Cigarette smoking and periodontal destruction in young adults

The relationship between cigarette smoking and periodontal destruction was assessed in young adults. Eighty-two regular dental attenders (21 current cigarette smokers, 61 non-smokers) aged between 20 and 33 years were examined. The smokers consumed on average 15.4 (+/- 7.3) cigarettes per day and had smoked for an average of 11.8 (+/- 7) years. Cigarette smokers had almost the same levels of plaque as non-smokers but had more proximal surfaces with subgingival calculus (P < 0.01) and which bled on probing (P < 0.05). Smokers had significantly more pockets > or = 4 mm (14.6 +/- 19.9) than non-smokers (5.8 +/- 7.9), P < 0.01. Only 2 (10%) of the smokers and 1 (2%) of the non-smokers had deep pocketing (> or = 6 mm). Smokers had significantly more sites (21.8 +/- 24.9) with periodontal attachment loss of > or = 2 mm than non-smokers (9.3 +/- 12.2), P < 0.01. Severe loss of periodontal attachment (> or = 6 mm) was present in 4 (19%) of smokers compared with 2 (3%) of non smokers. In total 4 (19%) of the smokers had "established periodontitis" compared with 1 (2%) of the non-smokers. The odds ratio for the presence of "established periodontitis" and smoking was 14.1 (confidence interval 1.5 to 132.9). It is concluded that cigarette smoking was a major environmental factor associated with accelerated periodontal destruction in this selected group of young adult regular dental attenders.     

Smoking in the Singapore Armed Forces

The Singapore Armed Forces has, since 1986, established a comprehensive smoking control programme which combines health education, counselling and administrative measures aimed at discouraging non-smokers from smoking, and encouraging smokers to quit the habit. The prevalence of regular smoking decreased from 28.6% in 1987 to 20.7% in 1993. The latest, 1993 survey as in past surveys covered 3,545 respondents, made up of regulars (32.0%), NSF (62.2%) and NUSAF (5.6%). The 1993 survey revealed that the majority of smokers (88.9%) in the SAF who consist primarily of 18 to 20-year-olds, had started smoking before enlistment. Most acquired the habit on their own (49.8%) or through influences outside the SAF (40.3%). Very few smokers became smokers through the influence of fellow soldiers (4.9%). The majority (87.7%) of smokers readily agreed that smoking is harmful, but this is not translated into practice. Health education efforts need to focus more on bringing about positive attitudinal and behavioural changes, rather than merely give information and advice. The young age of smoking onset (mean age of 14.3 years) In the SAF population surveyed points to the need to focus preventive efforts further upstream than hitherto emphasised.     

The volitional unit: a functional concept in cortico-motoneuronal connections in humans

AIM: The effect of breathing 100% oxygen on retinal and optic nerve head capillary blood flow in smokers and non-smokers was investigated using scanning laser Doppler flowmetry (SLDF) as a new non-invasive method to visualise and quantify ocular blood flow. METHOD: 10 eyes of 10 young healthy non-smoking volunteers (mean age 26 (SD 3) years) and nine eyes of nine young healthy smoking volunteers (mean age 26 (4) years) were investigated. All participants were asked not to smoke or consume caffeine containing drinks for at least 4 hours before the measurements. Blood flow measurements were performed before and after 100% oxygen was applied to the subjects through a mask over a period of 5 minutes (6 litres per minute). Juxtapapillary retinal and optic nerve head blood flow were determined in arbitrary units using SLDF representing a combination of laser Doppler flowmetry and a scanning laser system allowing visualisation and quantification of the retinal and optic nerve head blood flow. Blood flow was determined in an area of 100 microns x 100 microns. The level of carboxyhaemoglobin was determined in all subjects. A Wilcoxon matched pairs signed ranks test (non-parametric) was used for statistical evaluation. RESULTS: In the non-smoking group, retinal 'flow' was reduced by 33% (p = 0.005), optic nerve head 'flow' by 37% (p = 0.005). In the smoking group retinal flow was reduced by 10% (p = 0.01), optic nerve head flow by 13% (p < 0.008). The difference in reactivity to oxygen breathing between smokers and non-smokers was highly significant (p < 0.00001). Increased carboxyhaemoglobin levels were not found in either of the groups. A significant reduction of the mean arterial blood pressure of 6% (5%) (p < 0.02) was observed in the non-smoking group after administration of oxygen. CONCLUSION: These results indicate that hyperoxia leads to a decrease in capillary blood flow of the retina and optic nerve head secondary to vasoconstriction, and that smokers do not respond to oxygen breathing as non-smokers do. The findings might be based on factors such as long term effects of nicotine on the sympathetic and parasympathetic nervous system.     

Effectiveness of physicians-in-training counseling for smoking cessation in African Americans

This study examined the effectiveness of smoking cessation counseling by physicians-in-training (residents) with African-American patients. One hundred fifty-eight family and internal medicine residents at a large urban public general hospital participated in the study; two thirds of the residents underwent a 2-hour smoking cessation training program. Ninety-two of the trained physicians counseled from 1 to 18 patients. The majority of physicians were male, with 8% being current smokers. Over a 26-month period, 1086 patients were randomly assigned to intervention and control (usual care) groups. Mean patient age was 44 years, mean years smoking was 25, and mean number of cigarettes smoked per day was 14. There were no differences in biochemically validated smoking cessation rates between the intervention and control groups at 3 or 12 months postenrollment (2% versus 1.8% and 2.2% versus 2.8%, respectively). Losses to follow-up were high at both 3 and 12 months (38% and 40% respectively). Implications for future trials in minority populations are discussed. A brief physician-based smoking cessation message does not appear to be an effective strategy for use with African-American smokers in a large urban public general hospital.     

Notes on the intermediary form of incontinentia pigmenti

In a survey of a representative sample of 900 persons in Switzerland (excluding the Italian speaking parts comprising some 4-5 percent of the population), the smoking habits of the adult population were studied. Smokers were defined as persons smoking at least one cigarette or an equivalent weight of pipe tobacco or cigars per day. 51.8% of men and 29.0% of women over age 15 are smokers. Among male smokers of cigarettes only (42% of all men), over three quarters (77.6%) smoke ten cigarettes or more per day, i.e., a quantity found harmful to health; over one half (55.8%) smoke twenty or more cigarettes per day. Half of all female smokers smoke ten or more cigarettes, more than one in every four female smokers (28.8%) smoke twenty or more cigarettes per day. It is calculated that almost two thirds of all cigarettes sold in Switzerland are smoked by smokers of twenty or more cigarettes per day, and that almost three quarters are smoked by smokers of ten or more cigarettes. Among men, smoking habits are independent of social status, whereas among women, those with higher family incomes show more frequent smoking, but also more widespread cessation of smoking than with lower incomes. Thirty percent of adults having been smokers have given up the habit, so that among men and women above age 15, theree are now some 20% and 14% respectively, of ex-smokers. This corresponds to at least 700,000 former smokers in all of Switzerland. The trend to give up starts already in the group aged 15-24 (over 20% of men and women having ever smoked have given up) and becomes more marked with increasing age. A large part of male and female smokers would like to free themselves of the habit. 30% of male and 34% of female smokers indicate that they had tried seriously to stop smoking during the twelve months preceding the interview. Trying to give up was not significantly associated with intensity of smoking or social status. According to this survey, a majority of the population (57.6%) is in favor of reserving certain parts of restaurants to non-smokers, following the example of non-smokers-compartments in railway trains. In a situation where a non-smoker asks a co-worker in a closed room not to smoke, 78.3% take sides with the non-smoker, either by conceding to him a right to smoke-free air, or by demanding from the smoker to show consideration for the non-smoker. Only 10.9% demand from the non-smoker understanding for the smoker, or concede to the smoker a right to smoke at work. Women show more understanding for cause of the non-smoker than men. This difference is more marked among smokers and former smokers than among non-smokers. Inasmuch as the results of this study are comparable to those of earlier surveys conducted in Switzerland, ther is good agreement. The only exception is a significant increase of the proportion of former smokers in the past years.     

Sex difference in resistance to dexamethasone-induced apoptosis in NOD mice: treatment with 1,25(OH)2D3 restores defect

The purpose of the study was to evaluate the association between smoking during pregnancy and preterm birth. The overall rate of preterm delivery was 4.3%. Smokers had a 40% higher risk of preterm birth compared to non-smokers. A dose response relationship was found between smoking and risk of preterm birth. Adjustment for women's height, pre-pregnant weight, age of the mother, marital status, education, occupational status, and alcohol intake did not change the results. Among women with an intake of less than 400 mg of caffeine per day no difference in the risk of preterm birth between smokers and non-smokers was found. However, among women with an intake of more than 400 mg of caffeine per day, the risk of preterm birth was increased almost threefold among smokers compared to non-smokers. Furthermore, among women with a high intake of caffeine a dose response relationship was found between smoking and risk of preterm delivery.     

p53 mutations in non-small-cell lung cancers occurring in individuals without a past history of active smoking

Accumulating evidence suggests that the p53 gene is a good target for molecular epidemiological studies. We previously reported an association between the presence of p53 mutations and lifetime cigarette consumption. Although over 675 p53 mutations have been reported in lung cancers in the literature thus far, very little is known about the nature of such changes in lung cancers in the absence of a smoking background. In the present study, we therefore analysed 69 non-small-cell lung cancer specimens from individuals without any history of active smoking and identified p53 mutations in 26% of the cases. Statistical analysis of the present cohort of non-smokers also showed absence of significant relationship between p53 mutations and age, sex, histological type or disease stage. Comparison of mutational spectra between the present results in non-smokers and previously reported mutations in smokers clearly demonstrated G:C to T:A transversions to be significantly less frequent in non-smokers than in smokers (OR 5.35, 95% CI 1.77-16.12). Interestingly, G:C to C:G and G:C to A:T mutations were also observed in tumours of non-smokers at similar frequencies to G:C to T:A mutations, suggesting that these mutations can occur relatively frequently in the absence of active smoking. This study is, to our knowledge, the largest so far analysing a well-defined cohort of non-smokers in a single laboratory.     

Benign symmetrical lipomatosis: Madelung''s disease

The relationship between smoking and bladder cancer risk was investigated using data from a case-control study conducted between January 1994 and July 1996 in Alexandria, Egypt. Cases were 151 males with incident, histologically confirmed invasive cancer of the bladder, and controls were 157 males admitted to hospital for acute, non-neoplastic, non-urinary tract, non-smoking-related conditions. With reference to never smokers, ex-smokers had a multivariate odds ratio (OR) of 4.4 [95% confidence interval (CI) 1.7-11.7] and current smokers of 6.6 (95% CI 3.1-13.9). The ORs were 5.4 for < 20 and 7.6 for > or = 20 cigarettes per day. After adjustment for cigarette smoking, the ORs were 0.8 for waterpipe and 0.4 for hashish smokers. The risk was significantly related to duration of smoking (OR of 16.5 for > 40 years), and inversely related to age at starting (OR of 8.8 for starting < 20 years), and inversely related to time since quitting smoking. Compared with never smokers who did not report a clinical history of schistosomiasis, the OR was 9.4 for smokers with a history of schistosomiasis, and 10.7 for smokers ever employed in high-risk occupations compared with non-smokers not reporting such a history. Thus, our results, while not giving indications of an increased bladder cancer risk with habits other than cigarette smoking, found a remarkably strong association with various measures of cigarette smoking that could explain 75% of bladder cancer cases among males from Alexandria. The prevalence of smoking was very low among women, and consequently tobacco was not a relevant risk factor for female bladder cancer.     

Smoking, lipoproteins and coronary heart disease risk. Data from the Münster Heart Study (PROCAM)

AIMS: The mechanism of the increase in coronary heart disease risk associated with smoking is unclear, but may partly be due to smoking-related changes in intermediate risk factors such as lipid levels, fibrinogen and blood pressure. We therefore examined the distribution of these variables among smokers and non-smokers in the Münster Heart Study. METHODS: 20696 men, aged 41.7+/-2.7 years (mean +/- SD) and 10212 women, aged 37.0+/-2.6 years, were enrolled between 1978 and 1995. Thirty-two percent of women and 36% of men smoked. Compared to non-smokers, mean levels of low density lipoprotein cholesterol, total cholesterol, triglycerides and fibrinogen were increased, respectively, by 1.4%, 0.9%, 15% and 12.1% in male and by 2.0%, 5.5%, 12% and 3.4% in female smokers. Mean high density lipoprotein cholesterol levels, body mass index and blood pressure were reduced, respectively, by 6.4%, 3.8%, and 2% in male, and by 6.7% 1.2% and 2% in female smokers. In the subgroup of 4639 men aged 40 to 65 with 8 years of follow-up, the coronary event rate (definite myocardial infarction, sudden cardiac death) in cigarette smokers was more than twice that of non-smokers with otherwise identical risk factors. CONCLUSION: In the Münster Heart Study, smoking was associated with adverse changes in lipids (of greater magnitude in women), and fibrinogen (of greater magnitude in men). However, these changes explained only a small part of the smoking-related increase in coronary heart disease risk.     

Smoking patterns and cancer of the oral cavity and pharynx: a case-control study in Uruguay

A case-control study of cancer of the oral cavity and pharynx was conducted in Uruguay, between 1992 and 1996. 425 patients microscopically diagnosed with squamous cell carcinoma of the oral cavity and pharynx were frequently matched on age, residence, and urban/rural status with 427 hospitalised controls. The study was restricted to males. Smokers of black tobacco cigarettes were associated with an increased risk of 12.1 (95% confidence interval (CI) 7.6-19.4), when compared with non-smokers after fitting a model which included the matching variables, birthplace, education, and total alcohol consumption. Lifelong smokers of hand-rolled cigarettes displayed an odds ratio (OR) of 8.7 (95% CI 5.6-13.4), compared with non-smokers. When smokers were excluded from the calculations, the OR for smokers of black tobacco cigarettes was 3.0 (95% CI 2.0-4.6), compared with smokers of blond tobacco cigarettes, after controlling for the same variables mentioned above, plus pack-years, years since stopping, and filter use. Hand-rolling appears to be less important than smoking black tobacco in this study (OR 1.6, 95% CI 0.9-2.5). Thus, smoking black tobacco cigarettes appears to be an important habit in oral and pharyngeal carcinogenesis.     

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.     

Unemployment and change of tobacco habits: a study of young people from 16 to 21 years of age

In a cohort study of 1080 pupils who were followed for 5 years from when they left compulsory school (from age 16 to age 21 years), smoking habits were found to correlate with unemployment among both boys and girls. Pupils who were smokers in school had a higher risk of becoming unemployed than non-smokers. Irrespective of early smoking, smoking habits developed more unfavourably among unemployed young people than among those with no unemployment during the period studied. The odds ratio of being a smoker at the age of 21 years when unemployed more than 20 weeks during the observation period, compared with those without or with short unemployment, was 2.44 for men and 3.45 for women. When adjusted for the influence of socio-economic background, education, economy and smoking habits at the start of the period, the odds ratio was 1.7 (95% CI 1.01-2.86) for men and 2.0 (1.13-3.53) for women. The adjusted odds ratio for increasing or starting smoking during the period was 1.5 (95% CI 0.89-2.56) for men and 2.0 (1.18-3.35) for women. No significant correlation was found between snuffing and unemployment. Thus, it seems that unemployment is a risk factor for development of tobacco smoking in young people, especially among women.     

The relationship between smoking, cholesterol, and HDL-C levels in adult women

The purpose of this study was to determine the independent relationship between smoking quantity and cholesterol (TC) and lipoprotein levels (HDL-C) in women. A total of 805 female subjects were grouped as: non-smokers, ex-smokers, light smokers, moderate smokers, and heavy smokers. TC and HDL-C were examined before and after controlling for the coexisting risk factors of age, body composition, fitness level, dietary fat intake, family history of coronary artery disease, oral contraceptive, and alcohol use. Preliminary analysis demonstrated significant differences (p < .01) in TC between heavy smokers and all other groups and significant differences in HDL-C between heavy to moderate smokers and ex- and non-smokers. After adjusting for confounding variables, the differences in TC and HDL-C remained unchanged between the groups. It was concluded that heavy to moderate smoking was independently associated with higher TC and lower HDL-C levels, and that smoking abstinence or smoking cessation may be associated with healthier lipoprotein profiles in adult women. Based on these findings, it was recommended that employers consider the provision of health promotion programs including seminars, behavioral modification workshops, as well as financial incentives for employees to stop smoking.     

Frontopolar ictal epileptiform discharges on scalp electroencephalogram in temporal lobe epilepsy

OBJECTIVE: To determine the prevalence of the smoking habit among Mexican physicians as well as some of their attitudes and information on specific issues concerning smoking. MATERIAL AND METHODS: In 1993, a survey was carried out among 3,568 physicians of the three major official health care institutions in Mexico City. A questionnaire designed for The Mexican National Survey of Addictions (ENA 1993) was used. Prevalence of cigarette smoking, age of onset, number of cigarettes per day; also information and attitudes concerning smoking were assessed. RESULTS: The mean age was 37, 66% were males. Of the 3,488 (98%) surveyed, 26.9% were smokers (62% daily), 20.6% were ex-smokers and 52.5% non-smokers. There were differences related to age and sex (p < 0.05). Of daily smokers, 36% smoked between 1 and 5 cigarettes. There was a significant trend among ex-smokers that linked the time they had ceased smoking with the fear to start smoking again. Physicians were well informed of the relationship between cigarette smoking and lung cancer. Over 80% considered tobacco an addictive drug but only 65% were in favor of banning smoking from their workplaces and over 10% were not aware that it is forbidden to smoke inside health care facilities. CONCLUSIONS: These results differ from other studies that find the prevalence of smoking among physicians lower than in the general population. Our study revealed a greater prevalence of the smoking habit among female physicians and the number of cigarettes smoked per day was greater than in the general population regardless of sex.     

The effects of smoking outside workplaces on non-regular smokers

The introduction of workplace smoking bans has resulted in smokers smoking outside their workplaces (exiled smoking). Social identity theory postulates that this may cause antagonism between smokers and non-smokers, or where non-smokers were friends with smokers, pressure on non-smokers to smoke. This study examines perceptions and beliefs about exiled smoking in 166 non-smoking workers. They saw smokers as having a work benefit not available to them, but otherwise they were generally not drawn to the activity. Half had joined smokers outside for breaks, but of these only one-third had ever smoked. Those would smoked reported that they did not have a regular pattern of joining the same group of smokers. Although it may provide a conduit for susceptible non-smokers to take up smoking, exiled smoking does not appear to influence those who are not otherwise vulnerable.     

Selective modulation of non-protein sulfhydryl levels in Ehrlich ascites tumor bearing mice

OBJECTIVES: A total of 97 apparently healthy subjects were studied in order to establish the influence of smoking habits in studies on neurocardiovascular control and the QTc interval duration. MATERIAL AND METHODS: The study group consisted of 37 smokers and 60 non-smokers as the control. A 12-lead electrocardiogram was performed on all subjects to determine the duration of the QTc interval. Other aspects studied include heart rate variability at rest during 150 cardiac cycles using time domain: coefficient of variation and root mean squared successive difference; and frequency domain: low frequency band (0.04-0.15 Hz) and high frequency band (0.15-0.50 Hz), to determine total energy logarithm and maximum energy frequency. Additionally, conventional cardiovascular autonomic function tests, such as orthostasis, Valsalva maneuver and deep breathing were performed. RESULTS: No significant differences were observed in the duration of the QTc interval nor in time and frequency domain parameters, except in the maximum frequency in the high frequency band, which appeared significantly lower (p < 0.05) in smokers when compared to non-smokers (0.28 +1- 0.1 vs 0.33 +/- 0.1 Hz). No modifications were noted in the cardiovascular autonomic function tests applied to smokers and non-smokers, and the QTc interval was not linked to the rest of the variables studied. CONCLUSIONS: To conclude, smoking habits do not seem to have a significant influence in studies addressed to determine the impact of the autonomic nervous systems on cardiovascular control.     

Effect of smoking on sudden and premature death

BACKGROUND: Smoking has been related to coronary heart disease, and, in men, to sudden death. The results of a case-control study designed to assess the relationship between smoking and all causes of sudden and premature death are reported. METHODS: A questionnaire on the previous history and causes of death of all people buried in the Municipal Cemetery of Valencia (1986-1987) was administered to the relatives of the deceased. Among 4718 deaths, 284 victims of sudden death were identified, and 495 people who had not died suddenly were randomly sampled as controls. RESULTS: The proportion of smokers among the women studied was extremely low in contrast to 58.9% of men in the sudden death study group and 59.2% of men in the non-sudden death study group who smoked. Smokers died on average 10 years younger than non-smokers in the sudden-death group (63.3 +/- 12.3 and 73.3 +/- 11.0 years respectively; P < 0.001), and 8 years earlier in the non-sudden death group (68.5 +/- 13.3 and 76.8 +/- 13.2 years, respectively; P < 0.001). A logistic regression model showed that smokers had an adjusted relative risk of 0.81 for sudden death compared with non-smokers (95% confidence interval [CI]: 0.45-1.46). Smokers 65 years of age or under had a 2.7 times greater risk (95% CI: 1.49-5.04) of premature death than non-smokers. Similar results were found in patients from the coronary- and cardiac-death subgroups. CONCLUSIONS: Smoking is an independent risk factor for premature death but not for sudden death.     

The relationship between body mass and cigarette smoking using a biochemical index of smoking exposure

This study evaluated the relationship between smoking and body mass using objective indices of both smoking exposure (COHb) and body mass. The subjects were 4240 adults who participated in the Second National Health and Nutrition Examination Survey (NHANES II). Measurements of dietary intake, physical activity, demographics, body mass index (BMI) and blood carboxy-haemoglobin (COHb) were used in these analyses. After controlling for covariables of body mass, the results indicated that smokers displayed a significantly lower mass compared with non-smokers. Smokers with higher levels of COHb had lower BMIs than smokers at lower COHb levels. White smokers had lower BMIs with increasing COHb exposure whereas black smokers had BMIs at high COHb exposure similar to those of non-smokers. Results indicated that smokers weighed less than non-smokers and that the weight control 'benefits' of smoking were most pronounced in white subjects who were heavy smokers.     

Effects of cigarette smoking on antioxidant vitamin and activities of antioxidases

Levels of plasma vitamin C and E (P-VC, P-VE), beta-carotene (P-beta-Car), lipoperoxides (P-LPO), and activity of erythrocyte superoxide dismutase (E-SOD) were measured in 871 healthy smokers and 348 healthy non-smokers to study the relationship between cigarette smoking and antioxidant vitamins and oxygen free radicals. Results showed that levels of P-VC, P-VE, P-beta-Car and E-SOD reduced significantly, and level of P-LPO increased significantly in smokers, as compared with those in non-smokers. Levels of P-VC, P-VE, P-beta-Car and E-SOD reduced and level of P-LPO increased in 65 male smokers at the same age, with the increase of duration of smoking and quantity of cigarettes smoked, showing a linear correlationship. It suggested that there existed serious imbalance between oxidation and antioxidation in the bodies of smokers, and oxygen free radical reaction and reaction of lipoperoxidation obviously intensified.     

Contrasting renal effects of nicotine in smokers and non-smokers

BACKGROUND: Cigarette smoking is associated with acute increase in arterial pressure due to systemic vasoconstriction and decreased skin and coronary blood flow. Virtually all cardiovascular effects of cigarette smoking are due to nicotine. However, whether nicotine also affects the renal circulation and function in humans is at present unknown. METHODS: In the current study the acute effects of a 4-mg nicotine gum on arterial pressure, heart rate as well as renal haemodynamics and function were assessed in non-smokers and chronic smokers. RESULTS: In non-smokers, mean arterial pressure (+8 +/- 1 mmHg, P<0.001) and heart rate (+13 +/- 3 beats/min, P<0.001) increased whereas effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) decreased by 15 +/- 4% and 14 +/- 4% respectively; in addition, urinary cyclic GMP decreased by 51 +/- 12% in response to nicotine administration. In smokers, mean arterial pressure and heart rate increased similarly; however, in contrast with non-smokers, ERPF and GFR remained unchanged whereas urinary cyclic GMP rose by 87 +/- 43%. Changes in ERPF induced by nicotine were positively correlated with changes in urinary cyclic GMP. CONCLUSIONS: These findings indicate that nicotine administration is associated with renal vasoconstriction in healthy non-smokers, possibly through alteration of a cyclic-GMP-dependent vasoactive mechanism. Tolerance to the renal effect of nicotine was observed in chronic smokers, despite the maintenance of the systemic response to nicotine.