The University of Iowa Mobile Clinic (UIMC) is an interdisciplinary student-run free medical clinic founded in 2002. UIMC provides free health screenings, education, and basic services to underserved populations in Iowa: immigrants, refugees, migrant farmworkers, individuals experiencing homelessness, low-income individuals, and people who live in rural communities. Forty-four percent of patients surveyed use UIMC as their only source of care. Ninety-seven percent of patients surveyed rate care as excellent or good. UIMC is a crucial safety net health care resource in Iowa to improve health equity. (Am J Public Health. Published online ahead of print July 16, 2020: e1–e4. doi:10.2105/AJPH.2020.305755)

Women with a history of gestational diabetes mellitus (GDM) are at greater risk for cardiovascular disease (CVD) and type II diabetes mellitus (T2DM). Endothelium- and nitric oxide-dependent dilation are attenuated in the microvasculature of otherwise healthy women with a history of GDM and this reduction is mediated, in part, by increased oxidative stress. However, whether this attenuation also reduces insulin-mediated microvascular responses in these women is unknown. We hypothesized that 1) insulin-mediated vasodilation would be attenuated, and that 2) antioxidant treatment would increase these responses, in women with a history of GDM compared to matched women with a history of healthy pregnancy (HC). Nine HC (32±6 yrs.) and 8 GDM (33±6 yrs.) participated in 1 experimental visit. Three microdialysis fibers were placed in the ventral forearm for the local delivery of lactated Ringer’s (control), 15mM N G-nitro-L-arginine methyl ester (L-NAME; NO synthase-inhibition), or 5mM ascorbate (non-specific antioxidant). Following baseline measurements, increasing doses of insulin [10-8 -10-4 M] were added to the site-specific perfusates. Red blood cell flux was measured continuously with laser-Doppler flowmetry, and cutaneous vascular conductance was calculated (CVC=flux/MAP) and standardized to maximum (%CVC max; 28mM SNP + 43°C). Subjects with GDM had attenuated insulin-mediated vasodilation (GDM:16.0 ± 3.0 vs. HC: 31.3 ± 4.7 %CVCmax; p= 0.02) at the control site. L-NAME attenuated insulin-mediated dilation in HC (14.7 ± 3.5 %CVCmax, p=0.004) but not in GDM (12.2 ± 1.9 %CVCmax, p=0.48). Local ascorbate perfusion increased insulin-mediated dilation in GDM (27.6 ± 7.2 %CVCmax; p=0.04) but had no effect in HC (p=0.85). These data suggest that women with a history of GDM have attenuated microvascular vasodilation responses to insulin, and that this attenuation is mediated, in part, by increased oxidative stress. Supported by The UI Fraternal Order of Eagles Diabetes Research Center This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Tobacco and nicotine use cause vascular endothelial dysfunction, increasing lifetime cardiovascular disease risk. Chronic e-cigarette use is reported to decrease endothelial function, however the mechanism(s) mediating this reduction remain unclear. Using the cutaneous circulation as a model, we examined endothelium- and nitric oxide (NO)-dependent dilation, and the role of oxidative stress in attenuating these responses, in otherwise healthy, young chronic (≥6 months) e-cigarette users (EC) compared to healthy controls (HC). We hypothesized that: EC would have reduced endothelium- and NO-dependent dilation, and local tempol (superoxide scavenger) administration would increase these responses in EC. We further examined the effect of sex within HC and EC and hypothesized that female EC would have the greatest reduction in endothelium- and NO-dependent dilation. 20 HC (21±2 yrs; 10M/10F) and 18 EC (21±2 yrs; 10M/8F) underwent a standard local heating protocol (42°C; 0.1°C·s-1). Two intradermal microdialysis fibers were placed in the ventral forearm skin for local delivery of lactated Ringer’s (control), or 10μM tempol. After full expression of the local heating response, 15mM NG-nitro-L-arginine methyl ester (L-NAME; NO synthase-inhibition) was perfused. Red cell flux was measured continuously by laser-Doppler flowmetry, and cutaneous vascular conductance (CVC=flux/MAP) was standardized to maximum (%CVCmax; 28mM SNP + 43°C). Between groups, endothelium- (EC: 73 ± 15 vs HC: 87 ± 9 %CVCmax; p<0.001) and NO-dependent (EC: 48.1± 17.0% vs. HC: 61.8 ± 14.7%; p=0.011) dilation were attenuated in EC compared to HC. Local tempol perfusion increased endothelium- (83.8 ±12.1% p=0.007) and NO-dependent (61.4 ± 14.2% p=0.011) dilation in EC but had no effect in HC (all p>0.05). Within sex, female EC had lower endothelium- (EC: 69.9±3.4 vs HC: 89.1±3.5 %CVCmax; p<0.001) and NO-dependent (EC: 46.9±5.5 vs HC: 69.4±5.0%; p=0.005) dilation compared to female HC, but there were no differences between these responses in HC and EC males (both p>0.05). Tempol perfusion augmented endothelium- (83.4±4.4 %CVCmax; p=0.31) and NO-dependent (60.2±5.1%; p=0.04[AS1] ) dilation in EC females but had no effect in EC males (both p>0.05). These data suggest that otherwise healthy young adult e-cigarette users have reduced microvascular endothelium- and NO-dependent dilation. Within e-cigarette users, these results are driven by greater reductions in females, and superoxide contributes to these impairments. Supported by NIEHS/NIH P30 ES005605 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.