Systematic review of the relation between smokeless tobacco and cancer of the pancreas in Europe and North America

<p>Abstract</p> <p>Background</p> <p>Recent reviews claiming smokeless tobacco increases pancreatic cancer risk appear not to have considered all available epidemiological evidence; nor were meta-analyses included. We present a systematic review of studies from North America and Europe, since data are lacking from other continents. Risk is also difficult to quantify elsewhere due to the various products, compositions and usage practices involved.</p> <p>Methods</p> <p>Epidemiological studies were identified that related pancreatic cancer to use of snuff, chewing tobacco or unspecified smokeless tobacco. Study details and effect estimates (relative risks or odds ratios) were extracted, and combined by meta-analyses.</p> <p>Results</p> <p>Nine North American and two Scandinavian studies were identified. Reporting was limited in four studies, so only seven were included in meta-analyses, some providing results for never smokers, some for the overall population of smokers and non-smokers, and some for both.</p> <p>Giving preference to study-specific estimates for the overall population, if available, and for never smokers otherwise, the random-effects estimate for ever smokeless tobacco use was 1.03 (95% confidence interval 0.71–1.49) based on heterogeneous estimates from seven studies. The estimate varied little by continent, study type, or type of smokeless tobacco.</p> <p>Giving preference to estimates for never smokers, if available, and overall population estimates otherwise, the estimate was 1.14 (0.67–1.93), again based on heterogeneous estimates. Estimates varied (p = 0.014) between cohort studies (1.75, 1.20–2.54) and case-control studies (0.84, 0.36–1.97). The value for cohort studies derived mainly from one study, which reported an increase for never smokers (2.0, 1.2–3.3), but not overall (0.9, 0.7–1.2). This study also contributed to increases seen for snuff use and for European studies, significant only in fixed-effect analyses.</p> <p>The studies have various weaknesses, including few exposed cases, reliance in cohort studies on exposure recorded at baseline, poor control groups in some case-control studies, and lack of a dose-response. Publication bias, with some negative studies not being presented, is also possible.</p> <p>Conclusion</p> <p>At most, the data suggest a possible effect of smokeless tobacco on pancreatic cancer risk. More evidence is needed. If any risk exists, it is highly likely to be less than that from smoking.</p

The relation between smokeless tobacco and cancer in Northern Europe and North America. A commentary on differences between the conclusions reached by two recent reviews

<p>Abstract</p> <p>Background</p> <p>Smokeless tobacco is an alternative for smokers who want to quit but require nicotine. Reliable evidence on its effects is needed. Boffetta et al. and ourselves recently reviewed the evidence on cancer, based on Scandinavian and US studies. Boffetta et al. claimed a significant 60–80% increase for oropharyngeal, oesophageal and pancreatic cancer, and a non-significant 20% increase for lung cancer, data for other cancers being "too sparse". We found increases less than 15% for oesophageal, pancreatic and lung cancer, and a significant 36% increase for oropharyngeal cancer, which disappeared in recent studies. We found no association with stomach, bladder and all cancers combined, using data as extensive as that for oesophageal, pancreatic and lung cancer. We explain these differences.</p> <p>Methods</p> <p>For those cancers Boffetta et al. considered, we compared the methods, studies and risk estimates used in the two reviews.</p> <p>Results</p> <p>One major reason for the difference is our more consistent approach in choosing between study-specific never smoker and combined smoker/non-smoker estimates. Another is our use of derived as well as published estimates. We included more studies, and avoided estimates for data subsets. Boffetta et al. also included some clearly biased or not smoking-adjusted estimates. For pancreatic cancer, their review included significantly increased never smoker estimates in one study and combined smoker/non-smoker estimates in another, omitting a combined estimate in the first study and a never smoker estimate in the second showing no increase. For oesophageal cancer, never smoker results from one study showing a marked increase for squamous cell carcinoma were included, but corresponding results for adenocarcinoma and combined smoker/non-smoker results for both cell types showing no increase were excluded. For oropharyngeal cancer, Boffetta et al. included a markedly elevated estimate that was not smoking-adjusted, and overlooked the lack of association in recent studies.</p> <p>Conclusion</p> <p>When conducting meta-analyses, all relevant data should be used, with clear rules governing the choice between alternative estimates. A systematic meta-analysis using pre-defined procedures and all relevant data gives a lower estimate of cancer risk from smokeless tobacco (probably 1–2% of that from smoking) than does the previous review by Boffetta et al.</p

Cardiovascular time courses during prolonged immersed static apnoea

To define the dynamics of cardiovascular adjustments to apnoea during immersion, beat-to-beat heart rate (HR) and systolic (SBP) and diastolic (DBP) blood pressures were recorded in six divers during and after prolonged apnoeas while resting fully immersed in 27 degrees C water. Apnoeas lasted 215 +/- 35 s. Compared to control values, HR decreased by 20 beats min(-1) and SBP and DBP increased by 23 and 17 mmHg, respectively, in the initial 20 +/- 3 s (phase I). Both HR and BP remained stable during the following 92 +/- 15 s (phase II). Subsequently, during the final 103 +/- 29 s, SBP and DBP increased linearly to values about 60% higher than control, whereas HR remained unchanged (phase III). Cardiac output (Q') decreased by 35% in phase I and did not further change in phases II and III. Compared to control, total peripheral resistances were twice and three times higher than control, respectively, at the end of phases I and III. After resumption of breathing, HR and BP returned to control values in 5 and 30 s, respectively. The time courses of cardiovascular adjustments to immersed breath-holding indicated that cardiac response took place only at the beginning of apnoea. In contrast, vascular responses showed two distinct adjustments. This pattern suggests that the chronotropic control via the baroreflex is modified during apnoea. These cardiovascular changes during immersed static apnoea are in agreement with those already reported for static dry apnoeas

Modeling the Population Health Impact of Introducing a Modified Risk Tobacco Product into the U.S. Market

Philip Morris International (PMI) has developed the Population Health Impact Model (PHIM) to quantify, in the absence of epidemiological data, the effects of marketing a candidate modified risk tobacco product (cMRTP) on the public health of a whole population. Various simulations were performed to understand the harm reduction impact on the U.S. population over a 20-year period under various scenarios. The overall reduction in smoking attributable deaths (SAD) over the 20-year period was estimated as 934,947 if smoking completely went away and between 516,944 and 780,433 if cMRTP use completely replaces smoking. The reduction in SADs was estimated as 172,458 for the World Health Organization (WHO) 2025 Target and between 70,274 and 90,155 for the gradual cMRTP uptake. Combining the scenarios (WHO 2025 Target and cMRTP uptake), the reductions were between 256,453 and 268,796, depending on the cMRTP relative exposure. These results show how a cMRTP can reduce overall population harm additionally to existing tobacco control efforts

Experimental evaluation of the hydration status during fitness training

This study aims to analyze the hydration status in a large group 01 litness athletes and to understand the amount 01 Iluids that they habitually consume during a typical training session. lvIethods. One hundred lorty-eight volunteers (86 male [M], 62 Iemale [F]) aged 18-50 were examine (average age 32±8.3 years old, 77% between 18 and 38 years old). Average health: (M) 174±14 cm; (F) 164±12 cm. Average weight: (M) 74±16 Kg; (F) 57±9 Kg. Body Mass Index (BMI) on mean: (M) 24,08±1,42 Kglm2; (F) 21 ,04±0,27 Kglm2. Basai hydration status was determined by measuring urine specilic gravity (Usg) in the lirst urine sample collected alter waking. We have used changes in body mass to calculate the amount 01 water lost during exercise and to divide the subjects into three groups: dehydrated euhydrated and overhydrated. We also considered the amount and type 01 Iluids that they consumed during exercise. On the total sample, 20 athletes Irom the sample also underwent the "Sweat test", which consists in measuring sodium (Na+) and potassium (K+) concentrations in sweat to assess salt losses through sweating. Results. 1) Data on basai hydration status showed that 58% 01 the subjects are dehydrated, 39% euhydrated and 3% overhydrated; 2) 31 subjects lost more than 1% 01 their total body weight (measurements taken belore and alter training), which means that they lost too much water through sweating and did not consume sufficient fluid, thereby lalling into a hypertonic dehydration proli le. Discussion and cone/usions. Our study shows that over 50'1., 01 the litness athletes do not pay enough attention to their hydration status and begin their training in the condition of dehydration. In addition, more than 20% 01 the athletes do not drink enough during exercise, losing more than 10;', 01 their weight. Sport and nutrition professionals should stress the importance 01 hydration in improving litness athletes' performance and in reducing health risks

A survey on hydration and body composition among Italian young athletes.

BACKGROUND: Evidence shows that children water intake are below recommendations and are likely to be insufficient for maintain euhydration. Moreover, childhood obesity is becoming an epidemic. Interestingly, among other factors, the level of hydration may play a role in promoting weight regulation processes. AIMS: Assessing hydration status(HS); detecting daily water intake(DWI), hydration after exercise(HAE), body composition(BC);investigating possible correlations between these variables and practiced sport(PS). METHODS: 351 young athletes(YA)(7-17 years old) were recruited. A questionnaire was used to asses DWI, HAE and PS; to study BC we used BMI percentiles(BMIp), waist to height ratio(WHtR), bioimpedence analysis(BIA);HS was assessed using urine specific gravity(USG). Statistical analysis(Pearson’s chi square, ANOVA, MANOVA, Spearman’s rho test) was performed to test any possible relationships between the variables studied. RESULTS & DISCUSSION: we found similar prevalence of obesity and overweight(OW)(27.9%) to those observed in Italy from other studies, but the prevalence was significantly of YA(55.6%) were dehydrated(DH), probably because they had poor DWI(1400±580mL). Comparing DWI with recommendation for Adequate Intake of water(Italy RDAs-2012), we found that YA achieved them but they were not sufficient to achieve euhydration. Comparing DWI with the amount of water needed, estimated using basal metabolic rate(BMR)(ml/kcal energy expenditure), we found that YA did not achieve that amount. The majority of YA(87.7%) stated to drink after exercise, but the amount of water was very lower(500±200mL) than their real needs. DWI was related to the degree of OW, the more the OW the > the DWI. DWI was also related to the PS, YA practicing sports that emphasize leanness had FM if DH. Underweight YA had < FM if DH. Based on our findings we can assume that HS plays a key role in BC and there is a need to make more efforts to teach the importance of hydration in YA

Nitric oxide-related endothelial changes in breath-hold and scuba divers.

International audienceOBJECTIVE: Scuba and breath-hold divers are compared to investigate whether endothelial response changes are similar despite different exposure(s) to hyperoxia. DESIGN: 14 divers (nine scuba and five breath-holding) performed either one scuba dive (25m/25 minutes) or successive breath-hold dives at a depth of 20 meters, adding up to 25 minutes of immersion time in a diving pool. Flow-mediated dilation (FMD) was measured using echography. Peripheral post-occlusion reactive hyperemia (PORH) was assessed by digital plethysmography and plasmatic nitric oxide (NO) concentration using a nitrate/nitrite colorimetric assay kit. RESULTS: The FMD decreased in both groups. PORH was reduced in scuba divers but increased in breath-hold divers. No difference in circulating NO was observed for the scuba group. Opposingly, an increase in circulating NO was observed for the breath-hold group. CONCLUSION: Some cardiovascular effects can be explained by interaction between NO and superoxide anion during both types of diving ending to less NO availability and reducing FMD. The increased circulating NO in the breath-hold group can be caused by physical exercise. The opposite effects found between FMD and PORH in the breath-hold group can be assimilated to a greater responsiveness to circulating NO in small arteries than in large arteries