It is worth noting that in the young healthy cohort from our institution mentioned earlier, this observation was not seen, but rather peak NPY levels were positively correlated with peak oxygen consumption (r = 0.35, P = 0.006) and peak work rate (in watts; r = 0.43, P = 0.001), which was not seen in the CHF cohort. Here, NPY is linked to congestive heart failure.