The influence of government policies on the nurse practitioner and physician assistant workforce in the Netherlands, 2000-2022: a multimethod approach study.

BACKGROUND: Many countries are looking for ways to increase nurse practitioner (NP) and physician assistant/associate (PA) deployment. Countries are seeking to tackle the pressing issues of increasing healthcare demand, healthcare costs, and medical doctor shortages. This article provides insights into the potential impact of various policy measures on NP/PA workforce development in the Netherlands. METHODS: We applied a multimethod approach study using three methods: 1) a review of government policies, 2) surveys on NP/PA workforce characteristics, and 3) surveys on intake in NP/PA training programs. RESULTS: Until 2012, the annual intake into NP and PA training programs was comparable to the number of subsidized training places. In 2012, a 131% increase in intake coincided with extending the legal scope of practice of NPs and PAs and substantially increasing subsidized NP/PA training places. However, in 2013, the intake of NP and PA trainees decreased by 23% and 24%, respectively. The intake decreased in hospitals, (nursing) home care, and mental healthcare, coinciding with fiscal austerity in these sectors. We found that other policies, such as legal acknowledgment, reimbursement, and funding platforms and research, do not consistently coincide with NP/PA training and employment trends. The ratios of NPs and PAs to medical doctors increased substantially in all healthcare sectors from 3.5 and 1.0 per 100 full-time equivalents in medical doctors in 2012 to 11.0 and 3.9 in 2022, respectively. For NPs, the ratios vary between 2.5 per 100 full-time equivalents in medical doctors in primary care and 41.9 in mental healthcare. PA-medical doctor ratios range from 1.6 per 100 full-time equivalents in medical doctors in primary care to 5.8 in hospital care. CONCLUSIONS: This study reveals that specific policies coincided with NP and PA workforce growth. Sudden and severe fiscal austerity coincided with declining NP/PA training intake. Furthermore, governmental training subsidies coincided and were likely associated with NP/PA workforce growth. Other policy measures did not consistently coincide with trends in intake in NP/PA training or employment. The role of extending the scope of practice remains to be determined. The skill mix is shifting toward an increasing share of medical care provided by NPs and PAs in all healthcare sectors.

Facilitators for developing an interprofessional learning culture in nursing homes: a scoping review.

BACKGROUND: Healthcare professionals in nursing homes face complex care demands and nursing staff shortages. As a result, nursing homes are transforming into home-like personalised facilities that deliver person-centred care. These challenges and changes require an interprofessional learning culture in nursing homes, but there is little understanding of the facilitators that contribute to developing such a culture. This scoping review aims to identify those facilitators. METHODS: A scoping review was performed in accordance with the JBI Manual for Evidence Synthesis (2020). The search was carried out in 2020-2021 in seven international databases (PubMed, Cochrane Library, CINAHL, Medline, Embase, PsycINFO and Web of Science). Two researchers independently extracted reported facilitators that contribute to an interprofessional learning culture in nursing homes. Then the researchers inductively clustered the extracted facilitators into categories. RESULTS: In total, 5,747 studies were identified. After removing duplicates and screening titles, abstracts and full texts, 13 studies that matched the inclusion criteria were included in this scoping review. We identified 40 facilitators and clustered them into eight categories: (1) shared language, (2) shared goals, (3) clear tasks and responsibilities, (4) learning and sharing knowledge, (5) work approaches, (6) facilitating and supporting change and creativity by the frontline manager, (7) an open attitude, and (8) a safe, respectful and transparent environment. CONCLUSION: We found facilitators that could be used to discuss the current interprofessional learning culture in nursing homes and identify where improvements are required. Further research is needed to discover how to operationalise facilitators that develop an interprofessional learning culture in nursing homes and to gain insights into what works, for whom, to what extent and in what context.

How does government policy influence the employment and training of nurse practitioners and physician assistants? A realist analysis using qualitative interviews.

AIMS: The aim of this study was to develop insights into how and why Dutch government policies on deployment and training of nurse practitioners and physician assistants have effect and under what circumstances. DESIGN: A realist analysis using qualitative interviews. METHODS: Data analysis of 50 semi-structured interviews conducted in 2019 with healthcare providers, sectoral and professional associations, and training coordinators. Stratified purposive and snowball sampling were used. RESULTS: Policies stimulated employment and training of nurse practitioners and physician assistants by: (1) contributing to the familiarity of participants in the decision-making process in healthcare providers with and medical doctors' trust in these professions; (2) contributing to participants' motivation in employment and training; and (3) eliminating barriers perceived by medical doctors, managers and directors. The extent to which policies affected employment and training was largely determined by sectoral and organizational circumstances, such as healthcare demand and complexity, and decision-makers in healthcare providers (medical doctors or managers/directors). CONCLUSION: Effectuating familiarity and trust among participants in the decision-making process is a crucial first step. Next, policymakers can motivate participants and lower their perceived barriers by extending the scope of practice, creating reimbursement opportunities and contributing to training costs. Theoretical insights into nurse practitioner and physician assistant employment and training have been refined. IMPACT: The findings highlight how governments, health insurers, sectoral and professional associations, departments, councils, healthcare providers and professionals can facilitate and support nurse practitioner and physician assistant employment and training by contributing to familiarity, trust and motivation, and by clearing perceived barriers.

Skill mix change between physicians, nurse practitioners, physician assistants, and nurses in nursing homes: A qualitative study.

Nursing home physicians face heavy workloads, because of the aging population and rising number of older adults with one or more chronic diseases. Skill mix change, in which professionals perform tasks previously reserved for physicians independently or under supervision, could be an answer to this challenge. The aim of this study was to describe how skill mix change in nursing homes is organized from four monodisciplinary perspectives and the interdisciplinary perspective, what influences it, and what its effects are. The study focused particularly on skill mix change through the substitution of nurse practitioners, physician assistants, or registered nurses for nursing home physicians. Five focus group interviews were conducted in the Netherlands. Variation in tasks and responsibilities was found. Despite this variation, stakeholders reported increased quality of health care, patient centeredness, and support for care teams. A clear vision on skill mix change, acceptance of nurse practitioners, physician assistants, and registered nurses, and a reduction of legal insecurity are needed that might maximize the added value of nurse practitioners, physician assistants, and registered nurses.

Skill mix change between general practitioners, nurse practitioners, physician assistants and nurses in primary healthcare for older people: a qualitative study.

BACKGROUND: More and more older adults desire to and are enabled to grow old in their own home, regardless of their physical and mental capabilities. This change, together with the growing number of older adults, increases the demand for general practitioners (GPs). However, care for older people lacks prestige among medical students and few medical students are interested in a career in care for older people. Innovative solutions are needed to reduce the demand for GPs, to guarantee quality of healthcare and to contain costs. A solution might be found in skill mix change by introducing nurse practitioners (NPs), physician assistants (PAs) or registered nurses (RNs). The aim of this study was to describe how skill mix change is organised in daily practice, what influences it and what the effects are of introducing NPs, PAs or RNs into primary healthcare for older people. METHODS: In total, 34 care providers working in primary healthcare in the Netherlands were interviewed: GPs (n = 9), NPs (n = 10), PAs (n = 5) and RNs (n = 10). Five focus groups and 14 individual interviews were conducted. Analysis consisted of open coding, creating categories and abstraction. RESULTS: In most cases, healthcare for older people was only a small part of the tasks of NPs, PAs and RNs; they did not solely focus on older people. The tasks they performed and their responsibilities in healthcare for older people differed between, as well as within, professions. Although the interviewees debated the usefulness of proactive structural screening on frailty in the older population, when implemented, it was also unclear who should perform the geriatric assessment. Interviewees considered NPs, PAs and RNs an added value, and it was stated that the role of the GP changed with the introduction of NPs, PAs or RNs. CONCLUSIONS: The roles and responsibilities of NPs, PAs and RNs for the care of older people living at home are still not established. Nonetheless, these examples show the potential of these professionals. The establishment of a clear vision on primary healthcare for older people, including the organisation of proactive healthcare, is necessary to optimise the impact of skill mix change.

Effects of substituting nurse practitioners, physician assistants or nurses for physicians concerning healthcare for the ageing population: a systematic literature review.

AIMS: To evaluate the effects of substituting nurse practitioners, physician assistants or nurses for physicians in long-term care facilities and primary healthcare for the ageing population (primary aim) and to describe what influences the implementation (secondary aim). BACKGROUND: Healthcare for the ageing population is undergoing major changes and physicians face heavy workloads. A solution to guarantee quality and contain costs might be to substitute nurse practitioners, physician assistants or nurses for physicians. DESIGN: A systematic literature review. DATA SOURCES: PubMed, EMBASE, CINAHL, PsycINFO, CENTRAL, Web of Science; searched January 1995-August 2015. REVIEW METHODS: Study selection, data extraction and quality appraisal were conducted independently by two reviewers. Outcomes collected: patient outcomes, care provider outcomes, process of care outcomes, resource use outcomes, costs and descriptions of the implementation. Data synthesis consisted of a narrative summary. RESULTS: Two studies used a randomized design and eight studies used other comparative designs. The evidence of the two randomized controlled trials showed no effect on approximately half of the outcomes and a positive effect on the other half of the outcomes. Results of eight other comparative study designs point towards the same direction. The implementation was influenced by factors on a social, organizational and individual level. CONCLUSION: Physician substitution in healthcare for the ageing population may achieve at least as good patient outcomes and process of care outcomes compared with care provided by physicians. Evidence about resource use and costs is too limited to draw conclusions.

Physician substitution by mid-level providers in primary healthcare for older people and long-term care facilities: protocol for a systematic literature review.

AIM: This protocol describes a systematic review that evaluates the effects of physician substitution by mid-level providers (nurse practitioners, physician assistants or nurses) in primary healthcare for older people and long-term care facilities. The secondary aim is to describe facilitators and barriers to the implementation of physician substitution in these settings. BACKGROUND: Healthcare for older people is undergoing major changes, due to population ageing and reforms that shift care to the community. Besides, relatively few medical students are pursuing careers in healthcare for older people. Innovative solutions are needed to guarantee the quality of healthcare and to contain costs. A solution might be shifting care from physicians to mid-level providers. To date, no systematic review on this topic exits to guide policymaking. DESIGN: A quantitative systematic literature review using Cochrane methods. METHODS: The following databases will be searched for original research studies that quantitatively compare care provided by a physician to the same care provided by a mid-level provider: PubMed, EMBASE, CINAHL, PsycINFO, CENTRAL and Web of Science. Study selection, data extraction and quality appraisal will be conducted independently by two reviewers. Data synthesis will consist of a qualitative analysis of the data. Funding of the review was confirmed in August 2013 by the Ministry of Health, Welfare and Sport of the Netherlands. DISCUSSION: This review will contribute to the knowledge on effects of physician substitution in healthcare for older people and factors that influence the outcomes. This knowledge will guide professionals and policy administrators in their decisions to optimize healthcare for older people.

The effectiveness of substitution of hospital ward care from medical doctors to physician assistants: a study protocol.

BACKGROUND: Because of an expected shrinking supply of medical doctors for hospitalist posts, an increased emphasis on efficiency and continuity of care, and the standardization of many medical procedures, the role of hospitalist is increasingly allocated to physician assistants (PAs). PAs are nonphysician clinicians with medical tasks. This study aims to evaluate the effects of substitution of hospital ward care to PAs. METHODS/DESIGN: In a multicenter matched controlled study, the traditional model in which the role of hospitalist is taken solely by medical doctors (MD model) is compared with a mixed model in which a PA functions as a hospitalist, contingent with MDs (PA/MD model). Twenty intervention and twenty control wards are included across The Netherlands, from a range of medical specialisms. Primary outcome measure is patients' length of hospital stay. Secondary outcomes include indicators for quality of hospital ward care, patients experiences with medical ward care, patients health-related quality of life, and healthcare providers' experiences. An economic evaluation is conducted to assess the cost implications and potential efficiency of the PA/MD model. For most measures, data is collected from medical records or questionnaires in samples of 115 patients per hospital ward. Semi-structured interviews with healthcare professionals are conducted to identify determinants of efficiency, quality and continuity of care and barriers and facilitators for the implementation of PAs in the role of hospitalist. DISCUSSION: Findings from this study will help to further define the role of nonphysician clinicians and provides possible key components for the implementation of PAs in hospital ward care. Like in many studies of organizational change, random allocation to study arms is not feasible, which implies an increased risk for confounding. A major challenge is to deal with the heterogeneity of patients and hospital departments.

Implementation of the physician assistant in Dutch health care organizations: primary motives and outcomes.

Physician assistants (PAs) are trained to perform medical procedures that were traditionally performed by medical physicians. Physician assistants seem to be deployed not only to increase efficiency but also to ensure the quality of care. What is not known is the primary motive for employing PAs within Dutch health care and whether the employment of the PAs fulfills the perceived need for them. Supervising medical specialists who used PAs in their practices were interviewed about their primary motives and outcomes. The interviews were semistructured. Two scientists coded the findings with respect to motives and outcomes. In total, 55 specialists were interviewed about their motives for employing a PA, and 15 were interviewed about the outcomes of employing a PA. With respect to the primary motives for employing a PA, the most frequent motive was to increase continuity and quality of care, followed by relieving the specialist's workload, increasing efficiency of care, and substituting for medical residents. The outcomes were found to be consistent with the motives. In conclusion, the primary motive for employing a PA in Dutch health care is to increase continuity and quality of care.

A case vignette study to refine the target group of an intermediate care model: the Acute Geriatric Community Hospital.

PURPOSE: To refine the admission criteria of the Acute Geriatric Community Hospital (AGCH) by defining its target group boundaries with (geriatric) hospital care and other bed-based intermediate care models in the Netherlands. METHODS: A qualitative study consisting of a three-phase refinement procedure with case vignettes. Physicians, medical specialists, nurse practitioners, and physician assistants in hospitals (n = 10) or intermediate care facilities (n = 10) in the Netherlands participated. They collected case vignettes from clinical practice (phase one). The referral considerations and decisions for each case were then documented through surveys (phase two) and two focus groups (phase 3). For thematic data analysis, inductive and deductive approaches were used. RESULTS: The combination of medical specialist care (MSC) and medical generalist care (MGC), is unique for the AGCH compared to other intermediate care models in the Netherlands. Compared to (geriatric) hospital care, the AGCH offers a more limited scope of MSC. Based on these findings, 13 refined admission criteria were developed such as 'The required diagnostic tests to monitor the effectiveness of treatment are available at the AGCH'. Besides admission criteria, additional clinical and organizational considerations played a role in referral decision-making; 10 themes were identified. CONCLUSION: This case vignette study defined the target group boundaries between the AGCH and other care models, allowing us to refine the AGCH admission criteria. Our findings may help to determine the required competencies of the interdisciplinary AGCH team and to develop triage instruments. The identified consideration themes can be used as conceptual framework in further research. The findings may also be of interests for healthcare systems outside the Netherlands who aspire to design integrated care for older people closer to home.

The psychiatric-mental health nurse practitioner as coordinating practitioner in the Netherlands: A multiple case study.

BACKGROUND: Psychiatric-mental health nurse practitioners (PMHNPs) in the Netherlands have been allowed to perform the role of coordinating practitioner (CP) since 2018. This role is reserved for mental health care specialists who are trained and qualified at the master's degree level. Earlier studies have not addressed how PMHNPs perform that role and what mechanisms and contextual factors determine their performance. This understanding could help optimize their performance in this role and promote effective deployment of PMHNPs in mental health care. PURPOSE: To understand how PMHNPs perform this role and what mechanisms and contextual factors underlie that performance. METHODOLOGY: A multiple case study involving PMHNPs who work in various settings as CPs. Data were collected and analyzed using the realistic evaluation approach. RESULTS: We identified four mechanisms related to the performance of PMHNPs in the role of CP: (1) autonomous performance; (2) unique expertise; (3) accessibility, availability, and professional involvement; and (4) additional roles. The extent to which these mechanisms are present is largely determined by organizational factors, team factors, and individual factors. CONCLUSIONS: Psychiatric-mental health nurse practitioners are seeking to identify and interpret the role of CP. This study helps to elucidate the mechanism of role performance by PMHNPs and what they should focus on to deliver effective and patient-centered mental health care. IMPLICATIONS: Policymakers, health care professionals, and educators should consider the mechanisms and contextual factors to facilitate and support PMHNPs' employment and training in the role of CP.

Dietary arginine and linear growth: the Copenhagen School Child Intervention Study.

The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity was significant for the third and fourth quintile of arginine intake (2.5-2.8 and 2.8-3.2 g/d, respectively) compared with the first quintile ( < 2.2 g/d) (P for trend = 0.04). Protein intake (excluding arginine) was significantly associated with growth velocity; however, the association was weaker than the association between arginine intake and growth velocity (P for trend = 0.14). The results of the present study suggest a dose-dependent physiological role of habitual protein intake, and specifically arginine intake, on linear growth in normally growing children. However, since the study was designed in healthy children, we cannot firmly conclude whether arginine supplementation represents a relevant clinical strategy. Further research is needed to investigate whether dietary arginine may represent a nutritional strategy potentially advantageous for the prevention and treatment of short stature.

Developing an interprofessional learning and working culture to improve person-centred care in nursing homes: a realist action research protocol.

INTRODUCTION: Healthcare is changing due to the ageing of the general population, complex care demands and growing attention to person-centred care. To deal with these changes and provide the best possible person-centred care, the different professionals in nursing homes should all collaborate intensively. However, most professionals work within the field of their own expertise and share very little knowledge, experiences and insights. A lack of an interprofessional learning and working culture also prevents professionals with different expertise from working and learning intensively together to achieve high-quality person-centred care. There is a gap of knowledge about how to develop such a culture. Our aim is to provide insights into what actions, in what context and to what extent can contribute to an impactful development of an interprofessional learning and working culture. METHODS AND ANALYSIS: The realist action research design will be applied. It consists of three iterative steps: plan, act and observe, and reflect. First, we will formulate the theory about interprofessional learning and working culture and measure this culture by means of interviews, focus groups and questionnaires. Second, we will apply the nine principles of Practice Development to coach professionals from six Dutch nursing homes to improve their interprofessional learning and working culture. Finally, we will evaluate the impact of the changed attitudes and skills on healthcare practice. ETHICS AND DISSEMINATION: Approval for the project was given by the Hogeschool van Arnhem en Nijmegen (HAN) Research Ethics Committee, the Netherlands, registration number EACO 164.12/19. All organisations, professionals and residents/family members will be informed verbally and by letter about the study and asked for informed consent. The results will be presented in peer-reviewed scientific journals, professional journals and at symposia and conferences. The findings will be transferred to an online toolbox and e-learning modules for graduated professionals and students.

Presence or absence of carbohydrates and the proportion of fat in a high-protein diet affect appetite suppression but not energy expenditure in normal-weight human subjects fed in energy balance.

Two types of relatively high-protein diets, with a normal or low proportion of carbohydrates, have been shown effective for weight loss. The objective was to assess the significance of the presence or absence of carbohydrates and the proportion of fat in high-protein diets for affecting appetite suppression, energy expenditure, and fat oxidation in normal-weight subjects in energy balance. Subjects (aged 23 (sd 3) years and BMI 22·0 (sd 1·9) kg/m2) were stratified in two groups. Each was offered two diets in a randomised cross-over design: group 1 (n 22) - normal protein (NP; 10, 60 and 30 % energy (En%) from protein, carbohydrate and fat), high protein (HP; 30, 40 and 30 En%); group 2 (n 23) - normal protein (NP-g; 10, 60 and 30 En%), high protein, carbohydrate-free (HP-0C; 30, 0 and 70 En%) for 2 d; NP-g and HP-0C were preceded by glycogen-lowering exercise (day 1). Appetite was measured throughout day 2 using visual analogue scales (VAS). Energy expenditure (EE) and substrate oxidation (respiratory quotient; RQ) were measured in a respiration chamber (08.00 hours on day 2 until 07.30 hours on day 3). Fasting plasma ß-hydroxybutyrate (BHB) concentration was measured (day 3). NP-g and NP did not differ in hunger, EE, RQ and BHB. HP-0C and HP v. NP-g and NP, respectively, were lower in hunger (P < 0·05; P < 0·001) and RQ (P < 0·01; P < 0·001) and higher in EE (P < 0·05; P = 0·07) and BHB (P < 0·05; P < 0·001). Hunger and RQ were lower with HP-0C than HP (693 (sd 208) v. 905 (sd 209) mm VAS × 24 h, P < 0·01; 0·76 (sd 0·01) v. 0·81 (sd 0·02), P < 0·01); BHB was higher (1349 (sd 653) v. 332 (sd 102) µmol/l; P < 0·001). ΔHunger, ΔRQ, and ΔBHB were larger between HP-0C-NP-g than between HP-NP ( - 346 (sd 84) v. - 107 (sd 52) mm VAS ×  24 h, P < 0·01; - 0·09 (sd 0·00) v. - 0·05 (sd 0·00), P < 0·001; 1115 (sd 627) v. 104 (sd 42) µmol/l, P < 0·001). In conclusion, appetite suppression and fat oxidation were higher on a high-protein diet without than with carbohydrates exchanged for fat. Energy expenditure was not affected by the carbohydrate content of a high-protein diet.

Association between intake of dietary protein and 3-year-change in body growth among normal and overweight 6-year-old boys and girls (CoSCIS).

OBJECTIVE: Growth hormone (GH) affects linear growth and body composition, by increasing the secretion of insulin-like growth factor-I (IGF-I), muscle protein synthesis and lipolysis. The intake of protein (PROT) as well as the specific amino acids arginine (ARG) and lysine (LYS) stimulates GH/IGF-I secretion. The present paper aimed to investigate associations between PROT intake as well as intake of the specific amino acids ARG and LYS, and subsequent 3-year-change in linear growth and body composition among 6-year-old children. DESIGN: Children's data were collected from Copenhagen (Denmark), during 2001-2002, and again 3 years later. Boys and girls were separated into normal weight and overweight, based on BMI quintiles. Fat-free mass index (FFMI) and fat mass index (FMI) were calculated. Associations between change (Delta) in height, FMI and FFMI, respectively, and habitual PROT intake as well as ARG and LYS were analysed by multiple linear regressions, adjusted for baseline height, FMI or FFMI and energy intake, age, physical activity and socio-economic status. SETTING: Eighteen schools in two suburban communities in the Copenhagen (Denmark) area participated in the study. SUBJECTS: In all, 223 children's data were collected for the present study. RESULTS: High ARG intake was associated with linear growth (beta = 1.09 (se 0.54), P = 0.05) among girls. Furthermore, in girls, DeltaFMI had a stronger inverse association with high ARG intake, if it was combined with high LYS intake, instead of low LYS intake (P = 0.03). No associations were found in boys.ConclusionIn prepubertal girls, linear growth may be influenced by habitual ARG intake and body fat gain may be relatively prevented over time by the intake of the amino acids ARG and LYS.

Nurse practitioners leading the way: An exploratory study on the added value of nurse practitioners in outpatient care in the Netherlands.

BACKGROUND: Many Dutch nurse practitioners (NPs) work together with physicians and specialized nurses (SNs) in outpatient clinics, although the latter have questioned the added value of NPs in the outpatient clinic. Clarification of the distinction between and the added value of both nursing professions in relation to each other could lead to optimal use of the unique competencies of each type of nurse. PURPOSE: To explore NPs' perspectives on their added value in relation to SNs in the outpatient clinic. METHODOLOGICAL ORIENTATION: Data were analyzed by Braun and Clarke's thematic analysis. The CanMEDS competences were used to identify the NPs' comments about their practice. SAMPLE: Twelve semi-structured interviews were conducted with NPs from two hospital settings. CONCLUSIONS: The added value of NPs was most evident in: nursing leadership, integrating care and cure and performing an expert level of nursing expertise, and competencies in science. To optimize their roles, NPs and SNs need to make all team members aware of their unique competences and promote role clarification. IMPLICATIONS FOR PRACTICE: This study provides barriers in barriers that influence optimal positioning of NPs within the interdisciplinary team, stresses the importance of discussion on the optimal skill mix within the interdisciplinary team, and describes the NPs' leadership role because this is the encompassing link between the main competencies of their practice. Addressing and overcoming these findings could improve the NPs' positioning and effective collaboration within (the outpatient clinic's) interprofessional teams.

Dose-dependent satiating effect of whey relative to casein or soy.

Dietary protein plays a role in body weight regulation, partly because of its effects on appetite. The objective was to compare the effects of high or normal casein-, soy-, or whey-protein breakfasts on appetite, specific hormones, amino acid responses and subsequent energy intake. Twenty-five healthy subjects (mean+/-SEMBMI:23.9+/-0.3 kg/m2; age:22+/-1 years) received standardized breakfasts: custards with either casein-, soy, or whey-protein with either 10/55/35 (normal) or 25/55/20 (high)En% protein/carbohydrate/fat in a randomized, single-blind design. Appetite profile (Visual Analogue Scales) and amino acid concentrations were determined for 4 h whereas plasma glucose, insulin, active Glucagon-like Peptide 1 (GLP-1), and active ghrelin concentrations were determined for 3 h; the sensitive moment for lunch was determined. Subjects returned for a second set of experiments and received the same breakfasts, ad lib lunch was offered 180 min later; energy intake (EI) was assessed. At 10En%, whey decreased hunger more than casein or soy (p <0.05), coinciding with higher leucine, lysine, tryptophan, isoleucine, and threonine responses (p<0.05). At 25En% there were no differences in appetite ratings. Whey triggered the strongest responses in concentrations of active GLP-1 (p<0.05) and insulin (p<0.05) compared with casein and/or soy. There were no differences in EI. In conclusion, differences in appetite ratings between different proteins appeared at a normal concentration; at 10En% whey-protein decreased hunger more than casein- or soy-protein. At 25En% whey-protein triggered stronger responses in hormone concentrations than casein- or soy-protein. The results suggest that a difference in appetite ratings between types of protein appears when certain amino acids are above and below particular threshold values.

Pharmacological and physiological growth hormone stimulation tests to predict successful GH therapy in children.

Although the current use of growth hormone (GH) stimulation tests (GHSTs) is still subject to debate, the tests are widely used to diagnose GH deficiency. This literature review evaluates primarily the sensitivity, specificity and reliability of GHSTs and secondarily their convenience. Single pharmacological tests typically address only a single pathway in the complex physiological regulation of GH secretion and are therefore characterized by lower sensitivity, specificity and reliability than combined pharmacological tests or physiological tests. In spite of the high levels of sensitivity, specificity and reliability, physiological tests require considerably more effort to perform, from the physician as well as from the child. Therefore, a need for an alternative, convenient, physiological GHST still remains. Oral ingestion of dietary protein is convenient in practice and may induce more physiological stimulation of GH secretion, hence may be a promising valuable addition to the existing GHSTs in GH deficiency.

Effects of oral ingestion of amino acids and proteins on the somatotropic axis.

CONTEXT: GH is an important regulator of growth and body composition. It has been shown that GH release can be promoted by iv as well as oral administration of various amino acids (AAs), especially arginine (ARG) and lysine (LYS), which are amply present in soy protein. However, the effects of dietary protein on GH secretion are less well described. OBJECTIVE AND DESIGN: In an experiment, we compared the effects of oral ingestion of a mixture reflecting the AA composition of soy protein (AA), with oral ingestion of ARG + LYS, on GH secretion in eight healthy women (body mass index 19-25 kg/m(2); age, 18-24 yr). In a second experiment, we compared oral ingestion of hydrolyzed soy protein and complete soy protein with the AA mixture on GH secretion in eight healthy women (body mass index 19-26 kg/m(2); age, 19-36 yr). Both experiments were performed in a randomized, single-blind crossover design. GH, insulin, glucose, and plasma AA were determined every 20 min, during 3 h in the first experiment and during 5 h in the second experiment. RESULTS: Peak values of GH were higher after ingestion of the AA mixture compared with ingestion of ARG + LYS (P < 0.05). GH responses, as determined by area under the curve, did not significantly differ after ingestion of the complete soy protein, hydrolyzed soy protein, or AA mixture but were all higher than after placebo (P < 0.05). Insulin responses (area under the curve) were higher after ingestion of hydrolyzed soy protein, complete soy protein, and AA mixture, compared with placebo (P < 0.05). Glucose concentrations were unaffected. CONCLUSION: Ingestion of soy protein, either hydrolyzed or intact, as well as AAs reflecting soy protein, stimulates GH release to a similar extent.