Journal Title (Medline/Pubmed accepted abbreviation): Appl. Physiol. Nutr. Metab.
Page Numbers: 764-767
Summary of background and research design:
Background: Creatine supplementation helps diabetic patients control their blood sugar. Carnosine is a small molecule composed of 2 amino acids (β-alanine and histidine) that is found in high concentrations in skeletal muscle. Carnosine deficiency has been associated with diabetes-like symptoms and there is some evidence in mice that creatine may increase carnosine stores in skeletal muscle.
Hypothesis: Creatine supplementation will increase carnosine content in skeletal muscle.
Subjects: Twenty-five diabetic patients, age about 50-63 y.
Experimental design:randomized, double-blind, placebo-controlled study
Treatments: creatine (5 g/day) or a placebo (dextrose) every day for 12 wks
Protocol:The participants were involved in an exercise program during the supplementation period. Before and after the supplementation period, the participants were evaluated for carnosine concentrations in their soleus and gastrocnemius calf muscles (type I and type II predominant muscle fibers, respectively) using magnetic resonance spectroscopy (MRS). (This technique is non-invasive and very similar to MRI).
Summary of research findings:
There were no significant differences in muscle carnosine concentrations between the creatine group and the placebo group after the supplementation period.
Key practice applications:
Creatine supplementation at 5 d/day for 12 wks did not lead to increase carnosine concentrations in middle aged, type 2 diabetic patients. There is evidence that creatine helps diabetic patients maintain metabolic control, but carnosine concentrations do not appear to contribute to the mechanism.
The participants in this study were not athletes to begin with. It is not known if the same observation would be made in younger, type 2 diabetic athletes or people without diabetes. Dietary intakes of creatine and β-alanine in each group were not assessed.