Citations

Cerebral blood flow velocity responses to hypercapnia are blunted by the cyclooxygenase inhibitor indomethacin (INDO). We hypothesized that INDO would also attenuate middle cerebral artery blood flow velocity (MCAv) responses to an acute cognitive challenge. We evaluated the MCAv responses to an acute cognitive challenge in 20 healthy young (20‐35 yrs) and older (56‐76 yrs) healthy adults, including 10 men and 10 women before and 90 minutes after INDO administration. The cognitive challenge consisted of 2 blocks of the Stroop color word test: easy (3 colors) and difficult (8 colors). Mean arterial pressure (MAP), end‐tidal CO 2 , and MCAv were monitored throughout the protocol. There were no differences in MAP or end tidal CO 2 between trials. Indeed, MCAv was lower during INDO than baseline for both the easy (50±4 vs. 68±4 cm/s; p<0.01) and difficult (49±3 vs. 66±3 cm/s; p<0.001) cognitive challenges. Additionally, there was an Age x Sex interaction for the increase in MCAv during the easy cognitive task, with older men having a greater increase than older women (15±5 vs. ‐1±5%, respectively; p<0.05). This interaction was not statistically significant for the difficult cognitive task or during the INDO trial. In conclusion, similar to hypercapnia, the cyclooxygenase inhibitor INDO blunts cerebral blood flow velocity responses to an acute cognitive challenge. Funded by NIH grant HL 118154

Women with uterine fibroids (UF), benign tumors of the myometrium, have a greater prevalence of hypertension than women without UF. The mechanism of this predisposition is unclear. Individuals with borderline hypertension have endothelial dysfunction in the form of decreased endothelium‐dependent vasodilation in response to intra‐arterial acetylcholine infusion. It is possible that women with UF also demonstrate impaired endothelium‐dependent vasodilation prior to overt clinical hypertension. We measured forearm blood flow (FBF) using venous occlusion plethysmography at baseline and during intra‐arterial acetylcholine (ACH; 1.0‐4.0 μg/100 ml tissue/min) and sodium nitroprusside (SNP; 0.25‐2.00 μg/100 ml tissue/min) infusions in 4 normotensive women with UF (41±3 y) and 4 age‐matched normotensive women without UF. These women did not differ in body mass index or mean arterial pressure (97±4 vs. 103±6 mmHg, Control vs. UF; p>0.05). Baseline FBF was not different between the two groups (1.6±0.4 vs. 3.0±1.3 ml/100 ml tissue/min; Control vs. UF; p>0.05). FBF increased significantly from baseline in both groups at the highest doses of ACH and SNP; however, the change in FBF was not significantly different between groups (ACH: Δ8.6±1.6 vs. 9.5±4.1 ml/100 ml tissue/min; SNP: Δ9.8±3.0 vs. 13.1±4.6 ml/100 ml tissue/min; Control vs. UF; p>0.05). Our preliminary results suggest that FBF responses to ACH and SNP do not differ between women with and without UF; thus, impairments in endothelium‐dependent and ‐independent vasodilation do not appear to contribute to hypertension risk in normotensive women with UF. Funded by AHA and NIH.

Cerebrovascular reactivity to hypercapnia declines with age and low reactivity may be a biomarker of cognitive decline. Central elastic arteries that perfuse the brain stiffen with age, increasing their transmission of pulsatile mechanical forces into the cerebral microvasculature and impairing cerebral microvessel function. Habitual physical activity, however, has been shown to reduce central arterial stiffness and is associated with better cognitive function. Therefore, the purpose of this study was to evaluate cerebrovascular reactivity in young and older healthy adults who habitually exercise. We hypothesized that older adults who habitually exercised would have similar cerebrovascular reactivity when compared with young adults. However, because the underlying mechanisms of cerebral blood flow regulation may differ with age, we also evaluated blood pressure and central hemodynamic measures. We recruited 25 young (YA: age = 27 ± 1 y) and 20 older (OA: age = 59 ± 1 y) habitual exercisers. Middle cerebral artery velocity (MCAv) was recorded using transcranial Doppler ultrasound. In order to assess cerebrovascular reactivity, mean arterial pressure (MAP), end‐tidal carbon dioxide (ETCO 2 ), and MCAv were continuously recorded at rest and during stepwise elevations of inhaled CO 2 . Cerebrovascular conductance index (CVCi) was calculated as MCAv/MAP. Reactivity was calculated as the linear relationship between the change in ETCO 2 and the change in each variable of interest (MCAv, CVCi and MAP). Central arterial stiffness (carotid‐femoral pulse wave velocity, PWV) and central hemodynamics (augmentation index, AIx) were assessed by applanation tonometry. Older adults had higher MAP (YA: 85 ± 2 mmHg; OA: 90 ± 3 mmHg; p<0.05) and AIx (YA: 0 ± 3 %; OA: 20 ± 2 %; p<0.05) at rest compared with young adults. PWV was not statistically different between groups (YA: 4.9 ± 0.3 cm/s; OA: 5.7 ± 0.5 cm/s; p=0.18). MCAv and CVCi reactivity to hypercapnia were similar between young and older adults (MCAv reactivity, YA: 2.0 ± 0.2 cm/s/mmHg; OA: 2.2 ± 0.1 cm/s/mmHg; p=0.46, CVCi reactivity, YA: 0.018 ± 0.002 cm/s/mmHg 2 ; OA: 0.016 ± 0.001 cm/s/mmHg 2 ; p=0.42); however, older adults demonstrated higher MAP reactivity to hypercapnia (YA: 0.3 ± 0.1 a.u.; OA: 0.8 ± 0.1 a.u.; p<0.05). PWV and AIx were not associated with MCAv, CVCi, or MAP reactivity to hypercapnia (p>0.05). Our results suggest that habitual exercise preserves cerebrovascular reactivity; however, MAP reactivity is augmented with aging allowing older adults to sufficiently increase cerebral blood flow during hypercapnia. Support or Funding Information Supported by National Institute of Health grant HL118154 This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Pulse wave velocity (PWV) and sympathetic nerve activity increase with age. However, it is unknown if the age‐related increase in sympathetic activity influences PWV. We determined the effect of autonomic blockade on peripheral and central arterial stiffness in young (23 ± 4 yr) and older, postmenopausal (57 ± 3 yr) women before and during administration of trimethaphan camsylate. Arterial tonometry was used to measure carotid‐radial (peripheral) and carotid‐femoral (central) PWV. The groups did not differ in height, weight, BMI, or mean arterial pressure (MAP). At baseline, peripheral PWV did not differ between the groups. However, central PWV was significantly greater in older women compared with young women (8.2 vs. 6.1 m/s, respectively; p<0.05). Trimethaphan infusion caused a substantial drop in MAP; therefore, we corrected PWV for the change in MAP. Peripheral PWV was greater in older women compared with young women (0.12 vs. 0.08 m/s·mmHg −1 ; p<0.05). In addition, central PWV remained higher in older women during trimethaphan infusion (0.11 vs. 0.08 m/s·mmHg −1 in young; p<0.05). In conclusion, central PWV was greater in older women before and during autonomic blockade, whereas peripheral PWV was only higher in the older women after autonomic blockade. This suggests that peripheral PWV is influenced by sympathetic activity to a greater extent in young vs. older women. Funded by NIH

Aortic wave reflection increases with age, and is influenced by numerous factors, including sympathetic nerve activity. The purpose of this study was to examine the effect of autonomic blockade using trimethaphan camsylate on indices of aortic wave reflection in young (23±4 yr) and older postmenopausal (57±3 yr) women and determine if aging alters these interactions. Arterial tonometry was used to non‐invasively measure arterial waveforms from the radial artery before and during trimethaphan infusion. Aortic augmentation index (AI x ), augmented pressure, and left ventricular wasted energy (E w ) were higher in older women compared to young women at baseline (p<0.05). Mean arterial pressure was similar between young (93±5 mmHg) and older women (91±2 mmHg) at baseline. AI x (Δ −12±5%), augmented pressure (Δ −11±4 mmHg), and E w (Δ −2364±1020 dyne·cm 2 ·sec) decreased after autonomic blockade in older women (p<0.05 for all). In addition, the age‐related differences in AI x and aortic wave reflection persisted during autonomic blockade (p<0.05). In conclusion, autonomic blockade reduces augmentation index and aortic wave reflection in older women. Our results suggest that sympathetic activity contributes to the higher aortic wave reflection observed in older women.

There is a lack of pharmacogenetic predictors of outcome in gastric cancer patients. The aim of this study was to assess previously identified candidate genes associated with 5-fluorouracil (5-FU), cisplatin, or epirubicin toxicity or response in a cohort of resected gastric cancer patients treated on CALGB (Alliance) 80101. Gastric or gastroesophageal cancer patients randomized to adjuvant 5-FU/leucovorin or epirubicin/cisplatin/5-FU before and after 5-FU chemoradiation were genotyped for single nucleotide polymorphisms (SNPs) in GSTP1 (rs1695), ERCC1 (rs11615 and rs3212986), XRCC1 (rs25487), UGT2B7 (rs7439366) and the 28 base-pair tandem repeats in TYMS (rs34743033). Logistic regression and log rank tests were used to assess the association between each SNP and incidence of grade 3/4 neutropenia and leukopenia, overall (OS) and progression-free survival (PFS), respectively. Toxicity endpoint analyses were adjusted for the treatment arm, while OS and PFS were also adjusted for performance status, sex, age, lymph node involvement, and primary tumor site and size. Of 281 subjects with successful genotyping results and available clinical (toxicity and efficacy) data, 166 self-reported non-Hispanic White patients were included in the final analysis. There was a lack of evidence of an association among any SNPs tested with grade 3/4 neutropenia and leukopenia or OS and PFS. Age, lymph node involvement, and primary tumor size were significantly associated with OS and PFS. This study failed to confirm results of previous gastric cancer pharmacogenetic studies.

Vascular function in older women versus young women may differ based on the β‐adrenergic receptor‐mediated contribution to basal vascular tone. Thus, we tested the hypothesis that forearm blood flow (FBF) responses to the β‐receptor agonist isoproterenol (ISO) are blunted in older, postmenopausal women compared to young, premenopausal women. We used venous occlusion plethysmography to measure FBF in young (26 ± 3 yr; n = 13) and older (61 ± 6 yr; n = 12) women. FBF and mean arterial pressure (MAP) were measured at baseline and during ISO infusion at 1.0, 3.0, 6.0, and 12.0 ng/100 ml tissue/min. The two groups did not differ in body mass index or MAP. Baseline FBF (3.7 ± 1.7 vs. 2.9 ± 1.3 ml/100 ml/min, respectively) and forearm vascular conductance (FVC) (0.04 ± 0.02 vs. 0.03 ± 0.01 AU, respectively) were similar between young and older women. FBF and FVC remained similar between the groups for all ISO doses, including the 12.0 ng/100 ml tissue/min dose of ISO, for which the greatest difference between the groups would be expected; FBF was 10.7 ± 2.3 vs. 9.4 ± 2.1 ml/100 ml/min (young vs. older, respectively) and FVC was 0.11 ± 0.02 vs. 0.10 ± 0.02 AU (young vs. older, respectively). In conclusion, β‐adrenergic receptor‐mediated forearm responses to stimulation are similar between young and older women, suggesting that β‐adrenergic receptor response and contribution to vascular tone are preserved with aging in women. Funded by NIH

The relationship between mean arterial pressure (MAP), muscle sympathetic nerve activity (MSNA), and total peripheral resistance (TPR) is altered in young women versus men and postmenopausal women due to endogenous sex hormone differences. Exogenous sex hormones in the form of oral contraceptive pills (OCPs) may further affect this relationship. We performed a retrospective review of 136 premenopausal women in whom MSNA and arterial pressure were measured, including 78 women with natural menstrual cycles in the early follicular phase (26±1 yr) and 58 women in the placebo phase of OCPs (24±1 yr). TPR and cardiac output (CO) were measured in a subset of women in whom continuous intra‐arterial blood pressure was recorded. Compared to those with natural menstrual cycles, women on OCPs had greater MAP (89±1 vs. 84±1 mmHg, p<0.01) and tended to have lower MSNA (15±1 vs. 18±1 bursts/100 heart beats, p=0.06). MAP and MSNA were positively correlated (r=0.22, p<0.05), TPR and MSNA were positively associated (r=0.41, p<0.05) and CO and MSNA (r=‐0.44, p<0.05) were inversely associated in naturally cycling women (n=26) but not in women on OCPs (r=0.15, r=0.11, r=‐0.01, respectively; p>0.05; n=38). In contrast to naturally cycling women, there appears to be no relationship between MSNA and hemodynamics in women on OCPs, suggesting that these women may regulate their blood pressure differently than women. Grant Funding Source : Supported by NIH

6594 Background: Patient reported financial hardship (FH) in cancer care is a growing challenge for patients, their caregivers and healthcare providers. As treatment costs escalate, it is imperative to develop effective strategies to proactively recognize and mitigate FH within oncology practice. Using automated processes to screen and refer patients to appropriate resources is a potential option. At Mayo Clinic, screening for FH involves using a single financial strain question ‘ How hard is it for you to pay for the very basics like food, housing, medical care, and heating?’ completed by all cancer patients annually as part of the Social Determinants of Health (SDOH) assessment. In this study, we describe the prevalence and predictors for FH (denoted by the answer ‘hard and very hard’) in our patient population. Methods: Patients receiving cancer care at the three Mayo Clinic sites (Minnesota, Arizona, and Florida) who completed the FH screen at least once were included in this study. Demographics (age, gender, race/ ethnicity, insurance, employment status, marital status, and zip code) and disease state data for included patients was extracted from the EMR and Mayo Clinic Cancer Registry. Disease state was categorized by type of cancer (hematological or solid malignancy) and cancer stage. Zip code was used to derive median income, rural/urban residence and distance from the cancer center. Multivariable logistic regression models were utilized to examine factors associated with FH. Results: The final study cohort included 31,969 patients with median age 66 years (IQR 57,73), 51% females, and 76% married. Race/ethnicity composition was 93% White, 3% Black, and 4% Hispanic. 52% of patients had Medicare and 43% had commercial insurance. Other notable factors included 48% retired, 41% working/ students, 76% married, and 72% urban residents. Median time from cancer diagnosis was 1.1 year (IQR 0.1, 3.8) and median income was $64,406 (IQR 53,067, 82,038). 31% of patients had hematological malignancies, 20% of the cancers for which staging information was available were metastatic. FH was reported by 4% (n = 1194) of the patients. A significantly higher likelihood of endorsing FH (p < 0.001 for all) was noted in Hispanic (OR 1.64), Black (OR 1.84), American Indian/Alaskan native (OR 2.02), below median income (OR 1.48), rural (OR 1.17), self-pay (OR 2.77), Medicaid (OR 2.29), Medicare (OR 1.43), unemployed/disabled (OR 2.39), single (OR 2.07), or divorced (OR 2.43) patients. Older age, being retired, and living farther from the cancer center were associated with significantly less likelihood of endorsing FH. Conclusions: Our study successfully leveraged the EMR to identify key sociodemographic groups more likely to report FH. An electronic trigger to flag such patients at high-risk of FH and proactively address FH is currently being developed.