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.

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.

Reliability of a novel thermal imaging system for temperature assessment of healthy feet

Background

Thermal imaging is a useful modality for identifying preulcerative lesions (“hot spots”) in diabetic foot patients. Despite its recognised potential, at present, there is no readily available instrument for routine podiatric assessment of patients at risk. To address this need, a novel thermal imaging system was recently developed. This paper reports the reliability of this device for temperature assessment of healthy feet.

Methods

Plantar skin foot temperatures were measured with the novel thermal imaging device (Diabetic Foot Ulcer Prevention System (DFUPS), constructed by Photometrix Imaging Ltd) and also with a hand-held infrared spot thermometer (Thermofocus® 01500A3, Tecnimed, Italy) after 20 min of barefoot resting with legs supported and extended in 105 subjects (52 males and 53 females; age range 18 to 69 years) as part of a multicentre clinical trial. The temperature differences between the right and left foot at five regions of interest (ROIs), including 1st and 4th toes, 1st, 3rd and 5th metatarsal heads were calculated. The intra-instrument agreement (three repeated measures) and the inter-instrument agreement (hand-held thermometer and thermal imaging device) were quantified using intra-class correlation coefficients (ICCs) and the 95% confidence intervals (CI).

Results

Both devices showed almost perfect agreement in replication by instrument. The intra-instrument ICCs for the thermal imaging device at all five ROIs ranged from 0.95 to 0.97 and the intra-instrument ICCs for the hand-held-thermometer ranged from 0.94 to 0.97. There was substantial to perfect inter-instrument agreement between the hand-held thermometer and the thermal imaging device and the ICCs at all five ROIs ranged between 0.94 and 0.97.

Conclusions

This study reports the performance of a novel thermal imaging device in the assessment of foot temperatures in healthy volunteers in comparison with a hand-held infrared thermometer. The newly developed thermal imaging device showed very good agreement in repeated temperature assessments at defined ROIs as well as substantial to perfect agreement in temperature assessment with the hand-held infrared thermometer. In addition to the reported non-inferior performance in temperature assessment, the thermal imaging device holds the potential to provide an instantaneous thermal image of all sites of the feet (plantar, dorsal, lateral and medial views).

Trial registration

Diabetic Foot Ulcer Prevention System NCT02317835, registered December 10, 2014

The HubBLe Trial: haemorrhoidal artery ligation (HAL) versus rubber band ligation (RBL) for symptomatic second- and third-degree haemorrhoids: a multicentre randomised controlled trial and health-economic evaluation

BACKGROUND

Optimal surgical intervention for low-grade haemorrhoids is unknown. Rubber band ligation (RBL) is probably the most common intervention. Haemorrhoidal artery ligation (HAL) is a novel alternative that may be more efficacious.

OBJECTIVE

The comparison of HAL with RBL for the treatment of grade II/III haemorrhoids.

DESIGN

A multicentre, parallel-group randomised controlled trial.

PERSPECTIVE

UK NHS and Personal Social Services.

SETTING

17 NHS Trusts.

PARTICIPANTS

Patients aged ≥ 18 years presenting with grade II/III (second- and third-degree) haemorrhoids, including those who have undergone previous RBL.

INTERVENTIONS

HAL with Doppler probe compared with RBL.

OUTCOMES

Primary outcome - recurrence at 1 year post procedure; secondary outcomes - recurrence at 6 weeks; haemorrhoid severity score; European Quality of Life-5 Dimensions, 5-level version (EQ-5D-5L); Vaizey incontinence score; pain assessment; complications; and cost-effectiveness.

RESULTS

A total of 370 participants entered the trial. At 1 year post procedure, 30% of the HAL group had evidence of recurrence compared with 49% after RBL [adjusted odds ratio (OR) = 2.23, 95% confidence interval (CI) 1.42 to 3.51; p = 0.0005]. The main reason for the difference was the number of extra procedures required to achieve improvement/cure. If a single HAL is compared with multiple RBLs then only 37.5% recurred in the RBL arm (adjusted OR 1.35, 95% CI 0.85 to 2.15; p = 0.20). Persistence of significant symptoms at 6 weeks was lower in both arms than at 1 year (9% HAL and 29% RBL), suggesting significant deterioration in both groups over the year. Symptom score, EQ-5D-5L and Vaizey score improved in both groups compared with baseline, but there was no difference between interventions. Pain was less severe and of shorter duration in the RBL group; most of the HAL group who had pain had mild to moderate pain, resolving by 3 weeks. Complications were low frequency and not significantly different between groups. It appeared that HAL was not cost-effective compared with RBL. In the base-case analysis, the difference in mean total costs was £1027 higher for HAL. Quality-adjusted life-years (QALYs) were higher for HAL; however, the difference was very small (0.01) resulting in an incremental cost-effectiveness ratio of £104,427 per additional QALY.

CONCLUSIONS

At 1 year, although HAL resulted in fewer recurrences, recurrence was similar to repeat RBL. Symptom scores, complications, EQ-5D-5L and continence score were no different, and patients had more pain in the early postoperative period after HAL. HAL is more expensive and unlikely to be cost-effective in terms of incremental cost per QALY.

LIMITATIONS

Blinding of participants and site staff was not possible.

FUTURE WORK

The incidence of recurrence may continue to increase with time. Further follow-up would add to the evidence regarding long-term clinical effectiveness and cost-effectiveness. The polysymptomatic nature of haemorrhoidal disease requires a validated scoring system, and the data from this trial will allow further assessment of validity of such a system. These data add to the literature regarding treatment of grade II/III haemorrhoids. The results dovetail with results from the eTHoS study [Watson AJM, Hudson J, Wood J, Kilonzo M, Brown SR, McDonald A, et al. Comparison of stapled haemorrhoidopexy with traditional excisional surgery for haemorrhoidal disease (eTHoS): a pragmatic, multicentre, randomised controlled trial. Lancet 2016, in press.] comparing stapled haemorrhoidectomy with excisional haemorrhoidectomy. Combined results will allow expansion of analysis, allowing surgeons to tailor their treatment options to individual patients.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN41394716.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 88. See the NIHR Journals Library website for further project information.

Compliance with the 62-day target does not improve long-term survival

AIMS

Scottish Intercollegiate Guidelines Network (SIGN) guidelines require patients with colorectal cancer to wait no longer than 62 days from first referral to initiation of definitive treatment. We previously demonstrated that failure to meet with these guidelines did not appear to lead to poor outcomes in the short term. This study investigates whether this holds true over a longer period.

METHODS

The survival status of 1,012 patients treated for colorectal cancer between January 1999 and June 2005 was reviewed. As in the previous audit, patients were placed into four groups, standard met (elective), standard met (emergency), standard failed (elective) and standard failed (emergency). Parameters analysed were pathological staging, 30-day mortality, long-term survival and cause of death. Data was analysed using log rank and chi-squared tests.

RESULTS

Operative mortality was higher in patients meeting the standard (7% elective, 20% emergency) compared to those who did not meet the standard (4% elective, 7% emergency). The proportion of early stage disease (Dukes' A and B) was highest in elective patients who failed the standard (50%) and lowest in emergencies meeting the standard (30%). Long-term survival was greatest in elective patients who failed the standard with 52% alive in October 2011 compared to 34% of elective cases meeting the standard. The most common cause of recorded death was colorectal cancer in all groups.

CONCLUSIONS

Patients who were not treated within the time frame set by the SIGN guidelines survived for longer following surgery. Reasons for this are likely to be multifactorial and include pathological cancer stage.

Dietary management of maternal phenylketonuria with glycomacropeptide and amino acids supplements: A case report

BACKGROUND

In maternal PKU, protein substitute (PS) is provided by phenylalanine (PHE)-free l-amino acids (AA), but glycomacropeptide-based protein substitute (GMP) is an alternative consideration.

OBJECTIVE

To describe the first Portuguese Maternal Phenylketonuria (MPKU) partially managed with GMP.

CASE REPORT

A 31 year old MPKU female with classical PKU (mutations P281L/P281L), diagnosed by newborn screening, had a lifelong history of poor metabolic control. She has a history of partial bicornuate uterus and had a previous miscarriage in the first trimester. Pre-conception, her median blood PHE was 462 μmol/L but throughout pregnancy the median reduced to 258 μmol/L. GMP provided 30 g/day protein equivalent (46 mg/day PHE). Total protein equivalent from PS increased from 58 to 86 g/day during pregnancy but AA provided all additional protein equivalent intake. Both GMP and AA were well tolerated with no morning sickness. Normal morphologic evaluation and adequate fetal growth with cephalic biometry near the 5th percentile was determined. The infant was born at 39.3 weeks: weight 2570 g (3rd percentile), length 47.5 cm (10th percentile) and head circumference (HC) of 31.5 cm (1st percentile). In the neonatal period, the infant had craniofacial dimorphism with metopic suture prominence. Father also had bitemporal narrowing. By 12 months of age, the infant's weight (15th percentile), length (50th percentile) and HC (10th-50th percentile) were normal although bitemporal narrowing persisted.

CONCLUSIONS

This is the first case reporting the use of GMP in MPKU. Its PHE content did not adversely affect metabolic control although it only provided part of the PS intake. Some intrauterine development delay occurred in the last trimester, although we consider that this is unlikely to be associated with MPKU syndrome or the use of GMP. More published data is essential to examine the impact of using GMP in MPKU on morning sickness severity and aversion, maternal weight gain, blood amino acid concentrations and variability of blood PHE concentrations.

The complete European guidelines on phenylketonuria: diagnosis and treatment

Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine. If left untreated, PKU results in increased phenylalanine concentrations in blood and brain, which cause severe intellectual disability, epilepsy and behavioural problems. PKU management differs widely across Europe and therefore these guidelines have been developed aiming to optimize and standardize PKU care. Professionals from 10 different European countries developed the guidelines according to the AGREE (Appraisal of Guidelines for Research and Evaluation) method. Literature search, critical appraisal and evidence grading were conducted according to the SIGN (Scottish Intercollegiate Guidelines Network) method. The Delphi-method was used when there was no or little evidence available. External consultants reviewed the guidelines. Using these methods 70 statements were formulated based on the highest quality evidence available. The level of evidence of most recommendations is C or D. Although study designs and patient numbers are sub-optimal, many statements are convincing, important and relevant. In addition, knowledge gaps are identified which require further research in order to direct better care for the future.

Refining low protein modular feeds for children on low protein tube feeds with organic acidaemias

Children with inherited metabolic disorders (IMD) who are dependent on tube feeding and require a protein restriction are commonly fed by ‘modular tube feeds’ consisting of several ingredients. A longitudinal, prospective two-phase study, conducted over 18 months assessed the long-term efficacy of a pre-measured protein-free composite feed. This was specifically designed to meet the non-protein nutritional requirements of children (aged over 1 year) with organic acidaemias on low protein enteral feeds and to be used as a supplement with an enteral feeding protein source.

Methodology

All non-protein individual feed ingredients were replaced with one protein-free composite feed supplying fat, carbohydrate, and micronutrients. Thirteen subjects, median age 7.4y (3–15.5y), all nutritionally tube dependent (supplying nutritional intake: ≥ 90%, n = 12; 75%, n = 1), and diagnosed with organic acidaemias (Propionic acidaemia, n = 6; Vitamin B₁₂ non-responsive methyl malonic acidaemia, n = 4; Isovaleric acidaemia, n = 2; Glutaric aciduria type1, n = 1); were studied. Nutritional intake, biochemistry and anthropometry were monitored at week − 8, 0, 12, 26 and 79.

Results

Energy intake remained unchanged, providing 76% of estimated energy requirements. Dietary intakes of vitamins, minerals and essential fatty acids significantly increased from week 0 to week 79, but sodium, potassium, magnesium, decosahexanoic acid and fibre did not meet suggested requirements. Plasma zinc, selenium, haemoglobin and MCV significantly improved, and growth remained satisfactory. Natural protein intake met WHO/FAO/UNU 2007 recommendations.

Conclusions

A protein-free composite feed formulated to meet the non-protein nutritional requirements of children aged over 1 year improved nutritional intake, biochemical nutritional status, and simplified enteral tube feeding regimens in children with organic acidaemias.

Dietary practices in propionic acidemia: A European survey

Background

The definitive dietary management of propionic acidaemia (PA) is unknown although natural protein restriction with adequate energy provision is of key importance.

Aim

To describe European dietary practices in the management of patients with PA prior to the publication of the European PA guidelines.

Methods

This was a cross-sectional survey consisting of 27 questions about the dietary practices in PA patients circulated to European IMD dietitians and health professionals in 2014.

Results

Information on protein restricted diets of 186 PA patients from 47 centres, representing 14 European countries was collected. Total protein intake [PA precursor-free L-amino acid supplements (PFAA) and natural protein] met WHO/FAO/UNU (2007) safe protein requirements for age in 36 centres (77%). PFAA were used to supplement natural protein intake in 81% (n = 38) of centres, providing a median of 44% (14–83%) of total protein requirement. Seventy-four per cent of patients were prescribed natural protein intakes below WHO/FAO/UNU (2007) safe levels in one or more of the following age groups: 0–6 m, 7–12 m, 1–10 y, 11–16 y and > 16 y. Sixty-three per cent (n = 117) of patients were tube fed (74% gastrostomy), but only 22% received nocturnal feeds.

Conclusions

There was high use of PFAA with intakes of natural protein commonly below WHO/FAO/UNU (2007) safe levels. Optimal dietary management can only be determined by longitudinal, multi-centre, prospective case controlled studies. The metabolic instability of PA and small patient cohorts in each centre ensure that this is a challenging undertaking.

Fifteen years of using a second stage protein substitute for weaning in phenylketonuria: a retrospective study

BACKGROUND

In phenylketonuria (PKU), during weaning, it is necessary to introduce a second stage phenylalanine (Phe)-free protein substitute (PS) to help meet non-Phe protein requirements. Semi-solid weaning Phe-free PS have been available for >15 years, although no long-term studies have reported their efficacy.

METHODS

Retrospective data from 31 children with PKU who commenced a weaning PS were collected from clinical records from age of weaning to 2 years, on: gender; birth order; weaning age; anthropometry; blood Phe levels; age commenced and dosage of weaning PS and Phe-free infant L-amino acid formula; natural protein intake; and issues with administration of PS or food.

RESULTS

Median commencement age for weaning was 17 weeks (range 12-25 weeks) and, for weaning PS, 20 weeks (range 13-37 weeks). Median natural protein was 4 g day^-1 (range 3-11 g day^-1 ) and total protein intake was >2 g kg^-1 day^-1 from weaning to 2 years of age. Children started on 2-4 g day^-1 protein equivalent (5-10 g day^-1 of powder) from weaning PS, increasing by 0.2 g kg^-1 day^-1 (2 g day^-1 ) monthly to 12 months of age. Teething and illness adversely affected the administration of weaning PS and the acceptance of solid foods. Altogether, 32% of children had delayed introduction of more textured foods, associated with birth order (firstborn 80% versus 38%; P = 0.05) and food refusal when teething (80% versus 29%; P = 0.02).

CONCLUSIONS

Timing of introduction of solid foods and weaning PS, progression onto more textured foods and consistent feeding routines were important in aiding their acceptance. Any negative behaviour with weaning PS was mainly associated with food refusal, teething and illness. Parental approach influenced the acceptance of weaning PS.

The challenge of nutritional profiling of a protein-free feed module for children on low protein tube feeds with organic acidaemias

BACKGROUND

Enteral tube feeding for children with organic acidaemias (OA) is recommended. Protein restriction, providing minimum safe levels of protein intake, is advocated. Standard paediatric tube feeding formulae provide more than the minimum safe protein requirements and are unsuitable in OA without modification. Modified paediatric enteral feeds consist of several modular ingredients. The aim of this prospective longitudinal interventional study was to assess the efficacy of a premeasured novel protein-free module developed for children aged over 12 months compared to conventional practice.

METHODS

In total, 15 children with OA (11.6-31 kg) needing enteral feeding were recruited. The protein-free module, from either a protein-free infant feed or modular ingredients, was replaced by the study feed. To ensure metabolic stability, energy and protein intake were unchanged. Dietary intake, anthropometry and nutritional biochemistry were recorded at baseline and week 26.

RESULTS

Dietary intakes of magnesium (P = 0.02), sodium (P = 0.005), vitamin D (P = 0.04), docosahexaenoic acid (P = 0.01) and arachidonic acid (P = 0.001) significantly improved; plasma selenium (P = 0.002) and whole blood glutathione peroxidase (P = 0.02) significantly increased. Feed preparation accuracy as measured by composition analysis showed consistent errors both in pre- and study feeds.

CONCLUSIONS

A protein-free module improved nutritional intake and biochemistry, although feed preparation errors remained a common finding.

Dietary practices in isovaleric acidemia: A European survey

Background

In Europe, dietary management of isovaleric acidemia (IVA) may vary widely. There is limited collective information about dietetic management.

Aim

To describe European practice regarding the dietary management of IVA, prior to the availability of the E-IMD IVA guidelines (E-IMD 2014).

Methods

A cross-sectional questionnaire was sent to all European dietitians who were either members of the Society for the Study of Inborn Errors of Metabolism Dietitians Group (SSIEM-DG) or whom had responded to previous questionnaires on dietetic practice (n = 53). The questionnaire comprised 27 questions about the dietary management of IVA.

Results

Information on 140 patients with IVA from 39 centres was reported. 133 patients (38 centres) were given a protein restricted diet. Leucine-free amino acid supplements (LFAA) were routinely used to supplement protein intake in 58% of centres. The median total protein intake prescribed achieved the WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Centres that prescribed LFAA had lower natural protein intakes in most age groups except 1 to 10 y. In contrast, when centres were not using LFAA, the median natural protein intake met WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Enteral tube feeding was rarely prescribed.

Conclusions

This survey demonstrates wide differences in dietary practice in the management of IVA across European centres. It provides unique dietary data collectively representing European practices in IVA which can be used as a foundation to compare dietary management changes as a consequence of the first E-IMD IVA guidelines availability.

Glycomacropeptide in children with phenylketonuria: does its phenylalanine content affect blood phenylalanine control?

BACKGROUND

In phenylketonuria (PKU), there are no data available for children with respect to evaluating casein glycomacropeptide (CGMP) as an alternative to phenylalanine-free protein substitutes [Phe-free L-amino acid (AA)]. CGMP contains a residual amount of phenylalanine, which may alter blood phenylalanine control.

METHODS

In a prospective 6-month pilot study, we investigated the effect on blood phenylalanine control of CGMP-amino acid (CGMP-AA) protein substitute in 22 PKU subjects (13 boys, nine girls), median age (range) 11 years (6-16 years). Twelve received CGMP-AA and nine received Phe-free L-AA, (1 CGMP-AA withdrawal). Subjects partially or wholly replaced Phe-free L-AA with CGMP-AA. If blood phenylalanine exceeded the target range, the CGMP-AA dose was reduced and replaced with Phe-free L-amino acids. The control group remained on Phe-free L-AAs. Phenylalanine, tyrosine and Phe : Tyr ratio concentrations were compared with the results for the previous year.

RESULTS

In the CGMP-AA group, there was a significant increase in blood phenylalanine concentrations (pre-study, 275 μmol L^-1 ; CGMP-AA, 317 μmol L^-1 ; P = 0.02), a decrease in tyrosine concentrations (pre-study, 50 μmol L^-1 ; CGMP-AA, 40 μmol L^-1 ; P = 0.03) and an increase in Phe : Tyr ratios (pre-study, Phe : Tyr 4.9:1; CGMP-AA, Phe : Tyr 8:1; P = 0.02). In the control group there was a non-significant fall in phenylalanine concentrations (pre-study 325μmol/L: study 280μmol/L [p = 0.9], and no significant changes for tyrosine or phe/tyr ratios [p = 0.9]. Children taking the CGMP-AA found it more acceptable to L-AA.

CONCLUSIONS

Blood phenylalanine control declined with CGMP-AA but, by titrating the dose of CGMP-AA, blood phenylalanine control remained within target range. The additional intake of phenylalanine may have contributed to the change in blood phenylalanine concentration. CGMP-AA use requires careful monitoring in children.

Is breast best? Is early solid feeding harmful?

The health benefits of breastfeeding for babies and mothers have long been recognised and it is now globally recommended that it be continued exclusively for six months. Although there are few controlled trials to support this recommendation, the most important advantage is less morbidity from gastrointestinal infection in developing countries. There is also evidence that respiratory tract infections and atopic dermatitis is reduced, and the maternal risk of breast cancer decreases, particularly with a longer duration of breastfeeding and a high parity. There is little to suggest that exclusive breastfeeding for six months adversely affects infant growth, nutritional status or infant feeding skills, but more studies are needed. Equally, there is no evidence that introduction of solids from 17 weeks is harmful in developed countries. However, in the UK breastfeeding prevalence is low and solids are introduced early for the majority of infants and much can be done to positively encourage and support all mothers to continue breastfeeding for a longer period.

Understanding the Personality and Behavioral Mechanisms Defining Hypersexuality in Men Who Have Sex With Men

INTRODUCTION

Hypersexuality has been conceptualized as sexual addiction, compulsivity, and impulsivity, among others, in the absence of strong empirical data in support of any specific conceptualization.

AIM

To investigate personality factors and behavioral mechanisms that are relevant to hypersexuality in men who have sex with men.

METHODS

A sample of 242 men who have sex with men was recruited from various sites in a moderate-size mid-western city. Participants were assigned to a hypersexuality group or a control group using an interview similar to the Structured Clinical Interview for the Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition. Self-report inventories were administered that measured the broad personality constructs of positive emotionality, negative emotionality, and constraint and more narrow constructs related to sexual behavioral control, behavioral activation, behavioral inhibition, sexual excitation, sexual inhibition, impulsivity, attention-deficit/hyperactivity disorder, and sexual behavior.

MAIN OUTCOME MEASURES

Hierarchical logistic regression was used to determine the relation between these personality and behavioral variables and group membership.

RESULTS

A hierarchical logistic regression controlling for age showed a significant positive relation between hypersexuality and negative emotionality and a negative relation with constraint. None of the behavioral mechanism variables entered this equation. However, a hierarchical multiple regression analysis predicting sexual behavioral control indicated that lack of such control was positively related to sexual excitation and sexual inhibition owing to the threat of performance failure and negatively related to sexual inhibition owing to the threat of performance consequences and general behavioral inhibition

CONCLUSION

Hypersexuality was found to be related to two broad personality factors that are characterized by emotional reactivity, risk taking, and impulsivity. The associated lack of sexual behavior control is influenced by sexual excitatory and inhibitory mechanisms, but not by general behavioral activation and inhibitory mechanisms.

Retractions in orthopaedic research: A systematic review

Objectives

Despite the fact that research fraud and misconduct are under scrutiny in the field of orthopaedic research, little systematic work has been done to uncover and characterise the underlying reasons for academic retractions in this field. The purpose of this study was to determine the rate of retractions and identify the reasons for retracted publications in the orthopaedic literature.

Methods

Two reviewers independently searched MEDLINE, EMBASE, and the Cochrane Library (1995 to current) using MeSH keyword headings and the ‘retracted’ filter. We also searched an independent website that reports and archives retracted scientific publications (www.retractionwatch.com). Two reviewers independently extracted data including reason for retraction, study type, journal impact factor, and country of origin.

Results

One hundred and ten retracted studies were included for data extraction. The retracted studies were published in journals with impact factors ranging from 0.000 (discontinued journals) to 13.262. In the 20-year search window, only 25 papers were retracted in the first ten years, with the remaining 85 papers retracted in the most recent decade. The most common reasons for retraction were fraudulent data (29), plagiarism (25) and duplicate publication (20). Retracted articles have been cited up to 165 times (median 6; interquartile range 2 to 19).

Conclusion

The rate of retractions in the orthopaedic literature is increasing, with the majority of retractions attributed to academic misconduct and fraud. Orthopaedic retractions originate from numerous journals and countries, indicating that misconduct issues are widespread. The results of this study highlight the need to address academic integrity when training the next generation of orthopaedic investigators.

Cite this article: J. Yan, A. MacDonald, L-P. Baisi, N. Evaniew, M. Bhandari, M. Ghert. Retractions in orthopaedic research: A systematic review. Bone Joint Res 2016;5:263–268. DOI: 10.1302/2046-3758.56.BJR-2016-0047.

Protein substitutes for phenylketonuria in Europe: access and nutritional composition

BACKGROUND/OBJECTIVES

Protein substitutes (PS) are an essential component in the dietary management of phenylketonuria (PKU). PS are available as phenylalanine-free amino-acid mixtures (AAM), glycomacropeptide-based PS (GMP) and large neutral amino acids (LNAA). There is a lack of information regarding their availability in different countries and comparison of their nutritional composition is limited. The objectives of this study were to identify the number of PS available in different European countries and Turkey and to compare their nutritional composition.

SUBJECTS/METHODS

Members of the European Nutritionist Expert Panel on PKU (ENEP) (Portugal, Spain, Belgium, Italy, Germany, Netherlands, United Kingdom, Denmark and Turkey) provided data on PS available in each country. The nutritional composition of PS available in Portugal was analyzed.

RESULTS

The number of PS available in each country varied from 30 (Turkey) to 105 (Germany), with a median of 64. GMP was available only in Portugal, whereas LNAA was an option in Portugal, Italy, Turkey and Denmark. Some PS were designed for weaning. Many PS did not contain added fat and fiber. GMP contained the highest carbohydrate (CHO) and energy content as well as higher LNAA content compared with AAM. Only one AAM contained added fructo-oligosaccharides and galacto-oligosaccharides. AAM designed for the first year of life had the highest CHO, fat and LNAA contribution. Liquid AAM had lower CHO and fat contents compared with powdered AAM, but contained higher LNAA.

CONCLUSIONS

There was widely dissimilar numbers of PS available in different countries. Nutritional composition of different PS was variable and should be considered before prescription.

Comparison of optimised endovaginal vs external array coil T2-weighted and diffusion-weighted imaging techniques for detecting suspected early stage (IA/IB1) uterine cervical cancer

OBJECTIVE

To compare sensitivity and specificity of endovaginal versus external-array coil T2-W and T2-W + DWI for detecting and staging small cervical tumours.

METHODS

Optimised endovaginal and external array coil MRI at 3.0-T was done prospectively in 48 consecutive patients with stage Ia/Ib1 cervical cancer. Sensitivity/specificity for detecting tumour and parametrial extension against histopathology for a reading radiologist were determined on coronal T2-W and T2W + DW images. An independent radiologist also scored T2-W images without and with addition of DWI for the external-array and endovaginal coils on separate occasions >2 weeks apart. Cohen's kappa assessed inter- and intra-observer agreement.

RESULTS

Median tumour volume in 19/38 cases positive on subsequent histology was 1.75 cm(3). Sensitivity, specificity, PPV, NPV were: reading radiologist 91.3 %, 89.5 %, 91.3 %, 89.5 %, respectively; independent radiologist T2-W 82.6 %, 73.7 %, 79.1 %, 77.8 % for endovaginal, 73.9 %, 89.5 %, 89.5 %, 73.9 % for external-array coil. Adding DWI improved sensitivity and specificity of endovaginal imaging (78.2 %, 89.5 %); adding DWI to external-array imaging improved specificity (94.7 %) but reduced sensitivity (66.7 %). Inter- and intra-observer agreement on T2-W + DWI was good (kappa = 0.67 and 0.62, respectively).

CONCLUSION

Endovaginal coil T2-W MRI is more sensitive than external-array coil for detecting tumours <2 cm(3); adding DWI improves specificity of endovaginal imaging but reduces sensitivity of external-array imaging.

KEY POINTS

• Endovaginal more accurate than external-array T2-W MRI for detecting small cervical cancers. • Addition of DWI improves sensitivity and specificity of endovaginal T2-W imaging. • Addition of DWI substantially reduces sensitivity of external-array T2-W imaging.