Figure 1.
Flow chart of reports retrieved in databases. CK, creatine kinase; βGPA, beta-guanidinopropionic acid.
Figure 2.
The effect of βGPA on body weight.
The effect of βGPA on body weight of mice with a baseline body weight less than 50 grams (A), rats with a baseline bodyweight less than 300 grams (B) and more than or equal to 300 grams (C). This is a random-effects model. Squares are weighted mean differences in body weight. The size of the squares represents study weight and horizontal lines represent 95% CIs. Arrowheads depict data outside the scale. Black diamonds are pooled estimates. The weighted mean percentage change was calculated from the percentage change per study and the sample size. Results for the effect of βGPA on body weight of rats with a baseline body weight of more than 300 grams are not pooled because of heterogeneity in the direction of effect. * Male sex; † Female sex; ‡ Animal age ≤6 weeks; § Animal age >6 weeks; ∥ Dose of βGPA = 1% in the diet or drinking water; ¶ Dose of βGPA = 2% in the diet or drinking water; ** Dose of βGPA = other; †† Duration of intervention ≤10 weeks; ‡‡ Duration of intervention >10 weeks.
Figure 3.
The effect of βGPA on the creatine kinase system of skeletal muscle.
The effect of βGPA on skeletal muscle creatine (A), phosphocreatine (B), and ATP (C) in µmol per gram dry weight, total creatine (creatine+phosphocreatine) and mitochondrial creatine kinase activity (D), hexokinase (E),. This is a random-effects model. Squares are weighted mean differences in body weight. The size of the squares represents study weight and horizontal lines represent 95% CIs. Arrowheads depict data outside the scale. Black diamonds are pooled estimates. The weighted mean percentage change was calculated from the percentage change per study and the sample size. * Rat; † Mouse; ‡ Male sex; § Female sex; ∥ Animal age ≤6 weeks; ¶ Animal age >6 weeks; ** Type I fiber predominant muscle; †† Type II fiber predominant muscle; ‡‡ Dose of βGPA = 1% in the diet or drinking water; §§ dose of βGPA = 2% in the diet or drinking water; ∥∥ Dose of βGPA = other; ¶¶ Duration of intervention ≤3 weeks; *** Duration of intervention 3 to 10 weeks; ††† Duration of intervention >10 weeks.
Figure 4.
The effect of βGPA on the creatine kinase system of the heart.
The effect of βGPA on myocardial total creatine (A), phosphocreatine (B), ATP, and creatine kinase activity (D). This is a random-effects model. Squares are weighted mean differences in body weight. The size of the squares represents study weight and horizontal lines represent 95% CIs. Arrowheads depict data outside the scale. Black diamonds are pooled estimates. The weighted mean percentage change was calculated from the percentage change per study and the sample size. * Rat; † Mouse; ‡ Male sex; § Female sex; ∥ Animal age ≤6 weeks; ¶ Animal age >6 weeks; ** Dose of βGPA = 1% in the diet or drinking water; †† Dose of βGPA = 2% in the diet or drinking water; ‡‡ Dose of βGPA = other; §§ Duration of intervention ≤3 weeks; ∥∥ Duration of intervention 3 to 10 weeks; ¶¶ Duration of intervention >10 weeks.