The prevalence of current SLT use was high among rural women in Burkina Faso, and given the current state of epidemiologic transition, its relationship with noncommunicable diseases should make SLT use 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 suggest the socially permissive attitude towards SLT use by females. A lower standardized prevalence estimate of 3.86% (95% CI: 3.22-4.48) was noted two years earlier (in 2011 and only in the sample of women aged 15-49years) [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 the current SLT use is 10.1% (95% CI: 8.8-11.4) in Mozambique [20]. Studies focusing on female SLT consumption with details for 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 in Kenya were reported to be SLT users [21], as were 2.8% of women in Uganda [3]. Produced using a traditional technique, the SLT is equivalent to a local psychoactive product and widely available in rural Burkina Faso. There is no inventory concerning local psychoactive substances in Burkina Faso, and SLT seemed to be among the favorites for the rural Burkinabé women, as the roots of Sarcocephalus latifolius (plant which provides synthetic tramadol) or non-medical tramadol in Cameroon [22, 23], or khat/miraa in rural Kenya [24, 25].
Co-use of alcohol
Current SLT users were frequently current alcohol users (aOR = 2.80; 95% CI: 2.06-3.80), as has been reported for women in Cambodia (aOR = 1.49; 95% CI: 1.12-1.98) [26] 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 nicotine and ethanol molecules, respectively [27] and their synergistic interactive effects potentiate physical and psychological pleasure [28]. That explains why polyconsumption consisting in combining tobacco and alcohol was not surprising [29]. Unfortunately, tobacco and alcohol are considered major cardiovascular risk factors. Drinking alcohol is known to raise both HDL-C and total cholesterol concentrations [30], and the concurrent use of tobacco and alcohol enhances these increases [31]. Although the mean values of HDL- and total cholesterol were not higher in SLT users (compared to nonusers), the mean values of concurrent current SLT and alcohol users increased, significantly for total cholesterol (Table 2).
Blood pressure and SLT use
SLT use was associated with an increase in SBP (aOR = 1.01; p<0.05) or differential blood pressure (aOR = 1.01; p<0.05) (Table 3). Substantial nicotine is absorbed from SLT products [14]. The predominant cardiovascular effects of nicotine result from activation of the sympathetic nervous system, which causes a hypertensive effect [32], and the increase in SBP in our sample (aOR = 1.01; p<0.05) was consistent with this effect and corroborated by Onwuchekwa in rural Niger (aOR = 2.32; p<0.05 among rural residents) [33]. However, an age-related increase in SBP was reported that was greater in women than men [34, 35] and thus more perceptible in our sample. However, we observed a decrease in DBP (0.97; p<0.01) (Table 3) in SLT users. We should note that there was an increase in DBP level with age from an average of 78.4 (±9.5) mmHg at approximately 36 years of age to 83.1 (±11.8) at 53 years, and then a decrease to 73.4 (±10.1) at 69 years of age [36]. An inverse association of DBP and age is well-established [36] and it may partly explain our finding. Nicotine interacts with central oestrogenic pathways [37] which may contribute to explain the non-homogenous effects of nicotine on SBP and DBP. SLT is usually locally produced, using a non-standardized processed, and the tobacco is grown in different types of soils which mineralogic contents (such as sodium) may affect blood pressure in users [38]. In addition, the use of pesticides in rural Burkina Faso may cause soil contamination staining tobacco leaves [39], that has been implicated in BP increases [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], usually under similar conditions (i.e., dental health impairment conditions [44]). Unspecified effects of interactions between SLT and kola nut products on BP may be possible. In short, the cardiovascular disturbance in SLT users was evident in the respectable increase in the differential blood pressure (aOR = 1.01; p = 0.041; Table 3).
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 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 countries [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 would be used by those with dental symptoms to locally anaesthetize teeth or the oral cavity to be able to eat without pain. Such behaviour 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 behaviours involved gestural rituals [48] extending over time. Tooth and periodontal damage was common in SLT users [49], mainly in female chewers [50], while the intention to use SLT for dental pain suppression could establish a vicious circle between dental symptoms and the repeated and inefficient application of SLT as treatment.
Undernourishment
The prevalence we described (16.0%) was near to results reported in the previous studies in Burkina Faso (14.8% in rural plus urban women in 2010 [51] and 19.9% in 2016 [52]). The weighted level of 14.8% was considered to be the greatest among 33 SSA countries investigated, after the percentages in Senegal (20.8% in 2011) and Gambia (15.7% in 2013) [51]. Moreover, the high prevalence of 31.0% found by Ramsey et al. in rural Burkina Faso was the highest among the three rural African areas involved in their study [53]. SLT use was associated with undernourishment (aOR = 1.78; p<0.01), as it was in rural Ghanaian women (aOR = 2.78; p = 0.002) [54]. Tobacco delivers nicotine an anti-appetite component [55]. There was low food availability in rural Burkina Faso [56], and hunger related to the empty stomach generated discomfort. The belief that minimum food intake combined with SLT consumption helps allay hunger, further exposes to insufficient food intake. Similar habits were reported for addictions to tea and SLT among Malian Tuaregs living in Sahelian areas and suffering from hunger in a harsh climate [57].
No significant impairment in the lipid profile or blood sugar among SLT users
The authors reported a decrease in HDL cholesterol and an increase in total cholesterol among smokers and tobacco chewers (with respect to nonusers) [58, 59]. However, the SLT users and nonusers in our sample had identical mean values of HDL cholesterol and total cholesterol, and there was no significant risk of 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<0.001) and not by overweight/obesity (only 5.5% vs. 14.4% in nonusers; p<0.001; Table 2). The women in our study had only moderate or insufficient underlying fat matter in their bodies, including that in blood vessels. Similarly, there was no association with increased blood sugar in users; their mean blood sugar was in fact significantly lower (3.8 ± 1.5 mmol/l vs. 4.1 ± 1.5 in nonusers; p<0.05; 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 has been reported previously that elderly individuals have an increased number of cardiovascular risk factors [60], and the SSA countries under demographic and epidemiologic transitions were severely affected cardiovascular risk [61]. 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 would be effective in reducing prevalence and risk [62].
Limitations
We used national data from the STEPS survey, which studied the prevalence of and knowledge about concerning common risk factors for noncommunicable diseases. However, the sample size calculation was based on the prevalence of HBP. Data collection methods for dental symptoms were based only on self-reporting and did not include examinations by health professionals. Thus, self-reporting may have included incorrect statements and dental assessments.