PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of nihpaAbout Author manuscriptsSubmit a manuscriptHHS Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
 
J Natl Black Nurses Assoc. Author manuscript; available in PMC 2010 May 26.
Published in final edited form as:
J Natl Black Nurses Assoc. 2009 July; 20(1): 1–10.
PMCID: PMC2877127
NIHMSID: NIHMS200986

Effects of Genetic Counseling for Hypertension on Changes in Lifestyle Behaviors among African-American Women

Jacquelyn Y. Taylor, PhD, PNP-BC, RN, Assistant professor and Chun Yi Wu, BS, M.P.H., Doctoral student

Abstract

Genetic counseling research has been used for diseases such as breast and other cancers, but genetic counseling for hypertension has been understudied. African-American women have the highest prevalence of hypertension and cardiovascular disease of any group in the United States. Because hypertension and related cardiovascular sequela have a profound impact on the health and well being of African-American women, providing genetic counseling for hypertension is important in order to determine risk and to provide early interventions. The purpose of this study is to examine lifestyle changes among urban African-American women following genetic counseling for hypertension as compared to baseline. Specific lifestyle factors include the impact of changes in physical activity, of sodium intake, and of body mass index on systolic and diastolic blood pressure and pulse pressure. Results of this study indicated that systolic and diastolic blood pressure readings and pulse pressure readings decreased six months after genetic counseling, although the findings were not statistically significant. Body mass index remained relatively unchanged after genetic counseling, but minutes of increased physical activity was reported, although this was not significant. However, a statistically significant decrease in sodium intake (p = .033) was noted from baseline to 6-month follow-up after genetic counseling. With the exception of sodium, changes in lifestyle behaviors, blood pressure, and pulse pressure readings did not differ significantly from baseline. However, changes in lifestyle behaviors in a positive direction are important and worth noting. Further studies on genetic counseling for hypertension with longer follow-up periods are needed to determine the effectiveness of genetic counseling on changes in lifestyle behaviors and blood pressure readings.

Keywords: African-American, blood pressure, genetic counseling

Introduction

As information regarding genetic risk factors for disease becomes more available, genetic counseling is being recommended for families at risk for developing specific disorders, including hypertension (Kessler, Collier, & Halbert, 2007). Genetic counseling/education is defined as the process of educating people about genetics related to familial, psychological, and medical outcomes (Sivell, Elwyn, Gaff, Clarke, Iredale et al., 2007). Genetic counseling can help participants understand risk information when considering options for health management (Soldan, Street, Gray, Binedell, & Harper, 2000).

Wang, Gonzales, and Merajver (2004) referred to genetic counseling as “pertaining to the actual education and counseling provided, both before and after (if tested), the receipt of genetic test results.” Their assessment on genetic testing and related counseling services explored the goal of genetic counseling and what is termed as “success.” These goals included: educating patients about genetic conditions and risks, providing support, and facilitating informed decision making. According to Wang et al., genetic counseling can be a useful framework for assessing health outcomes. However, they also recognized that certain methodological limitations could limit the study of genetic counseling. For example, many research studies employ cross-sectional research designs to study genetic outcomes across generations, when the use of longitudinal designs could be more appropriate.

Literature suggested that genetic counseling might be more successful if the individual has a personal knowledge of a genetic disease within the family (Shiloh, 2006). Patients who have information on their familial disease history and participate in genetic testing often show positive lifestyle responses to counseling. For example, compared to those with less knowledge regarding their family medical histories, female carriers of an X-linked condition, who have an affected brother, were more likely to have genetic counseling prior to childbearing (Kay & Kingston, 2002). Individuals who participate in genetic counseling may interpret risk information that corresponds to their health beliefs on heredity, lifestyle, and family experiences (Emery, Kumar, & Smith, 1998). Walter, Emery, Braithwaite, and Marteau’s (2004) review of chronic diseases related to family risk contended that one’s perception of vulnerability was associated with the number of affected relatives and personal risk perceptions regarding age and gender.

Research on benefits of genetic counseling has been limited by self-selecting participants who exhibit psychological distress and seek genetic services (Wang et al., 2004). However, these participants tend to show little or no change in distress levels following genetic testing. Likewise, Cummings (2000) suggested that the weight of dispensing genetic information (whether positive, negative, or ambiguous) during counseling sessions can generate negative responses. This concept is evident in her study on genetic testing for breast cancer susceptibility and the extent of the necessary follow-up counseling. The research revealed that many women with negative hereditary outcomes gain a false sense of security regarding their development of breast cancer and consequently may not participate in screening on a regular basis.

A challenge in genetic counseling is in communicating relative risk data. Some individuals may experience difficulty in comprehending the probability of risk. For example, some people may be confused by the use of statistics in reference to genetic test findings (Hallowell, Foster, Eeles, Ardern-Jones, & Watson, 2004). Conflicting cultural and health beliefs and practices also have been known to hinder their understanding of risk. Further, genetic risk information often is provided to individuals who consider themselves healthy or who lack information about family history of genetic diseases. These situations can force participants who are undergoing genetic counseling to consider their risk in complex, abstract ways (Bottorff, Ratner, Johnson, Lovato, & Joab, 1998). Lifestyle behaviors are risk factors that also should be discussed when providing genetic counseling for chronic conditions such as hypertension.

Background and Significance

Lifestyle Behaviors Related to Hypertension

African-Americans who are diagnosed with hypertension have a greater frequency for developing stroke, coronary heart disease, congestive heart failure, as well as end stage renal disease than do their White counterparts. Hypertension occurs at a younger age and with greater severity among African-Americans when compared to other ethnic groups (Taylor, Washington, Artinian, & Lichtenberg, 2007).

Negative lifestyle behaviors (e.g., lack of physical activity, elevated body mass index [BMI], high sodium intake, etc.) are risk factors that can contribute to high blood pressure among African-Americans. Bassett, Fitzhugh, Crespo, King, and McLaughlin (2002) explored the relationship between leisure-time physical activity (LTPA), hypertension, and ethnicity. The prevalence of hypertension was 25% lower for respondents who completed five or more sessions per week of moderate-to-vigorous activity than for those who did not participate in LTPA. Regardless of physical activity levels, African-Americans had higher age-adjusted rates of hypertension than did Whites and Mexican Americans.

Severe obesity is generally higher in women than it is in men. Flack (2003) concluded that the age-adjusted prevalence of obesity was higher for African-American women (49.7%) than for either White women (30.1%) or Mexican American women (39.7%). Severe obesity also was higher in African-American women (15.1%) when compared to White women (4.9%) or Mexican American women (5.1%). This finding is important for African-American women as this group has a high prevalence of obesity and is at greater risk for high blood pressure. Douglas et al. (2003) contended that weight reduction could be effective in decreasing blood pressure. Results of the Trials of Hypertension Prevention (2001) reported that over time, a weight loss of 10 pounds could reduce blood pressure, along with the risk for developing hypertension.

Obesity and Salt Sensitivity

Obesity has been linked with “salt sensitivity” (impaired ability of the kidney to excrete sodium which leads to an increase in blood pressure that promotes natriuresis to correct the sodium balance, which then results in hypertension) and hypertension among African-Americans (Flack et al., 2002; Franco, Sanchez-Lozada, Bautista, Johnson, & Rodriguez-Iturbe, 2008). Weight plays a role in blood pressure response to sodium intake, as well as excretion, especially for women who are typically more salt sensitive than men (Flack, 2003; Flack et al., 2002). Salt sensitivity has been associated with blood vessel constriction, which can lead to increases in blood pressure. Because obesity and salt intake are contributing factors to hypertension, the Dietary Approaches to Stop Hypertension (DASH) diet has been used as a successful treatment in lowering African-American patients’ blood pressure readings. The DASH diet, which includes fruits, vegetables, fiber, and low-fat dairy foods, reduced fats and sodium, increased potassium, as well as reasonable intakes of protein, has been found to reduce high blood pressure in Africans-Americans (Douglas et al., 2003).

Genetic Counseling for Hypertension

McGoon et al. (2004) suggested that genetic counseling for hypertension should be carefully performed as part of a comprehensive program that addresses risks, benefits, and limitations of test results. Genetic testing and counseling should be performed only by trained professionals. Smerecnik et al. (2007) examined varied responses to positive and negative results for genetic testing for salt sensitivity. They explored two specific factors: (a) the impact of anticipated results on intention to adopt a low sodium diet, and (b) whether participants who expected negative results from genetic testing for salt sensitivity decreased their intentions to adopt a low sodium diet. Participants were more likely to restrict their salt intake if their genetic test results indicated a salt sensitivity. According to Smerecnik et al., self-efficacy and perceived severity of general health were positively connected to the intention to adopt a salt-restrictive diet. These findings suggested that when genetic counselors highlighted self-efficacy and perceived severity of general health, counselees could be motivated to change health behaviors.

Genetic Counseling among African-Americans

A substantial body of literature provided an explanation of why some African-Americans generally distrust research conducted by the American medical establishment (Harris, Gorelick, Samuels, & Bempong, 1996). This distrust evolved from the use of African-Americans in Tuskegee syphilis experiments (Laskey, Williams, Pierre-Louis, O’Riordan, Matthews et al., 2003). These findings provided support for the unwillingness of African-Americans to participate in biomedical research, especially for genetic testing and counseling. Limited research has been published on genetic counseling among African-Americans, with the exception of studies on breast cancer. Taylor (2009) also found that African-Americans are concerned about the use of their genetic testing regarding access to results, the length of time data is stored, and uses of the DNA, etc.

Clinical research has focused on the use of genetic testing to develop individualized counseling (Condit & Bates, 2005). The practice of individualized genetic counseling is intended to increase genetic knowledge and to improve understanding of perceptions regarding heredity and ethnicity. Studies show that educational practices intended for African-Americans should focus on improving their knowledge about genetic testing and counseling (Kessler, Collier, & Halbert, 2007). Further studies regarding African-Americans, genetic counseling, and lifestyle changes may be a positive addition to the growing body of literature on genetic counseling.

Purpose of the Study

The literature review reflects the understudied nature of genetic counseling for hypertension among African-Americans. While analyses of genome-wide association for hypertension have been studied, few articles have been published regarding the success rate of lifestyle changes post-genetic counseling, specifically for hypertension among African-Americans (Arnett et al., 2007; Taylor, Sun, Chu, Mosley, & Kardia, 2008).

The purpose of this study is to examine lifestyle changes among urban African-American women prior to and following genetic counseling for hypertension. Specific lifestyle factors include changes in physical activity, in sodium intake, and in body mass index, as well as their impact on systolic and diastolic blood pressure and pulse pressure. The research question for the present study is as follows:

Does participation in genetic counseling for hypertension risk result in improved lifestyle behaviors (decreased sodium intake, increases in minutes of physical activity, and decreases in body mass index) and declines in systolic and diastolic blood pressure and pulse pressure?

Methodology

Design

The study employed a descriptive correlational research design to address the research question posed. Correlations between variables (blood pressure, pulse pressure, and lifestyle behaviors) were examined to assess the strength and direction of the association between blood pressure and pulse pressure readings with lifestyle behaviors at baseline and again at the 6-month follow-up after the genetic counseling. A paired t-test comparison was conducted to determine mean differences before and after the genetic counseling.

Sample and Setting

This study used a convenience subgroup sample of 98 African-American women (N = 98) who participated in the “Hypertension and Heredity: Hypertension Genetic Polymorphisms in Three Generations of African American Women” parent study who were originally recruited from the Detroit Metropolitan area, after receiving approval from the Institutional Review Boards (IRB) at The University of Michigan and Wayne State University. In the parent study, “Hypertension and Heredity: Hypertension Genetic Polymorphisms in Three Generations of African American Women,” three generations of maternally, blood-related women were recruited to examine hypertension susceptibility genes. To meet the inclusion criteria for the parent study, participants were required to self-identify as African-American and have a living family of at least three generations to constitute the triad of grandmother-mother-granddaughter. Although participants self-identified as African-American, the recruiters were aware of the heterogeneity of Blacks in America that included, but was not limited to, Blacks of mixed heritage, African immigrants, Caribbean Blacks, and Blacks of various other origins (Brown, 2004). Participants must be able to read and write English at a sixth grade level. For those with the diagnosis of hypertension, blood pressure must average 140/90 or higher (Stage 1 or 2 hypertension) without medication. Individuals who reported taking antihypertensive medications were included in the study. Participants who were diabetic were included in the study if their average blood pressure was at least 130/80 without medication. Normotensive participants were also included in the study. Exclusion criteria included having co-morbidities of substance abuse, mental illness, end-stage cancer, end-stage renal disease, or other terminal illness. More detailed information on inclusion and exclusion criteria can be found in Wu, Prosser, & Taylor (under review).

Multiple procedures were used to recruit African-American women for the multigenerational genetic study. Specifically, women were recruited using the following methods: (a) the use of flyers posted in neighborhood areas including local stores, markets, and community centers; (b) advertisements and announcements at local churches; (c) advertisements and announcements at historically Black sororities; and, (d) the use of participant resource pools from the University of Michigan and Wayne State University (Taylor, 2009). After agreeing to participate in the study, informed consent was obtained during home visits that served as the site for data collection. Research assistants were trained by the principal investigator regarding all data collection methods, home visitations, and coordinating visits. Details regarding recruitment strategies can be found in Taylor (2009).

The parent study was expanded to offer participants an opportunity to take part in a follow-up study that measured changes in lifestyle behaviors after genetic counseling intervention. The present study included 98 African-American women who completed the genetic counseling follow-up. This sample size of 98 African-American women was sufficient for a power of .80 at an alpha level of .05 with a moderate effect size (Cohen, 1992).

Description of the Sample

A summary of demographic characteristics of the participants is presented in Table 1. The majority of the women (n = 30, 30.6%) were older than 55 years of age, followed by the second largest group who were between 46–55 years of age (n = 23, 23.5%). A majority of the participants reported having at least some college education or greater (n = 76, 78.6%), with most women having household incomes of less than $40,000 (n = 50, 51.1%). The majority of the women (n = 67, 68.4%) were single, divorced, separated, or widowed, with 30 (30.6%) reporting that they were married. Forty-two (42.9%) women were unemployed, while 50 (51%) had full-time jobs (more than 30 hours a week). Most women reported having health insurance coverage (n = 86, 87.8%), and a family history of hypertension (n = 85, 86.7%) (see Table 1).

Table 1
Frequency Distributions: Demographic Characteristics (N = 98)

Measures

Demographic Questionnaire

The demographic survey was developed to obtain information from participants regarding age, educational level, household income, marital status, and employment status. This instrument was used to provide a profile of participants.

Blood Pressure, Weight, and Height

Blood pressure was measured using a digital blood pressure monitor with a size appropriate upper arm cuff (model # A&D UA767PC). Blood pressure measurements represent an average of three seated blood pressure readings. Procedures for participant preparation for blood pressure measurement were in accordance with JNC-7 (2003) recommendations. Each of the three blood pressure readings was taken 5 minutes apart. Participants wore unrestrictive clothing, had their feet on the floor, their backs supported, and their arms at heart level. Weight was measured by an electronic scale (BWB/807 Tanita Tokyo, Japan). Height was measured by a portable stadiometer (Model 214 Road Rod, Seca Corporation, Hanover, MD).

Body mass index (BMI) was calculated using weight and height measurements. BMI is the relationship between weight and height that is associated with body fat and health risk. The formula for calculating BMI is weight in pounds divided by the height in inches squared. The result is then multiplied by 703 to provide the BMI. BMI from 18.5 to 24 is considered normal. BMI scores of less than 18.5 are considered underweight. BMI from 25 to 29 is considered overweight, with BMI outcomes of equal to or greater than 30 indicative of obesity (CDC, 2008).

Physical Activity

Thirty minutes of physical activity each day is recommended for people diagnosed with hypertension (Chobanian, Bakris, Black, Cushman, Green et al., 2003). To measure physical activity, participants were asked two questions: (a) if they took part in a minimum of 30 minutes of moderate or greater physical activity on any day in the past seven days, and (b) the total number of minutes of participation in moderate or greater physical activity over the past seven days. The total minutes of moderate or greater physical activity were used for analyses in this study. Participants reported minutes of physical activity at baseline (one-time genetic counseling session) and at the 6-month follow-up interview.

Sodium and Potassium Intake

Sodium and potassium intake (i.e., milligrams of sodium per day) were determined using self-reported data from two 24-hour food recalls, first at baseline and the second at the 6-month follow-up. Data were translated into nutrient intakes using computer software entitled the Food Processor (ESHA Research, Salem, OR). Multiple-day food recall is considered valid because it accurately represents a person’s usual or habitual intake (Block, 1982). Food recalls were collected during home visits on a weekday or a weekend day and asked participants to recall what they had eaten within the last 24 hours. Each recall took approximately 10 minutes. Food models and measuring cups and spoons were used as memory aids to assist participants in reporting accurate serving sizes. Information on sodium and potassium intake was collected at the baseline (one-time genetic counseling session) interview and at the 6-month follow-up.

Procedures

Genetic Counseling

Women in the present study had participated previously in a hypertension and heredity genetics study prior to the genetic counseling (Taylor, 2009). Participants who agreed to participate in the follow-up genetic counseling study were provided with information regarding their blood pressure, their body mass index, and their risk for hypertension based on factors delineated by the American Heart Association. Each participant participated in genetic counseling at baseline in her home, with the collection of data regarding lifestyle behavior, blood pressure readings, and questionnaire data. A second home visit was conducted 6 months following the genetic counseling for collection of blood pressure readings, lifestyle, and questionnaire data. The genetic counseling was not repeated.

The counseling included teaching the participants about simple and complex genetic traits for hypertension and how genes are passed from parents to children. Participants were taught the difference between dominant and recessive traits and the probability of how these traits might be expressed based on the combination of traits received from each parent. Each participant was then shown how to use a punnet square and asked to draw the punnet square as a game to demonstrate understanding. Each participant also was encouraged to draw their family pedigree to further enhance learning. Genetic counseling, including drawing of pedigree and the use of punnet square, lasted approximately 1 hour. The genetic counseling education session was provided by a registered nurse with extensive training in the genetics of hypertension. Once the genetic counseling was completed, each participant was provided with brochures from the American Heart Association regarding physical activity and dietary sodium recommendations (DASH diet) to reduce their individual risk for hypertension.

Data Analysis

SPSS version 16.0 (SPSS Corporation, Chicago, Illinois) was used to analyze the demographic, blood pressure, BMI, and lifestyle measures. Demographic characteristics, including educational level, household income, marital status, hours worked, health insurance, and family diagnosis of hypertension, were summarized using frequency distributions. Intercorrelation matrices were developed to determine the relationships between the variables at baseline and the 6-month follow-up. The difference of mean blood pressure readings (mm-Hg), BMI (kg/m2), pulse blood pressure (mm-Hg), physical activity (minutes/week), sodium intake (mg/day), and potassium intake (mg/day) were compared between baseline and follow-up using paired t-tests. All decisions on the statistical significance of the findings were based on a criterion alpha level of .05.

Results

Correlation Analyses

Pearson product moment correlations between lifestyle behaviors and blood pressure were obtained both at baseline and at follow-up (see Table 2 and Table 3, respectively). At baseline, systolic blood pressure was significantly correlated with age (r = .32, p = .001) and sodium intake (r = −.21, p = .037). Astatistically significant positive correlation was found between diastolic blood pressure and BMI (r = .24, p = .019). Age was correlated with sodium intake (r = −.20, p = .04) and potassium intake (r = .30, p = .003).

Table 2
Intercorrelations between Age, BMI, Blood Pressure, Pulse Pressure, Sodium Intake, Potassium Intake, and Physical Activity at Baseline.
Table 3
Intercorrelations between Age, BMI, Blood Pressure, Pulse Pressure, Sodium Intake, Potassium Intake, and Physical Activity at Follow-up.

At follow-up, systolic blood pressure was only correlated with age (r = .27, p = .007) (see Table 3). No statistically significant correlations were found between diastolic blood pressure and BMI or lifestyle behavior. However, potassium intake was correlated with BMI (r = −.31, p = .002) while this significant result was not shown at baseline.

Paired t-tests for Lifestyle Behavior and Blood Pressure

After genetic counseling intervention, all mean systolic blood pressures, diastolic blood pressures, and pulse pressures decreased slightly from baseline to follow-up (137.73 ± 22.11 mm-Hg to 134.10 ± 18.98 mm-Hg, 83.29 ± 11.76 mm-Hg to 82.05 ± 10.73 mm-Hg, and 54.08 ± 18.22 mm-Hg to 52.52 ± 15.64 mm-Hg respectively), but were not statistically significant. Women reported performing more physical activity after intervention (85.76 ± 80.92 min/week at baseline vs. 101.18 ± 130.68 min/week at follow-up) while their BMI (32.31 ± 7.23 kg/m2 at baseline vs 32.38 ± 7.31 kg/m2 at follow-up) was consistent over the two measurement periods, although these differences were not statistically significant. Women reduced their sodium intake by 402.22 mg/day after genetic counseling from a mean of 3200.51 mg/day (SD = 1415.02) at baseline to 2798.29 mg/day (SD = 1462.83) at follow-up, p = .033 (see Table 4). While women reduced their potassium intake of 82.53 mg per day after intervention, this change was not significant statistically.

Table 4
t-Tests for Paired Samples: Health Indicators (N = 98)

Discussion

African-American women have the highest prevalence of hypertension of any ethnic or gender group in the United States (AHA, 2005). While clinicians are aware that African-American women are at the greatest risk for hypertension, educating patients on negative lifestyle behaviors and genetic risks that may lead to a diagnosis of hypertension is important. Teaching positive lifestyle behaviors are a mainstay of hypertension management, however, a disconnect remains in terms of genetic health determinants that also may influence hypertension risk and control. In this study, providing genetic counseling by drawing a three-generation pedigree with each participant raised awareness regarding their risks for developing the disease. Studies have shown the importance of considering three-generation pedigrees when examining family history as a means of determining cardiovascular disease risk (MacLeod & McNally, 2008; Taylor, 2009). Taking the time to draw the family pedigrees and using the punnet square also provided awareness to participants regarding possible risks for their offspring of developing hypertension.

Although general practitioners may not have the time or expertise to engage patients at risk for hypertension in the educational activities of pedigree drawing and use of punnet squares, genetic counselors and nurse educators are well positioned for this role. Many nurses specialize in patient education to promote healthy lifestyles and reduce risks associated with disease development. Expanding the role of nurses with specialized training in genetics to provide genetic counseling in addition to health promotion activities for a healthy lifestyle seems ideal for patients who want to learn about their environmental and genetic risk factors for hypertension.

As expected, systolic blood pressure was significantly correlated in a positive direction with age at baseline. This finding was consistent with findings from previous research that increased systolic blood pressure could be explained as part of the normal aging process (Taylor, Washington, Artinian, & Lichtenberg, 2007). Also consistent with previous findings, this study showed that increases in BMI were correlated with increases in diastolic blood pressure (Douglas et al., 2003). However, findings of this study indicated a statistically significant relationship with increased systolic blood pressure and lowered sodium intake, which was inconsistent with reports by the American Heart Association (AHA) and the DASH diet (AHA, 2005).

Additionally, the present study found that age was also significantly related to lower sodium intake and increased potassium. The present study found that the lifestyle behavior for reduction in sodium intake decreased significantly after participation in genetic counseling.

It is not clear why older African-American women would have an inverse relationship with sodium intake as it relates to their systolic blood pressure. Hypertension literature indicated that increased sodium is a risk factor for increased blood pressure due to salt sensitivity among African-Americans, and increased dietary potassium is protective in reducing sodium and resulting in lower blood pressure (Flack et al., 2002). It is possible that women in the present study may not have been as salt sensitive as participants in other studies. At follow-up, correlations between age with sodium and potassium, and sodium with systolic blood pressure no longer remained statistically significant. This change may be due in part to declines in systolic blood pressure and increases in positive dietary lifestyle behaviors. Additional research with a larger sample is needed to explore this relationship further.

Potassium at follow-up was negatively correlated with BMI, with BMI increasing slightly from baseline to follow-up. A plausible reason for the relationship between BMI and potassium could be attributed to potassium-wasting drugs commonly used (e.g., diuretics) for the treatment of hypertension and cardiovascular disease. However, the present study did not collect information on the types of medication used to control hypertension in this sample to draw definite conclusions regarding the relationship between BMI and potassium.

This study has shown that some lifestyle behaviors (i.e., minutes of physical activity) improved, but not significantly, after genetic counseling for hypertension among African-American women. Although not statistically significant, both blood pressure readings and pulse pressure readings decreased slightly over time. Even though changes in many lifestyle behaviors (with the exception of sodium intake) and blood pressure readings did not significantly differ from baseline, the change in a healthy direction is important and worth noting. Healthy lifestyle changes (e.g., physical activity, healthy eating habits [DASH diet], sodium reduction, etc.) can help to reduce blood pressure.

Implications for Practice

Health professionals (nurses, physicians, psychologists, and social workers) should refer their clients (patients) to genetic nurse counselors or educators, especially if they are having difficulty in controlling or managing a chronic disease such as hypertension. Genetic counseling can be informative when learning about family history of hypertension, how it is passed from generation to generation, and how this knowledge could be used to minimize the effects of hypertension on future generations. Referral to genetic counseling with additional nursing guidance on healthy lifestyle behaviors would be a cost-effective, informative method for reducing health disparities for hypertension among African-American women.

It is the opinion of the authors that the participants responded well to genetic counseling and AHA educational materials on healthy lifestyle behaviors. Education regarding lifestyle modification is an important component of genetic counseling for hypertension. In addition, the AHA pamphlets provided to participants featured African-Americans on the cover and discussed the risk factors for hypertension specifically for African-Americans. Culturally sensitive materials are needed to encourage participants that successful lifestyle change is something they can attain to improve their health.

Limitations

This study only recruited African-American women and the findings may not be generalizable to women of other ethnic groups or to men. The study population was recruited from a large urban, midwestern city; therefore, the findings might not be generalizable to those who reside in other geographic areas. A control group that did not receive genetic counseling was not used in this study. As a result, the findings might not reflect the true effects of genetic counseling on lifestyle changes among African-American women. The use of a professional support system to help women continue their lifestyle behavior changes was not a part of the present study. Additional studies that offer genetic counseling along with the addition of a professional support system are needed to determine if long-term change in blood pressure can be sustained. This study had a short follow-up period and future studies with a longitudinal design are needed to examine further the effectiveness of genetic counseling for hypertension on changes in blood pressure and lifestyle behaviors among African-American women.

Conclusions

Because few studies have examined the effects of genetic counseling on blood pressure and pulse pressure among African-Americans, this innovative study contributes to the body of knowledge regarding the effects of genetic counseling on changes in lifestyle behaviors that can contribute to reducing hypertension health disparities within this population. Based on the results of this study, it is imperative that health professionals include genetic counseling in their treatment regimens for African-American patients with hypertension as a method to reduce blood pressure and pulse pressure. Information regarding both modifiable (lifestyle behaviors) and non-modifiable (genetic) risk factors for hypertension need to be considered when crafting individualized treatment and health prevention plans of care. Patients who are educated about both their genetic and lifestyle risks for hypertension might be more empowered to make positive lifestyle changes and reduce their risks for the development of hypertension or lower their blood pressure and pulse pressure readings. Although this study of genetic counseling for hypertension is one step toward helping to reduce health disparities, further longitudinal studies with longer testing intervals and with larger samples are needed to determine the long-term effects of genetic counseling on changes in lifestyle behaviors that result in decreased blood pressure and pulse pressure readings among African-Americans with hypertension.

Acknowledgments

Funding for this research was provided in part by National Institutes of Health Grants P30 NR009000 and 1 KL2 RR024987-01 to Jacquelyn Taylor.

Contributor Information

Jacquelyn Y. Taylor, Yale University, School of Nursing, New Haven, CT.

Chun Yi Wu, University of Michigan, School of Public Health, in Ann Arbor, MI.

References

  • American Heart Association (AHA) Metabolic syndrome: New guidance for prevention and treatment. 2005. Retrieved January 11, 2008, from www.americanheart.org/presenter.jtml?identifier=3033454.
  • Arnett DK, Baird AE, Barkley RA, Basson CT, Boerwinkle E, Ganesh SK, et al. Relevance of genetics and genomics for prevention and treatment of cardiovascular disease: A scientific statement from the American Heart Association Council on Epidemiology and Prevention, the Stroke Council, and the Functional Genomics and Translational Biology Interdisciplinary Working Group. Circulation. 2007;115(22):2878–2901. [PubMed]
  • Bassett DR, Jr, Fitzhugh EC, Crespo CJ, King GA, McLaughlin JE. Physical activity and ethnic differences in hypertension prevalence in the United States. Preventive Medicine. 2002;34(2):179–186. [PubMed]
  • Block G. A review of validations of dietary assessment methods. American Journal of Epidemiology. 1982;115(4):492–505. [PubMed]
  • Bottorff JL, Ratner PA, Johnson JL, Lovato CY, Joab SA. Communicating cancer risk information: The challenges of uncertainty. Patient Education and Counseling. 1998;33(1):67–81. [PubMed]
  • Brown DJ. Recruitment of Black Americans for research: A model of success. The Journal of Multicultural Nursing & Health. 2004;10(3):19–23.
  • Centers for Disease Control and Prevention (CDC) How is BMI calculated and interpreted? 2008. Retrieved February 11, 2008, from http://www.cdc.gov/nccdphp/dnpa/bmi/adult_BMI/about_adult_BMI.htm.
  • Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL, Jr, et al. The seventh report of the Joint Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Journal of the American Medical Association. 2003;289(19):2560–2572. [PubMed]
  • Cohen J. A power primer. Psychological Bulletin. 1992;112(1):155–159. [PubMed]
  • Condit C, Bates B. How lay people respond to messages about genetics, health, and race. Clinical Genetics. 2005;68(2):97–105. [PubMed]
  • Cummings S. The genetic testing process: How much counseling is needed? Journal of Clinical Oncology. 2000;18(21):60s–64s. [PubMed]
  • Douglas JG, Bakris GL, Epstein M, Ferdinand KC, Ferrario C, Black JM, et al. Management of High Blood Pressure in African Americans: Consensus Statement of the Hypertension in African Americans Working Group of the International Society on Hypertension in Blacks. Archives of Internal Medicine. 2003;163(5):525–541. [PubMed]
  • Emery J, Kumar S, Smith H. Patient understanding of genetic principles and their expectations of genetic services within the NHS: a qualitative study. Community Genetics. 1998;1(2):78–83. [PubMed]
  • Flack J. Hypertension and African Americans: Customizing treatment options. Therapeutic Spotlight. A self-study supplement to: Clinician Reviews. 2003:1–20.
  • Flack JM, Grimm RH, Jr, Staffileno BA, Elmer P, Yunis C, et al. New salt-sensitivity metrics: variability-adjusted blood pressure change and the urinary sodium-to-creatinine ratio. Ethnicity & Disease. 2002;12(1):10–19. [PubMed]
  • Franco M, Sanchez-Lozada LG, Bautista R, Johnson RJ, Rodriguez-Iturbe B. Pathophysiology of salt-sensitive hypertension: A new scope of an old problem. Blood Purification. 2008;26(1):45–48. [PubMed]
  • Hallowell N, Foster C, Eeles R, Ardern-Jones A, Watson M. Accommodating risk: Responses to BRCA1/2 genetic testing of women who have had cancer. Social Science & Medicine. 2004;59(3):553–565. [PubMed]
  • Harris Y, Gorelick PB, Samuels P, Bempong I. Why African Americans may not be participating in clinical trials. Journal of the National Medical Association. 1996;88(10):630–634. [PMC free article] [PubMed]
  • Kay E, Kingston H. Feelings associated with being a carrier and characteristics of reproductive decision making in women known to be carriers of X-linked conditions. Journal of Health Psychology. 2002;7(2):169–181. [PubMed]
  • Kessler L, Collier A, Halbert CH. Knowledge about genetics among African Americans. Journal of Genetic Counseling. 2007;16(2):191–200. [PubMed]
  • Laskey SL, Williams J, Pierre-Louis J, O’Riordan M, Matthews A, Robbins NH. Attitudes of African American premedical students toward genetic testing and screening. Genetics in Medicine. 2003;5(1):49–54. [PubMed]
  • MacLeod HM, McNally EM. A pilot study of family history risk assessment tool for cardiovascular disease. Journal of Genetic Counseling. 2008;17(5):499–507. [PubMed]
  • McGoon M, Gutterman D, Steen V, Barst R, McCrory D, Fortin TA, et al. Screening, early detection, and diagnosis of pulmonary arterial hypertension: ACCP evidence-based clinical practice guidelines. Chest. 2004;126(Suppl 1):14S–34S. [PubMed]
  • Shiloh S. Illness Representations, self-regulation, and genetic counseling: A theoretical review. Journal of Genetic Counseling. 2006;15(5):325–337. [PubMed]
  • Sivell S, Elwyn G, Gaff CL, Clarke AJ, Iredale R, Shaw C, et al. How risk is perceived, constructed and interpreted by clients in clinical genetics, and the effects on decision making: Systematic review. Journal of Genetic Counseling. 2007;17(1):30–63. [PubMed]
  • Smerecnik CM, Mesters I, van Keulen H, Scheffers I, Beeks E, Leeuw PW, et al. Should individuals be informed about their salt sensitivity status? First indications of the value of testing for genetic predisposition to low-risk conditions. Genetic Testing. 2007;11(3):307–314. [PubMed]
  • Soldan J, Street E, Gray J, Binedell J, Harper PS. Psychological model for presymptomatic test interviews: Lessons learned from Huntington disease. Journal of Genetic Counseling. 2000;9(1):15–31. [PubMed]
  • Taylor JY. Recruitment of three generations of African American women into genetic research. Journal of Transcultural Nursing. 2009;20(2):219–226. [PMC free article] [PubMed]
  • Taylor JY, Sun YV, Chu J, Mosley TH, Kardia SL. Interactions between metallopeptidase 3 polymorphisms rs679620 and BMI in predicting blood pressure in African American women with hypertension. Journal of Hypertension. 2008;26(12):2312–2318. [PMC free article] [PubMed]
  • Taylor JY, Washington OG, Artinian NT, Lichtenberg P. Parental stress among African American parents and grandparents. Issues in Mental Health Nursing. 2007;28(4):373–387. [PMC free article] [PubMed]
  • Walter FM, Emery J, Braithwaite D, Marteau TM. Lay understanding of familial risk of common chronic diseases: a systematic review and synthesis of qualitative research. Annals of Family Medicine. 2004;2(6):583–594. [PubMed]
  • Wang C, Gonzalez R, Merajver SD. Assessment of genetic testing and related counseling services: current research and future directions. Social Science & Medicine. 2004;58(7):1427–1442. [PubMed]
  • Wu CY, Prosser R, Taylor JY. Association of Symptoms of Depression and Social Support on Hypertension among Urban African American Women. Progress in Cardiovascular Nursing (under review)