A prospective hospital-based study was carried out over two year period (from October 2013 to September 2015) in the Departments of Neurology and Medicine, IMS & SUM Hospital, Bhubaneswar, Odisha, India. The inclusion criteria were: 1) Different types of acute stroke (haemorrhagic stroke, ischaemic stroke, subarachnoid haemorrhage), diagnosed clinically and radiologically; 2) Age of the subjects’ ≥16 years to ≤60 years; 3). The Fagerström Test for Nicotine Dependence for smokeless tobacco (FTND-ST) [9] more than 6 i.e., patient is highly dependent on nicotine [9,10]; 4) Follow-up data available for at least 6 months. Following were taken as the exclusion criteria: 1) Patients having other addictions like smoked tobacco, alcohol, intravenous drug abusers; 2) Stroke in patients with important risk factors like hypertension, diabetes, dyslipidemia, obesity, systemic vasculitis, coronary heart disease, atrial fibrillation, rheumatic heart disease, significant extracranial and intracranial stenosis; 3) History of Central Nervous System (CNS) infections.

Diagnosis of stroke was made on the basis of medical history, physical examination and neuroimaging. All patients were subjected to routine haematological, metabolic workup, electrocardiogram, echocardiography, MRI of brain and carotid doppler. Patients with clinical suspicion of vasculitis were investigated for antiphospholipid antibody, and prothrombotic factors. Patients were investigated for modifiable and non-modifiable vascular risk factors.

Current ST users were defined as patients addicted to either snuff or chewing tobacco at present [11]. Smoker was defined as a person having ≥ 1 pack-years smoked (1 pack = 20 cigarettes). Addicted alcohol consumer was defined as with alcohol consumption >70 gram/week [12]. Hypertension was defined as with increased systolic blood pressure >140 mmHg or diastolic >90 mmHg [13] or with past history of hypertension, or record of antihypertensive drugs usage. Diabetes mellitus was defined as documented diabetes in the medical records, or having a random blood glucose level of >11.1mmol/L (200mg/dl), fasting blood sugar level of ≥126mg/dl or those on anti-diabetics drugs [14]. According to NCEP ATP III criteria, dyslipidemia was defined with following criteria as, LDL-C≥130mg/d, Cholesterol>200 mg/dL, TG ≥150mg/dL; HDL-C≤39mg/dL [15]. Coronary heart disease was defined as a biochemical, electrocardiographic, or echocardiographic evidence of coronary event or a known past history of myocardial infarction or angina.

Anthropometric indices were done for evaluation of central and general obesity. World Health Organization’s recommendations for Asian population were used for body mass index categorization [16]. Informed consent was obtained from all the study subjects or relatives wherever applicable. Patients were referred to the psychiatrist for counseling and deaddiction measures and followed up for six months.

Data were collected in the preformed performa. Analysis was done using the Statistical Package for Social Sciences (SPSS), version 16.0 (Chicago, IL, USA). Descriptive statistics like percentage, mean, standard deviation were used wherever appropriate.

Out of 54 patients in our cohort, 42(77.8%) were males and 12(22.2%) were females. The age range was from 32 years to 57 years with mean age of 42.72(± 8.6) years [Table/Fig-1]. The incidence of stroke was maximum in the age group 40-59 years which comprised 45(83.3%) of the patients of entire study population. Out of the total study population, 96.3% patients were diagnosed as cases of ischemic stroke and 3.7% as haemorrhagic stroke as shown in [Table/Fig-2]. The ratio of ischemic stroke to haemorrhagic stroke was 26:1.

Patients presented to us with mean duration of 25.7 (±12.26) hours after stroke onset. None of the patient presented within window period of intravenous thrmbolysis. Patients were admitted as inpatient for mean of 10.4 (±2.67) days and managed conservatively. Complications of stroke during hospital stay were observed in 6 (11.1%) patients like haemorrhagic conversion (1 patient), deep venous thrombosis (1 patient), aspiration pneumonia (2 patients), and urinary tract infection (2 patients). We did not have mortality in our series. Complications during follow-up for six months were noted in 8 patients like restroke (1 patient), haemorrhagic stroke (1 patient), stroke pain syndrome (3 patients), significant spasticity (2 patients) and stroke shoulder syndrome (1 patient). As some patients had multi focal ischemic lesions, sites of involvement in MRI were more than the number of patients.

Intracerebral Haemorrhage FUNC score [18] of two haemorrhagic strokes were 9 and 11. Modified Rankin scale [19] after 5 days of hospital stay was mean 3.83 (±1.03) and after 6 months of follow-up was 2.1(±0.8). The Barthel Index [20] at presentation was mean 12.2(±3.32) and at final follow-up was 18(±2.3). At presentation the FTND-ST [9] score was mean 7.82(±1.3) and post 6 month follow-up was 2.04(±0.6). Patients were counseled for deaddiction. After 6 months follow-up 48(88.8%) patients had quit ST.

Main symptoms/signs associated with stroke during the time of hospitalization have been summarized in [Table/Fig-3]. [Table/Fig-4] shows site of lesion of ischemic stroke according to MRI of Brain (n=52). [Table/Fig-5] shows different types of ischemic strokes seen in this study (n=52) according to Oxfordshire community classification.

ST is consumed without combustion and is used nasally or orally (sucked, chewed, dipped, held in the mouth), resulting in absorption of nicotine and other chemicals across mucus membranes. Smoked tobacco, is usually burned or heated and then inhaled. Worldwide, ST products are available in plenty from simple cured tobacco to various elaborate products with different chemical ingredients. So, ST products vary greatly in composition and contain high levels of free nicotine, total nicotine, and various carcinogens (> 30 identified) [21].

The mode of ST use varies based on ingredient availability, geographic location, social and cultural norms and individual preferences. The various forms available for oral use are pan, gutkha (chewing), khaini, snus, lozenges (sucking), bajjar, gudakhu (local application), tuibur (gargling), and as nasal snuff for inhalation [21]. In our study, Pan (Betel leaf) was most commonly used in 21 (38.9%) patients with addiction for 14.6 (±3.27) years.

Across the globe, approximately 300 million people use ST. The majority of ST users (89%) live in South-East Asia of which Bangladesh, Myanmar and India host 86% of the global total [21]. The prevalence of ST consumption in India is 20% [22]. The consumption is significantly higher in males than in females (28% v/s 12%), and in rural population as compared with urban [23]. Lesser cost, easy affordability, misconceptions regarding its useful health effects and peer pressure among adolescents are important contributory factors for increased ST consumption. Some decades ago, in India, only locally made ST products such as betel quid with tobacco were available. However, recently due to large scale production of tobacco, varieties of ST products have become commonly available [22,23]. Most commonly used ST products in India include tobacco with lime, tobacco pan masala, tobacco with pan and betel quid.

Nicotine in cigarette smoke induces a variety of pathologic mechanisms like platelet activation, endothelial dysfunction, cellular inflammation, accelerated atherogenesis, sympathoadrenal activation, cardiac arrhythmia, relative insulin resistance and dyslipidemia, all of them contributing to cardiovascular disease [24]. ST also through similar mechanisms leads to vascular damage [25,26]. The regular consumption of ST products leads to exposure of as much nicotine per day as do regular Cigarette Smoking (CS) [27]. Nicotine that is inhaled in CS is absorbed quickly in the lungs, moves into the arterial circulation in high concentrations, and then to the brain and other organs. Nicotine from ST is absorbed much more slowly with absorption continuing for >30 minutes [28]. It is relevant, as the speed of absorption of nicotine and maximum blood levels reached are important determinants of the cardio vascular effects. Thus, the same daily nicotine dose from ST would cause less injury than from CS.

In our series, 96.3% strokes were ischemic in nature. Nicotine is an established risk factor for ischemic strokes which can induce cardiac arrhythmias as proven by different animal studies [6]. Apart from other mechanisms of nicotine inducing atherogenesis, cardiac embolization secondary to cardiac arrhythmia probably could be attributed to the increased incidence of ischemic stroke in our patients. However in our patients, cardiac arrhythmia could not be established at the time of presentation to us and probably long term cardiac monitoring will help to diagnose the occult one. We observed two haemorrhagic strokes in our case series due to ST use. One Swedish study showed increased risk of subarachnoid haemorrhage due to consumption of snuff [29]. Nicotine opens up the blood brain barrier in ischemic stroke, causing post-ischemic brain edema and more cellular injury [30]. Several studies have suggested that obesity, diabetes, increased levels of triglycerides resulting in metabolic syndrome, might be associated with the use of ST [31].

Various studies were done in western population to ascertain the association of ST consumption with occurrence of adverse CVD (Cardio vascular disease) like myocardial infarction, ischemic heart disease and cerebral stroke [25]. Balhara performed a meta-analysis for association of ST use and CVD in 2004 [32]. They suggested modest association between risk of CVD with ST use like Swedish snuff (snus) {relative risk (RR) 1.4, 95% confidence interval (CI) 1.2-1.6}. Later Boffetta et al., also performed a meta- analysis in 2009 [33]. Five studies that evaluated fatal stroke and eight studies that evaluated fatal myocardial infarction were analysed. The study showed greater risk of fatal myocardial infarction (Odds Ratio (OR) - 1.13, 95% CI 1.06-1.21) and fatal stroke (OR 1.40, 95% CI 1.28-1.54) with consumption of ST. Studies from middle and low income countries are sparse. Gupta et al., from India, after a prospective study of 5 year duration concluded that, relative risk of fatal cardiovascular event among users of ST was not significantly different from non-tobacco users [34]. A meta-analysis of studies from China, Taiwan and India reported insignificant association of tobacco use and CVD mortality in India but the relationship was significant in studies from Taiwan and China [35]. The concluding OR (odd ratio) was 1.26 (95% CI 1.12-1.40), which suggested moderate risk of cardiovascular mortality with ST use.

In the past, some studies have been undertaken to determine association of ST use and CVD risk factors [25]. A Swedish prospective study showed that, high dose consumption of snus was associated with increased risk of metabolic syndrome (OR 1.6, 95% CI 1.26-2.15) [36]. A cross-sectional population based study in Sweden on more than 30,000 patients showed that, ST users were 1.7 times (95% CI 1.1-2.1) more likely to have a systolic BP >160mmHg and 1.8 times (95% CI 1.5-2.1) more likely to have a diastolic BP> 90mmHg [37]. A population based case-control study in India by Gupta et al., showed ST users had a significantly greater prevalence of resting tachycardia, hypertension, low HDL, hypertriglyceridemia, hypercholesterolemia and diabetes compared to non-tobacco users [38]. In the present study, anterior circulation was the most common territory involved as confirmed by CT scan/MRI. Similar observations have been reported by Dash et al., in their study of young ischemic stroke [39].

This study is probably the first study from South East Asia on clinical symptomatology of stroke due to ST. We hypothesize that ischemic CVD in a ST user may be a manifestation of accelerated cerebrovascular atherogenesis. This is the primary pathological process seen in young age onset cardiovascular diseases.

The study is limited by the unavailability of a ‘gold standard test’ such as pathologic confirmation of exact mechanisms of stroke. Also, genetic analysis for prothrombotic state was not done. Another limitation was the inclusion bias attributable due to the hospital based single center design. This study encompasses a small number of stroke patients. Risk factors such as coronary artery disease and stenotic vascular diseases were not evaluated by angiography in subclinical and asymptomatic cases. It is also likely that patients with paroxysmal atrial fibrillation were missed.

To conclude, our results suggest that ST associated CVD is a predominant cause of young ischemic stroke. We require specific serum biochemical analysis for nicotine to quantify the level of addiction that will help us to further prognosticate. Present study’s clinical implication and public health effect might be substantial, despite the fact that the magnitude of the excess risk is small. More studies are required to elicit pathophysiological mechanisms of ST on vascular system, thrombosis, cellular mechanism and atherosclerosis.