Risk of Urinary Infections in Veterans on Empagliflozin With Concurrent Catheter Use.

There has been concern over whether to use sodium-glucose-cotransporter-2 (SGLT-2) inhibitors in patients that use catheters due to the concern for increased urinary tract infections (UTIs). The concern is that patients who use catheters are already at an increased risk for UTIs and that SGLT-2-inhibitors may promote bacterial growth due their mechanism of action, ie. increasing glycosuria. The objective of this study was to evaluate whether using empagliflozin, a SGLT-2-inhibitor, in patients who also use catheters, increases their risks for UTIs. A retrospective chart review of electronic health records at a single-center was completed of all Veterans who received an empagliflozin prescription and were also using catheters between October 1, 2015 and September 30, 2022. Veterans were included if they were using catheters for at least 2 months prior to starting empagliflozin and were on both therapies for at least 2 months concurrently. The primary outcome for this study is the number of UTIs occurring prior to and after beginning empagliflozin treatment. Additional secondary outcomes included change in A1c, change in body mass index (BMI), UTI-hospitalizations, and fungal infections. Of the 91 patients with concurrent empagliflozin and catheter-use, only 25 Veterans were included. There was an occurrence of .09 UTIs/month pre-empagliflozin compared to .07 post-empagliflozin (P = .61). There was an observed trend in Veterans with Type 2 Diabetes having an increased rate of UTIs. There was no statistically significant difference found in UTI rates when comparing catheters alone to concurrent catheter and empagliflozin-use.

Tonic and phasic nitric oxide signals in hippocampal long-term potentiation.

Nitric oxide (NO) participates in long-term potentiation (LTP) and other forms of synaptic plasticity in many different brain areas but where it comes from and how it acts remain controversial. Using rat and mouse hippocampal slices, we tested the hypothesis that tonic and phasic NO signals are needed and that they derive from different NO synthase isoforms. NMDA increased NO production in a manner that was potently inhibited by three different neuronal NO synthase (nNOS) inhibitors. Tonic NO could be monitored after sensitizing guanylyl cyclase-coupled NO receptors, allowing the very low ambient NO concentrations to be detected by cGMP measurement. The levels were unaffected by inhibition of NMDA receptors, nNOS, or the inducible NO synthase (iNOS). iNOS was also undetectable in protein or activity assays. Tonic NO was susceptible to agents inhibiting endothelial NO synthase (eNOS) and was missing in eNOS knock-out mice. The eNOS knock-outs exhibited a deficiency in LTP resembling that seen in wild-types treated with a NO synthase inhibitor. LTP in the knock-outs could be fully restored by supplying a low level of NO exogenously. Inhibition of nNOS also caused a major loss of LTP, particularly of late-LTP. Again, exogenous NO could compensate, but higher concentrations were needed compared with those restoring LTP in the eNOS knock-outs. It is concluded that tonic and phasic NO signals are both required for hippocampal LTP and the two are generated, respectively, by eNOS and nNOS, the former in blood vessels and the latter in neurons.