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Vitamin D for the Immune System in Cystic Fibrosis (DISC): a double-blind, multicenter, randomized, placebo-controlled clinical trial.
Tangpricha, V, Lukemire, J, Chen, Y, Binongo, JNG, Judd, SE, Michalski, ES, Lee, MJ, Walker, S, Ziegler, TR, Tirouvanziam, R, et al
The American journal of clinical nutrition. 2019;109(3):544-553
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Patients with cystic fibrosis (CF) have a mutation in a particular gene which results in derangements in chloride transport across epithelial surfaces, leading to abnormally thickened mucus on the surfaces of the lung, pancreas, intestines, and other organs. The aim of this study was to investigate the impact of high-dose vitamin D3 administered to adults with CF during and after an acute pulmonary exacerbation. The study is a double-blind, randomised, placebo-controlled clinical trial. Subjects were randomly assigned and stratified to one of the two groups: vitamin D (5 capsules of vitamin D3 containing 50,000 IU) or placebo (5 capsules that were identical in size, shape, and colour to the vitamin D3 capsule). Results demonstrated that high-dose vitamin D3 administration to adults with CF initiated at the time of a pulmonary exacerbation did not improve time to next pulmonary exacerbation or 1 year survival. Authors conclude that a high-dose vitamin D3 bolus, combined with maintenance therapy given to adults with CF during acute pulmonary exacerbation of CF did not improve 1 year survival or recovery of lung function.
Abstract
BACKGROUND Patients with cystic fibrosis (CF) have increased risk of vitamin D deficiency owing to fat malabsorption and other factors. Vitamin D deficiency has been associated with increased risk of pulmonary exacerbations of CF. OBJECTIVES The primary objective of this study was to examine the impact of a single high-dose bolus of vitamin D3 followed by maintenance treatment given to adults with CF during an acute pulmonary exacerbation on future recurrence of pulmonary exacerbations. METHODS This was a multicenter, double-blind, placebo-controlled, intent-to-treat clinical trial. Subjects with CF were randomly assigned to oral vitamin D3 given as a single dose of 250,000 International Units (IU) or to placebo within 72 h of hospital admission for an acute pulmonary exacerbation, followed by 50,000 IU of vitamin D3 or an identically matched placebo pill taken orally every other week starting at 3 mo after random assignment. The primary outcome was the composite endpoint of the time to next pulmonary exacerbation or death within 1 y. The secondary outcomes included circulating concentrations of the antimicrobial peptide cathelicidin and recovery of lung function as assessed by the percentage of predicted forced expiratory volume in 1 s (FEV1%). RESULTS A total of 91 subjects were enrolled in the study. There were no differences between the vitamin D3 and placebo groups in time to next pulmonary exacerbation or death at 1 y. In addition, there were no differences in serial recovery of lung function after pulmonary exacerbation by FEV1% or in serial concentrations of plasma cathelicidin. CONCLUSIONS Vitamin D3 initially given at the time of pulmonary exacerbation of CF did not alter the time to the next pulmonary exacerbation, 12-mo mortality, serial lung function, or serial plasma cathelicidin concentrations. This trial was registered at clinicaltrials.gov as NCT01426256.
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Diets with high or low protein content and glycemic index for weight-loss maintenance.
Larsen, TM, Dalskov, SM, van Baak, M, Jebb, SA, Papadaki, A, Pfeiffer, AF, Martinez, JA, Handjieva-Darlenska, T, Kunešová, M, Pihlsgård, M, et al
The New England journal of medicine. 2010;363(22):2102-13
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The recommended diet composition for best preventing and managing obesity has remained inconclusive. The aim of this trial is to test the efficacy of moderate fat diets that vary in protein content and glycaemic index for preventing weight regain after weight loss. After completing an 8-week low calorie diet, participants were assigned to a low protein and low-glycaemic-index diet, a low-protein and high-glycaemic-index diet, a high-protein and low-glycaemic index diet, a high-protein and high-glycaemic-index diet or a control diet. A total of 548 participants adhered to and completed the 26-week intervention following the 8-week intensive weight loss programme. This study found that participants assigned to the high-protein and low-glycaemic index diet maintained the initial weight loss and had a higher rate of completion compared with the other diets. The authors conclude that this diet composition appears to be ideal for prevention of weight regain in obese patients following successful weight loss.
Abstract
BACKGROUND Studies of weight-control diets that are high in protein or low in glycemic index have reached varied conclusions, probably owing to the fact that the studies had insufficient power. METHODS We enrolled overweight adults from eight European countries who had lost at least 8% of their initial body weight with a 3.3-MJ (800-kcal) low-calorie diet. Participants were randomly assigned, in a two-by-two factorial design, to one of five ad libitum diets to prevent weight regain over a 26-week period: a low-protein and low-glycemic-index diet, a low-protein and high-glycemic-index diet, a high-protein and low-glycemic-index diet, a high-protein and high-glycemic-index diet, or a control diet. RESULTS A total of 1209 adults were screened (mean age, 41 years; body-mass index [the weight in kilograms divided by the square of the height in meters], 34), of whom 938 entered the low-calorie-diet phase of the study. A total of 773 participants who completed that phase were randomly assigned to one of the five maintenance diets; 548 completed the intervention (71%). Fewer participants in the high-protein and the low-glycemic-index groups than in the low-protein-high-glycemic-index group dropped out of the study (26.4% and 25.6%, respectively, vs. 37.4%; P=0.02 and P=0.01 for the respective comparisons). The mean initial weight loss with the low-calorie diet was 11.0 kg. In the analysis of participants who completed the study, only the low-protein-high-glycemic-index diet was associated with subsequent significant weight regain (1.67 kg; 95% confidence interval [CI], 0.48 to 2.87). In an intention-to-treat analysis, the weight regain was 0.93 kg less (95% CI, 0.31 to 1.55) in the groups assigned to a high-protein diet than in those assigned to a low-protein diet (P=0.003) and 0.95 kg less (95% CI, 0.33 to 1.57) in the groups assigned to a low-glycemic-index diet than in those assigned to a high-glycemic-index diet (P=0.003). The analysis involving participants who completed the intervention produced similar results. The groups did not differ significantly with respect to diet-related adverse events. CONCLUSIONS In this large European study, a modest increase in protein content and a modest reduction in the glycemic index led to an improvement in study completion and maintenance of weight loss. (Funded by the European Commission; ClinicalTrials.gov number, NCT00390637.).