemistry was studied at baseline and 26 weeks only.

Results

At the end of 52 weeks only 48% of subjects were able to completely use CGMP-AA2 as their single source of protein substitute. At 52 weeks CGMP-AA2 provided a median of 75% (30–100) of the total protein substitute with the remainder being given as L-AA. Within the CGMP-AA2 group, blood Phe increased significantly between baseline and 52 weeks: [baseline to 26 weeks; baseline Phe 270 μmol/L (170–430); 26 weeks, Phe 300 μmol/L (125–485) p = 0.06; baseline to 52 weeks: baseline, Phe 270 μmol/L (170–430), 52 weeks Phe 300 μmol/L (200–490), p < 0.001)]. However, there were no differences between the CGMP-AA2 and L-AA group for Phe, Tyr, Phe:Tyr ratio or anthropometry at any of the three measured time points. Within the CGMP-AA2 group only weight (p = 0.0001) and BMI z scores (p = 0.0001) increased significantly between baseline to 52 weeks. Whole blood and plasma selenium were significantly higher (whole blood selenium [p = 0.0002]; plasma selenium [p = 0.0007]) at 26 weeks in the CGMP-AA2 group compared L-AA. No differences were observed within the L-AA group for any of the nutritional markers.

Conclusions

CGMP-AA increases blood Phe concentrations and so it can only be used partly to contribute to protein substitute in some children with PKU. CGMP-AA should be carefully introduced in children with PKU and close monitoring of blood Phe control is essential.

Electronic supplementary material

The online version of this article (10.1186/s13023-019-1011-y) contains supplementary material, which is available to authorized users.

Development of national consensus statements on food labelling interpretation and protein allocation in a low phenylalanine diet for PKU

BACKGROUND

In the treatment of phenylketonuria (PKU), there was disparity between UK dietitians regarding interpretation of how different foods should be allocated in a low phenylalanine diet (allowed without measurement, not allowed, or allowed as part of phenylalanine exchanges). This led to variable advice being given to patients.

METHODOLOGY

In 2015, British Inherited Metabolic Disease Group (BIMDG) dietitians (n = 70) were sent a multiple-choice questionnaire on the interpretation of protein from food-labels and the allocation of different foods. Based on majority responses, 16 statements were developed. Over 18-months, using Delphi methodology, these statements were systematically reviewed and refined with a facilitator recording discussion until a clear majority was attained for each statement. In Phase 2 and 3 a further 7 statements were added.

RESULTS

The statements incorporated controversial dietary topics including: a practical 'scale' for guiding calculation of protein from food-labels; a general definition for exchange-free foods; and guidance for specific foods. Responses were divided into paediatric and adult groups. Initially, there was majority consensus (≥86%) by paediatric dietitians (n = 29) for 14 of 16 statements; a further 2 structured discussions were required for 2 statements, with a final majority consensus of 72% (n = 26/36) and 64% (n = 16/25). In adult practice, 75% of dietitians agreed with all initial statements for adult patients and 40% advocated separate maternal-PKU guidelines. In Phase 2, 5 of 6 statements were agreed by ≥76% of respondents with one statement requiring a further round of discussion resulting in 2 agreed statements with a consensus of ≥71% by dietitians in both paediatric and adult practice. In Phase 3 one statement was added to elaborate further on an initial statement, and this received 94% acceptance by respondents. Statements were endorsed by the UK National Society for PKU.

CONCLUSIONS

The BIMDG dietitians group have developed consensus dietetic statements that aim to harmonise dietary advice given to patients with PKU across the UK, but monitoring of statement adherence by health professionals and patients is required.

Isolated primary bone tumours of the lesser trochanter: Demographics, diagnosis and management

Primary bone tumours arising from the lesser trochanter (LT) are rare and the literature describing them is sparse. In this paper, we describe the largest series of LT tumours describing the demographics, diagnosis and management.

METHODS

A retrospective search of prospectively maintained radiology and oncology databases was performed to identify bone tumours of the LT diagnosed between 2007 and 2018. Metastatic lesions were excluded. All cases were re-reviewed by a senior Radiologist and all case of isolated tumours of the LT were included.

RESULTS

23 cases of isolated LT tumours were identified. There were 15 males and 8 females. Mean age of our cohort was 32 (14-63) years. Most (n = 19, 82.6%) cases had classic radiological (Radiographic, MR Imaging and CT) features and therefore did not undergo biopsy. 4 patients had equivocal radiological investigations that required biopsy to confirm the diagnosis. MR imaging was the most commonly used imaging modality for diagnosis (n = 17, 73.9%)There was a broad range of tumour subtypes, and osteochondroma (n = 17, 73.9%) the most frequently diagnosed. Surgical excision was performed in 4 patients (all osteochondromas) and 4 patients underwent therapeutic radiological guided hip injections for symptomatic relief. The remaining cases were managed conservatively and where they were identified incidentally, no intervention was required.

CONCLUSION

We report the largest case series of isolated primary bone tumours of the LT. All isolated primary bone tumours of LT are benign. Osteochondroma is the most common. The diagnosis can be made with on radiological investigations in most patients.

Weaning practices in phenylketonuria vary between health professionals in Europe

Background

In phenylketonuria (PKU), weaning is considered more challenging when compared to feeding healthy infants. The primary aim of weaning is to gradually replace natural protein from breast milk or standard infant formula with solids containing equivalent phenylalanine (Phe). In addition, a Phe-free second stage L-amino acid supplement is usually recommended from around 6 months to replace Phe-free infant formula. Our aim was to assess different weaning approaches used by health professionals across Europe.

Methods

A cross sectional questionnaire (survey monkey®) composed of 31 multiple and single choice questions was sent to European colleagues caring for inherited metabolic disorders (IMD). Centres were grouped into geographical regions for analysis.

Results

Weaning started at 17–26 weeks in 85% (n = 81/95) of centres, >26 weeks in 12% (n = 11/95) and < 17 weeks in 3% (n = 3/95). Infant's showing an interest in solid foods, and their age, were important determinant factors influencing weaning commencement. 51% (n = 48/95) of centres introduced Phe containing foods at 17–26 weeks and 48% (n = 46/95) at >26 weeks. First solids were mainly low Phe vegetables (59%, n = 56/95) and fruit (34%, n = 32/95).

A Phe exchange system to allocate dietary Phe was used by 52% (n = 49/95) of centres predominantly from Northern and Southern Europe and 48% (n = 46/95) calculated most Phe containing food sources (all centres in Eastern Europe and the majority from Germany and Austria). Some centres used a combination of both methods.

A second stage Phe-free L-amino acid supplement containing a higher protein equivalent was introduced by 41% (n = 39/95) of centres at infant age 26–36 weeks (mainly from Germany, Austria, Northern and Eastern Europe) and 37% (n = 35/95) at infant age > 1y mainly from Southern Europe. 53% (n = 50/95) of centres recommended a second stage Phe-free L-amino acid supplement in a spoonable or semi-solid form.

Conclusions

Weaning strategies vary throughout European PKU centres. There is evidence to suggest that different infant weaning strategies may influence longer term adherence to the PKU diet or acceptance of Phe-free L-amino acid supplements; rendering prospective long-term studies important. It is essential to identify an effective weaning strategy that reduces caregiver burden but is associated with acceptable dietary adherence and optimal infant feeding development.

Low-radiation and high image quality coronary computed tomography angiography in “real-world” unselected patients

AIM

To determine the radiation dose and image quality in coronary computed tomography angiography (CCTA) using state-of-the-art dose reduction methods in unselected “real world” patients.

METHODS

In this single-centre study, consecutive patients in sinus rhythm underwent CCTA for suspected coronary artery disease (CAD) using a 320-row detector CT scanner. All patients underwent the standard CT acquisition protocol at our institute (Morriston Hospital) a combination of dose saving advances including prospective electrocardiogram-gating, automated tube current modulation, tube voltage reduction, heart rate reduction, and the most recent novel adaptive iterative dose reconstruction 3D (AIDR3D) algorithm. The cohort comprised real-world patients for routine CCTA who were not selected on age, body mass index, or heart rate. Subjective image quality was graded on a 4-point scale (4 = excellent, 1 = non-diagnostic).

RESULTS

A total of 543 patients were included in the study with a mean body weight of 81 ± 18 kg and a pre-scan mean heart rate of 70 ± 11 beats per minute (bpm). When indicated, patients received rate-limiting medication with an oral beta-blocker followed by additional intravenous beta-blocker to achieve a heart rate below 65 bpm. The median effective radiation dose was 0.88 mSv (IQR, 0.6-1.4 mSv) derived from a Dose Length Product of 61.45 mGy.cm (IQR, 42.86-100.00 mGy.cm). This also includes what we believe to be the lowest ever-reported radiation dose for a routine clinical CCTA (0.18 mSv). The mean image quality (± SD) was 3.65 ± 0.61, with a subjective image quality score of 3 (“good”) or above for 93% of patient CCTAs.

CONCLUSION

Combining a low-dose scan protocol and AIDR3D with a 320-detector row CT scanner can provide high quality images at exceptionally low radiation dose in unselected patients being investigated for CAD.

Computed tomography colonography: a new threat to the spleen?

We present a rare and previously undocumented potential complication of computed tomography (CT) colonography. CT colonography is a commonly performed investigation with a relatively low risk of complications. While splenic injury is a well-documented complication after colonoscopy, it has never been reported following CT colonography. A 64-year-old man presented with severe abdominal pain four hours after CT colonography. CT of his abdomen and pelvis revealed appearances consistent with intra-abdominal bleeding secondary to splenic injury. The patient immediately underwent an emergency laparotomy and splenectomy, revealing a grade III splenic capsular tear. Histological evaluation of splenic tissue showed normal morphology with no evidence of malignancy. While the aetiology of the patient's splenic injury remains uncertain, normal histopathology and the chronology of events represents an almost certain link to CT colonography.

Early feeding practices in infants with phenylketonuria across Europe

Background

In infants with phenylketonuria (PKU), dietary management is based on lowering and titrating phenylalanine (Phe) intake from breast milk or standard infant formula in combination with a Phe-free infant formula in order to maintain blood Phe levels within target range. Professionals use different methods to feed infants with PKU and our survey aimed to document practices across Europe.

Methods

We sent a cross sectional, survey monkey® questionnaire to European health professionals working in IMD. It contained 31 open and multiple-choice questions. The results were analysed according to different geographical regions.

Results

Ninety-five centres from 21 countries responded. Over 60% of centres commenced diet in infants by age 10 days, with 58% of centres implementing newborn screening by day 3 post birth. At diagnosis, infant hospital admission occurred in 61% of metabolic centres, mainly in Eastern, Western and Southern Europe. Breastfeeding fell sharply following diagnosis with only 30% of women still breast feeding at 6 months.

53% of centres gave pre-measured Phe-free infant formula before each breast feed and 23% alternated breast feeds with Phe-free infant formula. With standard infant formula feeds, measured amounts were followed by Phe-free infant formula to satiety in 37% of centres (n = 35/95), whereas 44% (n = 42/95) advised mixing both formulas together. Weaning commenced between 17 and 26 weeks in 85% centres, ≥26 weeks in 12% and < 17 weeks in 3%.

Discussion

This is the largest European survey completed on PKU infant feeding practices. It is evident that practices varied widely across Europe, and the practicalities of infant feeding in PKU received little focus in the PKU European Guidelines (2017). There are few reports comparing different feeding techniques with blood Phe control, Phe fluctuations and growth. Controlled prospective studies are necessary to assess how different infant feeding practices may influence longer term feeding development.

A comparison of four different imaging modalities - Conventional, cross polarized, infra-red and ultra-violet in the assessment of childhood bruising

Background

It is standard practice to image concerning bruises in children. We aim to compare the clarity and measurements of bruises using cross polarized, infra-red (IR) and ultra-violet (UV) images to conventional images.

Methods

Children aged <11 years with incidental bruising were recruited. Demographics, skin and bruise details were recorded. Bruises were imaged by standard protocols in conventional, cross-polarized, IR and UV lights. Bruises were assessed in vivo for contrast, uniformity and diffuseness, and these characteristics were then compared across image modalities. Color images (conventional, cross polarized) were segmented and measured by ImageJ. Bruises of grey scale images (IR, UV) were measured by a ‘plug in’ of ImageJ. The maximum and minimum Feret's diameter, area and aspect ratio, were determined. Comparison of measurements across imaging modalities was conducted using Wilcoxon rank sum tests and modified Bland-Altman graphs. Significance was set at p < 0.05.

Results

Twenty five children had 39 bruises. Bruises that were of low contrast, i.e. difficult to distinguish from surrounding skin, were also more diffuse, and less uniformity in vivo. Low contrast bruises were best seen on conventional and cross-polarized images and less distinctive on IR and UV images. Of the 19 bruises visible in all modalities, the only significant difference was maximum and minimum Feret's diameters and area were smaller on IR compared to conventional images. Aspect ratios were not affected by the modality.

Conclusions

Conventional and cross-polarized imaging provides the most consistent bruise measurement, particularly in bruises that are not easily distinguished from surrounding skin visually.

•

Diffuse bruises may be measured on conventional & cross polarized imaging.

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Infrared or ultraviolet imaging may not show bruises which are difficult to see in vivo.

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Measurements of bruises using infrared imaging may be smaller than other modalities.

First measurements of remaining shell areal density on the OMEGA laser using the Diagnostic for Areal Density (DAD)

A glass Cherenkov detector, called the Diagnostic for Areal Density (DAD), has been built and implemented at the OMEGA laser facility for measuring fusion gammas above 430 keV, from which remaining shell ⟨ρR⟩ _abl can be determined. A proof-of-principle experiment is discussed, where signals from a surrogate gas Cherenkov detector are compared with reported values from the wedge range filter and charged particle spectrometer and found to correlate strongly. The design of the more compact port-based DAD diagnostic and results from the commissioning shots are then presented. Once absolutely calibrated, the DAD will be capable of reporting remaining shell ⟨ρR⟩ _abl for plastic and glass capsules within minutes of a shot and with potentially higher precision than existing techniques.

Vascularized fibular epiphyseal transfer for proximal humeral reconstruction in children with a primary sarcoma of bone

Aims

Preserving growth following limb-salvage surgery of the upper limb in children remains a challenge. Vascularized autografts may provide rapid biological incorporation with the potential for growth and longevity. In this study, we aimed to describe the outcomes following proximal humeral reconstruction with a vascularized fibular epiphyseal transfer in children with a primary sarcoma of bone. We also aimed to quantify the hypertrophy of the graft and the annual growth, and to determine the functional outcomes of the neoglenofibular joint.

Patients and Methods

We retrospectively analyzed 11 patients who underwent this procedure for a primary bone tumour of the proximal humerus between 2004 and 2015. Six had Ewing’s sarcoma and five had osteosarcoma. Their mean age at the time of surgery was five years (two to eight). The mean follow-up was 5.2 years (1 to 12.2).

Results

The overall survival at five and ten years was 91% (confidence interval (CI) 95% 75% to 100%). At the time of the final review, ten patients were alive. One with local recurrence and metastasis died one-year post-operatively. Complications included seven fractures, four transient nerve palsies, and two patients developed avascular necrosis of the graft. All the fractures presented within the first postoperative year and united with conservative management. One patient had two further operations for a slipped fibular epiphysis of the autograft, and a hemi-epiphysiodesis for lateral tibial physeal arrest. Hypertrophy and axial growth were evident in nine patients who did not have avascular necrosis of the graft. The mean hypertrophy index was 65% (55% to 82%), and the mean growth was 4.6 mm per annum (2.4 to 7.6) in these nine grafts. At final follow-up, the mean modified functional Musculoskeletal Tumour Society score was 77% (63% to 83%) and the mean Toronto Extremity Salvage Score (TESS) was 84% (65% to 94%).

Conclusion

Vascularized fibular epiphyseal transfer preserves function and growth in young children following excision of the proximal humerus for a malignant bone tumour. Function compares favourably to other limb-salvage procedures in children. Longer term analysis is required to determine if this technique proves to be durable into adulthood. Cite this article: Bone Joint J 2018;100-B:535–41.

The safety of Lipistart, a medium-chain triglyceride based formula, in the dietary treatment of long-chain fatty acid disorders: a phase I study

BACKGROUND

Children with long-chain fatty acid β-oxidation disorders (LCFAOD) presenting with clinical symptoms are treated with a specialist infant formula, with medium chain triglyceride (MCT) mainly replacing long chain triglyceride (LCT). It is essential that the safety and efficacy of any new specialist formula designed for LCFAOD be tested in infants and children.

METHODS

In an open-label, 21-day, phase I trial, we studied the safety of a new MCT-based formula (feed 1) in six well-controlled children (three male), aged 7-13 years (median 9 years) with LCFAOD (very long chain acyl CoA dehydrogenase deficiency [VLCADD], n=2; long chain 3-hydroxyacyl CoA dehydrogenase deficiency [LCHADD], n=2; carnitine acyl carnitine translocase deficiency [CACTD], n=2). Feed 1 (Lipistart; Vitaflo) contained 30% energy from MCT, 7.5% LCT and 3% linoleic acid and it was compared with a conventional MCT feed (Monogen; Nutricia) (feed 2) containing 17% energy from MCT, 3% LCT and 1.1% linoleic acid. Subjects consumed feed 2 for 7 days then feed 1 for 7 days and finally resumed feed 2 for 7 days. Vital signs, blood biochemistry, ECG, weight, height, food/feed intake and symptoms were monitored.

RESULTS

Five subjects completed the study. Their median daily volume of both feeds was 720 mL (range 500-1900 mL/day). Feed 1 was associated with minimal changes in tolerance, free fatty acids (FFA), acylcarnitines, 3-hydroxybutyrate (3-HB), creatine kinase (CK), blood glucose, liver enzymes and no change in an electrocardiogram (ECG). No child complained of muscle pain or symptoms associated with LCFAOD on either feed.

CONCLUSIONS

This is the first safety trial reported of an MCT formula specifically designed for infants and children with LCFAOD. In this short-term study, it appeared safe and well tolerated in this challenging group.