Prognosis, proof and priorities in dietetic practice

The Dutch prevention policy document 2004-2007 expresses the need for more disease prevention interventions in the curative domain of health care. In hospitals the dietician is traditionally involved in preventive activities. The recent focus on prevention provides an opportunity to reflect on what facts and principles should guide priorities in hospital-based dietetic practices. This thesis consists of a collection of studies addressing patient selection based on future risks (prognosis), selection of interventions based on evidence for effectiveness (proof) and principles for priority setting based on a critical appraisal of the available scientific data and guidance of ethical values (priorities). The central question in this thesis is: What information, knowledge and values are needed to guarantee the quality of priority decisions in a hospital-based dietetic department? Chapter two presents two studies on undernutrition due to the gastrointestinal side-effects of intensive chemotherapy and total body irradiation in oncohaematological patients. The results may help dieticians to improve selection of patients who benefit either from parenteral nutrition support during admission (chapter 2.1) or from a more intensive counselling program during the recovery phase post-transplant (chapter 2.2) in order to prevent in-hospital complications as well as loss of (quality of) life time. The two studies in chapter three add to our knowledge on the effect sizes of specific dietary and lifestyle changes to prevent premature death in patients with coronary artery disease. The results show that effect sizes of dietary and lifestyle changes are relevant and comparable to the effects of routine prophylactic pharmacological treatments. Chapter four concerns patient selection policies of dietetic departments. Priority decisions should be guided by reflection on ethical values such as beneficence, autonomous choice and distributive justice and be based on the best available evidence. Professional accountability may be facilitated by explicit choices, transparent policy documents and openness for feedback. Exploring the implications, it is stated that at least three societal factors in western societies should be weighed in the priorities of hospital-based dieticians: the large burden of cardiovascular diseases, the substantial health disparities between socio-economic groups and the increasing frequency of unhealthy dietary behaviours. We conclude that priority decisions should be based on reliable information on the (future) needs of all relevant patient groups, knowledge about evidence-based benefits of dietary interventions and a clear vision on relevant ethical values. For those making the priority decisions, competencies related to appraisal of scientific data, ethical deliberation, coping with social diversity and quality management are essential

Beleving van obesitas: gewichtsverlies en de kwaliteit van leven na een dieetbehandeling met maaltijdvervangers

Doel van het onderzoek was na te gaan hoe de kwaliteit van leven van obesitaspatiënten is veranderd na een dieetinterventie. Het dieet met maaltijvervangers heeft een gunstig effect op het gewicht en de kwaliteit vanleven. Dit resultaat kan motiveren om een gezond eetpatroon te handhave

Effects of a stanol-enriched diet on plasma cholesterol and triglycerides in patients treated with statins

Background Plant stanols have been recommended in combination with individualized dietary interventions to reduce plasma cholesterol concentrations. It is unclear whether plant stanols in combination with dietary guidance in patients already using optimal doses of statins will further reduce fasting and postprandial lipids compared with standard care. Study design This single-blind, randomized study investigated the effect of plant stanols in margarines, combined with a lipid-lowering dietary intervention, in patients already on lipid-lowering medications at maximal doses not reaching their target lipid levels. Nutrition education was based on the stages of change theory. The control group (which served as the standard care control group) was also taking optimal doses of statins. This group received a margarine without plant stanols and a leaflet with Dutch nutrition guidelines. Fasting lipids were measured once in venous samples and postprandial lipemia was assessed by self-measured triglycerides in an outpatient setting. All subjects were given a capillary triglyceride measuring device (Accutrend GCT, Roche Diagnostics, Mannheim, Germany) and were instructed to measure their capillary triglycerides at six fixed timepoints throughout the day on three different days. The mean area under the triglyceride curve represented total daylong triglyceridemia, which has been shown to reflect postprandial triglyceridemia. Twenty patients were included, 11 in the intervention group and 9 in the control group. Results In the plant stanol group, low-density lipoprotein cholesterol decreased significantly by 15.6% ompared with a reduction of only 7.7% in the control group. The daylong triglyceridemia was similar in both groups at the beginning and at the end of the study, and no change was observed by the intervention. Conclusion Intensive dietary intervention with addition of plant stanols results in clinically relevant reduction of low-density lipoprotein cholesterol in patients optimally treated with statins, compared with similar patients on statins receiving only standard care. The use of a plant stanol-enriched margarine did not decrease postprandial triglyceridemia in these patient

Body weight recovery, eating difficulties and compliance with dietary advice in the first year after stem cell transplantation : a prospective study

Among healthcare professionals there is no consensus about the best policy to increase oral intake and promote recovery in the post-hospital phase after bone marrow or blood stem cell transplantation. In order to evaluate body weight recovery and compliance with dietary advice among these patients, we performed a prospective longitudinal study in the first year post transplant. At five time intervals (days 50, 75, 125, 200 and 350) patients received a nutritional questionnaire with items on nutrition-related symptoms, physical condition, body weight recovery and compliance with dietary advice. From the initial cohort of 135 patients 69 completed the study. Prevalence of eating difficulties was high (66% at day 50). Anorexia, dry mouth, altered taste, nausea and tiredness were the symptoms most strongly associated with eating difficulties. Compliance with dietary advice was poor. Conditioning regimen was found to be a prognostic factor for body weight status at day 350. In more than 50% of the TBI-treated patients body weight was not restored to 95% of the pretreatment value within 1 year after transplant. Future studies should focus on increasing energy and protein intake in the TBI-treated subgroup

Effects of a stanol-enriched diet on plasma cholesterol and triglycerides in patients treated with statins

Background Plant stanols have been recommended in combination with individualized dietary interventions to reduce plasma cholesterol concentrations. It is unclear whether plant stanols in combination with dietary guidance in patients already using optimal doses of statins will further reduce fasting and postprandial lipids compared with standard care. Study design This single-blind, randomized study investigated the effect of plant stanols in margarines, combined with a lipid-lowering dietary intervention, in patients already on lipid-lowering medications at maximal doses not reaching their target lipid levels. Nutrition education was based on the stages of change theory. The control group (which served as the standard care control group) was also taking optimal doses of statins. This group received a margarine without plant stanols and a leaflet with Dutch nutrition guidelines. Fasting lipids were measured once in venous samples and postprandial lipemia was assessed by self-measured triglycerides in an outpatient setting. All subjects were given a capillary triglyceride measuring device (Accutrend GCT, Roche Diagnostics, Mannheim, Germany) and were instructed to measure their capillary triglycerides at six fixed timepoints throughout the day on three different days. The mean area under the triglyceride curve represented total daylong triglyceridemia, which has been shown to reflect postprandial triglyceridemia. Twenty patients were included, 11 in the intervention group and 9 in the control group. Results In the plant stanol group, low-density lipoprotein cholesterol decreased significantly by 15.6% ompared with a reduction of only 7.7% in the control group. The daylong triglyceridemia was similar in both groups at the beginning and at the end of the study, and no change was observed by the intervention. Conclusion Intensive dietary intervention with addition of plant stanols results in clinically relevant reduction of low-density lipoprotein cholesterol in patients optimally treated with statins, compared with similar patients on statins receiving only standard care. The use of a plant stanol-enriched margarine did not decrease postprandial triglyceridemia in these patient

Effects of nutritional status and dietetic interventions on survival in Cystic Fibrosis patients before and after lung transplantation

Background: This study retrospectively investigated nutritional status, dietetic intervention and intake in Cystic Fibrosis (CF) patients before and after lung transplantation (LTX). Methods: Body Mass Index (BMI), Fat Free Mass Index (FFMI) and nutritional intake were retrieved from 75 out-patients aged 15-53 years. Patients were seen every 3-4 months during the waiting list time (range 0-81 months) and up to 116 months after LTX. Survival was measured in months. Results: The median BMI at baseline was 19.2 kg/m(2) (range: 15.3 to 28.4 kg/m(2)) with 29 patients (39%) below = 500 kcal less than recommended. Protein intake was 104 (range 60-187) g or 1.9 g/kg per day. Despite dietetic intervention with oral nutritional supplements (ONS) (36 patients), tube feeding (12 patients), or both (13 patients), HMI and FFMI hardly improved pre-LTX. LTX was performed in 51 patients (68%); 10 patients died during follow-up, median survival time was 41 months. A BMI 18.5 kg/m(2) was more prevalent in patients who died before LTX (6/9) or who died after LTX (4/10) than in patients who were still alive on the waiting list (5/15) or who survived LTX (14/41). Results for FFMI were comparable. From 6-12 months post-LTX, BMI and FFMI markedly improved, especially in underweight patients. Conclusion: A BM

Effect size estimates of lifestyle and dietary changes on all-cause mortality in coronary artery disease patients: a systematic review.

Background¿Guidelines for lifestyle and dietary modification in patients with coronary artery disease (CAD) are mainly supported by evidence from general population studies. CAD patients, however, differ from the general population in age (older) and treatment with preventive drugs. This review seeks to provide evidence for a prognostic benefit of lifestyle and dietary recommendations from studies in CAD patients. Methods and Results¿A literature search was performed on the effect of lifestyle and dietary changes on mortality in CAD patients. Prospective cohort studies and randomized controlled trials of patients with established CAD were included if they reported all-causes mortality and had at least 6 months of follow-up. The effect estimates of smoking cessation (relative risk [RR], 0.64; 95% CI, 0.58 to 0.71), increased physical activity (RR, 0.76; 95% CI, 0.59 to 0.98), and moderate alcohol use (RR, 0.80; 95% CI, 0.78 to 0.83) were studied most extensively. For the 6 dietary goals, data were too limited to provide reliable effect size estimates. Combinations of dietary changes were associated with reduced mortality (RR, 0.56; 95% CI, 0.42 to 0.74). Conclusions¿Available studies show convincingly the health benefits of lifestyle changes in CAD patients. Effect estimates of combined dietary changes look promising. Future studies should confirm these findings and assess the contribution of the individual dietary factors