Secondhand Smoke & Heart Attack Risk Poor Physical Fitness During Childhood & HeartDisease Risk During Adulthood
By, Robert A. Wascher, MD, FACS
The information in this column is intended for informational purposes only, and does not constitute medical advice or recommendations by the author. Please consult with your physician before making any lifestyle or medication changes, or if you have any other concerns regarding your health.
SECONDHAND SMOKE & HEART ATTACK RISK
In one of the most important public health research studies published in 2008, the Centers for Disease Control published an update of the Pueblo Heart Study on December 30th. This epidemiological study was performed, prospectively, over a 3-year period between 2002 and 2004 in Pueblo, Colorado. During the second half of this study, Pueblo enacted stringent legislation to eliminate smoking in public places. The incidence of admissions to hospitals for heart attack in the Pueblo area were monitored throughout the course of this study, both before and after the smoking ban was initiated.
Although there is abundant evidence linking chronic smoking with heart and lung disease, and with multiple types of cancer (including lung cancer, the #1 cause of cancer death in the United States, and throughout much of the world), most of these diseases arise after several years of smoking. However, recent research has shown us that many deleterious health effects associated with smoking occur almost instantaneously. These rapid-onset effects of smoking include an increase in blood clot formation (increased coagulability) and a loss in the normal ability of blood vessels to dilate when increased blood flow is required within vital organs, including the heart. Smoking also drives up carbon monoxide levels in the blood, which prevents oxygen-carrying red blood cells from picking up and delivering life-sustaining oxygen. (These adverse health effects are known to occur within 30 minutes of lighting up.) Moreover, these same acute-onset smoking-associated adverse health effects have been documented not only in smokers, but in nonsmoking bystanders who are exposed to secondhand smoke, as well.
There are a couple of factors that make this public health study so powerful, including its prospective design, and the fact that the entire population of the Pueblo area was assessed for changes in the incidence of heart attack following the implementation of a new ban on smoking in public places. Also, the heart attack admission rates for two adjacent communities without public smoking bans, including the much larger Colorado Springs area, added an important set of controls that have not been included in similar previous studies.
In the initial report of the results of this study, in November of 2005, the Pueblo Health Study researchers identified a 27 percent reduction in the number of admissions to Pueblo-area hospitals for heart attack during the second half of the original 3-year study, after the smoking ban had been enacted. (In the 18 months before the smoking ban went into effect, there were 399 heart attack patients admitted. During the second 18 months, there were only 291 heart attack admissions to the same hospitals.) The Centers for Disease Control update extends the initial 3-year results from the Pueblo Heart study through June 2006, thus adding an additional 18 months of follow-up data.
The updated data from this study reveals a striking cumulative reduction in the number of hospital admissions for heart attacks. When compared to the number of heart attack admissions that occurred prior to the enactment of the public smoking ban, there was an incredible 41 percent reduction in such admissions noted during the additional 18 months of follow-up data. Thus, within 3 years of implementing a public smoking ban, the number of heart attacks in Pueblo dropped, amazingly enough, by nearly one-half. At the same time, similar data collected from two surrounding communities without a public smoking ban showed no significant changes in heart attack admissions during the same timeframe.
I should note that, while this study did not separate smokers from nonsmokers, previous studies have shown that susceptible nonsmokers appear to be at an especially high risk of experiencing heart attacks due to exposure to secondhand smoke. (Other less comprehensive studies have also shown, as the Pueblo Heart Study did, that smoking bans quickly result in rapid declines in heart attack admissions.)
As with previous and similar studies, the beneficial effects of public smoking bans appear to be related to at least two factors. First, nonsmokers are spared exposure to the acutely toxic cardiovascular and lung effects of secondhand smoke. Secondly, strict public smoking bans have been shown not only to decrease smoking behaviors among smokers, but to also improve quitting rates among smokers.
While the Pueblo Heart Study is subject to the same limitations as other so-called observational studies, and other undetected factors may have also, therefore, contributed to the dramatic decline in heart attacks after the smoking ban was implemented, this study joins 8 previous and similar studies that also identified a significant reduction in heart attacks after public smoking bans were enacted. Taken together, these 9 studies strongly suggest that the dangers of secondhand smoke may be far greater than public health experts have previously believed. (According to the Centers for Disease Control, exposure to secondhand smoker causes at least 46,000 deaths due to heart disease every year, as well as 3,000 or more lung cancer deaths among nonsmokers each year.)
Based upon more than five decades of scientific data linking tobacco smoke with cancer, chronic lung disease, and cardiovascular disease, it still amazes me that there are so many communities that still permit smoking in public places, or that have enacted hopelessly anemic limitations on the ability of smokers to subject the 80 percent of the U.S. population that does not smoke to highly toxic secondhand tobacco smoke. An estimated 500,000 people die every year in the United States, alone, from completely preventable tobacco-associated diseases. This updated data from the Pueblo Heart Study should galvanize public health advocates and agencies, and government leaders, to better protect the public from unwanted exposure to tobacco smoke.
POOR PHYSICAL FITNESS DURING CHILDHOOD & HEART DISEASE RISK DURING ADULTHOOD
An interesting very long-term prospective clinical study from Norway has been following more than 1,000 volunteers who first entered the study, in 1979, as children (the Oslo Youth Study). In this study, which has just been published in the journal Pediatrics, all of the study’s volunteers were assessed for cardiovascular disease factors upon entering into the study at an average age of 13 years. Subsequently, the volunteers were reassessed at an average age of 15, 25, 33 and 44 years. The findings of this study are rather intriguing given the worsening epidemic of decreased physical activity and obesity among children in many countries throughout the world, including the United States.
Early on in this study, lower levels of physical fitness among the child volunteers were associated with an increased likelihood of obesity and increased blood pressure, which are known cardiovascular disease risk factors. However, as the children matured into adults, the impact of their previous childhood physical fitness levels upon known cardiovascular disease factors diminished with advancing age. By age 40, there was no longer any correlation between the level of physical fitness and physical activity that was present at 13 years of age and the presence or absence of cardiovascular disease factors in adulthood.
I do not want to send the wrong message here by quoting the results of this epidemiological study, but I do believe that there is a positive message here as long as one does not over-interpret the results of this research study (as with all observational studies, there are many potential sources of bias that can skew either the results of such studies, or the interpretation of their results). There is no question but that physically inactive children are at increased risk of becoming obese, or that obese children have a higher risk of the same diseases that plague obese adults. (These obesity-associated illnesses include arthritis, high blood pressure, lung disease, cardiovascular disease, diabetes, and cancer.) But what this study seems to suggest is that adverse cardiovascular risk factors associated with poor levels of physical fitness during childhood can be reversed by middle age. While this study leaves many unanswered questions, it does offer some reassurance that physically inactive and unfit children can still grow into otherwise healthy adults, presumably because they adopt healthier lifestyles that, over time, nullify the effects of childhood physical inactivity, including childhood obesity and hypertension.
Dr. Wascher is an oncologic surgeon, professor of surgery, widely published author, and the Director of the Division of Surgical Oncology at Newark Beth Israel Medical Center:
Copyright 2009. Robert A. Wascher, MD, FACS. All rights reserved.
Dr. Wascher's Archives:
10-26-2008: Smoking & Quality of Life
10-19-2008: Agent Orange & Prostate Cancer10-12-2008: Pomegranate Juice & Prostate Cancer10-5-2008: Central Obesity & Dementia; Diet, Vitamin D, Calcium, & Colon Cancer
9-21-2008: Does Tylenol® (Acetaminophen) Cause Asthma?
4-27-2008: Stents vs. Bypass Surgery for Coronary Artery Disease; The “DASH” Hypertension Diet & Cardiovascular Disease Prevention; Testosterone Therapy for Women with Decreased Sexual Desire & Function
4-6-2008: Human Papilloma Virus (HPV), Pap Smear Results & Cervical Cancer; Human Papilloma Virus (HPV) Infection & Oral Cancer; Hormone Replacement Therapy (HRT) & the Risk of Gastroesophageal Reflux Disorder (GERD)
12-16-2007: Honey vs. Dextromethorphan vs. No Treatment for Kids with Night-Time Cough, Acupuncture & Hot Flashes in Women with Breast Cancer, Physical Activity & the Risk of Death, Mediterranean Diet & Mortality