Discussion
Acne is an important risk factor for psychological morbidity in young and advanced ages in both genders. It is related to satisfaction with appearance, decreased self-esteem and self-confidence, and increased internalization (anxiety and depression) and suicidal tendency. In a meta-analysis obtained from 42 studies on anxiety in acne cases, a significant relationship was found between acne and depression and anxiety and acne. It has been reported that the prevalence of depression and anxiety are higher in acne cases (14). According to the hypothesis of Stokes and Pillsbury; Emotional conditions such as depression and anxiety disrupt the function and microbiota of the gastrointestinal system, which paves the way for local and systemic inflammation. It is thought that there may be a serious relationship between the bacteriology and physiology of the gastrointestinal system, inflammatory skin diseases and mood. In addition, based on the evidence, 40% of acne cases have hypochlorhydria. This insufficient stomach acidity causes colon bacteria to migrate to the distal part of the small intestine and this disrupts the normal intestinal microflora. According to the authorities, microbial flora changes triggered by stress increase intestinal permeability and predispose to systemic and local inflammation (2,3). Although the gut-brain skin axis hypothesis has been known for a long time, it is not well understood, but microbiome studies are opening the uncertainties here. In addition, the increase in Substance P secretion with the stimulation of the nerves that release substance P was observed in both acne cases and intestinal dysbiosis. Substance P is responsible for the release of proinflammatory cytokines in acne pathogenesis (15,16,17,18).
Multiple comorbidities associated with IBS have been reported as somatic pain syndromes (fibromyalgia, chronic fatigue syndrome, and chronic pelvic pain), other gastrointestinal diseases (gastroesophageal reflux dyspepsia), and psychiatric diseases (major depression, anxiety, and somatization) (19). Low-grade inflammation was found to be important in IBS pathogenesis. In a study, serum inflammatory cytokines were found to be increased in IBS cases compared to controls (20,21). Increase in small intestine bacterial flora is associated with anxiety and depression, and recovery of flora provides emotional improvement) (22,23). In half of the cases, IBS originates from the intestine first and psychological stress develops later(4,5,6,7). Parallel to the literature a significant difference was found between the anxiety scores of the acne cases and the control group in this study, but there was no relationship with depression. It can be due to the number of cases or the characteristics of the selected sample. Depressive patients may not have been detected due to their unwillingness to participate in this study. When looked in terms of intestinal habits and IBS, patients with acne and control group did not differ. There was no relationship between the global acne scores and bowel habits or IBS. In the recent study by Demirbaş et al., 300 acne patients were evaluated with Rome IV criteria and IBS was found significantly higher in patients with acne. IBS was also correlated with the global acne scores (24). In our study, Rome III criteria were used because it was validated and reliable in Turkish (Ozgürsoy Uran.et al) whereas Rome IV criteria has not been validated for Turkish population yet. Threshold values of Rome IV criteria are based on Western data and language issues are important; if it is not translated properly, it may lead to misunderstanding. The different results are due to the use of Rome IV criteria, which is criticized for reliability in non-Western population in many articles(25, 26). Among other studies on IBS and skin diseases relation, Shalom et al. showed that IBS increased in patients with chronic urticaria (27). İslamoğlu et al. Reported that IBS was more common in atopic dermatitis group. In the study of Kim et al., a relationship was found between rosacea and IBS, while an increase in acne rosacea was found in cases with IBS(28).
There are limited number of studies investigating the relationship between acne and physical activity. Alshammrie et al. did not find a significant relationship between physical exercise and acne(29). Similarly, in another study conducted in Tehran, it was reported that there was no relationship between physical activity and acne(30). In our study, in accordance with the literature, no difference was found between the acne cases and the control group in terms of physical activity.
In recent studies, the role of a low glycemic index high fiber diet in the course of acne vulgaris treatment has been shown (31). In the study conducted by Kaufmann et al., a significant improvement was observed in the skin in the study in which he consumed 30 g of high-fiber breakfast cereal per day (32). Smith et al. demonstrated the positive effect of a diet rich in fiber and low glycemic index diet(33). In our study, we could not find a relationship between fiber consumption and acne. Further studies are needed to evaluate both fiber and glycemic index impact in large case series.
In a study investigating acne vulgaris and BMI, it was found that the incidence of severe acne was increased in adolescents with high BMI compared to normal ones(34). Inflammatory acne lesions were increased in patients with higher BMI and non-inflammatory acne lesions were found to be increased in those with low BMI(34). High BMI also triggers high levels of insulin-like growth factor-1 (IGF-1) release. IGF-1 stimulates keratinocyte proliferation, sebaceous lipogenesis, and androgen synthesis (34). In our study, no statistical difference was found between the acne cases and the control group in terms of BMI.
Smoking is related with many adverse effects on the skin(35). Smoking affects sebum production, induce microcirculation and oxidative stress(36). According to a study by Schäfer et al. acne prevalence was significantly higher in active smokers like our study (37). Smoking can increase vascular endothelial inflammation, causing exacerbation of both acne lesions and irritable bowel syndrome (38). Contrary to expectations, there was no relation between smoking and irritable bowel syndrome in current study.
Coffee consumption reduces non-melanoma skin cancer, melanoma, and rosacea (39). Consumption of foods containing a high glycemic index negatively affects acne, but there is no information in literature about coffee interaction. In our study, acne patients were consuming more coffee. Coffee type was not questioned; it would be informative to make further studies with different coffee types. Older people consume mostly Turkish coffee and young people increasingly consume filter coffee or instant coffee in Turkey.
A limitation of this study is the relatively small sample size.