The prevalence of current SLT use was high among rural women in Burkina Faso, and its relationships with noncommunicable diseases in the current process of epidemiologic transition should make this practice a public health concern.
Prevalence of SLT use
The prevalence of current SLT use among rural women in Burkina Faso was 13.8% (95% CI: 12.2–15.5) while only one woman used ST. Such statistics revealed the socially permissive attitude toward SLT use by females. A lower standardized prevalence estimate of 3.86% (95% CI: 3.22–4.48) was noted two years later (in 2011 and not in nationally-representative sample) [1]. The current SLT use of 17.4% (95% CI: 14.5–20.5) was found in rural women in three Ethiopian pastoral communities in which SLT chewing was a longstanding tradition [6] and 10.1% (95% CI: 8.8–11.4) in Mozambique [20]. Studies focusing on female SLT consumption with details by subgroups of rural and urban women are scarce in SSA, especially in West Africa. However, 3.3% (of women and 4.7% of rural residents) were reported in Kenya [21] and 2.8% (of women) in Uganda [3].
Co-use of alcohol
Current SLT users were frequently current alcohol users (aOR = 2.80; 95% CI: 2.06–3.80), as reported for Cambodian women (aOR = 1.49; 95% CI: 1.12–1.98) [22] and in Kenya (aOR = 2.58; p = 0.001 for those with alcohol experience; aOR = 4.84; p = 0.007 for episodic binge drinkers) [21]. SLT and alcohol are both psychoactive substances containing, respectively, nicotine and ethanol molecules that individually induce dopaminergic or reward pathway activation [23, 24], and their synergistic interactive effects potentiate dopamine levels in the synapses, which might increase physical and psychological pleasure [25]. Klenowski and Tapper reported the existence of potential molecular and neuronal processes underlying the high incidence of ethanol and nicotine co-use, which emphasizes the development of ethanol and nicotine co-addiction [26]. It noted that nicotine delivered by SLT products may induce dependence or addiction [27] and that users’ combining different classes of psychoactive substances over time, called polyconsumption, was not surprising [28]. Unfortunately, tobacco and alcohol are considered the major cardiovascular risk factors.
SBP increase, DBP decrease, or differential blood pressure increase
SLT use was associated with an increase in SBP (aOR = 1.01; p = 0.017) or differential blood pressure (aOR = 1.01; p = 0.041) (Table 3). Substantial nicotine was absorbed from SLT products [14]. The predominant cardiovascular effects of nicotine result from activation of the sympathetic nervous system, resulting in a hypertensive effect [29], and the increase in SBP in our sample was consistent with this effect and corroborated by Onwuchekwa in rural Niger (aOR = 2.32; p < 0.05 among rural residents) [30]. The surprising results seemed to be the increase in SBP (aOR = 1.01; p = 0.017), although a decrease in DBP (0.97; p = 0.006) in SLT users was also observed (Table 3). Ganglionated plexuses are major constituents of the intrinsic cardiac nervous system, the final common integrator of regional cardiac control [31]. Cardinal et al. tested the hypothesis that nicotinic stimulation of individual ganglionated plexuses exerted divergent regional influences, affecting atrial as well as ventricular functions. Based on the results of their experimental study on canine hearts, they concluded that spatially divergent and overlapping cardiac regions were affected in response to nicotinic stimulation of neurons in individual ganglionated plexuses [32]. In addition, baroreflexes showed a cardiovascular regulation property in hypertension [33] and estrogen influenced baroreceptors’ sensitivity [34] and the specific hormonal effect in females should be considered. Nicotine interacts with central estrogenic pathways [35], which in turn may be modulated by the reproductive cycle [36]. These different modulations may support the nonhomogenous effects of nicotine on SBP and DBP in our sample, which included 19.0% of women aged > 49 years (suspected menopausal women), of whom more than 40% used SLT (Table 1). Data over the period of the menstrual cycle for non-menopausal women should have been completed. However, we also considered that the most commonly used form of SLT in Burkina Faso is chewing tobacco. It is usually locally produced (for personal use), the process is nonstandardized, and this tobacco is grown in different types of soils that have various physical and chemical characteristics. Soil composition affects the salt level in tobacco leaves. The salt dynamics of arid and semi-arid lands in Burkina Faso may affect mineralogic contents such as natrium in local SLT [37]. In addition, nationally, the use of pesticides is widespread for crops such as cotton, and the use of pesticides in rural Burkina Faso may cause soil contamination. Thus, the leaves of unregulated tobacco may include pesticides [38], and some pesticides, such as organochlorine, were implicated in BP increase [39]. The rate of absorption of tobacco contents (such as nicotine, salt, and pesticides) may vary among different forms of smokeless tobacco depending on the potential of hydrogen level of the product and the amount of nicotine [14, 40]. The effects of chronic consumption of kola nuts on the cardiovascular system should be considered [41, 42]. One adult out of two used kola nuts in Burkina Faso [43], and usually in the similar conditions (dental health impairment conditions [44]). Unspecified effects of interactions between SLT and kola nut products on BP may be possible. The knowledge on the content of locally grown tobacco leaves in Burkina Faso is relevant. In short, the cardiovascular disturbance in SLT users were underpinned by the increase in the units of differential blood pressure (aOR = 1.01; p = 0.041; Table 3) that should be respected and public health considerations should integrate this factor.
Dental symptoms
SLT use was associated with the presence of some dental symptoms (aOR = 2.59; 95% CI: 1.91–3.51). Cheema et al. reported an association with poor oral status (aOR = 3.90; 95% CI: 1.75–8.69) in Qatar [4]. Users of this psychoactive substance (SLT) develop some specific expectancies according to the different effects generated by its consumption depending on the specific context. Oro-dental pain and burning mouth syndrome were common, and poor oral health service utilization was reported in SSA [45, 46]. The nicotine delivered by SLT products increases sensory irritation [47], and because dental care is not available in rural Burkina Faso [44], rural women were likely to use SLT for the pain or discomfort associated with dental symptoms. Because chewing food might exacerbate dental pain, in the absence of treatment, SLT was be used by those with dental symptoms to locally anesthetize teeth or the oral cavity to be able to eat without pain. That behavior was noted in a supplemental qualitative study (interview) in three Ethiopian pastoral communities with a long tradition of SLT chewing [6]. Furthermore, psychoactive substance consumption resulting from addictive behaviors or habits involved gestural rituals [48], and stimuli associated with different stages of the smoking ritual triggered various neuronal responses, depending on addiction network activation or deactivation [49, 50]. Chewing tobacco involves manipulating its container and performing a hand gesture to place the tobacco bolus in the mouth. The memory of dental pain and the perception that the application of SLT will suppress that pain might trigger the accomplishment of SLT gestural rituals. Tooth periodontal damage was common in SL as SLT users [51], mainly in female chewers [52]. A deficiency in the host response exacerbated periodontal impairment or recovery [53], which could establish a vicious circle of dental symptoms, the persistent and inefficiency application of SLT as treatment.
Undernourishment
SLT use was associated with undernourishment (aOR = 1.78; p = 0.002) as in rural Ghanaian women (aOR = 2.78; p = 0.002) [54]. Nicotinic receptor-mediated regulated appetite and food intake [55] were related, and nicotine was considered to be the anti-appetite component of tobacco [56]. There was low food availability in Burkina Faso [57] that worsened in rural area and hunger related to the empty stomach generated discomfort. Food restrictions and going to bed hungry were reported in rural Ghanaian women [54]. In this context of chronic hunger, expectancies related to tobacco used as a psychoactive substance might include hunger extinction, and thus, rural women might adjust to immediate hunger through SLT consumption. Furthermore, the belief that minimum food intake combined with SLT absorption helps allay hunger may act as an appetite-suppressant, underpinning an insufficient food intake. Similar habits were reported about addictions to tea and SLT among Malian Tuaregs living in Sahelian areas and suffering from hunger in a hard climate [58]. Unfortunately, this manner of adapting to hunger did not offset weight impairment, and the means of all anthropometric parameters (weight, BMI, and waist circumference) in SLT users were significantly lower than for nonusers (Table 2). The decrease in the unit of waist circumference (aOR = 0.98; p = 0.023) in the SLT users was not surprising because an increase in waist circumference might result from the accumulation of excess subcutaneous fat in the abdomen area. Undernourishment implies moderate or insufficient fat in the body.
No significant impairment in the lipid profile and in blood sugar among SLT users
Authors reported a decrease in HDL cholesterol and an increase in total cholesterol levels among smokers and tobacco chewers (with reference to nonusers) [59, 60]. However, SLT users and nonusers in our sample had identical mean values of HDL cholesterol and total cholesterol, and there was no significant risk for lipid profile impairment in SLT users (Tables 2 & 3). These results were not surprising in our context because SLT users were more frequently affected by undernourishment (28.6% vs. 13.9% in nonusers; p = 0.0001) and not by overweight/obesity (only 5.5% vs. 14.4% in nonusers; p = 0.0002; Table 2). The women in our study had only moderate or insufficient underlying fat matter in their bodies, including in blood vessels. Similarly, there was no association with increased blood sugar in users; their mean blood sugar was in fact significantly higher (3.8 ± 1.5 mmol/l vs. 4.1 ± 1.5 in nonusers; p = 0.0223; Table 2). However, further investigations should consider the hypothesis of positive association.
Sociodemographic factor influences
SLT use increased with age in our study (Table 3). It also reported an increasing number of cardiovascular risk factors in the elderly [61], and the SSA countries, under the demographic and epidemiologic transitions, were severely affected [62]. An additional modifiable factor such as SLT use should be avoided. Uneducated people were frequently exposed to SLT use (Table 3) and indicated that formal instruction, as well as public health education, focused on cardiovascular risk factors and SLT-related health consequences should be effective in reducing prevalence and risk [63].