Hi @sallyj2, while studies in mice shouldn't be directly extrapolated to human, what you have experienced is interesting. LP-a is said to be genetically determined by both copies of parents' genes (they call it co-dorminance) and not affected by diet, exercise or drugs. There is a slight increase in postmenopausal women. Most people just need one test during their lifetime. Mine was done twice by accident, the difference was 60%. Since both of my results are at low end, 10 and 16nmol/L, they didn't trigger my nerve. The distributions of LPa among the population is very skewed. If you are at low end, the difference between tests might be inherent test errors. Did you go to the same lab? The results are also expressed in different units, nmol/L vs mg/L. Check and see if both of your results used the same units.