BACKGROUND: Diabetes mellitus has been reported to increase whole-body protein breakdown and thus loss of lean body mass. Cystic fibrosis-related diabetes (CFRD) is associated with undernutrition and increased mortality. OBJECTIVE: We hypothesized that CFRD is associated with increased whole-body protein breakdown, which results in negative protein balance, and that correction of the glucose intolerance with insulin therapy would normalize whole-body protein metabolism. DESIGN: Rates of whole-body protein turnover and protein balance were measured in 28 adults with cystic fibrosis (17 M, 11 F). Subjects were assessed with a modified oral-glucose-tolerance test and categorized as having normal glucose tolerance, impaired glucose tolerance, or CFRD with and without fasting hyperglycemia; then they were compared with previously diagnosed CFRD adults already receiving insulin therapy. Indexes of protein turnover were calculated from [15N]glycine and 15N in urinary urea. RESULTS: Analysis of variance for the 28 subjects showed that whole-body protein breakdown was highest (P<0.05) in patients with CFRD. Whole-body protein synthesis was not significantly affected by impaired glucose tolerance. Significant (P<0.05) improvement in net protein synthesis occurred in the CFRD group 3 mo after insulin therapy was administered. Follow-up studies of 3 subjects with CFRD showed significant improvement in net protein synthesis after insulin therapy. Monitoring of the protein homeostasis of the impaired glucose tolerance group gave clues to the progression of their metabolic homeostasis. CONCLUSION: CFRD has an adverse effect on protein homeostasis by increasing net protein synthesis.
BACKGROUND:Diabetes mellitus has been reported to increase whole-body protein breakdown and thus loss of lean body mass. Cystic fibrosis-related diabetes (CFRD) is associated with undernutrition and increased mortality. OBJECTIVE: We hypothesized that CFRD is associated with increased whole-body protein breakdown, which results in negative protein balance, and that correction of the glucose intolerance with insulin therapy would normalize whole-body protein metabolism. DESIGN: Rates of whole-body protein turnover and protein balance were measured in 28 adults with cystic fibrosis (17 M, 11 F). Subjects were assessed with a modified oral-glucose-tolerance test and categorized as having normal glucose tolerance, impaired glucose tolerance, or CFRD with and without fasting hyperglycemia; then they were compared with previously diagnosed CFRD adults already receiving insulin therapy. Indexes of protein turnover were calculated from [15N]glycine and 15N in urinary urea. RESULTS: Analysis of variance for the 28 subjects showed that whole-body protein breakdown was highest (P<0.05) in patients with CFRD. Whole-body protein synthesis was not significantly affected by impaired glucose tolerance. Significant (P<0.05) improvement in net protein synthesis occurred in the CFRD group 3 mo after insulin therapy was administered. Follow-up studies of 3 subjects with CFRD showed significant improvement in net protein synthesis after insulin therapy. Monitoring of the protein homeostasis of the impaired glucose tolerance group gave clues to the progression of their metabolic homeostasis. CONCLUSION: CFRD has an adverse effect on protein homeostasis by increasing net protein synthesis.
Authors: Connor Lewis; Scott M Blackman; Amanda Nelson; Ewa Oberdorfer; Daniel Wells; Jordan Dunitz; William Thomas; Antoinette Moran Journal: Am J Respir Crit Care Med Date: 2015-01-15 Impact factor: 21.405
Authors: Neda Rasouli; Stacey Seggelke; Joanna Gibbs; R Matthew Hawkins; Matthew L Casciano; Elizabeth Cohlmia; Jennifer Taylor-Cousar; Cecilia Wang; Rocio Pereira; Elisa Hsia; Boris Draznin Journal: J Diabetes Sci Technol Date: 2012-09-01
Authors: Antoinette Moran; Dorothy Becker; Samuel J Casella; Peter A Gottlieb; M Sue Kirkman; Bruce C Marshall; Bonnie Slovis Journal: Diabetes Care Date: 2010-12 Impact factor: 19.112
Authors: Antoinette Moran; Carol Brunzell; Richard C Cohen; Marcia Katz; Bruce C Marshall; Gary Onady; Karen A Robinson; Kathryn A Sabadosa; Arlene Stecenko; Bonnie Slovis Journal: Diabetes Care Date: 2010-12 Impact factor: 19.112
Authors: J L Taylor-Cousar; J S Janssen; A Wilson; C G St Clair; K M Pickard; M C Jones; S J Brayshaw; C S Chacon; C M Barboa; M K Sontag; F J Accurso; D P Nichols; M T Saavedra; J A Nick Journal: J Diabetes Res Date: 2016-11-24 Impact factor: 4.011