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Learn More. Additionally, more than twice as many African American women Obesity is usually measured using body mass index BMI. This study investigates the independent association of waist circumference with hypertension and diabetes in African American women. If a participant reported she had hypertension or had measured systolic blood pressure at or higher than mm Hg or measured diastolic blood pressure at or higher than 90 mm Hg, she was classified as having hypertension.
We used logistic regression models to test predictors of hypertension and diabetes.
Of study participants, had diabetes and were hypertensive. After controlling for all variables, waist circumference was independently associated with a 5-fold risk in hypertension and diabetes in African American women. Obesity is associated with hypertension and diabetes, which are risk factors for cardiovascular disease CVD 1.
Fifty-three percent of African American women are obese 2. Additionally, national data show that the prevalence of diagnosed type 2 diabetes is more than twice as high among African American women Abdominal adiposity is a risk factor for obesity-related complications, and there is increasing evidence that abdominal adiposity may be a contributing factor to complications not related to adiposity at the waist 45.
Body mass index BMIwaist-to-hip ratio, and waist circumference are commonly used measures for estimating abdominal adiposity 67. BMI is a simple and widely used clinical measure; however, BMI may not be a reliable indicator of health risk across all racial and ethnic groups 689. This may be due, at least in part, to errors inherent in the use of self-report measures of BMI 6. Considerable attention has been given to waist circumference as a complementary 10 and, in some cases, superior 8 assessment to BMI.
Waist circumference is a practical method for assessing CVD risk factors in whites 11 ; however, few studies have examined the association between waist circumference and risk factors in African Americans 912 Our study objective was to examine the independent association of waist circumference with hypertension and diabetes in African American women.
We hypothesize that the risk of hypertension and diabetes would be higher for women with larger waist circumference, independent of sociodemographic and health-related variables. It represents a university-church partnership to promote physical activity and healthy eating among members of African Methodist Episcopal AME churches.
The primary goals of FAN are to increase physical activity, increase fruit and vegetable consumption, and improve blood pressure among its participants. Our study was part of the overall FAN study. FAN uses a randomized de with a delayed-intervention control group and takes place in 3 waves Each wave lasts approximately 30 months and completes an intervention cycle, 15 months for churches randomized to early intervention and 15 months for churches receiving the delayed intervention.
Outcome measures are taken at baseline and at post intervention. At the end of the month intervention, delayed-intervention churches have an opportunity to implement the FAN program, but no further follow-up occurs.
Details of the overall intervention study are described elsewhere Our study uses baseline data from the larger FAN study through and thus is a cross-sectional de. Presiding elders of 4 geographically defined districts in South Carolina Kingstree, Georgetown, Columbia, and Mount Pleasant sent a letter introducing the FAN program to pastors in their districts. Interested churches were asked to complete and return a contact information form to FAN staff, who then made follow-up telephone calls to pastors to address questions or concerns.
Churches agreeing to participate in FAN were asked to a memorandum of agreement. Pastors usually deated the church health director or another church leader to serve as FAN coordinator.
This person acted as the liaison between the church and FAN staff in recruiting members of their congregation to take part in a measurement session. Small churches were asked to recruit at least 13 members; medium churches, 32 members; and large churches, 63 members. More recruitment details are provided elsewhere Written informed consent was obtained from all participants, and our study was approved by the institutional review board of the University of South Carolina.
We included only women in our study because of the small percentage of men participating in FAN. Participants completed a survey assessing sociodemographic characteristics age, marital status, and educationphysical activity levels, diet, and general health. To be eligible for our study, participants had to be at least 18 years of age and free of serious medical conditions or disabilities that would make physical activity difficult.
They had to attend worship services at least once a month and plan to reside in the area for the next 2 years. These criteria were presented in the informed consent form; therefore, nonqualifying participants were self-excluded.
Participants removed shoes, excess clothing, and all items in their pockets before having their height and weight measured. A Seca digital scale Seca Corporation, Hanover, Maryland measured weight to the nearest tenth of a kilogram, and a Seca stadiometer Seca Corporation, Hanover, Maryland measured height to the nearest quarter of an inch. We calculated BMI by dividing weight in kilograms by height in meters squared.
Because the BMI of very few participants was in the normal weight category, the normal weight and overweight groups were combined in analyses and defined as not obese. Participants were asked to remove all excess clothing before we measured waist circumference. The measurement was taken at the end of expiration.
We measured waist circumference, recorded to the nearest tenth of a centimeter, 2 to 3 times and used the average of the 2 closest measurements within 2 cm. Before measuring blood pressure, we asked participants to sit quietly for 5 minutes with legs uncrossed and to remove any excess clothing. We used the average of the second and third readings. Hypertension was classified as mean systolic blood pressure at or higher than mm Hg, mean diastolic blood pressure at or higher than 90 mm Hg, or self-reported hypertension.
To assess diabetes, we asked participants if they had ever been told by a doctor, nurse, or other health professional that they had diabetes.
We excluded 5 items from the questionnaire to make the process less burdensome for participants and added a single item measuring frequency of dancing and moving during church services. Hours per week spent in light- moderate- and vigorous-intensity physical activity ie, all activities with metabolic equivalent values of 2.
This scale correlates moderately with hour recall measures of fruit and vegetable consumption 20which are considered the gold standard in dietary research We used SAS statistical software version 9. Frequencies, means, and standard deviations were calculated for self-report, demographic, and health-related behaviors. Total physical activity was positively skewed at baseline but was normalized with a square-root transformation.
Logistic regression analyses were used to examine the associations between waist circumference independent variable, defined as normal, increased risk, or substantially increased risk and both diabetes and hypertension dependent variables.
Because analyses that ed for dependency among participants from the same church ie, participants nested within churches did not differ from those that did not for this dependency, the latter are presented because of their simplicity in interpretation. Multivariate analysis was conducted to control for numerous potential confounding variables known to influence each of the dependent variables. Model 1 included only waist circumference.
To control for potential sociodemographic confounding variables that may be associated with hypertension and diabetes, adjustments for age continuouseducation less than high school graduate or high school graduate, some college or moreand marital status married, not married were included in model 2.
The final adjusted model model 4 included waist circumference and all sociodemographic and health-related variables. At baseline, a total of women participated in FAN; we excluded of these women from our study because data were missing on 1 or more variables needed for analyses.
Data on participants were included in the analysis Table 1. Most participants had at least some college education Mean age was Most study participants had hypertension On average, participants consumed 3. Increased-risk and substantially increased-risk waist circumference both showed positive associations with diabetes. In model 3, the odds of having diabetes were ificantly greater for those with a substantially increased-risk waist circumference than for those with an increased-risk waist circumference.
Nationally, the prevalence of hypertension and diabetes is highest among African Americans 2who are also at greatest risk for illness and death related to diabetes 2.
African American women in particular have the highest prevalence of hypertension in the United States compared with all other racial and ethnic groups of both sexes, which further increases their risk of illness and death from CVD 2. Additionally, the group most disproportionately affected by obesity is African American women 2.
Because a large percentage of African American women in the United States are overweight or obese and because a large percentage of these women have hypertension or diabetes, research needs to focus on the public health effect of increased abdominal adiposity.
One study suggests that the relationship between BMI and hypertension or BMI and diabetes is weaker for African Americans than for other racial groups Despite this finding, there is limited research regarding the use of waist circumference measurements to assess increased risk for diabetes and hypertension in African American women.
Data from the National Health and Nutrition Examination Survey further show that African American women have most recently past 5 years had the greatest increase 6. This clinically defined waist circumference threshold for abdominal obesity has been associated, independent of BMI, with hypertension 23 - 25 and type 2 diabetes 24 - 26 in predominantly white populations; however, in some minority populations a J-shaped relationship has been reported 27 and, in some cases, no association Additionally, compared with all African American women in South Carolina based on South Carolina Behavioral Risk Factor Surveillance System dataour study participants had higher rates of hypertension In our sample, increased waist circumference was also associated with higher risk of hypertension and diabetes independent of BMI.
Despite the high correlation between BMI and waist circumference, a major finding was that after controlling for sociodemographic and health-related variables, including BMI, an independent and ificant association between waist circumference and both diabetes and hypertension remained.
Thus, waist circumference still explains variance in diabetes and hypertension that BMI does not. Our are consistent with findings.
Okosun et al 9 assessed the association of waist circumference and risk of hypertension and type 2 diabetes in populations from several different African origins. Findings from this cross-sectional study showed that waist circumference was ificantly and positively associated with blood pressure and fasting blood glucose, regardless of origin 9. further showed that participants in the highest waist circumference quartile Studies have shown that abdominal adiposity has adverse effects on health, regardless of BMI Furthermore, in the last decade, it appears there have been greater increases in the prevalence of abdominal adiposity among African American women A major public health concern in the United States is the reduction of racial health disparities CVD and associated risk factors ie, obesity, hypertension, diabetes, and physical inactivity disproportionately affect the lives of African American women 2.
The prevalence of CVD-associated risk factors was high in our study. Public health goals and objectives must be clearly defined to target the health effect of increased abdominal adiposity and health risk factors, especially among African American women.
Measurements of waist circumference can be useful in the assessment of abdominal obesity and disease risk Traditionally, BMI has been used to determine obesity and categorize persons into weight that may be associated with greater health risk. However, a normal BMI does not necessarily indicate normal levels of abdominal adiposity Waist circumference should be considered a practical method for assessing risk factors for CVD in African American women, as it has been shown to be for white women 11 The use of BMI and waist circumference together could enable better assessment of individual health risks.