Glutamine supplementation in cystic fibrosis: A randomized placebo-controlled trial.

RATIONALE: Pulmonary infection and malnutrition in cystic fibrosis are associated with decreased survival. Glutamine has a possible anti-microbial effect, with a specific impact against Pseudomonas aeruginosa. We aimed to test the hypothesis that oral glutamine supplementation (21 g/day) for 8 weeks in adults with cystic fibrosis would decrease pulmonary inflammation and improve clinical status. METHODS: The study design was a randomized double-blind placebo-controlled study design with an iso-nitrogenous placebo. The primary analysis was intention to treat, and the primary outcome was change in induced sputum neutrophils. RESULTS: Thirty-nine individuals were recruited and thirty-six completed the study. Glutamine supplementation had no impact on any of the outcome measures in the intention-to-treat analysis. In the per protocol analysis, glutamine supplementation was associated with an increase in induced sputum neutrophils (P = 0.046), total cells (P = 0.03), and in Pseudomonas isolation agar colony forming units (P = 0.04) compared to placebo. CONCLUSIONS: There was no effect of glutamine supplementation on markers of pulmonary inflammation in the intention-to-treat analysis.

Measures of body habitus are associated with lung function in adults with cystic fibrosis: a population-based study.

BACKGROUND: Body habitus differences may explain some of the variation in lung function between individuals with cystic fibrosis (CF). We tested the hypothesis that measures of lean muscle mass and obesity are independently associated with lung function in CF. METHODS: Cross-sectional study design using UK CF registry data from 2096 clinically stable adults. RESULTS: Serum creatinine and BMI were positively and independently associated with FEV1 and FVC. One standard deviation increment in serum creatinine was associated with an FEV1 increase of 171ml (95% confidence intervals CI: +116 to +227ml) in males and 90ml (95% CI: +46 to +133ml) in females. Compared to the reference group of 20-24.9kg/m(2), those with a BMI<20kg/m(2) had lower FEV1 with values of -642ml (95%CI: -784 to -500ml) for males and -468ml (95%CI: -564 to -372ml) for females. CONCLUSIONS: Prospective studies and controlled trials are required to ascertain if these associations have therapeutic potential in modifying disease progression.

Impact of adopting low sodium diet on biomarkers of inflammation and coagulation: a randomised controlled trial.

BACKGROUND: A low sodium diet is an established intervention in the treatment of impaired renal function and hypertension which may modulate cardiovascular risk independent of recognised antihypertensive effects. Epidemiological data suggest that dietary sodium intake may be associated with systemic inflammation: another potential pathophysiological mechanism by which sodium intake may modify vascular disease. METHODS: We tested the hypothesis that adopting a low sodium diet may decrease biomarkers of systemic inflammation or coagulation using data from a randomised double-blind placebo-controlled trial. Participants (n=171; aged 18-65 years) in a randomised double-blind placebo-controlled trial of a low sodium diet for 6 weeks provided paired serum samples for analysis to assess the impact of adopting a low sodium diet on biomarkers of systemic inflammation and coagulation. RESULTS: There was a significant difference in 24-hour sodium urinary excretion between the low sodium intake and the normal sodium intake groups of 43 mmol (p<0.001). In the primary analysis there was no effect of adopting a low sodium diet on serum D-dimers, but high-sensitivity C-reactive protein (hsCRP) was reduced by 1.13 mg/L (95% confidence interval [95% CI], 0.03 to 2.22). However, after elimination of outlying high values for baseline serum hsCRP (>10 mg/L), this effect was attenuated (-0.47 mg/L; 95% CI, -1.25 to 0.31). CONCLUSIONS: Using data from a randomised double-blind placebo-controlled trial in asthma with objective confirmation of adherence to the low sodium diet, we report that adopting a low sodium diet for 6 weeks has no effect on measures of systemic inflammation or coagulation.