Serum lipase levels are increased in acute pancreatitis. Lipase is an enzyme that is produced by the pancreas and is involved in the digestion of fats. In acute pancreatitis, there is inflammation of the pancreas, which leads to leakage of lipase into the bloodstream, causing an increase in serum lipase levels.
Diabetes mellitus and myocardial infarction are not typically associated with an increase in serum lipase levels. Obstructive jaundice can also cause an increase in serum lipase levels, but this is less common than in acute pancreatitis.