Final answer:
The platelet count is higher in blood obtained via skin puncture compared to venous blood due to the increased likelihood of clot formation and platelet aggregation in capillary blood samples.
Step-by-step explanation:
The test value that will be significantly higher in blood obtained by a skin puncture compared to venipuncture is the platelet count. Capillary blood collected from skin punctures can contain a higher concentration of platelets because it is more likely to clot, and during clotting, platelets can become activated and aggregate. In contrast, venous blood is typically collected into tubes that contain anticoagulants preventing clot formation and thus providing a more accurate count of individual, unclumped platelets.
As for other test values like glucose level, hemoglobin level, and white blood cell count, these should not significantly differ between blood obtained by skin puncture and venous blood if proper techniques are used during collection and analysis. It's important to consider that individual patient factors and collection technique can also influence test results, making it critical to follow clinical guidelines and standardized procedures for blood collection.
Remember, the Glucose Tolerance Test (GTT) is used to assess the body's response to glucose and is crucial in diagnosing conditions like diabetes mellitus when blood glucose level falls around normal values or there is no glucosuria despite suspicions of diabetes.