Abstract
Objectives: It has been hypothesized that Sasang constitutional types (SCTs) have a specific hypoactive organ, which can account for vulnerability to related diseases or symptoms. This study examined the relationship between SCTs and irritable bowel syndrome (IBS).
Design: Cross-sectional study in a population-based cohort study in Korea.
Participants: 1362 individuals (705 men and 657 women) who participated in the Korean Genome and Epidemiology Study.
Outcome measures: The participants were classified into SCTs by the integrated diagnostic model and asked about symptoms related to IBS using the Rome II criteria.
Results: The prevalence of IBS differed significantly among the SCTs, with 33 (18.3%) of the So-eum (SE) type, 74 (9.9%) of the Tae-eum (TE) type, and 57 (13.2%) of the So-yang (SY) type having IBS. Even after adjustment for possible confounders, the SE type for both sexes continued to show 1.82-fold (95% confidence interval [CI], 1.05–3.16) excess odds of having IBS. Men with SE type had a 2.97 times (95% CI, 1.34–6.58) and a 2.50 times (95% CI, 1.15–5.47) significantly higher odds of having IBS than the TE and SY types, respectively. In analysis for the joint effect of SCT and psychological stress, the multivariate odds ratio of IBS was 3.21 (95% CI, 1.33–7.75) for the SE type and Psychological Well-Being Index-Short Form (PWI-SF) score (<27), and 5.83 (95% CI, 1.80–18.88) for the SE type and PWI-SF (≥27) compared with the TE type and PWI-SF score (<27).
Conclusions: The SE type of SCT is an independent risk factor for IBS. The findings support the hypothesis that persons with SE type are vulnerable to gastrointestinal diseases.
Introduction
Sasang constitutional medicine (SCM) is a traditional alternative and complementary medicine in Korea introduced by Korean physician Jema Lee (AD 1837–1900). In SCM theory, humans are classified into four distinct Sasang constitutional types (SCTs)—Tae-yang (TY) type, Tae-eum (TE) type, So-yang (SY) type, and So-eum (SE) type—and individuals who belong to each constitution have differing drug responses, disease susceptibility, and different organ activity.1 The ultimate goals of SCM are to provide individualized therapy to patients in order to minimize the risk of adverse outcome and to maximize treatment efficacy.1
Studies have sought to identify distinct characteristics of the four constitutions as a means of best individualizing the treatment approach.2–6 Generally, the personality traits of the TY type include a creative, positive, progressive temperament, and the type is characterized by hyperactive lung and hypoactive liver functions. The SY type personality is unstable, easily bored, and restrained; this type is more vulnerable to urinary diseases due to hypoactive kidney function. The TE type temperament is gentle, resilient, and humorous; physiologically, TE types are characterized by hyperactive liver and hypoactive lung functions. Finally, the SE type is characterized by a negative and self-directed personality and nervous mind; physiologically, the associated hyperactive kidney and hypoactive spleen function result in dysfunction of food intake and digestion.
SCTs are vulnerable to diseases related to their corresponding hypoactive organ. Hence, many studies have investigated the association between SCTs and pathologic conditions. The TY type is vulnerable to muscular malfunctions because of higher catabolism/anabolism ratio, which might lead to reduced muscle protein synthesis.1,7 In contrast, the TE type tends to be an anabolism-dominant state, which stimulates energy storage.1 The TE type has a higher likelihood of having cardiovascular and metabolic disorders, such as diabetes mellitus (DM), hypertension (HTN), and hyperlipidemia.8–10 The hypoactive kidney function of the SY type manifests as enhanced susceptibility to urinary system diseases, such as cystis and renal diseases.11–13 The SE type, which is dysfunctional in food intake and digestion, frequently reports chronic indigestion, gastroptosis, and gastroadynamics.8,12,14,15
Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders. IBS is characterized by abdominal discomfort or pain, bloating, abnormal stool form, and frequency and changes in bowel habits without an organic disease.16,17 The prevalence of IBS is approximately 10%–20% in the general global population, although it varies according to the diagnostic criteria used.16,18,19 In Korea, the prevalence of IBS is 2.2%–6.6%20,21 and 22.3%22 when diagnosed by Rome II criteria and Manning criteria, respectively. IBS can result from a variety of causes involving genetic factors, dietary, inflammation, psychiatric stress, and dysregulation of the autonomic nervous system in the gut, which leads to altered motility and visceral hypersensitivity.23–25 IBS negatively affects health-related quality of life and work productivity, and appreciably increases health care costs.26,27
The hypotheses here are that the presence of IBS will be higher in the SE type than other constitutions for the following reasons: (1) dysfunction in the digestive system is frequently reported in the SE type, (2) IBS can be triggered or exacerbated by stress, and (3) the SE type has a temperament vulnerable to psychological stress. This study investigated the association between the SCTs and IBS in a population-based cohort in Korea.
Methods
Study sample
A cross-sectional design was adopted using data acquired from participants enrolled in the Korean Genome and Epidemiology Study (KoGES). Briefly, the cohort consisted of 5020 Koreans aged 40 to 69 years who participated from 2001 and who had undergone a comprehensive health examination at Korea University Ansan Hospital. The participants had biannual follow-up and were examined for demographic information, anthropometric measurements, biochemical analyses, and blood pressure. In addition, all participants completed an interview-based questionnaire on demographic information, medical history, and health conditions. Cohort members were followed up biennially with a scheduled site visit for similar interviews and health examination. In this study, 1362 individuals (705 men and 657 women) who completed the IBS questionnaire and were classified as one of the SCT types (TE, SE, and SY; none were classified as TY type) were included for the analysis. All participants signed an informed consent form. The Institutional Review Board at the Korea University Ansan Hospital reviewed and approved this study.
Classification of SCTs
An integrated diagnostic model was used to classify the participants as each constitutional type.3 The accuracy of the diagnostic method used in the present study is 64% in men and 55.2% in women. The model integrates four individual quantitative data (facial images, body shape, voice features, and response to a questionnaire on personality and physiologic symptoms) into an integrated value. Briefly, the facial images of participants were photographed with a digital camera and variables expressing facial characteristics were extracted via image processing techniques from the images. Variables such as width, height, areas, angle, depth, and ratio of face shape, forehead, eye, upper eyelid, and noses were included for facial points and contours. Measurements for the body shape analysis include the following 11 items: forehead circumference, neck circumference, axillary circumference, chest circumference, rib circumference, waist circumference, pelvic circumference, hip circumference, height, weight, and body–mass index (BMI). The Hidden Markov Model Toolkit (Cambridge University Engineering Department, Cambridge, United Kingdom) program and the Praat voice analysis program (University of Amsterdam, Amsterdam, the Netherlands) were used to extract voice features. Among the initially selected several hundred features, only a voice signal having the minimum duration of 40 ms was selected for final diagnostic model after application of a genetic algorithm-based feature selection technique.
The questionnaire for SCTs elicits information on personality characteristics and physiologic symptoms. It consisted of 67 multiple-choice questions that can specify general temperaments, eating habits (e.g., regular meals, frequency of meals eaten each day, and eating speed) and physiologic symptoms (e.g., perspiration, excrement, discomfort in the body, location of discomfort during illness, and existence of fatigue).
Definition of IBS
Rome II criteria were used to diagnose IBS.28 For a diagnosis of IBS, abdominal pain or discomfort for at least 12 weeks in the preceding 12 months associated with two or more of the following must have existed: (1) relief with defecation; (2) onset associated with a change in frequency of stool; and/or (3) onset associated with a change in the form (appearance) of stool.
Questionnaire on lifestyle, measurement of anthropometric and biochemical parameters, and definition of chronic diseases
BMI was calculated by dividing weight in kilograms by height in meters squared. Waist circumference (cm) was measured at the narrowest point between the lower rib and the iliac crest. Blood pressure (BP) was measured with a mercury sphygmomanometer in a sitting position. Questions on the smoking status (never, former, or current), alcohol consumption (g/d), income (monthly wage of <100, 100–200, 200–400, >400×104 won), physical activity (metabolic equivalent per hour daily), exercise (30 min two times per week, yes or no), and regular meals (0–2 days/week, 3–4 days/week, 6–7 days/week) were included in the questionnaire. Levels of total cholesterol, triglyceride (TG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and high-sensitivity C-reactive protein (hsCRP) was determined in the Seoul Clinical Laboratories (Seoul, Korea). The participants were defined as having HTN if systolic BP/diastolic BP exceeded 140/90 mmHg or antihypertensive medications were used. DM was defined using antihyperglycemic agents or insulin, or with fasting glucose >126 mg/dL.
Questionnaire on sleep and mood status
Self-reported sleep duration, daytime sleepiness, and depressive mood were evaluated. To address sleep duration, the participants were queried on the average nightly number of hours of sleep estimated over the prior month. Daytime sleepiness was assessed by the Epworth Sleepiness Scale.29 Participants who had a score >11 were defined as having excessive daytime sleepiness. A Korean translated Beck Depression Inventory (BDI) questionnaire was used to define depression.30,31 Depressive mood was defined with a score >16.32 Degree of psychological distress was assessed using the Psychological Well-Being Index-Short Form (PWI-SF). A PWI-SF score ≥27 indicated a high risk of experiencing distress.33
Statistical analyses
Statistical analyses were performed with SAS software, version 9.1 (SAS Institute, Cary, NC). Descriptive data on characteristics of participants are presented as mean±standard deviation for continuous variables and as percentages for categorical variables. One-way analysis of variance analysis and chi-square test for continuous variables and categorical variables were conducted to evaluate significant differences of the means among the SCTs, respectively. Bonferroni post hoc test was performed for multiple comparisons. Multiple logistic regression models were examined to identify an independent association between IBS and the SCTs after adjustment for age, sex, BMI, regular meals, smoking status, alcohol consumption, total physical activity, depression, income, and presence of HTN and DM. Multiple logistic regression analyses were repeated with stratification by sex. The null hypothesis was rejected at a p-value <0.05.
Results
Characteristics of study sample
The 1362 participants who completed the questionnaire for IBS and were classified per SCT were included for the analysis. Table 1 describes the demographic and clinical characteristics of the SCTs. Among 750 participants who belonged to the TE type, 74 (9.9%) had IBS. Thirty-three (18.3%) of the SE type had IBS. IBS was found in the 57 (13.2%) of the SY type. The mean age of the participants was 52.9±7.5 years, 49.7±5.5 years, and 50.8±6.3 years for the TE, SE, and SY types, respectively (p<.0001). The TE type showed a significantly older age; higher frequency of women; higher BMI; greater alcohol consumption, physical activity, TG, systolic and diastolic BP, and presence of HTN and DM; and lower HDL cholesterol than those of the SE and SY types. Total cholesterol was significantly higher in the TE type compared with the SE type. Smoking status and income significantly differed among the SCTs. Level of hsCRP, which is a marker of systemic inflammation,34 did not differ among the SCTs. IBS was the most prevalent in men of the SE type (p<.001), while no significant association was observed in women among the SCTs.
Table 1.
General Characteristic of Participants According to Sasang Constitutional Types
| Variable | TE | SE | SY | p-Value |
|---|---|---|---|---|
| Participants (n) | 750 | 180 | 432 | |
| Age (y) | 52.9±7.5* | 49.7±5.5 | 50.8±6.3 | <0.0001 |
| Women, n (%) | 452 (60.3) | 91 (50.6) | 162 (37.5) | <0.0001 |
| BMI (kg/m2) | 26.2±2.3* | 21.4±1.7 | 23.2±2.1 | <0.0001 |
| Smoking, n (%) | ||||
| Never | 389 (51.9) | 121 (67.2) | 304 (70.4) | <0.0001 |
| Former | 226 (30.1) | 28 (15.6) | 72 (16.7) | |
| Current | 135 (18) | 31 (17.2) | 56 (13.0) | |
| Alcohol consumption (g/d) | 4.7±7.1* | 2.3±3.9 | 2.8±5.6 | <0.0001 |
| Regular meals, n (%) | 0.35 | |||
| 0–2/wk | 72 (9.7) | 13 (7.2) | 53 (12.3) | |
| 3–4/wk | 87 (11.7) | 21 (11.7) | 53 (12.3) | |
| 6–7/wk | 587 (78.7) | 146 (81.1) | 324 (75.3) | |
| Income, n (%) | 0.02 | |||
| <100×104 won | 94 (12.5) | 14 (7.8) | 45 (10.4) | |
| 100–200×104 won | 119 (15.9) | 31 (17.2) | 68 (15.7) | |
| 200–400×104 won | 327 (43.6) | 100 (55.6) | 222 (51.4) | |
| >400×104 won | 210 (28) | 35 (19.4) | 97 (22.5) | |
| Exercise 30 min 2 times/wk, n (%) | 204 (42.3) | 47 (36.7) | 135 (45.5) | 0.12 |
| Physical activity (MET) | 198.8±364.8* | 137.7±184.7 | 168.5±222.9 | 0.03 |
| Total cholesterol (mg/dL) | 199.1±34.1** | 191.0±33.7 | 194.8±32.6 | <0.01 |
| Triglyceride (mg/dL) | 156.2±101.9* | 108.3±54.7 | 121.4±80.0 | <0.0001 |
| HDL cholesterol (mg/dL) | 43.3±9.2* | 46.9±10.8 | 47.0±10.7 | <0.0001 |
| LDL cholesterol (mg/dL) | 125.6±30.8 | 122.6±27.9 | 124.2±29.0 | 0.43 |
| hsCRP (mg/dL) | 1.4±2.2 | 1.2±2.4 | 1.3±3.0 | 0.45 |
| SBP (mmHg) | 114.3±13.7* | 108.1±15.3 | 108.9±14.5 | <0.0001 |
| DBP (mmHg) | 76.8±9.7* | 72.9±9.7 | 72.4±10.2 | <0.0001 |
| HTN, n (%) | 215 (28.7) | 25 (13.9) | 63 (14.6) | <0.0001 |
| DM, n (%) | 142 (18.9) | 13 (7.2) | 46 (10.6) | <0.0001 |
| IBS, n (%) | ||||
| Men | 40 (8.9) | 21 (23.1) | 16 (9.9) | <0.001 |
| Women | 34 (11.4) | 12 (13.5) | 41 (15.2) | 0.41 |
Values expressed with a plus/minus sign are the mean±standard deviation.
p<0.0001 versus SE and SY types.
p<0.05 versus SE type.
TE, Tae-eum type; SE, So-eum type; SY, So-yang type; BMI, body–mass index; MET, metabolic equivalents per hour daily; HDL, high-density lipoprotein; LDL, low-density lipoprotein; hsCRP, high-sensitivity C-reactive protein; SBP, systolic blood pressure; DBP, diastolic blood pressure; HTN, hypertension; DM, diabetes mellitus; IBS, irritable bowel syndrome.
Sleep and mood status according to SCT
Given that IBS can be developed or exacerbated by psychiatric stress and the significant associations between sleep disturbances and IBS,35–37 we compared the factors of sleep and mood among the SCT types (Table 2). Among variables of mood status, PWI-SF score and psychological distress were significantly higher in the SE type than in the TE and SY types, implying that SE individuals experience more psychological stress than do other constitutions. Self-reported sleep duration and excessive daytime sleepiness did not differ among the SCTs.
Table 2.
Sleep and Mood Profiles According to Sasang Constitutional Types
| Variable | TE | SE | SY | p-Value |
|---|---|---|---|---|
| Participants (n) | 750 | 180 | 432 | |
| BDI score | 7.9±6.6 | 8.6±6.3 | 7.4±6.4 | 0.08 |
| Depressed mood, n (%) | 96 (12.8) | 23 (12.8) | 42 (9.7) | 0.27 |
| PWI-SF score | 17.3±8.5 | 19.8±8.6*,** | 17.1±8.0 | <0.001 |
| Psychological distress, n (%) | 101 (13.5) | 38 (21.1) | 51 (11.8) | 0.01 |
| Self-reported sleep duration (h) | 6.7±1.3 | 6.7±1.2 | 6.8±1.5 | 0.81 |
| EDS, n (%) | 62 (8.3) | 13 (7.2) | 46 (10.6) | 0.27 |
Values expressed with a plus/minus sign are the mean±standard deviation.
BDI, Beck Depression Inventory; PWI-SF, Psychological Well-Being Index-Short Form; EDS, excessive daytime sleepiness.
p<0.001 versus TE type.
p<0.0001 versus SY type.
Odds ratios for IBS according to SCT
To estimate odds ratios (ORs) for IBS in relation to constitutional types, a logistic regression analysis was conducted in both sexes (Table 3). In crude analysis by sex, the SE type was more likely to have IBS than the TE type. Even after adjustment for age, sex, BMI, alcohol consumption, smoking status, income, physical activity, HDL cholesterol, TG, HTN, DM, and PWI-SF score, the SE type of both sexes continued to show 1.82-fold (95% confidence interval [CI], 1.05–3.16; p=0.03) greater odds of having IBS. However, the OR was not significant when compared with the SY type in both crude and multivariate analyses. In sex-specific analysis, men with SE type had a 2.97 times (95% CI, 1.34–6.58; p<0.01) and 2.50 times (95% CI, 1.15–5.47; p=0.02) higher odds of having IBS than those with the TE type and SY type, respectively, after adjustments for multiple variables. However, in women this association was not found in either crude or multivariate analyses.
Table 3.
Odds Ratio of Irritable Bowel Syndrome in Relation to Sasang Constitutional Types
| Estimated odds ratios of IBS (95% CI) | ||||
|---|---|---|---|---|
| Group | SE vs. TE [ref.] | p-value | SE vs. SY [ref.] | p-Value |
| Men and women | ||||
| Crude | 2.05 (1.31–3.21) | <0.01 | 1.48 (0.92–2.36) | 0.1 |
| Model 1a | 1.77 (1.03–3.03) | 0.04 | 1.47 (0.91–2.37) | 0.12 |
| Model 2b | 1.82 (1.05–3.16) | 0.03 | 1.39 (0.86–2.27) | 0.18 |
| Men | ||||
| Crude | 3.09 (1.72–5.55) | <0.001 | 2.74 (1.35–5.57) | <0.01 |
| Model 1c | 2.86 (1.36–6.00) | <0.01 | 2.60 (1.24–5.45) | 0.01 |
| Model 2d | 2.97 (1.34–6.58) | <0.01 | 2.50 (1.15–5.47) | 0.02 |
| Women | ||||
| Crude | 1.21 (0.60–2.45) | 0.6 | 0.87 (0.44–1.74) | 0.69 |
| Model 1c | 1.21 (0.51–2.90) | 0.66 | 0.92 (0.45–1.88) | 0.83 |
| Model 2d | 1.30 (0.53–3.20) | 0.56 | 0.84 (0.40–1.76) | 0.65 |
Data were adjusted for age, sex, and body–mass index (calculated as weight in kilograms divided by height in meters squared).
Data were adjusted for age, sex, body–mass index (calculated as weight in kilograms divided by height in meters squared), smoking status (never, former, or current), alcohol consumption (g/d), income (monthly wage of <100, 100–200, 200–400, >400×104 won [South Korean Currency]), physical activity (metabolic equivalent per hour daily), Psychological Well-Being Index-Short Form score (<27 or ≥27), high-density lipoprotein cholesterol, triglyceride, and presence of hypertension and diabetes mellitus.
Data were adjusted for the same variables with a except for sex.
Data were adjusted for the same variables with b except for sex.
CI, confidence interval; ref, reference.
Joint effects of the SCTs and PWI-SF score on IBS in men
Table 4 presents the joint effects of the SCTs and PWI-SF score, a variable that reveals the degree of depression, on IBS in male participants. In multivariate analysis for the SCTs and PWI-SF, the multivariate ORs of IBS were 3.21 (95% CI, 1.33–7.75; p<0.01) for the SE type and PWI-SF score (<27), 5.83 (95% CI, 1.80–18.88; p<0.01) for the SE type and PWI-SF score (≥27), and 3.87 (95% CI, 1.06–14.18; p=0.04) for the SY type and PWI-SF score (≥27) compared with the TE type and PWI-SF score (<27). However, no significant association was observed in the analysis for the joint effect of the TE type and PWI-SF (≥27) and the SY type and PWI-SF score (<27) when compared them with the TE type and PWI-SF score (<27).
Table 4.
Odds Ratio of Irritable Bowel Syndrome in Men for Joint Effect of Psychological Well-Being Index-Short Form Score with Sasang Constitutional Types
| Joint effects of PWI-SF and SCTs | Participants (n) | Multivariate OR (95% CI)a | p-Value |
|---|---|---|---|
| PWI-SF (<27) and TE type | 401 | Reference | NA |
| PWI-SF (≥27) and TE type | 51 | 2.35 (0.98–5.63) | 0.06 |
| PWI-SF (<27) and SE type | 72 | 3.21 (1.33–7.75) | <0.01 |
| PWI-SF (≥27) and SE type | 19 | 5.83 (1.80–18.88) | <0.01 |
| PWI-SF (<27) and SY type | 145 | 1.10 (0.50–2.39) | 0.82 |
| PWI-SF (≥27) and SY type | 17 | 3.87 (1.06–14.18) | 0.04 |
Data were adjusted for age, sex, body–mass index (calculated as weight in kilograms divided by height in meters squared), smoking status (never, former, or current), alcohol consumption (g/d), income (monthly wage of <100, 100–200, 200–400, >400×104 won), physical activity (metabolic equivalent per hour daily), Psychological Well-Being Index-Short Form score (<27 or ≥27), high-density lipoprotein cholesterol, triglyceride, and presence of hypertension and diabetes mellitus.
SCT, Sasang constitutional type; OR, odds ratio; NA, not applicable.
Discussion
The aim of this study was to examine the association between the SCTs and IBS in a large population in Korea. Based on cross-sectional data from the KoGES, these findings reveal that the SE type is an independent risk factor for IBS, even after controlling for potential confounders. However, the significant association was found only in men. In addition, a synergistic effect of psychological stress and the SE type on IBS was evident.
Previous studies for the SCTs and gastrointestinal function have been based on the response to questionnaires regarding symptoms related to the gastrointestinal system, and these studies have consistently reported high frequencies of indigestion, abdominal pain, and abnormal appearance of stool in the SE type,8,12,14 which are symptoms suspicious for IBS. No previous studies, however, appear to have investigated the direct association of IBS and the SCTs.
Findings from most epidemiologic studies performed in Western countries have consistently reported that IBS is more prevalent in women than in men,38,39 and the number of patients who seek health care services for IBS is 2–4 times higher in women than in men.40,41 But, unlike in previous studies performed in the United States and other Western industrialized countries, the current study found a significant association only in men in the SE type when multivariate logistic regression analysis stratified by sex was performed. Moreover, in other studies conducted in Asian countries, including Korea, IBS was reported to occur in men more often than in women.42–44 The reason for the discrepancy in the occurrence of IBS according to sex between Western and Asian countries is unclear but could be the result of cultural, psychosocial, or healthcare access issues, rather than purely sex-related physiologic differences.45
The mechanism underlying the relationship between the SE type and IBS is unknown. The cause of IBS seems to be multifactorial. Inflammation is known to affect IBS.46 However, we found no significant difference in the potential factor among the SCTs (e.g., hsCRP [Table 1]). Stress response to psychological stress can also be a possible mediator for the relationship. When stress occurs, several systems involved in brain outputs relaying emotional function, such as the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS), are altered to control stability or homeostasis of the body (allostasis).24,47,48
The HPA axis and ANS play pivotal roles in the regulation of sensitivity, motility, secretion, and immune function in the gastrointestinal system.24,47,49 Thus, sustained stress may result in abnormal susceptibility or motility of the gastrointestinal system, which can account for the pathogenesis of IBS by altering the HPA axis and ANS, in terms of brain-gut interactions.24,50 To examine the contribution of stress on the IBS among the SCTs, we performed an analysis stratified by PWI-SF score. A high degree of psychological stress defined as PWI-SF score (≥27) additionally increased the OR of having IBS in the SE and SY types. The trend was also evident in the TE type but was not statistically significant. The analysis showed that the joint effect of a high level of psychological stress and the presence of the SE type was more detrimental for IBS than the sole effect of the presence of the SE type. However, given that those with the SE type, who have an inherently low stress level, already have significantly higher odds of having IBS, high psychological stress found in the SE type cannot entirely explain the high prevalence of IBS in this type.
Some limitations of this study are worth noting. First, the causal relationship could not be established because the study was cross-sectional. Second, the age of participants was limited to middle age. Given that prevalence of IBS is relatively high in younger people and is markedly less in those older than 50 years of age, as well as that 40% of IBS cases occur between 35 and 50 years of age,21 the possibilities of bias from age distribution cannot be ruled out. Third, we did not perform a subtype analysis of IBS, which could have provided detailed information on the features of IBS in the SCTs, because of the small number of participants when divided into the subgroups. Fourth, we did not have any diet information among the SCTs. Dietary factors can be important in inducing symptoms related with IBS.51 Fifth, a strict definition of IBS in the absence of other organic causes, such as a structural or biochemical alteration, should be confirmed through colonoscopy,28 but in a large cohort-based epidemiologic study it is very difficult to perform such an examination.
In conclusion, SE type is an independent risk factor for IBS. These findings support the hypothesis that the SE type is vulnerable to diseases related to the gastrointestinal system. Further investigations are required to elucidate the mechanisms underlying the association.
Acknowledgments
This research was supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Ministry of Science, ICT & Future Planning (No. 2012-0009830, No. 2006-2005173), and by a fund (2005-E71001-00, 2006-E71005-00) by research of Korea Centers for Disease Control and Prevention. S.K.L. was supported by a Korea University Grant.
Author Disclosure Statement
No competing financial interests exist.
References
- 1.Kim JY, Pham DD. Sasang constitutional medicine as a holistic tailored medicine. Evid Based Complement Altern Med 2009;6Suppl 1:11–19 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Chae H, Lyoo IK, Lee SJ, et al. . An alternative way to individualized medicine: psychological and physical traits of Sasang typology. J Altern Complement Med 2003;9:519–528 [DOI] [PubMed] [Google Scholar]
- 3.Do JH, Jang ES, Ku BC, et al. . Development of an integrated Sasang constitution diagnosis method using face, body shape, voice, and questionnaire information. BMC Complement Altern Med 2012;12:85. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Lee SW, Jang ES, Lee J, Kim JY. Current researches on the methods of diagnosing sasang constitution: an overview. Evid Based Complement Altern Med 2009;6:43–49 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Park H, Ju J, Kim J, Kim K. A study on clinical application of the QSCCll (Questionnaire for the Sasang Constitution Classification ll). J Sasang Constitut Med 2002;14:35–44 [Google Scholar]
- 6.Pham DD, Cha SW, Kim JY. Re-interpretation of traditional Asian medicine with constitutional perspective. Integr Med Res 2013;2:1–6 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Baracos VE. Hypercatabolism and hypermetabolism in wasting states. Curr Opin Clin Nutr Metab Care 2002;5:237–239 [DOI] [PubMed] [Google Scholar]
- 8.Jang ES, Kim HS, Lee HJ, et al. . The clinical study on the ordinary and pathological symptoms according to Sasang constitution. J Sasang Constitut Med. 2007;19:144–155 [Google Scholar]
- 9.Lee J, Lee E, Yoo J, et al. . The Sasang constitutional types can act as a risk factor for hypertension. Clin Exp Hypertens. 2011;33525–532 [DOI] [PubMed] [Google Scholar]
- 10.Lee TG, Koh B, Lee S. Sasang constitution as a risk factor for diabetes mellitus: a cross-sectional study. Evid Based Complement Alternat Med 2009;6Suppl 1:99–103 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Kim YW, Kim JW. A clinical study of the type of disease and symptom according to Sasang constitution II. J Sasang Constitut Med 1999;11:119–135 [Google Scholar]
- 12.Lee YO, Kim JW. A clinical study of the type of disease and symptom according to sasang constitution classification. J Sasang Constitut Med 2002;14:74–84 [Google Scholar]
- 13.Sohn EH, Kwack CK, Lee EJ. Assessment of the clinical efficacy of the health index in the Sasang constitutions: short form-36 based study. J Sasang Constitut Med 2004;16:25–33 [Google Scholar]
- 14.Baek TH, Choi JR, Park SS. A correlation research of digestion according to Sasang constitution. J Sasang Constitut Med 2004;16:112–119 [Google Scholar]
- 15.Lee MS, Sohn KW, Kim YH, et al. . Digestive system-related pathophysiological symptoms of Sasang typology: systematic review. Integr Med Res 2013;2:39–48 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Longstreth GF, Thompson WG, Chey WD, et al. . Functional bowel disorders. Gastroenterology 2006;130:1480–1491 [DOI] [PubMed] [Google Scholar]
- 17.Manning AP, Thompson WG, Heaton KW, Morris AF. Towards positive diagnosis of the irritable bowel. Br Med J 1978;2:653–654 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Chang FY, Lu CL, Chen TS. The current prevalence of irritable bowel syndrome in Asia. J Neurogastroenterol Motil 2010;16:389–400 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Tan YM, Goh KL, Muhidayah R, et al. . Prevalence of irritable bowel syndrome in young adult Malaysians: a survey among medical students. J Gastroenterol Hepatol 2003;18:1412–1416 [DOI] [PubMed] [Google Scholar]
- 20.Cho YS, Choi MG, Shin SJ, et al. . The prevalence of irritable bowel syndrome in Asan city; questionnaire survey in random Korean population. Korean J Neurogastroenterol Motil 2004;10:49–56 [Google Scholar]
- 21.Rhee PL. Definition and epidemiology of irritable bowel syndrome. Korean J Gastroenterol 2006;47:94–100 [PubMed] [Google Scholar]
- 22.Ji SW, Park HJ, Lee JI, et al. . A comparison and validity of various diagnostic criteria of irrtable bowel syndrome. Korean J Neurogastroenterol Motil 2002;8:21–30 [Google Scholar]
- 23.El-Salhy M. Irritable bowel syndrome: diagnosis and pathogenesis. World J Gastroenterol 2012;18:5151–5163 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Mayer EA. The neurobiology of stress and gastrointestinal disease. Gut 2000;47:861–869 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Sperber AD, Drossman DA. Irritable bowel syndrome: a multidimensional disorder cannot be understood or treated from a unidimensional perspective. Therap Adv Gastroenterol 2012;5:387–393 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Creed F, Ratcliffe J, Fernandez L, et al. . Health-related quality of life and health care costs in severe, refractory irritable bowel syndrome. Ann Intern Med. 2001;134(9 Pt 2):860–868 [DOI] [PubMed] [Google Scholar]
- 27.Whitehead WE, Burnett CK, Cook EW, 3rd, Taub E. Impact of irritable bowel syndrome on quality of life. Dig Dis Sci 1996;41:2248–2253 [DOI] [PubMed] [Google Scholar]
- 28.Thompson WG, Longstreth GF, Drossman DA, et al. . Functional bowel disorders and functional abdominal pain. Gut 1999;45Suppl 2:II43–47 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Johns MW. A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep 1991;14:540–545 [DOI] [PubMed] [Google Scholar]
- 30.Beck AT, Ward CH, Mendelson M, et al. . An inventory for measuring depression. Arch Gen Psychiatry 1961;4:561–571 [DOI] [PubMed] [Google Scholar]
- 31.Hahn HM, Youn TH, Shin YW, et al. . A standardization study of Beck Depression Inventory. J Korean Neuropsychiatr Assoc 1986;25:13 [Google Scholar]
- 32.Lee Y, Song J. A study of the reliability and the validity of the BDI, SDS, and MMPI-D scales. Korean J Clin Psychol 1991;10:98–113 [Google Scholar]
- 33.Jang S. Stress. In: Jang S, ed. Collection of Health Statistics and Standardization of Measurement. Seoul, Korea: Gaechook Press, 2000: pp. 92–132 [Google Scholar]
- 34.Visser M, Bouter LM, McQuillan GM, et al. . Elevated C-reactive protein levels in overweight and obese adults. JAMA. 1999;282:2131–2135 [DOI] [PubMed] [Google Scholar]
- 35.Elsenbruch S, Thompson JJ, Hamish MJ, et al. . Behavioral and physiological sleep characteristics in women with irritable bowel syndrome. Am J Gastroenterol. 2002;97:2306–2314 [DOI] [PubMed] [Google Scholar]
- 36.Ranjbaran Z, Keefer L, Farhadi A, et al. . Impact of sleep disturbances in inflammatory bowel disease. J Gastroenterol Hepatol 2007;22:1748–1753 [DOI] [PubMed] [Google Scholar]
- 37.Rotem AY, Sperber AD, Krugliak P, et al. . Polysomnographic and actigraphic evidence of sleep fragmentation in patients with irritable bowel syndrome. Sleep 2003;26:747–752 [DOI] [PubMed] [Google Scholar]
- 38.Drossman DA, Whitehead WE, Camilleri M. Irritable bowel syndrome: a technical review for practice guideline development. Gastroenterology 1997;112:2120–2137 [DOI] [PubMed] [Google Scholar]
- 39.Talley NJ. Irritable bowel syndrome: definition, diagnosis and epidemiology. Baillieres Best Pract Res Clin Gastroenterol 1999;13:371–384 [DOI] [PubMed] [Google Scholar]
- 40.Harvey RF, Salih SY, Read AE. Organic and functional disorders in 2000 gastroenterology outpatients. Lancet 1983;1:632–634 [DOI] [PubMed] [Google Scholar]
- 41.Mitchell CM, Drossman DA. Survey of the AGA membership relating to patients with functional gastrointestinal disorders. Gastroenterology 1987;92(5 Pt 1):1282–1284 [DOI] [PubMed] [Google Scholar]
- 42.Gwee KA. Irritable bowel syndrome in developing countries—a disorder of civilization or colonization? Neurogastroenterol Motil 2005;17:317–324 [DOI] [PubMed] [Google Scholar]
- 43.Kumano H, Kaiya H, Yoshiuchi K, et al. . Comorbidity of irritable bowel syndrome, panic disorder, and agoraphobia in a Japanese representative sample. Am J Gastroenterol 2004;99:370–376 [DOI] [PubMed] [Google Scholar]
- 44.Lu CL, Chang FY, Lang HC, et al. . Gender difference on the symptoms, health-seeking behaviour, social impact and sleep quality in irritable bowel syndrome: a Rome II-based survey in an apparent healthy adult Chinese population in Taiwan. Aliment Pharmacol Ther 2005;21:1497–1505 [DOI] [PubMed] [Google Scholar]
- 45.Heitkemper MM, Jarrett ME. Update on irritable bowel syndrome and gender differences. Nutr Clin Pract 2008;23:275–283 [DOI] [PubMed] [Google Scholar]
- 46.Heitkemper M, Jarrett M, Jun SE. Update on irritable bowel syndrome program of research. J Korean Acad Nurs 2013;43:579–586 [DOI] [PubMed] [Google Scholar]
- 47.Kearney DJ, Brown-Chang J. Complementary and alternative medicine for IBS in adults: mind-body interventions. Nat Clin Pract Gastroenterol Hepatol. 2008;5:624–636 [DOI] [PubMed] [Google Scholar]
- 48.McEwen BS, Wingfield JC. The concept of allostasis in biology and biomedicine. Horm Behav 2003;43:2–15 [DOI] [PubMed] [Google Scholar]
- 49.Heitkemper M, Burr RL, Jarrett M, et al. . Evidence for autonomic nervous system imbalance in women with irritable bowel syndrome. Dig Dis Sci 1998;43:2093–2098 [DOI] [PubMed] [Google Scholar]
- 50.Tanaka Y, Kanazawa M, Fukudo S, Drossman DA. Biopsychosocial model of irritable bowel syndrome. J Neurogastroenterol Motil 2011;17:131–139 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 51.Floch MH. Use of diet and probiotic therapy in the irritable bowel syndrome: analysis of the literature. J Clin Gastroenterol. 2005;39(5 Suppl 3):S243–246 [DOI] [PubMed] [Google Scholar]