INTRODUCTION
Vietnamese Americans constitute the second fastest growing Asian subgroup in the US.
1 In 2004, this population exceeded 1.25 million, with nearly half living in California.
2 Most are foreign-born, and a majority (55%) have limited English proficiency.
2 Vietnamese Americans have low educational attainment, high unemployment, and low self-rated health.
3‐
12 They have marked health disparities, including the highest cervical and liver cancer incidence rates of any ethnic groups.
13,
14 Limited access to health care, traditional health beliefs, lack of knowledge about health, and impaired physician-patient communication are important health-related barriers faced by this population.
8
Among Asian Americans and Pacific Islanders, heart disease and stroke (i.e., cardiovascular diseases) are the second and third most common causes of death, respectively,
15 and the incidence rates for these diseases have been rising for some Asian subgroups.
16,
17 In general, there is a lack of data on cardiovascular diseases for Asian-American subgroups. In 1992, data from the California Behavioral Risk Factor Surveillance System (BRFSS) showed that fewer Vietnamese had a cholesterol test compared with the general population.
3 More recent studies of Vietnamese Americans have reported a high prevalence of hypertension, low levels of exercise, and knowledge about cardiovascular diseases and their risk factors, but they have been limited by the use of convenience sampling.
18‐
20 Some population-based studies have described high prevalence of tobacco use among Vietnamese American men.
21,
22 This study differs from prior published studies in that it is a population-based study with a sufficient sample size to provide reliable population-based estimates of cardiovascular disease prevalence, risk factors, knowledge, and related behaviors among Vietnamese Americans and in that it compares these results to a similar survey of non-Hispanic whites.
RESULTS
Table
1 shows the sociodemographic characteristics of 4,254 Vietnamese and 19,324 non-Hispanic White respondents. Vietnamese Americans were older, more likely to have lower educational attainment, less likely to be employed, and more likely to report an annual household income less than $25,000 (all
p < 0.05).
Table 1
Sociodemographic Characteristics among Vietnamese Americans in Santa Clara County, California, and non-Hispanic whites in California (2002–2005)
Age (years)* | | |
18–34 | 26.7 (25.1, 28.3) | 33.9 (33.1, 34.8) |
35–54 | 43.8 (42.2, 45.4) | 39.5 (38.7, 40.4) |
55+ | 29.5 (28.0, 30.9) | 26.5 (25.8, 27.3) |
Sex | | |
Male | 48.9 (47.2, 50.6) | 49.3 (48.4, 50.2) |
Education* | | |
Less than high school | 28.7 (27.2, 30.1) | 17.2 (16.4, 18.0) |
High school graduate | 25.3 (23.8, 26.7) | 23.6 (22.8, 24.4) |
Some college or higher | 46.0 (44.4, 47.7) | 59.1 (58.2, 60.1) |
Employment* | | |
Employed | 45.7 (44.1, 47.4) | 51.1 (50.2, 52.0) |
Self-employed | 4.3 (3.7, 5.0) | 9.7 (9.3, 10.2) |
Out of work | 13.3 (12.2, 14.5) | 6.6 (6.1, 7.0) |
Homemaker/student/retired | 27.3 (25.9,28.8) | 27.8 (27.0, 28.6) |
Unable to Work | 9.4 (8.5, 10.3) | 4.8 (4.4, 5.2) |
Annual household income* | | |
<$25,000 | 43.9 (42.2, 45.5) | 29.5 (28.7, 30.4) |
$25,000 to <$50,000 | 22.3 (20.7, 23.5) | 23.2 (22.5, 24.0) |
≥$50,000 | 21.6 (20.2, 23.0) | 38.8 (38.0, 39.6) |
Unknown | 12.4 (11.3, 13.5) | 8.4 (7.9, 8.9) |
Cardiovascular diseases, health behaviors, and risk factors are presented in Table
2. The age-standardized prevalence of diabetes mellitus, coronary heart disease, and hypertension were lower among Vietnamese Americans than among non-Hispanic whites. The differences were small but statistically significant (p < 0.05). Vietnamese Americans with hypertension were more likely to take blood pressure medications compared to non-Hispanic whites. Both groups had similar prevalence of stroke and hypercholesterolemia. Obesity was rare among Vietnamese Americans (2.1% with BMI ≥30 kg/m
2).
Table 2
Cardiovascular Diseases and Risk Factors Among Vietnamese Americans in Santa Clara County, California, and Non-Hispanic Whites in California (2002–2005)
History of Diseases and Treatment |
Diabetes mellitus*†
| 5.3 (4.7, 6.0) | 7.3 (6.8, 7.8) |
Stroke†
| 2.3 (1.5, 3.4) | 2.5 (2.0, 3.0) |
Coronary heart disease*†
| 3.1 (2.3, 4.3) | 5.7 (5.0, 6.4) |
Hypertension*†
| 22.4 (21.2, 23.6) | 24.5 (23.6, 25.4) |
Taking blood pressure medication if has hypertension* | 75.2 (72.1, 77.9) | 65.5 (63.1, 67.8) |
Ever had cholesterol checked†
| 73.0 (71.4, 74.6) | 74.4 (73.3, 75.5) |
Has high cholesterol if has cholesterol checked†
| 30.2 (28.6, 31.9) | 30.7 (29.5, 32.0) |
Risk Factors |
Body mass index*†
| | |
Normal (<25 kg/m2) | 80.6 (79.2, 82.0) | 41.0 (40.2, 41.9) |
Overweight (25-<30 kg/m2) | 17.3 (16.0, 18.7) | 37.3 (36.4, 38.2) |
Obese (≥30 kg/m2) | 2.1 (1.6, 2.7) | 21.7 (20.9, 22.4) |
Fruits and vegetables intake (times/day)*†
| | |
None | 5.5 (4.8, 6.4) | 4.9 (4.5, 5.4) |
1 or 2 | 42.9 (41.2, 44.7) | 33.9 (33.0, 34.9) |
3 or 4 | 35.2 (33.6, 36.9) | 33.3 (32.4, 34.3) |
5 or more | 16.3 (15.1, 17.6) | 27.8 (26.9, 28.8) |
Physical activity*
†
| | |
Meets recommendation | 22.7 (21.2, 24.2) | 33.7 (32.5, 34.9) |
Some activity but did not meet recommendation | 37.2 (35.5, 38.9) | 54.2 (53.0, 55.5) |
No moderate or vigorous activity | 40.1 (38.4, 41.8) | 12.1 (11.3, 13.0) |
Smoking status, men*†
| | |
Current | 29.8 (27.5, 32.3) | 19.0 (17.9, 20.1) |
Former | 19.3 (17.5, 21.2) | 28.5 (27.4, 29.6) |
Never | 50.9 (48.3, 53.5) | 52.5 (51.2, 53.9) |
Smoking status, women*†
| | |
Current | 1.1 (0.7, 1.7) | 12.3 (11.5, 13.0) |
Former | 1.1 (0.7, 1.7) | 20.4 (19.6, 21.2) |
Never | 97.8 (97.0, 98.4) | 67.4 (66.3, 68.4) |
Compared to non-Hispanic whites, Vietnamese Americans were less likely to eat fruits and vegetables five or more times daily (16.3% vs 27.8%, p < 0.05) or to engage in moderate or vigorous physical activity (40.1% vs 12.1%, p < 0.05). Among men, Vietnamese Americans were more likely than non-Hispanic whites to be current smokers (29.8% vs 19.0%, p < 0.05).
The age-adjusted prevalence of diabetes mellitus was higher among Vietnamese Americans who responded in the Vietnamese language than among those who responded in English (5.6% vs 3.5%, p < 0.05), while the prevalences of coronary heart disease, stroke, hypertension, and hypercholesterolemia were similar. Vietnamese speakers were less likely than those who responded in English to consume more fruits and vegetables and to meet physical activity recommendations (all p < 0.05) (Table
3). Vietnamese-speaking men were more likely to be current smokers than English-speaking Vietnamese men (31.4% vs 28.1%, p < 0.05). Although English-speaking Vietnamese women were more likely to be current smokers (1.5% vs 0.8%, p < 0.05) and Vietnamese-speaking women were more likely to be past smokers (1.3% vs 0.4%, p < 0.05), 98% of the Vietnamese women, regardless of the language they spoke, were never smokers.
Table 3
Cardiovascular Risk Factors, Knowledge, and Related Health Behaviors Among Vietnamese- speaking and English-speaking Vietnamese in Santa Clara County, California (2002–2005)
Risk Factors |
Body mass index | | |
Normal (<25 kg/m2) | 80.8 (79.1, 82.4) | 80.6 (77.7, 83.2) |
Overweight (25-<30 kg/m2) | 17.3 (15.8, 19.0) | 17.1 (14.6, 19.8) |
Obese (≥30 kg/m2) | 1.9 (1.4, 2.6) | 2.3 (1.5, 3.5) |
Fruits and vegetables intake (times/day)* | | |
None | 5.2 (4.3, 6.3) | 5.9 (4.4, 7.9) |
1 or 2 | 45.9 (43.7, 48.0) | 35.9 (32.7, 39.2) |
3 or 4 | 34.0 (32.0, 36.1) | 38.3 (35.0, 41.7) |
5 or more | 14.9 (13.4, 16.5) | 19.9 (17.3, 22.7) |
Physical activity* | | |
Meets recommendation | 21.3 (19.6, 23.1) | 25.4 (22.5, 28.6) |
Some activity but did not meet recommendation | 35.9 (33.8, 38.0) | 39.1 (35.8, 42.4) |
No moderate or vigorous activity | 42.8 (40.7, 45.0) | 35.5 (32.3, 38.9) |
Smoking status, men* | | |
Current | 31.4 (28.5, 34.5) | 28.1 (23.8, 32.8) |
Former | 20.9 (18.7, 23.3) | 14.5 (11.5, 18.2) |
Never | 47.7 (44.5, 50.9) | 57.4 (52.4, 62.2) |
Smoking status, women* | | |
Current | 0.8 (0.4, 1.5) | 1.5 (0.8, 3.0) |
Former | 1.3 (0.8, 2.0) | 0.4 (0.1, 1.4) |
Never | 98.0 (97.0, 98.6) | 98.0 (96.5, 98.9) |
Knowledge |
Knew to call 911 if have a heart attack or stroke | 84.2 (82.6, 85.7) | 86.1 (83.4, 88.4) |
Knew chest pain is a symptom of heart attack | 57.8 (55.6, 59.9) | 60.1 (56.7, 63.3) |
Knew sudden numbness or weakness is a symptom of stroke | 66.0 (64.0, 68.0) | 69.0 (65.7, 72.1) |
Correct knowledge of heart attack symptoms and action | 0.6 (0.3, 1.1) | 1.2 (0.7, 2.0) |
Correct knowledge of stroke symptoms and action | 4.2 (3.4, 5.1) | 4.0 (3.0, 5.4) |
There was no significant difference in the knowledge of symptoms of heart attack and stroke between Vietnamese-speaking and English-speaking Vietnamese Americans (Table
3). Most Vietnamese Americans (85%) knew that they should “call 911” if they had a heart attack or stroke, but only 59% knew that chest pain was a symptom of heart attack, and only 67% knew that sudden numbness or weakness of the face, arms, or legs was a symptom of stroke. Only 5% and 22% of Vietnamese Americans could identify all five correct symptoms for heart attack or stroke, respectively. Less than 1% and 5% of Vietnamese Americans had the correct knowledge of symptoms and action (five correct symptoms, one incorrect symptom, and “call 911”) for heart attack and strokes, respectively.
DISCUSSION
To our knowledge, this is the first in-depth report of a population-based survey of cardiovascular risk factors and knowledge of symptoms of heart attack and stroke among Vietnamese Americans. Compared with non-Hispanic whites in California, Vietnamese Americans reported lower prevalences of obesity, diabetes mellitus, coronary heart disease, and hypertension, similar prevalences of hypercholesterolemia and stroke, lower frequency of fruit and vegetable intake, and higher rates of physical inactivity and, among men, cigarette smoking. Among Vietnamese Americans, those who responded in the Vietnamese language were more likely to eat fruits and vegetables less frequently on a daily basis, engage in no moderate or vigorous physical activity, and, among men, be current smokers.
Some studies have reported that Asians suffer from obesity-related problems at a lower BMI cutoff than the usual standards.
29,
30 In this study, compared to non-Hispanic whites, Vietnamese Americans had a much lower prevalence of obesity, but a similar prevalence of hypercholesterolemia and only slightly lower prevalences of diabetes mellitus and hypertension. Higher BMI has been shown to be associated with US birthplace in Asian-American populations.
31 We did not measure birthplace, but there was no difference in BMI between Vietnamese Americans who responded in Vietnamese or in English.
Physical inactivity is an important cardiovascular risk factor, and 40% of Vietnamese Americans, compared to 12% of non-Hispanic whites, did not engage in any moderate or vigorous activity. Physical activity measures in this study included walking, gardening, and other activities that raise the heart rate, as well as typical exercise, such as running. Thus, cultural differences in activities that constitute exercise are unlikely explanations for this difference. Little has been published about how Vietnamese Americans view exercise or what type of activity would engage them. We did find here that those who spoke Vietnamese were slightly less likely to report adequate physical activity. Thus, more research is needed to delineate the barriers and interventions needed to promote exercise among this population.
Cigarette smoking is another important risk factor for cardiovascular diseases. Smoking prevalence in the general male population of California have declined from 28.2% in 1985 to 17.0% in 2005.
32 However, the prevalence among Vietnamese men in Santa Clara County, California, has barely declined, from 35% in 1996
33 to 31.2% in 2001
22 to 29.8% in this study. This slight decline has occurred despite the availability of a toll-free quitline with Vietnamese-language capability, multimedia campaigns in the Vietnamese language, and medications to treat nicotine addiction.
34,
35 Clearly, new approaches, which may have to be more directed and intensive, are needed to reduce smoking among men in this population. Efforts should also be made to maintain the low rates of smoking among Vietnamese-American women since there may be a rise in smoking with acculturation among Asian Americans.
36
Vietnamese Americans may not meet the Healthy People 2010 recommendations for fruit and vegetable consumption (75% with at least two daily servings of fruit and 50% with at least three daily servings of vegetables).
37 This finding is rather surprising, because the typical Vietnamese diet is high in carbohydrates and low in fat
38, and Vietnamese Americans report a strong preference for fruits and vegetables.
39 Measurement problems may underlie this finding. Five of the six items in the questionnaire ask for “times” rather than “servings,” and it is possible that Vietnamese Americans may eat more than one serving of fruit or vegetables at a time. It is important for future studies of nutrition among Vietnamese and Asian Americans to assess the best method to collect accurate dietary intake data.
Another problem identified by this study is the lack of knowledge of heart attack and stroke symptoms. Recognition of these symptoms is important, because early treatment can save lives and prevent morbidity. Only 59% of Vietnamese Americans in this study knew that chest pain was a symptom for heart attack, compared to 95% of Americans in the 2001 BRFSS.
28 In our study, there was no differences in knowledge of symptoms between English-speaking and Vietnamese-speaking Vietnamese Americans. An educational campaign targeting Vietnamese Americans in both languages about the symptoms of heart attack and stroke may be needed.
The findings in this report are subject to some limitations. Persons without telephones and those who used only cell phones were not included in the survey. Because estimates were based on self-reported data, the prevalence of certain chronic conditions might be under- or overestimated. Although most of the measures included in this report have high or moderate reliability and validity,
40 they have not been evaluated in Vietnamese populations.
Our study shows that the self-reported prevalences of cardiovascular diseases are somewhat lower among Vietnamese Americans than among non-Hispanic whites. However, Vietnamese Americans have significant disparities in cardiovascular risk factors, such as physical inactivity and cigarette smoking among men, as well as in knowledge of heart attack and stroke symptoms. It is likely that, in the absence of change, the rates of adverse cardiovascular outcomes, such as heart attacks and strokes, will rise. The findings from this study underscore a need for further research into understanding the determinants of cardiovascular risk factors and into developing culturally appropriate interventions to address them in this understudied population.