What happens to glucose oxidation with age during cyclic PN?

• A. Decreases
• B. Increases
• C. Fluctuates
• D. No change

Answer: (A)

Glucose oxidation tends to decrease with age during cyclic PN because aging reduces the body's ability to oxidize carbohydrates efficiently. Mitochondrial oxidative capacity diminishes and insulin-stimulated glucose disposal becomes less effective, leading to a shift toward greater fat oxidation. In cyclic PN, where glucose is delivered in bursts, older individuals often show a blunted glucose oxidation response to these boluses, so a smaller portion of the infused glucose is burned for energy. This combination—reduced mitochondrial function, increased fatty acid oxidation, and insulin resistance—drives the overall decline in glucose oxidation with age. It doesn’t typically rise with age, and while some day-to-day variation can occur, the general trend is a decrease rather than no change or fluctuating increases.