Effect of smoking habit on the frequency of micronuclei in human lymphocytes: results from the Human MicroNucleus project

The effect of tobacco smoking on the frequency of micronuclei (MN) in human lymphocytes has been the object of many population studies. In most reports, the results were unexpectedly negative, and in many instances smokers had lower frequencies of MN than non-smokers. A pooled re-analysis of 24 databases from the HUMN international collaborative project has been performed with the aim of understanding the impact of smoking habits on MN frequency. The complete database included 5710 subjects, with 3501 non-smokers, 1409 current smokers, and 800 former smokers, among subjects in occupational and environmental surveys. The overall result of the re-analysis confirmed the small decrease of MN frequencies in current smokers (frequency ratio (FR) = 0.97, 95% confidence interval (CI) = 0.93-1.01) and in former smokers (FR = 0.96, 95% CI = 0.91-1.01), when compared to non-smokers. MN frequency was not influenced by the number of cigarettes smoked per day among subjects occupationally exposed to genotoxic agents, whereas a typical U-shaped curve is observed for non-exposed smokers, showing a significant increase of MN frequency in individuals smoking 30 cigarettes or more per day (FR = 1.59, 95% CI = 1.35-1.88). This analysis confirmed that smokers do not experience an overall increase in MN frequency, although when the interaction with occupational exposure is taken into account, heavy smokers were the only group showing a significant increase in genotoxic damage as measured by the micronucleus assay in lymphocytes. From these results some general recommendations for the design of biomonitoring studies involving smokers can be formulated. Quantitative data about smoking habit should always be collected because, in the absence of such data, the simple comparison of smokers versus non-smokers could be misleading. The sub-group of heavy smokers (> or =30 cigarettes per day) should be specifically evaluated whenever it is large enough to satisfy statistical requirements. The presence of an interaction between smoking habit and occupational exposure to genotoxic agents should be always tested.     

Chromosome aberrations among cigarette smokers in Colombia

Worldwide, the annual morbimortality caused by cigarette smoking is a major public health concern. In Colombia, up to 33% of the adult population has smoked at some point in life, raising important national issues on the disease burden from tobacco. The aim of this study was to establish whether cigarette smoking increases the frequency of chromosome aberrations (CA) in peripheral blood lymphocytes of smokers (n = 52) compared with non-smokers (n = 52) in Popayán, Colombia. After signing a consent form, volunteers provided a blood sample (20 ml) to establish cell cultures at 52 h. For CA analysis, 100 complete metaphase cells from each subject were evaluated. The CA frequency was significantly higher in smokers (8.38 +/- 0.61) than in non-smokers (3.13 +/- 0.29), showing the highest number of CA (14.83 +/- 1.01) among heavy smokers (>20 pack-years). Interestingly, light smokers (< or =10 pack-years) also showed a significant increase in CA when compared to non-smokers (6.62 +/- 0.53 versus 3.13 +/- 0.29, P < 0.01, respectively). In addition, a significant positive correlation was found between the frequency of CA and the intensity of smoking in pack-years (R2 = 0.60). Our study indicates that the genotoxic effects in lymphocytes from smokers are most likely caused by cigarette smoke constituents, providing scientific evidence to encourage national campaigns to prevent tobacco consumption.     

Adolescent smokers seen in general practice: health,lifestyle, physical measurements,and response to antismoking advice.

OBJECTIVE--To compare physical, lifestyle, and health characteristics of adolescent smokers and non-smokers and their initial response to anti-smoking counselling. DESIGN--Adolescents aged 13, 15, and 17 years were identified from age-sex registers and invited by letter for a general practice health check. SETTING--Three general practices in the MRC general practice research framework. MAIN OUTCOME MEASURES--Blood pressure, body mass index, saliva cotinine concentration, peak flow rate, alcohol consumption, exercise, duration of sleep, and stated persistent health problems. RESULTS--73% of the adolescents (491) attended for the health check. A total of 68 (14%) were regular smokers. By age 17 those who smoked regularly had a significantly lower systolic blood pressure than those who had never smoked regularly (by 6 mm Hg; p = 0.025) despite a significantly higher body mass index (by 1.5; p <0.001) [corrected]. Cotinine concentrations increased with smoking exposure, from 0.7 ng/ml when no family member smoked to 155 ng/ml in active smokers of six or more cigarettes a week. Significantly more regular smokers than never regular smokers drank greater than or equal to 8 g alcohol a day (chi 2 = 15.2 adjusted for age and sex p less than 0.001); regular smokers exercised less (1.0 hrs/week in boys and 0.8 hrs/week in girls v 3.4 hrs/week in boys and 2.2 hrs/week in girls; p less than 0.001) and slept less (8.0 hrs/night v 8.5 hrs/night at age 17; p less than 0.005). Persistent health problems, mostly asthma or allergic symptoms, were reported by 25% (17/68) of the smokers and 16% (60/381) of the non-smokers. Of the smokers given counselling, 60% (26/43) made an agreement with the practice doctor or nurse to give up smoking. CONCLUSION--General practice is an appropriate setting for adolescents to receive advice on healthy lifestyle, which should not focus solely on smoking.     

Smoking,lung function,and body weight.

In a cross-sectional study of steelworkers aged 45-55 years, smokers (n = 105; mean weight 76.1 kg) were found to weigh significantly less than non-smokers (n = 54; 81.6 kg) and ex-smokers (n = 51; 82.6 kg). The lower weight of smokers was attributable to a group with airflow obstruction (n = 37; forced expiratory volume in one second/vital capacity (FEV1/VC) less than 66%), who weighed less (4.8 kg; p less than 0.05) than smokers with normal FEV1/VC (n = 68). In smokers, but not in ex-smokers or non-smokers, body mass index and FEV1/VC ratio were closely related (r = 0.34; p less than 0.001). This association was apparently not due to an effect of body weight on lung function. Weight loss in smokers may be the consequence of impaired lung function or reflect the effect of cigarette smoking on both the respiratory tract and metabolism in susceptible subjects.     

A comparative biomonitoring study of populations residing in regions with low and high risk of lung cancer using the chromosome aberration and the micronucleus tests

Chromosome aberration (CA) and micronucleus (MN) tests were performed in peripheral blood lymphocytes from people residing in two districts of Chiang Mai, Thailand, a high-risk area, Saraphi (n=107), where the lung cancer incidence is three-fold higher than in a low-risk area, Chom Thong (n=118). The percentage of cells with CAs was significantly lower in the Saraphi population than in the Chom Thong population (0.47+/-0.91 versus 1.04+/-1.18, P=0.0001) as was the percentage of CAs (0.49+/-0.91 versus 1.08+/-1.21, P<0.0001) and the mitotic indices (1.25+/-0.44 versus 1.33+/-0.33, P=0.025). The frequency of MN in binucleated (BN) cells, however, was significantly higher in the Saraphi population (12.01+/-3.57 versus 9.99+/-3.11, P<0.0001) as was the percentage of BN cells with MN (1.14+/-0.31 versus 0.93+/-0.23, P<0.0001). There was no difference in the nuclear division indices (1.49+/-0.07 versus 1.47+/-0.11, P=0.1759) between the two populations. With regard to the effect of confounding factors, it was found that cigarette smoking influenced both CA and MN frequencies, and that the chewing of fermented tea leaves or betel nuts affected CA and sex affected MN frequencies. An increasing of CA and MN frequencies were seen in smokers and chewers over non-smokers and non-chewers, with CA frequencies being higher in Chom Thong smokers and chewers and MN frequency being higher in Saraphi smokers. However, pesticide exposure and alcohol consumption had no impact on CA and MN frequencies. Due to the conflicting results obtained in the two tests, we cannot make a clear statement regarding the potential effects of the environmental exposures in the two study populations.     

A survey on the cytogenetic status of the Croatian general population by use of the cytokinesis-block micronucleus assay

The cytokinesis-block micronucleus assay (CBMN) was used to assess the variability and determine possible influences of external and internal factors on the background levels of cytogenetic damage in peripheral blood lymphocytes (PBL) of 50 healthy volunteers selected at random from the general population of Croatia. The mean MN frequency for all subjects was 4.74+/-0.31 per 1000 cells and the mean cytokinesis-block proliferation index (CBPI) was 1.82+/-0.01. The mean frequency of nucleoplasmic bridges (NPB) for all subjects was 0.06+/-0.04 and of nuclear buds (NB) 0.12+/-0.05. The canonical correlation analyses indicate a positive non-significant correlation between the MN frequency and age, gender and smoking habits. Results of factor structure and canonical weights showed that age and gender rather than smoking habits control the incidence of MN in PBL of healthy volunteers. The lowest median value of MN was observed in subjects younger than 30 years (both smoking and non-smoking). Generally, non-smokers had lower median values of MN compared to smokers. In non-smokers, males showed lower micronucleus incidence than females. Within the non-smokers smaller differences in the median values of MN between subgroups (male and female; age subgroups) were observed. Among smokers, females had a two-fold higher median value of MN frequency than males, but this difference was not significant (p=0.2643, Mann-Whitney U test). Canonical correlation analyses indicate a strong and significant correlation between cell proliferation parameters (M1-M4 and CBPI) and age, gender and smoking habits. The most sensitive parameters were M3 and M4. Age had the strongest effect on M3, while M4 was highly influenced by smoking habits. Gender had an equal non-significant effect on both parameters. The usefulness of the new criteria for the cytokinesis-block MN assay measuring DNA damage as a sensitive biomarker in biomonitoring studies is confirmed.     

Sister-chromatid exchanges in lymphocytes of smokers in an experimental study

The frequency of sister-chromatid exchanges (SCEs) was studied in peripheral blood lymphocytes of 26 young male smokers and 10 non-smokers who had recently entered military service. The levels of SCEs were examined in 4 consecutive blood samples taken after short experimental periods of smoking only low-tar (LT) or medium-tar (MT) cigarettes. The incidence of SCEs was significantly higher in the the group of smokers than in the group of non-smokers. The SCE levels of the smokers were found to be associated with the personal smoking history; the observed increase in the SCE frequency correlated with the years of smoking measured as cumulative pack years. The difference in type of cigarette did not influence the SCE frequencies.     

Human urine mutagenicity study comparing cigarettes which burn or only heat tobacco

Cigarette smokers have been reported to void urine which is more mutagenic, as measured in the Ames bacterial mutation assay, than urine voided by non-smokers. Condensate from the mainstream smoke of a cigarette which heats, but does not burn tobacco (test cigarette) showed no evidence of mutagenicity in a battery of in vitro genotoxicity assays under conditions in which condensate from the mainstream smoke of cigarettes that burn tobacco was mutagenic. The objective of this study was to determine whether the absence of mutagenic activity observed in the in vitro assays would be reflected in the urine of smokers of the test cigarette. 72 subjects (31 smokers and 41 non-smokers) were enrolled in a 6-week study, with the smokers randomly divided into 2 groups. The study was designed as a double crossover, with each smoker smoking both test (tobacco-heating) and reference (tobacco-burning) cigarettes. This design allowed each smoker to serve as his or her own control while at the same time allowing comparisons between groups of non-smokers and smokers of both test and reference cigarettes. 24-h urine samples were collected twice a week and concentrated using XAD-2 resin. Urine concentrates were tested in Ames bacterial strains TA98 and TA100, with and without metabolic activation and with and without beta-glucuronidase/aryl sulfatase. Individuals who smoked the test cigarette voided urine which was significantly less mutagenic than that voided when they smoked reference cigarettes. The mutagenicity of urine from smokers who smoked the test cigarette and non-smokers did not differ under any of the assay conditions used in this study.     

Prospective study of effect of switching from cigarettes to pipes or cigars on mortality from three smoking related diseases.

OBJECTIVE: To estimate the extent to which cigarette smokers who switch to cigars or pipes alter their risk of dying of three-smoking related diseases-lung cancer, ischaemic heart disease, and chronic obstructive lung disease. DESIGN: A prospective study of 21520 men aged 35-64 years when recruited in 1975-82 with detailed history of smoking and measurement of carboxyhaemoglobin. MAIN OUTCOME MEASURES: Notification of deaths (to 1993) classified by cause. RESULTS: Pipe and cigar smokers who had switched from cigarettes over 20 years before entry to the study smoked less tobacco than cigarette smokers (8.1 g/day v 20 g/day), but they had the same consumption as pipe and cigar smokers who had never smoked cigarettes (8.1 g) and had higher carboxyhaemoglobin saturations (1.2% v 1.0%, P < 0.001), indicating that they inhaled tobacco smoke to a greater extent. They had a 51% higher risk of dying of the three smoking related diseases than pipe or cigar smokers who had never smoked cigarettes (relative risk 1.51; 95% confidence interval 0.96 to 2.38), a 68% higher risk than lifelong non-smokers (1.68; 1.16 to 2.45), a 57% higher risk than former cigarette smokers who gave up smoking over 20 years before entry (1.57; 1.04 to 2.38), and a 46% lower risk than continuing cigarette smokers (0.54; 0.38 to 0.77). CONCLUSION: Cigarette smokers who have difficulty in giving up smoking altogether are better off changing to cigars or pipes than continuing to smoke cigarettes. Much of the effect is due to the reduction in the quantity of tobacco smoked, and some is due to inhaling less. Men who switch do not, however, achieve the lower risk of pipe and cigar smokers who have never smoked cigarettes. All pipe and cigar smokers have a greater risk of lung cancer than lifelong non-smokers or former smokers.     

Cigarette smoking depletes cells spontaneously secreting Th(1) cytokines in the human airway

Cigarette smoking may modify the immune balance in the airway since it alters the course of diseases in which immune system has an important role. This study examined whether cigarette smoking could affect the distribution of cells secreting Th(1) or Th(2) cytokines in the human airway. We utilized cytokine ELISPOT assay to detect and quantitate the frequencies of cells spontaneously secreting cytokines in bronchoalveolar lavage fluid (BALF). BALF was collected from six non-smokers and four heavy cigarette smokers without clinical airway symptoms. Cytokine ELISPOT assay was performed to quantitate cells secreting interleukin (IL-)2, IL-4 and interferon (IFN-)gamma with or without phorbor 12-myristate 13-acetate (PMA) stimulation. There were no cells spontaneously secreting IL-2 detected in all samples from smokers whereas most of non-smokers had detectable IL-2-secreting cells. The number of IFN-gamma-secreting cells was also extremely decreased in smokers. Mitogen-stimulated Th(1) cytokine-secreting cells were again significantly decreased in smokers' airways. The frequency of IL-2-secreting cells and CD4/CD8 ratio in BALF had a weak positive correlation. IL-4-secreting cells were not detected in any samples from both groups. These results show that cigarette smoking depletes Th(1) cytokine-secreting cells in the human airway. It may explain the susceptibility of smokers to certain airway disease conditions such as viral or mycobacterial infections and allergic diseases.     

Water-pipe smoking and metabolic syndrome: a population-based study

Water-pipe (WP) smoking has significantly increased in the last decade worldwide. Compelling evidence suggests that the toxicants in WP smoke are similar to that of cigarette smoke. The WP smoking in a single session could have acute harmful health effects even worse than cigarette smoking. However, there is no evidence as such on long term WP smoking and its impact on chronic health conditions particularly cardiovascular and metabolic conditions. Therefore, we conducted this study to investigate the relationship between WP smoking and metabolic syndrome (MetS). This was a cross-sectional study carried out in Punjab province of Pakistan using the baseline data of a population-based study - Urban Rural Chronic Diseases Study (URCDS). Information was collected by trained nurses regarding the socio-demographic profile, lifestyle factors including WP smoking, current and past illnesses. A blood sample was obtained for measurement of complete blood count, lipid profile and fasting glucose level. MetS was ascertained by using the International Diabetic Federation's criteria. We carried out multiple logistic regressions to investigate the association between WP smoking and MetS. Final sample included 2,032 individuals - of those 325 (16.0%) were current WP smokers. Age adjusted-prevalence of MetS was significantly higher among current WP smokers (33.1%) compared with non-smokers (14.8%). Water-pipe smokers were three times more likely to have MetS (OR 3.21, 95% CI 2.38-4.33) compared with non-smokers after adjustment for age, sex and social class. WP smokers were significantly more likely to have hypertriglyceridemia (OR 1.63, 95% CI 1.25-2.10), hyperglycaemia (OR 1.82, 95% CI 1.37-2.41), Hypertension (OR 1.95, 95% CI 1.51-2.51) and abdominal obesity (OR 1.93, 95% CI 1.52-2.45). However, there were no significant differences in HDL level between WP smokers and non-smokers. This study suggests that WP smoking has a significant positive (harmful) relationship with MetS and its components.     

A polymorphism of the methionine synthase reductase gene increases chromosomal damage in peripheral lymphocytes in smokers

The cytogenetic effects of cigarette smoke has been evaluated as one of many potential confounders in a large number of biomonitoring studies of occupationally or environmentally exposed populations and control subjects. Despite the well-known presence of carcinogens in the cigarette smoke, the results in the scientific literature linking smoking habits to micronuclei (MN) frequency, one of the cytogenetic markers, are rather controversial. Here, we investigated the relationships among MN frequency, smoking habits and five folate metabolic enzyme gene polymorphisms (MTHFR C677T and A1298C, MTR A2756G, MTRR A66G and TYMS 3'UTR) in 132 healthy Japanese men who were non-habitual drinkers. In never- and former-smokers, no statistically significant differences in the mean MN frequencies were observed according to the five folate metabolic enzyme gene polymorphisms. In current-smokers, however, subjects with the AA genotype for MTRR had a significantly higher mean MN frequency than the AG genotypes for MTRR (p<0.05). Furthermore, among subjects with the AA genotype for MTRR, current-smokers were found to have a significantly higher mean MN frequency than never- and former-smokers (p<0.05). To further characterize this association, we stratified the smoking status into five groups: non-smokers (never-smokers and former-smokers), 1-10 cigarettes/day, 11-20 cigarettes/day, 21-30 cigarettes/day and >or=31 cigarettes/day. There was an overall trend for the mean MN frequency in subjects with the MTRR AA genotype to increase as the number of cigarettes smoked per day increased (p<0.01, Jonckheere-Terpstra test). The results of our preliminary study suggest that the MTRR AA genotype acts to increase the MN frequency resulting from cigarette smoking. Therefore, studies on human genotoxicity based on cytogenetic markers of MN should take into account both the MTRR polymorphism and the potential confounding effect of smoking, although these preliminary findings need to be validated in larger populations because of the relatively small sample size.     

Delay discounting and probability discounting as related to cigarette smoking status in adults

This study examined relations between adult smokers and non-smokers and the devaluation of monetary rewards as a function of delay (delay discounting, DD) or probability (probability discounting, PD). The extent to which individuals discount value, either as a function of a reward being delayed or probabilistic, has been taken to reflect individual differences in impulsivity. Those who discount most are considered most impulsive. Previous research has shown that adult smokers discount the value of delayed rewards more than adult non-smokers. However, in the one published study that examined probability discounting in adult smokers and non-smokers, the smokers did not discount the value of probabilistic rewards more than the non-smoker controls. From this past research, it was hypothesized that measures of delay discounting would differentiate between smokers and non-smokers but that probability discounting would not. Participants were 54 (25 female) adult smokers (n = 25) and non-smokers (n = 29). The smokers all reported smoking at least 20 cigarettes per day, and the non-smokers reported having never smoked. The results indicated that the smokers discounted significantly more than the non-smokers by both delay and probability. Unlike past findings, these results suggest that both delay and probability discounting are related to adult cigarette smoking; however, it also was determined that DD was a significantly stronger predictor of smoking than PD.     

The influence of smoking on plasma folate and lipoproteins in Alzheimer disease, mild cognitive impairment and depression

The risk for Alzheimer's disease (AD) is associated with lifestyle factors, especially cigarette smoking. In this study we investigated the influence of smoking on the serum levels of folic acid, LDL and HDL in AD patients, patients with minimal cognitive impairment (MCI) and patients with major depression. We investigated a total of n = 374 patients in the diagnostic categories:, AD: n = 272, MCI: n = 60, Major depression: n = 42. We found significantly lower HDL levels in smokers and previous smokers in comparison to non-smokers, p<0,05. The LDL: HDL ratio in smokers was significant higher (+20%) compared to previous smokers and non-smokers, p < 0.05. The mean levels of folic acid were statistically significant (p<0.05) lower (-24%) in smokers compared to non-smokers. Patients with MCI and Alzheimer;s disease (and also major depression) who are "smokers" show serum levels of HDL and folic acid that are known to be strong risk factors for vascular damage and increased risk for vascular brain damage and impaired cognitive function. Therefore cessation of smoking, substitution with folate or statin therapy of smoking patients with MCI or AD might be beneficial to slow down further cognitive decline.     

Smoking and leanness: evidence for change in Finland.

Many studies have shown smokers to weigh less than non-smokers, which is plausible given the metabolic effects of cigarette smoke. The interrelation between smoking and relative body weight and its change over time were analysed by using data from Finnish population based surveys from 1982 and 1987. Among both men and women the inverse association between smoking and body mass index was clearly weakened between 1982 and 1987. In 1987 among men aged 25-44 smoking was positively related to body mass index. Moreover, the relation between smoking and waist to hip girth ratio was positive in both sexes at all ages. Years of smoking was nevertheless confirmed as a significant inverse predictor of relative weight. A cluster of unfavourable health habits, including high consumption of alcohol and saturated fats, especially emerged among younger smokers. This may have been due to different selection of smokers in Finland, where smoking increasingly seems to be a form of deviant or risk taking behaviour. It is concluded that at a population level the metabolic effects of smoking seem to be increasingly overridden by several other unfavourable health behaviours of smokers.     

Sister-chromatid exchange and cell proliferation in cultured lymphocytes of passively and actively smoking restaurant personnel

Sister-chromatid exchange frequencies were measured in peripheral lymphocytes of 12 cigarette smokers, 20 passive smokers, and 14 non-smokers with no regular exposure to tobacco smoke. All active and passive smokers worked as waiters and waitresses in restaurants. The passive smokers showed neither an increased mean SCE value nor an increased number of high SCE frequency cells (HFCs) when compared to non-exposed non-smokers. The incidence of SCEs and HFCs was observed to be elevated (P less than 0.01; P less than 0.05, resp.) among the active smokers. The proliferation rate of lymphocytes in whole blood cultures from the different exposure groups was also studied. The proportion of cells in first mitosis was lower and the mean replication index (RI) higher among the smokers than among non-smoker controls. However, no significant correlation was observed between the individual mean SCE and the replication index.     

Products of 5-lipoxygenase and myeloperoxidase activities are increased in young male cigarette smokers

Abstract The significance of 5-lipoxygenase and myeloperoxidase activities has not been extensively studied among young male smokers. Leukotriene B(4), 20-hydroxy-leukotriene B(4), 20-carboxy-leukotriene B(4) and 3-chlorotyrosine were measured in plasma and urinary samples of young male smokers at 8 hours following cigarette abstinence and an hour after cigarette smoking. Leukotriene B(4) and 3-chlorotyrosine were determined in neutrophils isolated from these individuals. The levels of these markers were compared with those of age-matched controls. In vitro studies were performed to evaluate the production of leukotriene B(4) and 3-chlorotyrosine from human neutrophils following exposure to nicotine and cotinine. Thirty male smokers (mean age, 27.4 years) and 28 male non-smokers (mean age, 28.7 years) were studied. Plasma levels of leukotriene B(4), 20-carboxy-leukotriene B(4) and 3-chlorotyrosine were higher in smokers than in non-smokers; leukotriene B(4) and 20-carboxy-leukotriene B(4) levels increased further an hour after cigarette smoking. Peripheral neutrophils isolated from smokers showed greater expressions of myeloperoxidase and 5-lipoxygenase activities compared with non-smokers, while plasma leukotriene B(4) and 3-chlorotyrosine were correlated significantly with high-sensitivity C-reactive protein and plasma nicotine concentrations. Exposure of human neutrophils to nicotine and cotinine resulted in a higher production of leukotriene B(4) and 3-chlorotyrosine. To conclude, leukotriene B(4) and 3-chlorotyrosine levels are increased in young male cigarette smokers. These results suggest that cigarette smoking aggravates neutrophil-mediated inflammation by modulating the activities of myeloperoxidase and 5-lipoxygenase pathways.     

Detectability and perceived intensity for formaldehyde in smokers and non-smokers

Formaldehyde emanating from cigarette smoke and emissions frombuilding materials is an important contaminant of indoor airand an interesting gaseous compound in the study of smokers'sensitivity to odor. With the aid of hood exposures to 18 formaldehydeconcentrations (7.5 to 1000 ppb), odor detection thresholds(method of constant stimuli) and perceived odor intensities(method of magnitude estimation) were determined among heavycigarette smokers (22 women) and non-smokers (22 aged-matchedwomen). To adjust for individual differences in response behavior,the odor thresholds were corrected for false alarms resultingfrom purified air presentations and the scale values of odorintensity were calibrated according to the master scale principleusing loudness of pink noise as a reference scale [42 to 96dB(A)]. The results showed significantly higher odor detectionthresholds for smokers than for non-smokers, 94 and 55 ppb,respectively, and significantly lower odor intensities reportedby smokers than non-smokers. In evaluating the observers' audiograms,the smokers displayed significantly higher thresholds of hearingthan the non-smokers. The results support the possibility thathabitual cigarette smoking may result in decreased sensitivityof sensory systems in general.     

Association of Leisure-Time Physical Activity to Cardiovascular Disease Prevalence in Relation to Smoking among Adult Nevadans

It is well known that cigarette smoking and physical activity have significant impacts on cardiovascular disease (CVD) mortality and morbidity. Meanwhile, it is of interest to understand whether physical activity protects against CVD for smokers in a similar manner as it does for non-smokers. The present study examined how leisure-time physical activity (LTPA) is associated with the prevalence of CVD in relation to smoking status among adult Nevadans, using data from the 2010 Nevada Behavioral Risk Factor Surveillance System. Of the 3,913 survey respondents, 8.5% self-reported that they had ever been diagnosed with CVD. People with a history of CVD were significantly less likely to engage in LTPA than those with no history of CVD (p < 0.05). After adjusting for common sociodemographic variables, it was revealed that people with CVD were twice more likely to not engage in LTPA than their counterparts independent of smoking status. Without taking LTPA into account, the odds of having CVD for current and former smokers was 1.87–2.25 times higher than the odds for non-smokers. Interestingly, however, if LTPA was accounted for, there was no significant difference in the odds of having CVD between current and non-smokers. These results indicate that LTPA is inversely associated with the prevalence of CVD independent of smoking status, and that regular physical activity may protect against CVD for smokers as well as for non-smokers. Physical activity, along with smoking cessation, should be promoted to better prevent and control CVD among smokers.     

A comparative study of the plasma level of arginase and rhodanese in smokers and non-smokers

The purpose of this investigation was to determine and compare the activities of arginase and rhodanese in the blood plasma of cigarette smokers and non-smokers.The activity of arginase in the blood plasma of smokers was higher than arginase activity in the non-smokers (NS), however,in the smokers with diseases (SWD), the increase was significant. The comparison between the activity of rhodanese in the SWD, smokers without diseases (SWOD) and NS blood plasma revealed a decrease in the activity of rhodanese in NS and no significant difference in the three groups with P=0.8677. This paper reported the enhancing effect of cigarette smoking could have on the disease state of smokers due to high arginase activity. Keywords; Rhodanese, Arginase, Cigarette smoking, Plasma.