Conditions: Cystic Fibrosis
Keywords: CF, cystic fibrosis, exercise
Allocation: NON_RANDOMIZED | Intervention model: PARALLEL
Enrollment: 64
Healthy volunteers: yes

Brief summary:
Perhaps one of the most disturbing aspects of Cystic Fibrosis (CF) is the associated premature death. Oxidative stress has been observed in patients with CF and exercise intolerance has been shown to predict mortality in patients with CF, regardless of how healthy their lungs are. A critical barrier to improving the quality of life and longevity in patients with CF is our lack of knowledge regarding the different reasons why patients with CF cannot exercise to the level of their peers. We have collected preliminary data to support our central hypothesis that oxidative stress contributes to the impairment in blood vessel function at rest and during exercise which ultimately oxygen transport and delivery resulting in exercise intolerance. Exercise is therapeutic medicine for patients with CF and this investigation represents a major breakthrough in the approach to begin understanding the physiological mechanisms which contribute to exercise intolerance in these patients.

Detailed description:
The overall goals of this proposal are to provide mechanistic evidence that oxidative stress contributes to 1) endothelial dysfunction and 2) exercise intolerance in patients with CF. This study consists of two separate sub-studies, or protocols. Protocol 1: AOC tested the effect of an antioxidant cocktail (AOC) on endothelial function at rest and during exercise in CF patients. Protocol 2: BH4 tested the effect of tetrahydrobiopterin (BH4) on endothelial function at rest and during exercise in CF patients.

Arms:
arm 1: measurements at baseline and 2 hours following the antioxidant cocktail that is comprised of over the counter vitamins (vitamin C 1000mg, vitamin E 600 IU, and alpha lipoic acid 600 mg) that will be given in two doses, 30 minutes apart. arm 2: measurements at baseline and 3 hours following the single dose of 5mg/kg Kuvan® or sapropterin dihydrochloride which is a synthetic preparation of the dihydrochloride salt of naturally occurring tetrahydrobiopterin (BH4).BH4 has been shown in past studies to increase NO bioavailability. arm 3: measurements at baseline and 3 hours following the single dose of 20mg/kg Kuvan® or sapropterin dihydrochloride which is a synthetic preparation of the dihydrochloride salt of naturally occurring tetrahydrobiopterin (BH4).BH4 has been shown in past studies to increase NO bioavailability. arm 4: baseline measurements were done with no intervention

Interventions: intervention 1: BH4 5mg intervention 2: BH4 20mg intervention 3: Antioxidant Cocktail
Intervention descriptions: intervention 1: Kuvan® or sapropterin dihydrochloride is a synthetic preparation of the dihydrochloride salt of naturally occurring tetrahydrobiopterin (BH4). Subjects received an oral dose of 5 mg/kg of Kuvan® (Biomarin Pharmaceuticals Inc.) intervention 2: Kuvan® or sapropterin dihydrochloride is a synthetic preparation of the dihydrochloride salt of naturally occurring tetrahydrobiopterin (BH4). Subjects received an oral dose of 20 mg/kg of Kuvan® (Biomarin Pharmaceuticals Inc.) intervention 3: Vitamin C (1000 mg) , Vitamin E (600 IU) , and alpha-lipoic acid (600 mg). all BID

Protocol document: