Epinephrine release in response to hypotension is a primary stimulus for muscle lactate production in this model of hemorrhagic shock. Hypoxia alone does not explain the increased lactate levels because tissue perfusion was not altered by the adrenergic antagonists. These observations challenge the rationale behind lactate clearance as an end point for resuscitation after hemorrhagic shock.

In this study, we explored the determinants of vitamin D status in a large cohort of stable, Long-term renal transplant (RTx) patients. Serum 25(OH)D concentrations, and bone biochemistry parameters, were retrospectively analyzed from 266 RTx patients (>10 yr post-engraftment) presenting to clinic over the course of a year. Forty-five percent of the cohort were vitamin D deficient (<37.5 nM), 38% insufficient (37.5 75-nM), and 17% sufficient (>75 nM). Serum 25(OH)D concentrations were higher in patients presenting in summer (p<0.001) and in more active patients (p<0.05). RTx patients with non-melanoma skin cancer (NMSC) (n=45) had higher 25(OH)D concentrations than patients without NMSC (n=221; p<0.05) despite these patients being older, having worse eGFR, transplanted for longer, and less active physically (p<0.05). Lower 25(OH)D concentrations were associated with higher PTH concentrations (p<0.05) which, in the setting of widespread hypovitaminosis, suggests that secondary hyperparathyroidism was common in this cohort. In conclusion, season and activity status are important determinants of vitamin D status. We report, for the first time, that NMSC is associated with higher 25(OH)D, probably through increased UV radiation exposure. Long-term RTx patients may benefit from oral vitamin D supplementation, but this requires a randomized controlled trial to confirm.

No abstract