Abstract :
Introduction: Prediabetes is an insulin resistant state where blood glucose levels are higher than normal
but not high enough to be classified as Diabetes. Lifestyle modifications such as diet and physical
exercise can prevent its progression to Type 2 diabetes. The adipose tissue and skeletal muscle are
dependent on insulin for glucose uptake. Myostatin is a myokine known to restrict muscle growth by
activation of SMAD(homologues of the Drosophila protein, mothers against decapentaplegic (Mad) and
the Caenorhabditis elegans protein Sma signaling pathways). Myostatin expression is down regulated by
exercise and weight loss. Myostatin levels have been shown to be increased in the causal pathway of
acquired insulin resistance associated with physical inactivity. Increased serum Myostatin levels also are
seen in cancer and obesity.
Objectives: To assess the effect of lifestyle modification on Myostatin levels in patients with pre-diabetes
and to correlate the same with insulin resistance.
Materials and Methods: After obtaining ethical clearance from Ethics Committee of the Institute, 40
pre-diabetics visiting the Ramaiah Medical Hospital for treatment were included in the study. With their
consent, blood samples were drawn for estimation of FBS, Insulin and Myostatin. The patient was advised
moderate intensity physical activity comprising of brisk walk for 150 minutes a week for a period of 3
months. They were called for a follow up after 3 months and blood samples were drawn for estimation of
FBS, Insulin and Myostatin.
Results and Conclusion: Serum Myostatin levels decreased significantly in individuals who exercised
(P-value of 0.002) and increased in individuals who did not exercise with a P-value of 0.048. Serum
Myostatin appears to be a promising biomarker to objectively assess lifestyle modifications introduced in
pre-diabetics.
Keyword :
Prediabetes, Myostatin, Exercise, Insulin resistance.