Contemporary female smokers in the us are younger and of lower socioeconomic status

doi:10.4236/health.2011.36060

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Vol.3, No.6, 357-361 (2011)

doi:10.4236/health.2011.36060

Health

Contemporary female smokers in the US are younger

and of lower socioeconomic status

——A brief report of the 2008-2009 results from Sister to Sister: The Women’s Heart Health

Foundation Registry

Jennifer L. Jarvie1, Yun Wang2, Caitlin E. Johnson3, JoAnne M. Foody3,4*

1University of Colorado School of Medicine, Aurora, USA;

2Department of Biostatistics, Harvard School of Public Health, Boston, USA;

3Department of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, USA;

4Harvard Medical School, Boston, USA; *Corresponding Author: [email protected]

Received 2 March 2011; revised 3 May 2011; accepted 10 May 2011.

ABSTRACT

Smoking is the most common cause of prema-

ture cardiovascular disease in women, but con-

temporary data is lacking. We sought to inves-

tigate the differences between female smokers

and nonsmokers in the US. Methods: Using a

registry of almost 19,000 women who attended

free public heart screenings sponsored by Sis-

ter to Sister between 2008 and 2009 in 17 large

US cities, we compared the means for lipid val-

ues, cardiometabolic measures, and differences

in sociodemographic information between smok-

ers and nonsmokers. Secondary outcomes were

age and race-adjusted odds for obesity, the

metabolic syndrome, hypertension, a non-HDL >

160 mg/dl, and a serum glucose ≥ 126 mg/dl

between smoking and nonsmoking women.

Results: The final sample included 18,892

women (49.8 ± 14.3 years, 37% black, and 32%

white, 14% Hispanic), with 1,216 (6.4%) current

smokers. Smokers were younger than non-

smokers (45.6 ± 13.0 vs 50.1 ± 14.4 years, p <

0.001), with lower HDL levels (55.5 ± 17.4 vs 58.6

± 17.4, p < 0.001), and higher triglycerides (148.8

± 103.7 vs 145.5 ± 93, p = 0.4082). There were no

significant differences in LDL between smokers

versus nonsmokers. There were more black and

white women in the smoking group. Smoking

women were more likely to meet criteria for the

metabolic syndrome (OR 1.22; 95% CI 1.00 - 1.49)

and have a non-HDL > 160 mg/dl (OR 1.19; 1.01 -

1.39). Insurance and income data showed a sig-

nificant inverse relationship between smoking

prevalence and increasing household income.

Conclusions: In this richly diverse sample of

women, female smokers were younger and of

lower socioeconomic status than nonsmokers

with significant differences in cardiometabolic

risk factors.

Keywords: Cigarette Smoking; Cardiovascular

Risk Factors; Women; Prevention

1. INTRODUCTION

Smoking is the strongest risk factor for premature

cardiovascular disease (CVD) in women [1]. While it is

well established that smoking triples CVD death, dou-

bles stroke risk, and increases peripheral vascular dis-

ease 10-fold, nearly 1 in 5 women continue to smoke [2].

While smoking rates continue to decrease in men,

rates of decline in women have plateaued [3,4]. Reasons

for the plateau are unclear and few contemporary data

exist for women. Utilizing data from a richly diverse

group of community-based women, we investigated the

characteristics of female smokers and nonsmokers.

2. METHODS

2.1. Study Sample

The study sample included women who attended free

Sister to Sister (STS) public heart screenings held annu-

ally in 17 large US cities in 2008 and 2009 (Atlanta, GA,

Baltimore, MD, Boston, MA, Chicago, IL, Dallas, TX,

Detroit, MI, Jacksonville, FL, Los Angles, CA, Miami,

FL, St. Louis, MO, Tampa, FL, and Washington, DC

held fairs in both 2008 and 2009, while Charlotte, NC,

Indianapolis, IN, New York, NY, Philadelphia, PA, and

Phoenix, AZ held fairs in 2008 only).

Screenings consisted of a standardized questionnaire

J. L. Jarvie et al. / Health 3 (2011) 357-361

358

assessing sociodemographic information, current smok-

ing status as yes/no, and personal history of CVD. In

addition, cardiometabolic measurements were obtained

by trained healthcare professionals. Participants who

attended 2009 fairs were queried regarding annual

household income and insurance status.

2.2. Outcomes

Cardiometabolic measures included a single auto-

mated blood pressure measurement, height, weight, body

mass index (BMI) calculation, and waist circumference

(WC) measurement taken above the iliac crest and re-

ported to the nearest 0.1 inch. Plasma glucose and cho-

lesterol were measured using fingerstick technology on

the Cholestech® LDX Analyzer (Hayward, CA). Cho-

lesterol measures included total cholesterol (TC),

high-density lipoprotein (HDL) cholesterol, and triglyc-

erides (TG). Non-HDL cholesterol and low-density

lipoprotein (LDL) cholesterol were calculated.

Hypertension (HTN) was defined as a systolic blood

pressure (SBP) ≥ 140 mmHg and/or a diastolic blood

pressure (DBP) ≥ 90 mmHg. Criteria for the metabolic

syndrome (MetS) were defined using the updated NCEP

ATP III guidelines [5], which included 3 or more of the

following: WC ≥ 35 inches, TG ≥ 150 mg/dl, HDL < 50

mg/dl, SBP ≥ 130 mmHg or DBP ≥ 85 mmHg, or a fast-

ing glucose ≥ 100 mg/dl.

All forms and procedures were approved by Quorum

Institutional Review Board (Seattle, WA).

2.3. Statistical Analysis

Descriptive and bivariate analyses were conducted to

compare demographics, comorbidities, vital signs, and

lab test data between smoker and non-smoker groups.

Chi-square tests and Wilcoxen rank-sum tests were used

for categorical variables and continuous variables, re-

spectively. A hierarchical generalized linear model

(HGLM) was developed to assess the risk difference

between smoking and nonsmoking groups for each out-

come measure and adjusted for age. We calculated 95%

confidence intervals (CI) for each estimate obtained

from the model. A dummy variable was created in the

model to represent records that had missing age, and

excluded records with missing BMI, vital signs, and lab

test data for each outcome measure. All statistical testing

was 2-sided, at a significance level of 0.05, and all

analyses were conducted using SAS version 9.2 (SAS

Institute Inc., Cary, NC).

3. RESULTS

Participant characteristics are listed in Table 1. The

final sample included 18,892 women (mean age 49.8 ±

14.3 years) with 37% (7,030) non-Hispanic black

women, 32% (5,991) non-Hispanic white women, 14%

(2,665) Hispanic women, and 17% of women in the

“other” category, which included 6% of women who

Table 1. Sister to Sister heart screening participant characteristics 2008 & 2009.

Nonsmokers Smokers p-value

Number of Participants (%) 17676 (93.6) 1216 (6.7) …

Mean Age (SD) 50.1 (14.4) 45.6 (13.0) < 0.001

Sociodemographics Total % Total %

Non-Hispanic Black 6529 36.9 501 41.2 …

Non-Hispanic White 5577 31.6 414 34.1 …

Hispanic 2491 14.1 174 14.3 …

Other* 3079 17.4 127 10.5 …

Lab Values Mean SD Mean SD

Total Cholesterol (mg/dl) 194.5 42.6 192 42.6 0.0809

HDL Cholesterol (mg/dl) 58.6 17.4 55.5 17.4 < 0.001

LDL Cholesterol (mg/dl) 110.1 36.2 110.4 36.4 0.8208

Triglycerides (mg/dl) 145.5 93.0 148.8 103.7 0.4082

Non-HDL (mg/dl) 136.9 41.8 136.8 43.8 0.9626

Glucose (mg/dl) 105.5 31.8 105.9 27.9 0.7122

Cardiometabolic Measures Mean SD Mean SD

Systolic Blood Pressure (mmHg) 126.9 19.7 125.6 19.9 0.0383

Diastolic Blood Pressure (mmHg) 77.0 12.8 78.2 13.8 0.0062

BMI (kg/m2) 27.9 6.3 28.1 6.3 0.2649

J. L. Jarvie et al. / Health 3 (2011) 357-361

359359

Waist Circumference (in) 36.2 6.0 36.3 6.1 0.5724

*Other race/ethnicity includes 6% of women with race/ethnicity other than black, Hispanic, or white and 11% of women with unknown race/ethnicity. HDL =

igh-density lipoprotein; LDL = low-density lipoprotein; BMI = body mass index; Ellipses (…) indicate test was not performed. h

listed racial and ethnic backgrounds other than black,

white, or Hispanic and 11% of women with unknown

race/ethnicity. Of the total, 1,216 (6.4%) were current

smokers and 17,676 (93.6%) were current nonsmokers.

Smokers were significantly younger (45.6 ± 13.0 years)

than nonsmokers (50.1 ± 14.4 years), with higher

triglycerides (148.8 ± 103.7 mg/dl vs 145.5 ± 93 mg/dl,

respectively), and significantly lower HDL levels (55.5 ±

17.4 mg/dl vs 58.6 ± 17.4 mg/dl, respectively). Smokers

also had a significantly lower mean systolic blood pres-

sure compared with nonsmokers (125.6 ± 19.9 mmHg vs

126.9 ± 19.7 mmHg, respectively), but a significantly

higher mean diastolic blood pressure compared with

nonsmokers (78.2 ± 13.8 mmHg vs 77.0 ± 12.8 mmHg,

respectively). Proportionally, there was a higher makeup

of non-Hispanic black and non-Hispanic white women

in the smoking group (41.2% and 34.1%, respectively)

compared with the nonsmoking group (37.0% and

31.6%, respectively).

A higher proportion of smokers were obese (35.4%)

and met criteria for the MetS (37.2%) compared with

nonsmoking women (32.6% and 34%, respectively)

(data not shown). A strong relationship between age and

smoking status was observed (Figure 1), such that there

were more smokers among the younger age groups.

Significant differences existed in insurance status be-

tween smokers and non-smokers (Figure 2a), where

only 45% of smokers had private insurance compared

with 54.8% of nonsmokers, and a higher makeup of

smokers were uninsured (40.5%) or on Medicaid (5.4%)

compared with nonsmokers (33.7% and 2.3%, respec-

tively). A significant inverse relationship was observed

between female smoking prevalence and annual house-

hold income (Figure 2b).

Risk adjusted outcomes revealed smokers had a sig-

nificantly higher risk of the MetS (OR 1.22; 95% CI 1.00

- 1.49) as well as a non-HDL > 160 mg/dl (OR 1.19; 95%

CI 1.01 - 1.39) compared with nonsmokers (Table 2).

Figure 1. Smoking prevalence was higher among younger women.

J. L. Jarvie et al. / Health 3 (2011) 357-361

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Figure 2. Socioeconomic differences between smokers and nonsmokers.

Table 2. Risk adjusted outcomes in Sister to Sister women.

Obesity MetS HTN Non-HDL > 160 Glucose ≥ 126

Group

OR (95% CI) OR (95% CI) OR (95% CI) OR (95% CI) OR (95% CI)

Age-Adjusted 1.00 (1.00 - 1.01) 1.02 (1.02 - 1.03) 1.04 (1.04 - 1.05) 1.02 (1.02 - 1.03) 1.03 (1.02 - 1.03)

Nonsmoker 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference) 1.00 (reference)

Smoker 1.12 (0.98 - 1.28) 1.22 (1.00 - 1.49) 1.02 (0.87 - 1.19) 1.19 (1.01 - 1.39) 1.15 (0.94 - 1.41)

Odds ratios were drawn from a logistic model adjusted for age and race. Reference Groups: Nonsmokers reference for comparison with smokers. BMI = Body

Mass Index; MetS = Metabolic Syndrome; OR = Odds Ratio; 95% CI = 95% Confidence Interval; Obesity defined as BMI ≥30. MetS defined as any combina-

tion of 3 or more of the following: waist circumference ≥ 35 in, triglycerides ≥ 150 mg/dl, HDL < 50 mg/dl, SBP ≥ 130 mmHg or DBP ≥ 85 mmHg, and/or

fasting glucose > 100 mg/dl.

4. COMMENTS

In this cross-sectional analysis of a richly diverse

sample of community women in the US, smokers were

younger, with lower HDL cholesterol levels, higher TG

levels, and a higher proportion of women who met crite-

ria for the MetS. The prevalence of smoking decreased

with increasing annual household income, and a higher

proportion of women who smoked were uninsured or on

Medicaid.

Our findings are consistent with US data from the

2008 National Health Interview Survey, where preva-

lence of smoking was highest among adults < 65 years

of age [1]. Further, results from the Nurses’ Health Study

showed that women who start smoking before the age of

15 have the highest risk of CVD mortality (relative risk

9.94; 95% CI 5.15 - 19.19) [6]. These findings illustrate

the importance of aggressive smoking prevention efforts

directed towards younger women given that it negates

otherwise typical cardioprotection in a premenopausal

woman.

Women smokers had an average HDL cholesterol 3

mg/dl lower than nonsmoking women—translating into

a 12% increased risk for CVD [7]. This was coupled

with increased rates of obesity and the MetS, each in-

creasing CVD risk. While we expected to see hypergly-

cemia in the smoking group given earlier reports of the

association between cigarette smoke and insulin resis-

tance [8-12], this was not the case, although increased

rates of obesity and the MetS may be earlier markers.

Our overall smoking rate was notably low (6.7%) and

may be a reflection of health-seeking persons who attend

health screenings. These women would be less likely to

smoke or continue smoking given their concern for

overall wellness, although we also captured a substantial

number of women without health coverage looking for

free services. Therefore, we feel our results are gener-

alizable and our findings are consistent with previous

investigations [1,13].

Although this study adds to the outdated body of lit-

erature on the differences between smokers and non-

smokers, this study does have limitations. First, while

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the majority of women attending the fair were fasting,

some were not. Fasting status was recorded at the time

of testing, but a non-fasting state could result in elevated

glucose, TG, and LDL. Second, a single blood pressure

measure was taken for most women, which may have

overestimated mean blood pressure measures, although

women with high readings received additional confir-

matory measures, which would increase the accuracy of

high findings. Third, former smoking status was not col-

lected and many women may have been former smokers.

However, cardiovascular risk drops precipitously after

smoking cessation and approaches that of nonsmokers

within several years [6,14,15]. Fourth, we were unable to

account for medication use, which could have resulted in

the under-estimation of HTN, hyperlipidemia, and hy-

perglycemic rates if controlled.

5. CONCLUSION

Female smokers who attended STS heart screening

fairs in 2008 and 2009 were younger than nonsmokers

and of lower socioeconomic status with significantly

lower levels of HDL cholesterol and higher risk of the

MetS. Taken together, these differences substantially

increase a female smoker’s risk of a cardiovascular event,

and signal the need for more aggressive smoking pre-

vention programs targeted at younger populations from

lower socioeconomic neighborhoods.

6. ACKNOWLEDGEMENTS

We would like to thank Mrs. Irene K Pollin MSW, founder of the

Sister to Sister Foundation, for her leadership and insights and her

continued support for events and research that promote awareness and

prevention of heart disease in women.

Dr. Foody was supported in part by a grant from the Irene and Abe

Pollin Foundation and Sister to Sister: The Women’s Heart Health

Foundation. Dr. Jarvie was supported by the Sarnoff Cardiovascular

Research Foundation, Inc.

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