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Position Statement Heart Disease in Adult Nonsmokers Scientific Data Do Not Support A Proposed Warning Label on Exposure to ETS and Heart Disease in Adult Nonsmokers There are currently 21 studies in the worldwide scientific literature on reported ETS exposures and heart disease in adult nonsmokers. The studies are epidemiologic surveys that examine the frequency and distribution of heart disease within a selected nonsmoking population. The focus of the studies is a comparison of heart disease rates in nonsmoking women married to smokers and those married to nonsmokers. Nearly three-fourths (15 out of 21) of the studies fail to report a statistically significant increased risk for heart disease among nonsmokers married to smokers. (See Table i, attached) The six studies that report statistically significant associations are scientifically very weak, with major methodological problems including small and unrepresentative samples, inadequate control of potential confounding factors, unreliable and inconsistent data on heart disease endpoints and unreliable estimates of ETS exposure. Seven of the spousal smoking studies also assess reported exposure to ETS in the workplace; none reports a statistically significant increased risk for heart disease. The authors of a recent review of the ETS/heart disease literature from the Congressional Research Service (CRS), the research arm of the U.S. Congress, identified at least 18 potential confounders for heart disease in epidemiologic studies on ETS, including blood pressure, cholesterol, body weight, personal history of heart disease, exercise, diabetes, diet, etc. They noted that "these factors are not all independent of one another, but only 4 of the 12 epi studies controlled for at least 6 of them. Over half of the cases in the combined analysis came from one study, which failed to control for any of the potential confounders listed above.''~ i. "Environmental Tobacco Smoke and Lung Cancer Risk, " Congressional Research Service, U.S. Congress, Washington, D.C , November 14, 1995: 68 • •

The authors of the CRS Report also observe that the "biological plausibility" of the ETS/heart disease risk claim has been questioned by some investigators. They note that the estimated relative risks in epidemio!ogic studies on heart disease in nonsmokers are "much greater than would be predicted from an analysis of nicotine levels in passive and active smokers. Studies of urinary cotinine levels indicate that passive smokers receive less than 1% of the nicotine exposure of active smokers. Carbon monoxide exposure from passive smoking is also likely to be a small fraction of the amount to which active smokers are exposed." (CRS Report, p. 67) Overall, claims concerning ETS exposure and biological mechanisms involved in adverse cardiovascular effects remain based on minimal and inadequate data. To date, the published literature fails to provide scientifically convincing data for a biologically plausible mechanism by which ETS exposure might be involved in the development of heart disease in nonsmokers.

i 1 TABLE 1 ETS/HEART DISEASE RELATIVE RISKS i} Butler (1988)~ Dobson, et (1991):° Garland, et (1985)~ He, et al. (1989)I~ He, et al. (1994)~ Helsing, (1988)~4 Hirayama (1984):~ Hole, et al. (1989) ~ Humble, et al. (1990):~ Jackson (19891~' Gender F F M M F F F M F M F F F F M F F M÷F F M F M F P/c P ? P P P P P P ? C C C C ? C C Relative Risk 95% Cl Exposure Setting (Home/Work) 0.41 0.13 - 1.30 Home AHSMOG cohort: "Live with smoker i-i0 years." 0.61 0,31 - I.!9 Home AHSMOG cohort: :'Live with smoker ll+ years." 1.46 0.70 - 3.08 Home A~SMOG cohort: "Live with smoker 1-10 years." 1.53 0.92 - 2.54 Home A~SMOG cohort: "Live with smoker ll+ years." !.26 0.68 - 2.33 Work AHSMOG cohort: "Work with smoker 1-10 years." 0.76 0,37 - 1.55 Work AZSMOG cohort: "Work with smokers ii+ years." 1.85 1.00 - 3.44 Work AHSMOG cohort: "Work with smoker 1-10 years.~' 1.86 0.99 - 3.48 Work AHSMOG cohort: "Work with smoker ii+ years." 1.40 0.51 - 3.84 Home "Spouse pairs" cohort. 0.97 1.86 Home Work 0.17 - 2.62 Work ps,10, bu~ CI Home not given Chinese language. 2.46, 0.95 O. 66 2.7 1.5" p<.01~ but CI not given 0.56 - 2.72 0.86 - 4.00 1.01 l 5.55 Work 1.24 i .85 2.36* "Any exposure" (home and/or work) 1.31" i,i0 - 1.60 Home 1.24" 1.10 - 1,40 Home 1,15 0.94 - 1.42 Home Lee (1992) recalculation. 2.01" 1.21 - 3,35 Home 1.59 0.99 - 2.57 Home Home Home Work Work 0.9 - 5.9 218 l 199.0 0.4 3.6 0.9 30.! 23.50" 1.2 5.2 Dissertation.

Gender P/C La Vecchia, et M÷F C al. (1993)~ Lee, ecal. M+F C (1986)~° LeVois and M P Layard (1995) F P [CPS-I]n LeVois and M P Layard {!995) F P [CPS-II] LeVois and M C Layard (1995) F C Mar¢in, et al. F C (1986)n Muscat and M C Wynder (!985)~ F C M C F C M C F C Palmer, et al. F C (1988)~4 Svendsen, e~ M P al, (1987)~ M P [MRFIT]M P M P Tunstall-Pedoe, M/F P et al. (1995)~ Relative Risk 95% CI Exposure Setting (Home/Work) Comments 1.21 0.57 Z~52 Home Letter to editor. 1.03 0,65 !.~2 Home See endnote for additional data, especially regarding workplace relevance. 0.97 0,90 1.05 Home ~alysis of previously 1.03 0.98 1.08 Home unpublished ACS data. 0.97 0.S7 1,08 Home ~-~alysis of previously 1.00 0.88 1,14 Home unpublished ACS da~a. 0.97 0.73 1.28 Home National Mortality Followback 0.99 0.84 1.!6 Home Sur~ey. 3.4* p<.01,but CI Home Conference abstract. not given 1.3 1.7 0.97 0.92 1.2 1.0 "Adult exposure" ~'Adu!t exposure" "Childhood exposure" "Childhood exposure" Work exposure Work exposure 0.7 - 2.4 0.7 - 3.7 0.53 - 1.46 0.5 - 1,86 0.~ - 2.2 0.4 - 2.5 1.20 Not glven Home Conference abstract. 2.23 0.72 - 6.82 Home CHD death. 1.61 0.96 - 2.71 Home Fatal or nonfatal CHD. 2.6 ,5 12.7 Work CHD death. 1.4 .8 2.5 Work Fatal or nonfatal CHD. 1.20 0.90 1.70 Home See endnote for additional data. Reported to be statistically confidence. Prospective or case-control. significant at the 95% level of