Caucasian American Adults Research Articles

Rapid onset vasodilation in response to forearm muscle contraction in Hispanic American and Caucasian American Adults

Hispanic Americans (HA) are the fastest growing ethnic populations in the U.S., estimated to double in the next four decades. According to NHANES 2013-2016 data, prevalence of type 2 diabetes (T2D) is 15.1% in HA men and 14.1% in HA women, compared to 9.4 and 7.3% in non-Hispanic Caucasian American (CA) men and women, respectively. Even HA children have a 5-fold higher rate of T2D compared to their age-matched CA counterparts. Impaired vascular function is a hallmark of T2D however, limited number of studies have investigated the effect of ethnicity on vascular function at rest and during exercise. To our knowledge, only one study has reported a higher flow-mediated dilation at rest in healthy HA compared to CA adults. Hence, the purpose of this study was to investigate the rapid onset vasodilation in response to a single muscle contraction of the forearm at progressively increasing intensity (20, 40, and 60% of maximum voluntary contraction (MVC)) in young, healthy HA compared to age- and weight-matched CA individuals. A single muscle contraction model was chosen to isolate the robust local vasodilatory responsiveness of the vasculature without increases in sympathetic nerve activity or large hemodynamic changes. We hypothesized that HA would demonstrate an attenuated forearm vascular conductance (FVC) and forearm blood flow (FBF) in response to skeletal muscle contractions, compared to CA group. Young, healthy HA (n=4) and CA (n=4) adults performed skeletal muscle contractions at 20%, 40 % and 60% of their maximum voluntary contraction (MVC). To isolate the effect of mechanical compression during muscle contractions, FBF and FVC responses to a brachial cuff inflation were also measured. Heart rate (ECG), mean arterial pressure (MAP; finger photoplethysmography) and forearm blood flow (FBF; duplex Doppler ultrasound) were measured. FVC was calculated as FBF/MAP. Baseline FBF (CA: 115.21 ± 48.9 and HA: 68.89 ± 21.9 ml/min; p=0.27), MAP (CA: 82 ± 7.48 and HA: 81 ± 2.87 mmHg; p=0.77), FVC (p=0.15), and MVCs (CA: 67 ± 26.8 and HA: 70 ± 7.4 kg; p=0.82) were similar between the groups. Following single muscle contractions, both groups exhibited an intensity dependent increase in FVC and FBF, however, there was no difference between HA and CA groups. For instance, following muscle contraction at 40% MVC, peak FVC (%Δ) was 251% ± 46.35 in HA and 189% ± 34.98 in CA (race effect p = 0.23, time effect = 0.01, interaction p = 0.029). Similarly, peak %Δ FBF or %Δ FVC following 60% contractions were similar between the groups (FVC: 327% ± 84.36 in HA vs. 286% ± 74.45 in CA (race effect p=0.62, time effect p<0.01, interaction effect p=0.01)). Both groups exhibited a similar response to brachial cuff inflation for peak FVC (p=0.21) and peak FBF (p=0.30). Our preliminary findings indicate that HA have a preserved rapid onset vasodilation in response to a single forearm contraction when compared to CA adults. Supported by Kinesiology and Health Education UT Austin Start-up Account 19-2635-91 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.

Forearm vascular conductance responses to rhythmic handgrip in young Hispanic American adults compared to Caucasian American adults

Hispanic American (HA) individuals have double the prevalence and earlier onset of Type 2 Diabetes (T2D) compared to Caucasian American (CA) individuals. The underlying mechanisms for this disproportionately high incidence of T2D in HA individuals remains unknown. Impaired vascular dysfunction is a well-known hallmark of T2D however, very few studies have investigated vascular function in HA population. Equivocal results have been reported regarding flow-mediated dilation (FMD), a measure of endothelium-mediated, nitric oxide-dependent vasodilation in response to a cuff inflation, in HA population. In addition, vascular responsiveness during exercise has not been investigated in this racial group. Previous studies have indicated that exercise at increasing workloads elicits progressive increases in shear stress causing intensity-dependent vasodilation, which is primarily mediated by NO. Therefore, we aim to extend the previous findings by evoking a stepwise increase in shear stress during three exercise workloads to investigate the vascular function in HA adults during exercise. We tested the hypothesis that HA individuals would exhibit an attenuated forearm blood flow (FBF) and forearm vascular conductance (FVC) compared to CA individuals during RHG (rhythmic handgrip exercise). Forearm blood flow (duplex Doppler ultrasound), heart rate (ECG) and mean arterial pressure (MAP; finger photoplethysmography) were measured in young, healthy CA (n = 17 (7M/10F)) as well as in young, healthy HA (n = 13 (7M/6F)) during three trials of RHG performed at 15%, 30%, and 45% of their maximum voluntary contraction (MVC). As studies have reported sex differences in vascular function in HA previously, data will be presented in different sexes(Mean±standard deviation). In men, baseline FBF (CA: 121.1±45.6, HA: 98.7±34.5, p=0.28), MAP (CA: 84±6, HA: 85±7, p=0.47), FVC (calculated as FBF/MAP, p=0.28), and MVCs (CA: 79±15, HA: 74±17, p=0.19) were similar between groups. Similarly, in women, baseline FBF (CA: CA: 67.8±22.6, HA: 67.3±5.2, p=0.98), MAP (CA: 84±9, HA: 82±6, p=0.64), FVC (p=0.95), and MVC (CA: 49±6, HA: 53±13, p=0.21) were not different between groups. In men, an intensity-dependent increase in FVC and FBF was observed, with no difference between the racial groups (e.g., %Δ FVC 45%MVC CA=417±296% vs. HA=367±84% in HA; race effect p=0.40, intensity effect p<0.01, interaction p=0.32). Increase in MAP was also not significant (e.g., ΔMAP 45%MVC CA=8±5, HA=11±7, p=0.50) In women, a similar intensity-dependent increase in FVC and FBF was observed (e.g., %Δ FVC 45%MVC: 455±164% in CA, 418±104% in HA; race effect p=0.48, intensity effect p<0.01, interaction p=0.92). Increase in MAP was also not significant. (e.g., ΔMAP 45%MVC CA=15±8, HA=12±8, p=0.41) These preliminary findings indicate that vascular function during rhythmic handgrip exercise is preserved in Hispanic men and women, compared to their white counterparts. Kinesiology and Health Education UT Austin Start-Up Account 19-2635-91 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.

Race affects the association of obesity measures with insulin sensitivity

Race differences in body composition and fat distribution may in part explain the differences in insulin sensitivity and the disproportionate burden of type 2 diabetes in African Americans. To determine if differences in body composition and fat distribution explain race differences in insulin sensitivity and identify obesity measures that were independently associated with insulin sensitivity. Participants were 113 lean, overweight, and obese African-American and Caucasian-American adults without diabetes. Skeletal muscle insulin sensitivity was determined using a hyperinsulinemic-euglycemic clamp (SIClamp, insulin rate:120 mU/m2/min). Subcutaneous abdominal adipose tissue (SAAT), intra-abdominal adipose tissue (IAAT), and liver fat were measured by MRI; leg fat, total fat, and lean mass were measured by DXA. Race-by-adiposity interactions were significant in cross-sectional analyses utilizing multiple linear regression models for SIClamp (P<0.05); higher BMI, fat mass, SAAT, leg fat, and liver fat were associated with lower SIClamp in Caucasian Americans but not African Americans. Race-by-IAAT interaction was not significant (P=0.65). A central fat distribution (SAAT adjusted for leg fat) was associated with lower SIClamp in African Americans (β = -0.45, SE=0.11, P<0.001) but not Caucasian Americans (β = -0.42, SE=0.30, P=0.17). A peripheral fat distribution (leg fat adjusted for IAAT/SAAT) was associated with a higher SIClamp in African Americans (β = 0.11, SE=0.05, P=0.02) but lower SIClamp in Caucasian Americans (β = -0.28, SE=0.14, P=0.049). Lean mass was inversely associated with SIClamp in African Americans (β = -0.05, SE=0.03, P=0.04) but not Caucasian Americans (β = 0.08, SE=0.05, P=0.10) in the model for leg fat. Measures of overall adiposity were more strongly associated with SIClamp in Caucasian Americans, whereas body fat distribution and lean mass showed stronger correlations with SIClamp in African Americans. Insulin sensitivity may have a genetic basis in African Americans that is reflected in the pattern of body fat distribution. These findings suggest a race-specific pathophysiology of insulin resistance, which has implications for the prevention of diabetes and related cardiometabolic diseases.

The effectiveness of Selective Serotonin Reuptake Inhibitors (SSRI) for Treatment of Obsessive Compulsive Disorder (OCD) in Adolescents and Children: A Systematic Review and Meta-Analysis

American Indian people have high suicide rates. However, little epidemiological data is available on depression prevalence, a suicide risk factor, in this population. Some research suggests that depression scales may perform differently for American Indian people. However, the Patient Health Questionnnaire-9 (PHQ-9), a depression scale widely-used in clinical practice, had not been assessed for cross-cultural measurement invariance with American Indian people.In this retrospective study of existing electronic health record (EHR) data in an upper Midwestern healthcare system, we assessed the measurement invariance of the standard one-factor PHQ-9 and five previously identified two-factor models for 4443 American Indian and 4443 Caucasian American adults (age >= 18) with a PHQ-9 in the EHR from 12/1/2005 to 12/31/2017. We also conducted subgroup analyses with adults ages >= 65.Models showed good fits (e.g., CFI > 0.99, RMSEA < 0.05) and internal consistency reliability (ordinal alpha > 0.80). All models displayed measurement invariance between racial groups. Factor correlation was high for two-factor models, providing support for the one-factor model. American Indian adults had significantly higher odds of PHQ-9 total scores >= 10 and >= 15 than Caucasian American adults.Data came from a single healthcare system.The PHQ-9 exhibited cross-cultural measurement invariance between American Indian and Caucasian American adults, supporting the PHQ-9 as a depression screening tool in this clinical care population. American Indian adults also had higher levels of depression than Caucasian Americans. Future research could confirm the generalizability of our findings to other American Indian populations.

The measurement invariance of the Patient Health Questionnaire-9 for American Indian adults

BackgroundAmerican Indian people have high suicide rates. However, little epidemiological data is available on depression prevalence, a suicide risk factor, in this population. Some research suggests that depression scales may perform differently for American Indian people. However, the Patient Health Questionnnaire-9 (PHQ-9), a depression scale widely-used in clinical practice, had not been assessed for cross-cultural measurement invariance with American Indian people. MethodsIn this retrospective study of existing electronic health record (EHR) data in an upper Midwestern healthcare system, we assessed the measurement invariance of the standard one-factor PHQ-9 and five previously identified two-factor models for 4443 American Indian and 4443 Caucasian American adults (age >= 18) with a PHQ-9 in the EHR from 12/1/2005 to 12/31/2017. We also conducted subgroup analyses with adults ages >= 65. ResultsModels showed good fits (e.g., CFI > 0.99, RMSEA < 0.05) and internal consistency reliability (ordinal alpha > 0.80). All models displayed measurement invariance between racial groups. Factor correlation was high for two-factor models, providing support for the one-factor model. American Indian adults had significantly higher odds of PHQ-9 total scores >= 10 and >= 15 than Caucasian American adults. LimitationsData came from a single healthcare system. ConclusionsThe PHQ-9 exhibited cross-cultural measurement invariance between American Indian and Caucasian American adults, supporting the PHQ-9 as a depression screening tool in this clinical care population. American Indian adults also had higher levels of depression than Caucasian Americans. Future research could confirm the generalizability of our findings to other American Indian populations.

Carbohydrate nutrition and risk of adiposity-related cancers: results from the Framingham Offspring cohort (1991-2013).

Higher carbohydrate intake, glycaemic index (GI), and glycaemic load (GL) are hypothesised to increase cancer risk through metabolic dysregulation of the glucose-insulin axis and adiposity-related mechanisms, but epidemiological evidence is inconsistent. This prospective cohort study investigates carbohydrate quantity and quality in relation to risk of adiposity-related cancers, which represent the most commonly diagnosed preventable cancers in the USA. In exploratory analyses, associations with three site-specific cancers: breast, prostate and colorectal cancers were also examined. The study sample consisted of 3184 adults from the Framingham Offspring cohort. Dietary data were collected in 1991-1995 using a FFQ along with lifestyle and medical information. From 1991 to 2013, 565 incident adiposity-related cancers, including 124 breast, 157 prostate and sixty-eight colorectal cancers, were identified. Cox proportional hazards models were used to evaluate the role of carbohydrate nutrition in cancer risk. GI and GL were not associated with risk of adiposity-related cancers or any of the site-specific cancers. Total carbohydrate intake was not associated with risk of adiposity-related cancers combined or prostate and colorectal cancers. However, carbohydrate consumption in the highest v. lowest quintile was associated with 41 % lower breast cancer risk (hazard ratio (HR) 0·59; 95 % CI 0·36, 0·97). High-, medium- and low-GI foods were not associated with risk of adiposity-related cancers or prostate and colorectal cancers. In exploratory analyses, low-GI foods, were associated with 49 % lower breast cancer risk (HR 0·51; 95 % CI 0·32, 0·83). In this cohort of Caucasian American adults, associations between carbohydrate nutrition and cancer varied by cancer site. Healthier low-GI carbohydrate foods may prevent adiposity-related cancers among women, but these findings require confirmation in a larger sample.

Engaging Chinese American Adults in Advance Care Planning: A Community-Based, Culturally Sensitive Seminar

Ethnic minority groups are less engaged than Caucasian American adults in advance care planning (ACP). Knowledge deficits, language, and culture are barriers to ACP. Limited research exists on ACP and advance directives in the Chinese American adult population. Using a pre-posttest, repeated measures design, the current study explored the effectiveness of a nurseled, culturally sensitive ACP seminar for Chinese American adults on (a) knowledge, completion, and discussion of advance directives; and (b) the relationship between demographic variables, advance directive completion, and ACP discussions. A convenience sample of 72 urban, community-dwelling Chinese American adults (mean age=61 years) was included. Knowledge, advance directive completion, and ACP discussions increased significantly after attending the nurse-led seminar (p<0.01). Increased age correlated with advance directive completion and ACP discussions; female gender correlated with ACP discussions. Nursing education in a community setting increased advance directive knowledge and ACP engagement in Chinese American adults.

Effects of Ethnically Diverse Photographic Stimuli on Preference and Discourse Tasks in African American and Caucasian American Adults

This study determined whether using photographic stimuli displaying different ethnicity (African American vs. Caucasian American) influenced preference, word count, and number of content units produced by African American or Caucasian American participants. Six photograph pairs depicting common scenes were developed, differing only by model ethnicity. Participants sorted photographs by preference and described each photograph from which word count and content unit were determined. Each group showed significant preference for photographs of their own ethnicity. Caucasian Americans produced significantly more words than African Americans. Caucasian Americans also produced significantly more content units. Caucasian Americans produced more content units for African American scenes (nonsignificant). Results suggest that ethnic groups prefer photographic stimuli representing their own ethnicity. Other factors may influence the amount and content of speech produced. If African Americans typically produce less speech with less content than Caucasian American counterparts, separate normative data may be needed for each ethnic group.

A patient self-assessment tool to measure communication behaviors during doctor visits about hypertension

Objective To develop a preliminary version of a post-doctor visit self-assessment tool that patients with hypertension can use to evaluate their communication behaviors. High-quality communication between patient and doctor may have a positive effect on blood pressure control in hypertensive patients. Patients’ communicative behaviors such as asking questions influence those of doctors, but most existing measurement tools assess doctors’ behaviors rather than patients’. Methods The tool is intended for use by African American or Caucasian American adults with hypertension, regardless of literacy level. The project included theory-based development of the item pool, usability testing (8 individuals), and cognitive response testing (13 additional individuals). Main results After multiple iterations, the preliminary version includes 138 items in 7 theory-based domains. Conclusion and Practice Implications The self-assessment tool is ready for testing of item and scale reliability and validity and consequent item reduction. This tool could prove useful in trials evaluating whether patients with hypertension who learn to be better communicators are more likely to achieve blood pressure control. In addition, because it asks patients to reflect on their use of specific behaviors that can be learned, the tool might also help patients in clinical practice to assume more active roles during their medical interactions.

A stories-based interactive DVD intended to help people with hypertension achieve blood pressure control through improved communication with their doctors

Objective Our goal was to develop an interactive DVD to help African American and Caucasian American adults with hypertension learn how to become better communicators during medical interactions. Material was to be presented in several formats, including patients’ narratives (stories). Methods To develop the narratives we recruited members of the target audience and elicited stories and story units in focus groups, interviews, and seminars. Story units were ranked-ordered based on conformance with the theory of planned behavior and narrative qualities and then melded into cohesive stories. The stories were recounted by actors on the DVD. Results 55 adults (84% women; 93% African American) participated in a focus group, interview, or seminar; transcripts yielded 120 story units. The most highly rated units were woven into 11 stories. The six highest rated stories/actor–storytellers were selected for presentation on the DVD. Conclusion We achieved our goal of developing an easy-to-use, story-driven product that may teach adults how to talk effectively with their doctors about hypertension. The DVD's effectiveness should be tested in a randomized trial. Practice implications Behavioral interventions aimed at improving patients’ ability to communicate during doctor visits may be useful adjuncts in the achievement of BP goals.

A confirmatory factor analysis of specific phobia domains in African American and Caucasian American young adults

The current study investigated factors related to specific phobia domains and differences in patterns among African American and Caucasian American adults. Subjects were 100 African Americans and 121 Caucasian Americans who completed the Fear Survey Schedule—Second Edition (FSS-II). Fears related to specific phobia domains were first examined, with frequencies differing between African American and Caucasian American samples on three of the six specific phobia domains. A confirmatory factor analysis was conducted to determine the patterns of specific phobias among the African American sample. The trimmed model for the African American sample included natural environment, animal and social anxiety specific phobia factors as latent, exogenous variables. Data from the Caucasian American sample provided a poor fit to this model. Instead, the trimmed model for the Caucasian American sample included the situational, animal and social anxiety factors. The natural environment-type specific phobia factor did not have adequate fit for the Caucasian American sample as in the African American sample. Results indicated that different factor loading patterns of fear-related stimuli may exist among African American and Caucasian American young adults. Potential explanations and future directions are discussed.