INS and diabetes mellitus: Haap et al. [21] further demonstrate (in healthy subjects without a diagnosis of diabetes mellitus) a negative correlation between phosphate and post-prandial two-hour glucose (r = -0.13, p < 0.0001), in addition to a positive correlation between insulin sensitivity and phosphate (r = 0.10, p = 0.0006); a plausible explanation for these significant associations is that low phosphate leads to depleted intracellular adenosine triphosphate, which may alter intracellular energy metabolism.