Pramil N. Singh

Waterpipe smoking and nicotine exposure: A review of the current evidence

The waterpipe, also known as shisha, hookah, narghile, goza, and hubble bubble, has long been used for tobacco consumption in the Middle East, India, and parts of Asia, and more recently has been introduced into the smokeless tobacco market in western nations. We reviewed the published literature on waterpipe use to estimate daily nicotine exposure among adult waterpipe smokers. We identified six recent studies that measured the nicotine or cotinine levels associated with waterpipe smoking in four countries (Lebanon, Jordan, Kuwait, and India). Four of these studies directly measured nicotine or cotinine levels in human subjects. The remaining two studies used smoking machines to measure the nicotine yield in smoking condensate produced by the waterpipe. Meta-analysis of the human data indicated that daily use of the waterpipe produced a 24-hr urinary cotinine level of 0.785 microg/ml (95% CI = 0.578-0.991 microg/ml), a nicotine absorption rate equivalent to smoking 10 cigarettes/day (95% CI = 7-13 cigarettes/day). Even among subjects who were not daily waterpipe smokers, a single session of waterpipe use produced a urinary cotinine level that was equivalent to smoking two cigarettes in one day. Estimates of the nicotine produced by waterpipe use can vary because of burn temperature, type of tobacco, waterpipe design, individual smoking pattern, and duration of the waterpipe smoking habit. Our quantitative synthesis of the limited human data from four nations indicates that daily use of waterpipes produces nicotine absorption of a magnitude similar to that produced by daily cigarette use.

Vegetarian Dietary Patterns and Mortality in Adventist Health Study 2

IMPORTANCE Some evidence suggests vegetarian dietary patterns may be associated with reduced mortality, but the relationship is not well established. OBJECTIVE To evaluate the association between vegetarian dietary patterns and mortality. DESIGN Prospective cohort study; mortality analysis by Cox proportional hazards regression, controlling for important demographic and lifestyle confounders. SETTING Adventist Health Study 2 (AHS-2), a large North American cohort. PARTICIPANTS A total of 96,469 Seventh-day Adventist men and women recruited between 2002 and 2007, from which an analytic sample of 73,308 participants remained after exclusions. EXPOSURES Diet was assessed at baseline by a quantitative food frequency questionnaire and categorized into 5 dietary patterns: nonvegetarian, semi-vegetarian, pesco-vegetarian, lacto-ovo-vegetarian, and vegan. MAIN OUTCOME AND MEASURE The relationship between vegetarian dietary patterns and all-cause and cause-specific mortality; deaths through 2009 were identified from the National Death Index. RESULTS There were 2570 deaths among 73,308 participants during a mean follow-up time of 5.79 years. The mortality rate was 6.05 (95% CI, 5.82-6.29) deaths per 1000 person-years. The adjusted hazard ratio (HR) for all-cause mortality in all vegetarians combined vs nonvegetarians was 0.88 (95% CI, 0.80-0.97). The adjusted HR for all-cause mortality in vegans was 0.85 (95% CI, 0.73-1.01); in lacto-ovo-vegetarians, 0.91 (95% CI, 0.82-1.00); in pesco-vegetarians, 0.81 (95% CI, 0.69-0.94); and in semi-vegetarians, 0.92 (95% CI, 0.75-1.13) compared with nonvegetarians. Significant associations with vegetarian diets were detected for cardiovascular mortality, noncardiovascular noncancer mortality, renal mortality, and endocrine mortality. Associations in men were larger and more often significant than were those in women. CONCLUSIONS AND RELEVANCE Vegetarian diets are associated with lower all-cause mortality and with some reductions in cause-specific mortality. Results appeared to be more robust in males. These favorable associations should be considered carefully by those offering dietary guidance.

Electrophysiologic and antiarrhythmic effects of sotalol in patients with life-threatening ventricular tachyarrhythmias.

Sotalol is a unique beta-blocker that lengthens cardiac repolarization and effective refractory period (ERP). Its efficacy after intravenous (1.5 mg/kg) and oral (160 to 480 mg bid) administration was therefore evaluated in 37 patients with refractory recurrent ventricular tachycardia/fibrillation (VT/VF). Thirty-five patients, 33 with inducible VT/VF, underwent electrophysiologic testing. Intravenous sotalol lengthened the ERP in the atrium (+24.6%, p less than .01), atrioventricular node (+24.9%, p less than .01), and ventricle (+14.9%, p less than .01). It also significantly lengthened sinus node recovery time, corrected QT interval (QTc), and the AH interval, but not the HV interval. Sotalol prevented reinduction of VT/VF in 15 patients (45.5%). Twenty-five of the 33 patients (15 with positive results of electrophysiologic tests; 10 with negative results) were given oral sotalol. The drug was ineffective in seven (26.9%) and aggravated arrhythmia in one (3.8%). In four patients sotalol was withdrawn because of side effects; arrhythmias recurred late in two (7.7%). Eleven patients (42.3%) have continued on oral sotalol over a mean follow-up period of 9.2 +/- 8.6 months. Sotalol reduced (n = 21) total premature ventricular complex (PVC) count on the Holter electrocardiogram by 73% (p less than .01), paired PVCs by 89% (p less than .01), and beats of ventricular tachycardia by 95% (p less than .01). In 52% (n = 11), total reduction in PVCs was at least 85%, and incidence of paired and tachycardiac beats was reduced at least 90% (group A). In the remainder (n = 10), PVC suppression was not significant (group B). Group A included nine patients with nonreinducible VT/VF and two in whom it was reinducible; in group B, eight of 10 patients had reinducible VT/VF. The difference between the two groups (Fisher exact test) was significant (p less than .01). The prevention of reinduction of VT/VF by intravenous sotalol and suppression of spontaneously occurring arrhythmias by the oral drug were both predictive of long-term drug efficacy. Sotalol is a significant advance in the short- and long-term management of life-threatening ventricular tachyarrhythmias.

Meats, Processed Meats, Obesity, Weight Gain and Occurrence of Diabetes among Adults: Findings from Adventist Health Studies

Aim: To examine the relation between meat intake and diabetes occurrence in adults. Methods: In a prospective cohort study we examined the relation between diet and incident diabetes recorded among 8,401 cohort members (ages 45–88 years) of the Adventist Mortality Study and Adventist Health Study (California, USA) who were non-diabetic at baseline. During the 17-year follow-up, we identified 543 incident diabetes cases. Results: (1) Subjects who were weekly consumers of all meats were 29% (OR = 1.29; 95% CI 1.08, 1.55) more likely (relative to zero meat intake) to develop diabetes. (2) Subjects who consumed any processed meats (salted fish and frankfurters) were 38% (OR = 1.38; 95% CI 1.05–1.82) more likely to develop diabetes. (3) Long-term adherence (over a 17-year interval) to a diet that included at least weekly meat intake was associated with a 74% increase (OR = 1.74; 95% CI 1.36–2.22) in odds of diabetes relative to long-term adherence to a vegetarian diet (zero meat intake). Further analyses indicated that some of this risk may be attributable to obesity and/or weight gain – both of which were strong risk factors in this cohort. It is noteworthy that even after control for weight and weight change, weekly meat intake remained an important risk factor (OR = 1.38; 95% CI 1.06–1.08) for diabetes. Conclusions: Our findings raise the possibility that meat intake, particularly processed meats, is a dietary risk factor for diabetes.

Body Mass and 26-year Risk of Mortality from Specific Diseases among Women Who Never Smoked

We examined the relation between Quetelets body mass index (BMI) and age-adjusted mortality risk from specific diseases in a 26-year prospective cohort study of 12,576 non-Hispanic white women who had never smoked. To account for effects due to antecedent disease, we focused on women surviving 15–26 years after their report of body weight. High BMI (>27 kg per m2) decreased the risk of fatal respiratory disease (hazard ratios of 0.7 for ages 30–54 years and 0.6 for ages 55–74 years) but increased risk in all other disease categories. Low BMI (<21 kg per m2) increased the risk of fatal respiratory disease (hazard ratios of 2.0 for ages 30–54 years and 1.4 for ages 55–74 years). Among middle-aged women (ages 30–54 years), we found that low BMI also increased the risk of certain fatal cardiovascular diseases (hazard ratios of 1.5 for cerebrovascular death and 2.5 for hypertensive and other cardiovascular deaths), but the increase in the risk of fatal cerebrovascular disease did not remain (hazard ratio of 0.4) after exclusion of subarachnoid and intraparenchymal hemorrhage deaths from the endpoint. Although the inverse relation between BMI and risk of fatal respiratory disease was also evident in the subset who reported body weight 17 years after baseline, further restriction of this subset to stable-weight women reporting no history of respiratory disease resulted in a U-shaped relation. Data from this subset also indicated that weight loss substantially increased the risk of fatal respiratory disease. These findings implicate high and low BMI as risk factors for fatal respiratory disease but suggest that the risk due to high BMI was obscured by weight loss that followed the onset of disease. The overall findings support an association between obesity and a higher risk of fatal disease but also raise the possibility that apparently healthy, never-smoking women can experience a higher long-term risk of fatal cardiovascular and respiratory diseases due to a lower body weight. (Epidemiology 1998;9:246–254)

Vegetarian Dietary Patterns and the Risk of Colorectal Cancers

IMPORTANCE Colorectal cancers are a leading cause of cancer mortality, and their primary prevention by diet is highly desirable. The relationship of vegetarian dietary patterns to colorectal cancer risk is not well established. OBJECTIVE To evaluate the association between vegetarian dietary patterns and incident colorectal cancers. DESIGN, SETTING, AND PARTICIPANTS The Adventist Health Study 2 (AHS-2) is a large, prospective, North American cohort trial including 96,354 Seventh-Day Adventist men and women recruited between January 1, 2002, and December 31, 2007. Follow-up varied by state and was indicated by the cancer registry linkage dates. Of these participants, an analytic sample of 77,659 remained after exclusions. Analysis was conducted using Cox proportional hazards regression, controlling for important demographic and lifestyle confounders. The analysis was conducted between June 1, 2014, and October 20, 2014. EXPOSURES Diet was assessed at baseline by a validated quantitative food frequency questionnaire and categorized into 4 vegetarian dietary patterns (vegan, lacto-ovo vegetarian, pescovegetarian, and semivegetarian) and a nonvegetarian dietary pattern. MAIN OUTCOMES AND MEASURES The relationship between dietary patterns and incident cancers of the colon and rectum; colorectal cancer cases were identified primarily by state cancer registry linkages. RESULTS During a mean follow-up of 7.3 years, 380 cases of colon cancer and 110 cases of rectal cancer were documented. The adjusted hazard ratios (HRs) in all vegetarians combined vs nonvegetarians were 0.78 (95% CI, 0.64-0.95) for all colorectal cancers, 0.81 (95% CI, 0.65-1.00) for colon cancer, and 0.71 (95% CI, 0.47-1.06) for rectal cancer. The adjusted HR for colorectal cancer in vegans was 0.84 (95% CI, 0.59-1.19); in lacto-ovo vegetarians, 0.82 (95% CI, 0.65-1.02); in pescovegetarians, 0.57 (95% CI, 0.40-0.82); and in semivegetarians, 0.92 (95% CI, 0.62-1.37) compared with nonvegetarians. Effect estimates were similar for men and women and for black and nonblack individuals. CONCLUSIONS AND RELEVANCE Vegetarian diets are associated with an overall lower incidence of colorectal cancers. Pescovegetarians in particular have a much lower risk compared with nonvegetarians. If such associations are causal, they may be important for primary prevention of colorectal cancers.

Aortoiliac stent deployment versus surgical reconstruction: Analysis of outcome and cost

PURPOSE The purpose of this study is to compare complication rate, primary patency, and cost of stent deployment with direct surgical reconstruction for the treatment of severe aortoiliac occlusive disease. METHODS From March 1, 1992, to May 31, 1996, 119 patients receiving treatment for aortoiliac occlusive disease were analyzed after exclusions. Sixty-five patients had stent deployment and 54 patients had surgical reconstruction. Data were evaluated within and between the groups by univariate and multivariate logistic regression, life-table, t-test, and cross tabulation with chi2 analysis. RESULTS There was no significant difference between the groups with regard to demographic features or presenting symptoms (all p values > 0.07). Incidence of procedure-related complications was similar (p = 0.30). However, there were more systemic complications in the surgery group (15 versus 2; RR = 5.5, p < 0.01) and more vascular complications in the stent group (16 versus 3; RR = 12, p < 0.002). Incidence and type of late complications were not appreciably different (all p values > 0.05). Cumulative primary patency rate of bypass grafts was significantly better than stented iliac arteries at 18 months (93% versus 77%), 30 months (93% versus 68%) and 42 months (93% versus 68%); p = 0.002, log rank. Multivariate analysis identified female gender (RR = 4.6, p = 0.03), ipsilateral SFA occlusion (RR = 5.6, p = 0.01), procedure-related vascular complication (RR = 9.7, p = 0.002), and hypercholesterolemia (RR = 5.0, p = 0.02) as independent predictors of bypass graft or stent thrombosis. Mean total hospital cost per limb treated did not differ significantly between surgery and stent deployment groups (

Characteristics and clinical significance of silent myocardial ischemia in unstable angina

9383 versus

Mentoring Cambodian and Lao health professionals in tobacco control leadership and research skills

8626, respectively; p = 0.66, t-test). CONCLUSIONS Treatment of severe aortoiliac occlusive disease by surgical reconstruction or stent deployment has a similar complication rate. Mean hospital cost per limb treated is essentially equal. However, cumulative primary patency rate of bypass grafts is superior to stents. Therefore, considering the elements of cost and patency, surgical revascularization has greater value. The benchmark for cost-effective treatment of severe aortoiliac occlusive disease is direct surgical reconstruction.

Tobacco use among adults in Cambodia: evidence for a tobacco epidemic among women

The frequency and duration of transient myocardial ischemia on Holter recordings, analyzed by the compact analog technique, were determined in 41 patients (all men, mean age 54) with unstable angina (33 with angiographic evidence). There were 781 episodes of ischemia: 392 (50%) with ST-segment depression, 242 (31%) with ST elevation, 45 (6%) with ST elevation and depression in different leads, 70 (9%) with pseudonormalization of T waves and 32 (4%) with T-wave augmentation. Ventricular arrhythmias were associated with 18% of the episodes. The mean duration of ischemic episodes was 14 minutes (range 30 seconds to almost 12 hours); most were less than 5 minutes. Only 154 (20%) of the 781 episodes of ischemia were associated with pain. Conversely, 77 episodes of chest pain were not associated with electrocardiographic changes. Analysis of the temporal sequence of heart rate during the development of ischemia (analyzed in 415 episodes) showed that in only 43 (10%) the heart rate at the beginning of ischemia was significantly (greater than 6 beats/min) higher than that at 5 minutes (baseline) before the onset of ischemia. At the peak of the ischemic abnormality, the mean heart rate increase was 10% and returned to baseline at the end of the ischemic episode. The data indicate that 80% of ischemic episodes in unstable angina are silent and over 90% are not triggered by increases in heart rate; apparently increased oxygen demand is an uncommon cause of ischemia in unstable angina. Although most of the episodes were short-lived, some were extremely protracted without the development of myocardial infarction. The findings are of therapeutic significance.