What is GSP?
Glycation is the non-enzymatic bonding of a sugar molecule to a protein or lipid molecule. Glycated serum proteins (GSP) are proteins that have undergone glycation and circulate in the blood. The vast majority (90%) of GSP consists of glycated albumin. GSP concentration is an indication of the average amount of glucose (glycemia) in the blood over the previous two to three weeks while glycated hemoglobulin, particularly HbA1c, is a measurement of glycemia over the past two to three months. Therefore, GSP closes the information gap between daily glucose measurement and quarterly HbA1c measurement to provide a full spectrum monitoring of glycemic control for patients with diabetes. Furthermore, HbA1c may be of limited value in some situations such as pregnancy, reduced RBC lifespan and hemodialysis. GSP may be altered independent of glycemia by factors that influence albumin metabolism. Interestingly, GSP level is lower in some patients with various types of cancer and lower GSP level may be associated with poor survival in certain types of cancer, probably because of albumin deficiencies in cancer patients.
GSP are precursors of advanced glycation end-products (AGEs). AGEs contribute to a variety of microvascular and macrovascular diseases. Studies have suggested that measuring GSP and HbA1c provides a better assessment of the long term risk of developing diabetic complications.
What are the risk factors for abnormal GSP?
Diabetes and diabetic complications are the major causes for higher GSP (>290 μmol/L). Borderline GSP values may indicate increased risk of diabetes. Lifestyle factors, like diets high in sugar, fat and salt, are risk factors for increased GSP levels. Diseases or conditions with altered albumin metabolism or protein levels such as the nephrotic syndrome, cirrhosis, thyroid disease, hyperuricemia, hypertriglyceridemia, smoking, liver, thyroid, and renal diseases can alter GSP level.
Cancer may be associated with low GSP values.
Besides reducing sugar intake, some ways to modify high GSPs include: