Serum creatinine as an indicator of lean body mass in vegetarians and omnivores

Growing numbers of Americans are adopting vegetarian or vegan diets. While risk for some chronic conditions may be lower when following these diets, concern remains over the ability to consume adequate amounts of various nutrients, notably, protein. Knowing that serum creatinine is a reliable marker of muscle mass, this study examined the relationships between serum creatinine, lean body mass (LBM), handgrip strength, and protein intake in healthy vegetarian (n = 55) and omnivorous (n = 27) adults. Significantly higher protein intakes (+31%), LBM (+7%), serum creatinine (+12%) and handgrip strength (+14%) were observed for the omnivore participants compared to vegetarian participants. Positive correlations (p < 0.001) were noted between creatinine and LBM (R-2 = 0.42), creatinine and handgrip strength (R-2 = 0.41), protein intake and LBM (R-2 = 0.29), and handgrip strength and LBM (R-2 = 0.69). These data show that serum creatinine concentrations were lower in vegetarian women and men in comparison to their omnivorous counterparts and that serum creatinine concentrations correlate with LBM and strength in healthy adults, regardless of diet.

Automated summary

A growing number of Americans are adopting vegetarian or vegan diets, raising concerns about sufficient protein intake. This study found that vegetarian participants had lower protein intake, lean body mass, serum creatinine, and handgrip strength compared to omnivorous participants. However, regardless of diet, serum creatinine concentrations correlated with lean body mass and strength in healthy adults.