An analysis of respiratory symptoms is shown in Tables 2 and 3. The results confirm the findings in the previous report of 298 women. Daily chronic cough was unusual in nonsmokers and ex-smokers, but the prevalence became progressively greater with increase in the number of cigarettes smoked (Table 2(a)). The prevalence of cough was significantly greater in all smoking groups compared with nonsmokers and ex-smokers (P<0.001). Sputum production followed the same pattern as cough and the prevalence of sputum production was greater in all smoking groups than among nonsmokers and exsmokers (P<0.001) (Table 2(b)). Sputum volume was usually small but there were 17 women who produced more than a tablespoonful in 24 hours and, of these, 16 were moderate or heavy smokers and one was a nonsmoker (Table 2(c)). The sputum was usually clear, white or gray but there was an increased prevalence of yellow or green sputum (at least in part or with colds) in moderate and heavy smokers. Seven women had usually yellow or green sputum (one moderate and six heavy smokers). There was a progressive increase in the prevalence of chronic bronchitis (chronic cough and sputum present on most days during at least three months in each of two successive years),2 with increase in cigarette smoking, and the differences between smoking groups and nonsmoking groups were highly significant (P<0.001) (Table 2(d)). Almost half of the heavy smokers might be considered to have chronic bronchitis. Many of the smokers had had an increase in sputum in the previous five years and even during the previous year, and there were significant differences between nonsmokers and smokers in this respect (P<0.05), (Table 2(e)).
Wheezing occurred in a few of the nonsmokers, usually at times of respiratory infections but this symptom was found with increasing frequency with increase in number of cigarettes smoked (Table 3(a)). If wheezing “at any time” was considered, there were very significant differences between the nonsmoking groups and the moderate and heavy smokers (P < 0.001).
Dyspnea was analyzed according to five grades. Grade 1 was within normal limits of exercise tolerance, and most of the volunteers were in this grade (Table 3(b)). Grade 2 (could walk at a normal speed on the level but short of breath on hills and stairs) was found with increasing frequency with increase in cigarette smoking. Grade 3 (limited to slow walking on the level) was found in seven smokers (five of whom were heavy smokers) and in one nonsmoker. None of the volunteers was in grades 4 or 5 (limited to 100 yards of slow walking on the level, or shortness of breath on any exertion, respectively). There was a significant difference between nonsmokers and heavy smokers in respect to the presence of grade 2 or 3 dyspnea (P<0.001).
Colds “went to the chest” more frequently in the moderate and heavy smokers than in the nonsmokers (P<0.005 and P<0.001 respectively), (Table 3(c)). Most women had one or two colds each year and there appeared to be little relationship between the number of colds each year and smoking history. However, more than five colds a year occurred in five women of whom one was a moderate smoker and four were heavy smokers.
An analysis of past illnesses showed no pattern of difference in the prevalence of pneumonias, pleurisy, sinusitis. A past history of attacks of acute bronchitis was found more in moderate and heavy smokers than in the other groups (P<0.05). A family history of chronic bronchitis was found more frequently in moderate and heavy smokers than in the nonsmokers and light smokers (P0.05).
In an analysis of the prevalence of all the clinical symptoms, no significant differences were demonstrated between nonsmokers and ex-smokers (P>0.05), (Tables2and3).
On physical examination, there were only minimal abnormalities (Table 4). Smokers were not significantly thinner than nonsmokers, nor were nonsmokers more prone to being overweight than smokers.
The inferior right lung border in the midclavicular line was more frequently low (suggestive of hyperinflation of the lungs) in the heavy smokers compared with nonsmokers but the differences were not statistically significant (P>0.05), (Table 4(a)). Rhonchi heard during ordinary chest examinations or heard at the mouth during full expiration assisted by chest compression were uncommon in nonsmokers and light smokers but were present in about one third of moderate and heavy smokers (Table 4(b)). There were significant differences between the prevalence of rhonchi in nonsmokers and ex-smokers compared with moderate and heavy smokers (P< 0.001) and between light smokers compared with moderate and heavy smokers (P<0.05). Breath sounds were considered to be fair rather than good in similar numbers of smokers and nonsmokers (Table 4(c)).
Although the abnormalities were considered minor, chest examination was abnormal more frequently in the moderate and heavy smokers than in the non-smokers and ex-smokers (P<0.005), (Table 4(d)).
The mean resting heart rate of the light smokers was slightly slower (68 per minute) than any of the other groups (73 to 74 per minute) and this was significant statistically (P<0.05). The average systolic blood pressure of the heavy smokers was slightly higher (125 mm Hg) compared with the light and moderate smokers (118 and 120 mm Hg respectively) and this was statistically significant (P<0.05). There were no statistically significant differences among the groups in the diastolic blood pressure.
Fluoroscopy showed no differences among the groups in respect to whether the lung fields darkened well at the end of forced expiration (Table 4(e)). However, there was a significantly increased number of heavy and moderate smokers compared with nonsmokers where the lung fields darkened less rapidly during full expiration than in the nonsmokers (P<0.005). Diaphragmatic movement was similar for both left and right diaphragms (average: 2 cm), and there were no differences among the various groups. The small degree of diaphragmatic movement was probably due to the measurement being made from the pulmonary resting position to full inspiration. Minor abnormalities in the chest films were not uncommon, and took the form of small apical areas of fibrosis, Ghon foci and hilar calcifications. There were no differences in the prevalence or types of abnormalities among smokers and nonsmokers.
The electrocardiogram showed abnormalities in about 10 percent of women, usually in the form of slight T wave changes, prolonged PR intervals, or low voltages. The mean PR interval was similar in all groups (0.16 sec). The abnormalities on the electrocardiogram were not significantly different in prevalence or type among the various groups.
It was difficult to obtain sputum specimens, even after the use of the hot aerosol of saline propylene glycol, from the nonsmokers, ex-smokers and light smokers, and specimens were obtained from only about 25 percent of these subjects. The volunteers who smoked the most produced sputum specimens most easily, and sputum specimens were obtained from 46.7 percent of moderate smokers and 54.5 percent of heavy smokers. The cytologic abnormalities of the sputum are summarized in Table 5, and only those changes which had statistical significance are recorded in the table. Where more than one specimen of sputum was obtained (one before the tests and one after the respiratory function tests), the specimen with the most marked cytologic changes was used in the analysis.
None of the specimens showed malignant cells. Macrophages were found more frequently in the moderate smokers than in the nonsmoking groups. Hemosiderin was not seen in any of the sputum specimens.
Epithelial squamous cells were found in almost all specimens, and there was no difference in the number found in the smokers and nonsmokers. Moderate metaplasia and dyskaryosis were found more frequently in the smokers than in the nonsmokers, but the differences were not statistically significant There was little difference in the number of cells with degenerative abnormalities among the smokers and nonsmokers.
Columnar cells were frequently present in the specimens and were significantly higher in number in the heavy smokers compared with the nonsmokers. Degenerative and irritative changes showed a similar pattern with heavy smokers having significantly higher numbers of these cells than nonsmokers.
The presence of inspissated mucus was noted with similar frequency in smokers and nonsmokers. Curschmann’s spirals were relatively infrequent but were more common in the moderate and heavy smokers than in the other groups, although only the moderate smokers showed a statistically significant increase compared with nonsmokers.
Examination for various inflammatory cells showed no difference in the presence of neutrophils among the groups but lymphocytes and giant cells were more frequently present in the heavy and moderate smokers than in the nonsmoking groups.
Yeast cells were found occasionally but their prevalence among smokers and nonsmokers did not differ.
Eosinophils were found only in one nonsmoker and one moderate smoker.
Respiratory Function Tests
The adjusted mean values for age, height and weight (±SE) of the results of the pulmonary function tests and a summary of the results of the t tests are shown in Table 6. The results were almost identical to those reported for the first 298 women.
The following pulmonary functions showed statistically significant lower values in the smokers than in the nonsmokers: forced vital capacity, forced expiratory volume (one second), maximal mid-expiratory flow rate, specific conductance and diffusing capacity and fractional uptake of carbon monoxide during exercise. Hemoglobin and hematocrit were higher in the smokers compared with the nonsmokers. Although the arterialized blood oxygen pressure was lower in the smokers than in the nonsmokers, the differences did not reach statistical significance.
Airway resistance in the heavy smokers was greater than in the other groups. Changes in Raw and SGaw after the carbon dust inhalations were slight and there were no differences between the smokers and nonsmokers. Intrathoracic gas volume was similar among the groups, both before and after the inhalation of carbon particles.
Table 2—Prevalence of Cough and Sputum Production in 500 Women Related to Smoking Habit
|Nonsmokers||Ex-smokers||Light Smokers||Moderate Smokers||Heavy Smokers|
|(c) Sputum volume|
|More than one|
|(d) Chronic bronchitisf||10||5.5||1||1.6||9||22.5||25||27.2||57||46.3|
|(e) Increase in sputum ft|
|During previous year||1||7.1||0||0.0||6||50.0||8||29.6||23||38.3|
Table 3—Prevalence of Wheezing, Dyspnea and Cold•in the Chest in 500 Women Related to Smoking Habit
|Nonsmokers No. %
|Ex-smokers No. %||Light Smokers No. %||Moderate Smokers No. %||Heavy Smokers No. %|
|Occasionally with colds||11||6.0||3||4.8||5||12.5||16||17.4||26||22.1|
|Occasionally without colds||4||2.2||0||0.0||5||12.5||15||16.3||28||22.8|
|Most of the time||3||1.6||0||0.0||1||2.5||3||3.3||14||11.4|
|(c) Colds in the chest||53||29.0||19||30.6||13||32.5||44||47.8||64||52.0|
Table 4—Physical Examination in 500 Women Related to Smoking Habit
|Nonsmokers No. %
|Ex-smokers No. %||Light Smokers No. %||Moderate Smokers No. %||Heavy Smokers No. %
|(a) Inferior right lung border low*||8||4.7||2||3.4||3||8.3||9||10.2||13||11.0|
|(b) Rhonchi present||16||8.7||9||14.5||6||15.0||35||38.0||43||35.0|
|(c) Breath sounds fair||12||6.6||6||9.7||5||12.5||5||5.4||8||6.5|
|(d) Chest examination, abnormal||16||8.7||10||16.1||9||22.5||39||42.4||46||37.4|
|(e) Fluoroscopy: on forced expiration lung fields darken slower than normal||9||4.9||6||9.7||4||10.0||11||12.0||19||15.4|
Table 5—Sputum Cytologic Finding» in 500 Women Related to Smoking Habit
|Nonsmokers (49)** (N)
No. of Sputum Specimens %f
|Ex-Smokers (14) (E)
No. of Sputum Specimens %
|Light Smokers (12)
No. of Sputum Specimens %
|Moderate Smokers (43) (M)
No. of Sputum Specimens %
|Heavy Smokers (67) (H)
No. of Sputum Specimens %
+ + +ОГ + + + +
|8||16.3||0||0.0||2||16.7||16||37.2||18 26.9||M >NE;H>I|
|Columnar cells Number + or + +||33||67.3||10||71.4||11||91.7||33||76.7||59 88.1||H>N|
|Degenerative changes + or + +||18||36.7||6||42.9||9||75.0||21||48.8||40 59.7||L>N;H>N|
|Irritative changes + or + +||16||32.7||7||50.0||4||33.3||14||32.6||38 56.7||H>M,N|
|Curschmann’s spiral Number + or + +||3||6.1||1||7.1||1||8.3||10||23.3||11 16.4||M >N|
|Lymphocytes Number + or + +||32||65.3||8||57.1||9||75.0||31||72.1||55 82.1||H>NE|
|Giant cells Number + or + +||4||8.2||3||21.4||1||8.3||10||23.3||16 23.9||M>N,H>N|
Table 6—Result» of Pulmonary Function Teat* Shown at Adjusted Valuet for Mean ± SE in 500 Women Related to Smoking Habit
|Moderate Smokers Heavy Smokers (M) (H)||Group
|FVC, liter||3.09 ± 0.03||3.15 ± 0.05||3.01 ± 0.07||2.98 ± 0.04||2.95 ± 0.04||H<NfEt;M<N*E*|
|FEVi, liter||2.64 ± 0.02||2.66 ± 0.04||2.55 ± 0.05||2.51 ± 0.03||2.48 ± 0.03||H<NtEt;M<NfEt|
|FEVi/FVC, %||85.67 ± 0.45||84.90 ± 0.77||85.15 ± 0.96||84.65 ± 0.63||83.97 ± 0.55||H<N*|
|MMF, liter/sec||3.35 ± 0.06||3.32 ± 0.09||3.32 ± 0.12||3.17 ± 0.08||3.03 ± 0.07||H<NfE*L*|
|Arterialized blood pH, unit||7.432 ± 0.002||7.437 ± 0.003||7.432 ± 0.003||7.430 ± 0.002||7.428 ± 0.002||H<E*|
|Arterialized blood PcOi mm Hg||36.7 ± 0.2||36.2 ± 0.4||37.2 ± 0.5||36.8 ± 0.3||37.3 ± 0.3||H>E*|
|Arterialized blood Po* mm Hg||85.7 ± 0.6||85.7 ± 1.1||84.2 ± 1.4||85.1 ± 0.9||83.7 ± 0.8||NS|
|Hematocrit, % EXERCISE||39.7 ± 0.1||39.9 ± 0.3||39.7 ± 0.3||40.6 ± 0.2||41.6 ± 0.2||H>NfEtLtMf
|Pulse||103.4 ± 1.0||101.4 ± 1.7||103.2 ± 2.1||102.2 ± 1.4||102.9 ± 1.2||NS|
|Respiratory rate, breaths/min||16.2 ± 0.4||15.9 ± 0.6||16.1 ± 0.8||16.2 ± 0.5||17.2 ± 0.4||NS|
|Vt, liter||1.228 ± 0.030||1.241 ± 0.051||1.268 ± 0.063||1.990 ± 0.042||1.225 ± 0.036||NS|
|VE, liter/min||18.47 ± 0.32||18.34 ± 0.55||19.13 ± 0.68||18.43 ± 0.45||19.43 ± 0.39||NS|
|Dux>, ml/min/mm Hg||27.27 ± 0.44||26.54 ± 0.76||26.52 ± 0.93||26.25 ± 0.63||23.44 ± 0.53||H<NfEtLtMf|
|Fractional CO uptake, %||46.0 ± 0.4||45.7 ± 0.7||44.8 ± 0.8||44.7 ± 0.5||42.1 ± 0.5||H<NtEfLtMt;M<N*|
|Vce, liter/min||0.775 ± 0.013||0.773 ± 0.022||0.826 ± 0.027||0.766 ± 0.018||0.807 ± 0.016||NS|
|VE/Voj, liter/100 ml||2.40 ± 0.03||2.41 ± 0.05||2.38 ± 0.06||2.44 ± 0.04||2.45 ± 0.04||NS|
|End tidal, PcOj mm Hg||37.5 ± 0.3||36.9 ± 0.5||36.8 ± 0.6||37.5 ± 0.4||36.4 ± 0.3||H<N*M*|
|Change of SaO? from rest %||-0.40 ± 0.07||-0.37 ± 0.12||-0.17 ± 0.15||–0.21 ± 0.10||-0.38 ± 0.08||NS|
|Raw, cm H»0/li ter/sec||1.82 ± 0.05||1.75 ± 0.09||1.89 ± 0.11||1.90 ± 0.08||2.18 ± 0.07||H>NtEfL*M*|
|Raw (Ci), cm HjO/liter/sec||1.86 ± 0.06||1.62 ± 0.10||1.92 ± 0.12||1.91 ± 0.08||222 ± 0.07||H>NfEtL*M|
|Raw (Cj), cm HiO/liter/sec||1.76 ± 0.06||1.67 ± 0.10||1.90 ± 0.12||1.85 ± 0.08||2.18 ± 0.07||H>NtEfMt|
|SGaw, liter/eec/cm HjO/liter||0.182 ± 0.006||0.210 ± 0.011||0.168 ± 0.014||0.171 ± 0.009||0.154 ± 0.008||H<NfEt|
|SGaw (Ci), liter/sec/cm HjO/liter||0.181 ± 0.007||0.227 ± 0.012||0.169 ± 0.015||0.177 ± 0.010||0.152 ± 0.008||H<NtEfM*|
|SGaw (Cj), liter/eec/cm HjO/liter||0.007 ± 0.007||0.222 ± 0.012||0.168 ± 0.015||0.182 ± 0.010||0.158 ± 0.008||H<NfEt|