Elisa K. Tong

Prospective Study of Obstructive Sleep Apnea and Incident Coronary Heart Disease and Heart Failure The Sleep Heart Health Study

Background— Clinic-based observational studies in men have reported that obstructive sleep apnea is associated with an increased incidence of coronary heart disease. The objective of this study was to assess the relation of obstructive sleep apnea to incident coronary heart disease and heart failure in a general community sample of adult men and women. Methods and Results— A total of 1927 men and 2495 women ≥40 years of age and free of coronary heart disease and heart failure at the time of baseline polysomnography were followed up for a median of 8.7 years in this prospective longitudinal epidemiological study. After adjustment for multiple risk factors, obstructive sleep apnea was a significant predictor of incident coronary heart disease (myocardial infarction, revascularization procedure, or coronary heart disease death) only in men ≤70 years of age (adjusted hazard ratio 1.10 [95% confidence interval 1.00 to 1.21] per 10-unit increase in apnea-hypopnea index [AHI]) but not in older men or in women of any age. Among men 40 to 70 years old, those with AHI ≥30 were 68% more likely to develop coronary heart disease than those with AHI <5. Obstructive sleep apnea predicted incident heart failure in men but not in women (adjusted hazard ratio 1.13 [95% confidence interval 1.02 to 1.26] per 10-unit increase in AHI). Men with AHI ≥30 were 58% more likely to develop heart failure than those with AHI <5. Conclusions— Obstructive sleep apnea is associated with an increased risk of incident heart failure in community-dwelling middle-aged and older men; its association with incident coronary heart disease in this sample is equivocal.

Association of active and passive smoking with risk of breast cancer among postmenopausal women: a prospective cohort study

Objective To examine the association between smoking and risk of invasive breast cancer using quantitative measures of lifetime passive and active smoking exposure among postmenopausal women. Design Prospective cohort study. Setting 40 clinical centres in the United States. Participants 79 990 women aged 50–79 enrolled in the Women’s Health Initiative Observational Study during 1993–8. Main outcome measures Self reported active and passive smoking, pathologically confirmed invasive breast cancer. Results In total, 3520 incident cases of invasive breast cancer were identified during an average of 10.3 years of follow-up. Compared with women who had never smoked, breast cancer risk was elevated by 9% among former smokers (hazard ratio 1.09 (95% CI 1.02 to 1.17)) and by 16% among current smokers (hazard ratio 1.16 (1.00 to 1.34)). Significantly higher breast cancer risk was observed in active smokers with high intensity and duration of smoking, as well as with initiation of smoking in the teenage years. The highest breast cancer risk was found among women who had smoked for ≥50 years or more (hazard ratio 1.35 (1.03 to1.77) compared with all lifetime non-smokers, hazard ratio 1.45 (1.06 to 1.98) compared with lifetime non-smokers with no exposure to passive smoking). An increased risk of breast cancer persisted for up to 20 years after smoking cessation. Among women who had never smoked, after adjustment for potential confounders, those with the most extensive exposure to passive smoking (≥10 years’ exposure in childhood, ≥20 years’ exposure as an adult at home, and ≥10 years’ exposure as an adult at work) had a 32% excess risk of breast cancer compared with those who had never been exposed to passive smoking (hazard ratio 1.32 (1.04 to 1.67)). However, there was no significant association in the other groups with lower exposure and no clear dose response to cumulative passive smoking exposure. Conclusions Active smoking was associated with an increase in breast cancer risk among postmenopausal women. There was also a suggestion of an association between passive smoking and increased risk of breast cancer.

China at the crossroads: the economics of tobacco and health

Objective: To analyse economic aspects of tobacco control policy issues in China. Methods: Published and collected survey data were used to analyse economic consequences of smoking. Economic analysis was used to address the role of tobacco farmers and the cigarette industry in the Chinese economy. Results: In the agricultural sector, tobacco has the lowest economic rate of return of all cash crops. At the same time, the tobacco industry’s tax contribution to the central government has been declining. Conclusion: Economic gains become less important as the negative health impact of smoking on the population garners more awareness. China stands at a crossroads to implement the economic promises of the World Health Organization’s Framework Convention on Tobacco Control and promote the health of its population.

Tobacco Industry Efforts Undermining Evidence Linking Secondhand Smoke With Cardiovascular Disease

Background— The scientific consensus that secondhand smoke (SHS) increases cardiovascular disease (CVD) risk by 30% is based on epidemiological and biological evidence. The tobacco industry has contested this evidence that SHS causes CVD, but how and why they have done it has not been described. Methods and Results— About 50 million pages of tobacco industry documents were searched using general keywords and names of industry consultants and scientists. Tobacco industry–funded epidemiological analyses of large data sets were used to argue against an epidemiological association between SHS and CVD and smoke-free regulations, but these analyses all suffered from exposure misclassification problems that biased the results toward the null. More recent industry-funded publications report an increased risk of CVD associated with SHS but claim a low magnitude of risk. When early tobacco industry–funded work demonstrated that SHS increased atherosclerosis, the industry criticized the findings and withdrew funding. RJ Reynolds focused on attacking the biological plausibility of the association between SHS and CVD by conducting indirect platelet aggregation studies, exposure chamber experiments, and literature reviews. Although these studies also suffered from exposure misclassification problems, several produced results that were consistent with a direct effect of SHS on blood and vascular function. Instead, RJ Reynolds attributed these results to an unproven epinephrine-related stress response from odor or large smoke exposure, which supported their regulatory and “reduced-harm” product development efforts. Philip Morris’ recent “reduced-harm” efforts seem supportive of a similar corporate agenda. Conclusions— The tobacco industry attempted to undermine the evidence that SHS causes CVD to fight smoke-free regulations while developing approaches to support new products that claim to reduce harm. The industry interest in preserving corporate viability has affected the design and interpretation of their cardiovascular studies, indicating the need for great caution in current debates about future tobacco industry regulation and development of reduced-harm tobacco products.

Interaction Between Smoking and Obesity and the Risk of Developing Breast Cancer Among Postmenopausal Women The Women's Health Initiative Observational Study

Obesity is a well-established risk factor for postmenopausal breast cancer. Recent studies suggest that smoking increases the risk of breast cancer. However, the effect of co-occurrence of smoking and obesity on breast cancer risk remains unclear. A total of 76,628 women aged 50-79 years enrolled in the Womens Health Initiative Observational Study were followed through August 14, 2009. Cox proportional hazards regression models were used to estimate hazard ratios and 95% confidence intervals. Over an average 10.3 years of follow-up, 3,378 incident cases of invasive breast cancer were identified. The effect of smoking on the risk of developing invasive breast cancer was modified significantly by obesity status among postmenopausal women, regardless of whether the obesity status was defined by body mass index (P(interaction) = 0.01) or waist circumference (P(interaction) = 0.02). A significant association between smoking and breast cancer risk was noted in nonobese women (hazard ratio = 1.25, 95% confidence interval: 1.05, 1.47) but not in obese women (hazard ratio = 0.96, 95% confidence interval: 0.69, 1.34). In conclusion, this study suggests that the effect of smoking exposure on breast cancer risk was modified by obesity among postmenopausal women. The modification effect did not differ by general versus abdominal obesity.

Changing Conclusions on Secondhand Smoke in a Sudden Infant Death Syndrome Review Funded by the Tobacco Industry

Background. Prenatal and postnatal exposure to tobacco smoke adversely affects maternal and child health. Secondhand smoke (SHS) has been linked causally with sudden infant death syndrome (SIDS) in major health reports. In 1992, the US Environmental Protection Agency (EPA) first noted an association between SHS and SIDS, and both prenatal exposure and postnatal SHS exposure were listed as independent risk factors for SIDS in a 1997 California EPA report (republished in 1999 by the National Cancer Institute) and a 2004 US Surgeon General report. The tobacco industry has used scientific consultants to attack the evidence that SHS causes disease, most often lung cancer. Little is known about the industry’s strategies to contest the evidence on maternal and child health. In 2001, a review was published on SIDS that acknowledged funding from the Philip Morris (PM) tobacco company. Tobacco industry documents related to this review were examined to identify the company’s influence on the content and conclusions of this review. Methods. Tobacco industry documents include 40 million pages of internal memos and reports made available to the public as a result of litigation settlements against the tobacco industry in the United States. Between November 2003 and January 2004, we searched tobacco industry document Internet sites from the University of California Legacy Tobacco Documents Library and the Tobacco Documents Online website. Key terms included “SIDS” and names of key persons. Two authors conducted independent searches with similar key terms, reviewed the documents, and agreed on relevancy through consensus. Thirty documents were identified as relevant. Two drafts (an early version and a final version) of an industry-funded review article on SIDS were identified, and 2 authors independently compared these drafts with the final publication. Formal comments by PM executives made in response to the first draft were also reviewed. We used Science Citation Index in July 2004 to determine citation patterns for the referenced SIDS reviews. Results. PM executives feared that SHS and maternal and child health issues would create a powerful and emotional impetus for smoke-free areas in the home, public areas, and the workplace. In response to the 1992 US EPA report on SHS, the Science and Technology Department of PM’s Switzerland subsidiary, Fabriques de Tabac Reunies, searched for “independent” consultants to publish articles addressing SHS. The first industry-funded article was a literature review focusing on smoking and SIDS, conducted by consultant Peter Lee and co-author Allison Thornton, which stated that the association between parental smoking and SIDS could have been attributable to the failure to control fully for confounders. That first review has only been cited once, in the subsequent industry-funded review. In 1997, PM commissioned a consultant, Frank Sullivan, to write a review, with coauthor Susan Barlow, of all possible risk factors for SIDS. The first draft concluded that prenatal and postnatal smoking exposures are both independent risk factors for SIDS. After receiving comments and meeting with PM scientific executives, Sullivan changed his original conclusions on smoking and SIDS. The final draft was changed to emphasize the effects of prenatal maternal smoking and to conclude that postnatal SHS effects were “less well established.” Changes in the draft to support this new conclusion included descriptions of Peter Lee’s industry-funded review, a 1999 negative but underpowered study of SIDS risk and urinary cotinine levels, and criticisms of the conclusions of the National Cancer Institute report that SHS was causally associated with SIDS. In April 2001, the Sullivan review was published in the United Kingdom journal Paediatric and Perinatal Epidemiology, with a disclosure statement that acknowledged financial support from PM but did not acknowledge contributions from PM executives in the preparation of the review. By 2004, the Sullivan SIDS review had been cited at least 19 times in the medical literature. Conclusions. PM executives responded to corporate concerns about the possible adverse effects of SHS on maternal and child health by commissioning consultants to write review articles for publication in the medical literature. PM executives successfully encouraged one author to change his original conclusion that SHS is an independent risk factor for SIDS to state that the role of SHS is “less well established.” These statements are consistent with PM’s corporate position that active smoking causes disease but only public health officials conclude the same for SHS. The author’s disclosure of industry funding did not reveal the full extent of PM’s involvement in shaping the content of the article. This analysis suggests that accepting tobacco industry funds can disrupt the integrity of the scientific process. The background of this SIDS review is relevant for institutions engaged in the debate about accepting or eschewing funding from the tobacco industry. Those who support acceptance of tobacco industry funds argue that academic authors retain the right to publish their work and maintain final approval of the written product, but this argument fails to recognize that the tobacco industry funds work to ensure that messages favorable to the industry are published and disseminated. Clinicians, parents, and public health officials are most vulnerable to the changed conclusions of the SIDS review. The national SIDS “Back to Sleep” campaign has been very successful in reducing SIDS rates. However, estimates of SIDS risk from SHS (odds ratios range from 1.4 to 5.1) have considerable overlap with estimates of risk from prone sleep positioning (odds ratios range from 1.7 to 12.9). With the Back to Sleep campaign well underway, efforts to address parental smoking behavior in both the prenatal and postnatal periods should be intensified. The tobacco industry’s disinformation campaign on SHS and maternal and child health can be counteracted within clinicians’ offices.

Light and intermittent smoking among California's Asian Americans

INTRODUCTION Asian Americans, along with other ethnic minorities, have been described to be more likely than Whites to be light and intermittent smokers. Characterizing Asian American smoking behavior accurately on a population level requires oversampling groups of different national origin and including non-English-speaking participants. METHODS We analyzed the California Health Interview Survey to compare moderate/heavy (> or =10 cigarettes/day), light (0-9 cigarettes/day), and intermittent (not daily) smoking patterns in Asian Americans with those of Whites. We also examined whether social and demographic factors that had been associated with Asian American smoking prevalence also were associated with light and intermittent smoking patterns in each of the national origin groups. RESULTS Most Asian American smokers were more likely to be light and intermittent smokers (range = 36.6%-61.5% for men and 29.9%-81.5% for women) compared with Whites, with lower mean cigarette consumption. Asian American light and intermittent smokers were more likely than moderate/heavy smokers to be women (odds ratio [OR] = 2.12, 95% CI = 1.14-3.94), highly educated (OR = 3.16, 95% CI = 1.21-8.28), not Korean (compared with Chinese; OR = 0.32, 95% CI = 0.13-0.79), and bilingual speakers with high English language proficiency compared with English-only speakers (OR = 2.83, 95% CI = 1.21-6.84). Asian American intermittent smokers were more likely than daily smokers to be women (OR = 2.25, 95% CI = 1.08-4.72) and to have lower household income. DISCUSSION The predominance of Asian American light and intermittent smoking patterns has important implications for developing effective tobacco control outreach. Further studies are needed to elaborate the relationship between biological, psychosocial, and cultural factors influencing Asian American smoking intensity.

Smoking and Diabetes: Does the Increased Risk Ever Go Away?

Recent studies reported that smoking cessation leads to higher short-term risk of type 2 diabetes than continuing to smoke. However, the duration of increased diabetes risk following smoking cessation needs further investigation. We followed 135,906 postmenopausal women aged 50-79 years enrolled in the Womens Health Initiative between September 1, 1993, and December 31, 1998, over an average of 11 years to examine the association between smoking cessation and risk of diabetes using Cox proportional hazard multivariable-adjusted regression models. Compared with that for never smokers, the risk for diabetes was significantly elevated in current smokers (hazard ratio = 1.28, 95% confidence interval: 1.20, 1.36) but was even higher in women who quit smoking during the first 3 years of follow-up (hazard ratio = 1.43, 95% confidence interval: 1.26, 1.63). Among former smokers, the risk of diabetes decreased significantly as the time since quitting increased and was equal to that of never smokers following a cessation period of 10 years. In new quitters with low cumulative exposure (<20 pack-years), diabetes risk was not elevated following smoking cessation. In conclusion, the risk of diabetes in former smokers returns to that in never smokers 10 years after quitting, and even more quickly in lighter smokers.

Smoking Behaviors Among Immigrant Asian Americans Rules for Smoke-Free Homes

BACKGROUND Higher acculturation is associated with Asian-American smoking prevalence decreasing in men and increasing in women. Asian immigrants in California are significantly more likely than their counterparts in Asia to have quit smoking. Smoke-free environments may mediate this acculturation effect because such environments are not widespread in Asia. METHODS In 2006, Asian-American current and former smokers were analyzed using the 2003 California Health Interview Survey. A multivariate logistic regression analysis examined how the interaction between having a smoke-free-home rule and immigrating to the U.S. is associated with status as a former smoker and lighter smoking. RESULTS For recent Asian immigrants (<10 years in the U.S.) and longer-term residents (born/>or=10 years in the U.S.), having a smoke-free-home rule was associated with status as a former smoker (OR 14.19, 95% CI=4.46, 45.12; OR 3.25, 95% CI=1.79, 5.90, respectively). This association was stronger for recent immigrants (p=0.02). Having a smoke-free-home rule was associated with lighter smoking only for longer-term residents (OR 5.37, 95% CI=2.79, 10.31). CONCLUSIONS For Asian Americans, smoke-free-home rules are associated with status as a former smoker, particularly among recent immigrants, and lighter smoking in long-term residents. Interventions encouraging Asian Americans to adopt smoke-free-home rules should be evaluated.

Smoke-Free Policies Among Asian-American Women Comparisons by Education Status

BACKGROUND California has significantly decreased racial/ethnic and educational disparities in smoke-free home and indoor work policies. Californias ethnic-specific surveys present an opportunity to disaggregate data and examine the impact of Californias smoke-free social norm campaign for Asian-American women. METHODS The California Tobacco Use Surveys for Chinese Americans and Korean Americans were conducted in 2003 and analyzed in 2008 to compare women with lower (<or= high school graduate) or higher education status for smoke-free policy adoption and enforcement. RESULTS Lower-educated and higher-educated women had similar proportions of smoke-free policies at home (58%) or indoor work (90%). However, lower-educated women were more likely than higher-educated women to report anyone ever smoking at home (OR=1.62, 95% CI=1.06, 2.48, p=0.03) and exposure during the past 2 weeks at an indoor workplace (OR=2.43, 95% CI= 1.30, 4.55, p=0.005), even after controlling for ethnicity, smoke-free policy, knowledge about the health consequences of secondhand smoke exposure, and acculturation. There was no interaction between education and knowledge about secondhand smoke health harms. CONCLUSIONS The intended consequences of Californias tobacco-control efforts have resulted in similar rates of smoke-free policies at home and in indoor work environments among Asian-American women across educational levels. However, an unintended consequence of this success is a disparity in enforcement by educational status, with lower-educated Asian-American women reporting greater smoke exposure despite similar rates of knowledge about the health consequences of secondhand smoke exposure. Besides establishing policies, lower-educated Asian-American women may need to be empowered to assert and enforce their right to smoke-free environments.