Suggestion of new possibilities in approaching individual variability in appetite through constitutional typology: a pilot study

Unravelling the Effects of Soluble Dietary Fibre Supplementation on Energy Intake and Perceived Satiety in Healthy Adults: Evidence from Systematic Review and Meta-Analysis of Randomised-Controlled Trials

Consumption of soluble dietary fibre is recommended as part of a healthy diet. Evidence has shown that soluble dietary fibre slows gastric emptying, increases perceived satiety and plays a significant role in appetite regulation. This systematic review examined the effects of soluble dietary fibre using randomised-controlled trials (RCTs). Three different electronic databases were used, namely PubMed, Scopus® and the Cochrane Central Register of Controlled Trials (CENTRAL). Effect size (Cohen's d) was calculated based on the intergroup mean difference and standard deviation (SD) followed by Cochran's Q and I² determination. The effect size was statistically pooled in the meta-analyses and presented as a forest plot. The risk of bias was high for each study as assessed using the Jadad scale. Meta-analysis of statistically pooled data for guar gum showed a sizeable effect on post-meal energy intake, followed by β-glucan, alginate, polydextrose and pectin, with pooled effect sizes of -0.90, -0.44, -0.42, -0.36 and -0.26, respectively. Guar gum (5 g) effectively reduced energy intake when prepared in milk beverages compared with control milk (p < 0.001). Alginate, when prepared in liquid (5 g) or solid (9 g) meals, effectively reduced energy intake compared with control (p < 0.001). A high dose of polydextrose (25 g) prepared in liquid meal form significantly reduced energy intake (p = 0.01). This study suggests that soluble fibres are not all created equal. Further interventional studies are needed to determine whether combinations of these soluble fibres might have greater effects than individual fibres per se.

Body temperature regulation: Sasang typology-based perspective

Global warming induces a dramatic elevation of heat-related morbidity and mortality worldwide. Individual variation of heat stress vulnerability depends on various factors such as age, gender, living area and conditions, health status, and individual innate characteristics. Sasang typology is a unique form of Korean traditional medicine, which is based on the hypothesis that constitution-specific traits of an individual determine the particular distinctive tendency in various aspects, including responses to the external environment. Recent scientific evidence shows that Sasang types differ in body composition, metabolic profile, susceptibility to certain disease patterns, and perspiration. This review aims to interpret these findings under the context of heat balance consisting of heat production (H_prod), heat loss (H_loss), and heat load (H_load). Based on the published data, at a given body mass, the TaeEum type tended to have a lower H_prod at rest and at the exhaustion state, which may indicate the lower metabolic efficiency of this type. Meanwhile, the surface-to-mass ratio and heat capacity of the TaeEum type appear to be lower, implying a lower heat dissipation capacity and heat storage tolerance. Thus, because of these characteristics, the TaeEum type seems to be more vulnerable to heat stress than the other constitutions. Differences in temperature regulation across constitutional types should be taken into account in daily physical activity, health management, and medical research.

The obesity-risk variant of FTO is inversely related with the So-Eum constitutional type: genome-wide association and replication analyses

Background

Body constitutional types described in the traditional Korean medicine system, Sasang constitutional medicine, are heritable, as has been revealed by twin and family studies. Thus, individuals with the same constitution type usually have similar pathophysiological and psychological traits. In several recent genome-wide association (GWA) analyses performed to identify constitution-associated variants, the association signals were not replicated due to small sample size and dissimilar, non-objective methods for classification of the constitutional types.

Methods

We conducted GWA analysis and followed replication analysis in two large populations (5,490 subjects: 3,810 subjects at discovery stage and 1,680 subjects at replication stage) to identify the replicable constitution-associated variants, wherein subjects with the highest tertile of constitution probability values versus the reference with the lowest tertile of the values obtained from a recently developed constitution analysis tool were compared.

Results

We found that the obesity-risk variant in intron 1 of the fat mass and obesity–associated (FTO) gene was replicably inversely associated with the So-Eum (SE) type, characterized by reduced appetite, slim body, and cautious personality (rs7193144 in combined samples: odds ratio = 0.729, p = 1.47 × 10⁻⁷), and substantial association signal remained after controlling for body mass index (BMI). In contrast, the association of the variant with the Tae-Eum type, characterized by high body mass, disappeared after controlling BMI.

Conclusions

In summary, the obesity-risk variant in FTO intron 1 was inversely associated with the SE type, independent of BMI, which corresponded well with the characteristics of the SE type, such as the lowest body mass and lowest susceptibility to metabolic disorders among the constitutional types. Therefore, the obesity-risk variant of FTO associated with body mass increase might be involved in the determination of body constitution type.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0609-4) contains supplementary material, which is available to authorized users.

Genetic loci associated with changes in lipid levels leading to constitution-based discrepancy in Koreans

Background

Abnormal lipid concentrations are risk factors for atherosclerosis and cardiovascular disease. The pathological susceptibility to cardiovascular disease risks such as metabolic syndrome, diabetes mellitus, hypertension, insulin resistance, and so on differs between Sasang constitutional types.

Methods

We used multiple regression analyses to study the association between lipid-related traits and genetic variants from several genome-wide association studies according to Sasang constitutional types, considering that the Tae-Eum (TE) has predominant cardiovascular risk.

Results

By analyzing 26 variants of 20 loci in two Korean populations (8,597 subjects), we found that 12 and 5 variants, respectively, were replicably associated with lipid levels and dyslipidemia risk. By analyzing TE and non-TE type (each 2,664 subjects) populations classified on the basis of Sasang constitutional medicine, we found that the minor allele effects of three variants enriched in TE type had a harmful influence on lipid risk (near apolipoprotein A-V (APOA5)-APOA4-APOC3-APOA1 on increased triglyceride: p = 8.90 × 10^-11, in APOE-APOC1-APOC4 on increased low-density lipoprotein cholesterol: p = 1.63 × 10^-5, and near endothelial lipase gene on decreased high-density lipoprotein cholesterol: p = 4.28 × 10^-3), whereas those of three variants (near angiopoietin-like 3 gene, APOA5-APOA4-APOC3-APOA1, and near lipoprotein lipase gene on triglyceride and high-density lipoprotein cholesterol) associated in non-TE type had neutral influences because of a compensating effect.

Conclusions

These results implied that the minor allele effects of lipid-associated variants may predispose TE type subjects to high cardiovascular disease risk because of their genetic susceptibility to lipid-related disorders.

Development and validation of the digestive function assessment instrument for traditional korean medicine: sasang digestive function inventory

Objective. This study was conducted for development and validation of the Sasang Digestive Function Inventory (SDFI) with type-specific digestive function-related symptoms for identification of Sasang type and pathological pattern. Methods and Materials. We selected questionnaire items for pathophysiological symptoms using internal consistency analysis and examined construct validity using 193 healthy participants. Test-retest reliability with a four-week interval as well as convergent validity was examined using the Nepean Dyspepsia Index-Korean (NDIK), Functional Dyspepsia-Related Quality of Life (FDQOL), Dutch Eating Behavior Questionnaire (DEBQ), and Body Mass Index (BMI). Results. The 21-item SDFI showed satisfactory internal consistency (Cronbach's alpha = 0.743) and test-retest reliability (r = 0.886, P < 0.001). Three extracted subscales, SDFI-Digestion, SDFI-Appetite, and SDFI-Eating pattern, explained 56.02% of the total variance. The SDFI showed significant (P < 0.001) correlation with total symptom score of NDIK, FDRQOL-Eating status, DEBQ-External Eating scale, and BMI. The SDFI score of the Tae-Eum (50.62 ± 8.05) type was significantly (P < 0.001) larger than that of the So-Eum (43.11 ± 11.26) type. Conclusion. Current results demonstrated the reliability and validity of the SDFI and its subscales, which can be utilized as an objective instrument for diagnosis of Sasang types and assessment of the type-specific digestive function.

Re-interpretation of traditional Asian medicine with constitutional perspective

There has been a rapid increase in tailored medicine that emphasizes the complex inter-individual interactions, and this increase has paralleled recent significant achievements in genomics and Systems Biology. However, attempts to create a virtual human have been limited to low-levels of organization, such as gene-protein networks, due to the lack of systematic concepts at the higher levels of organisms (organ, individual, and environment). Constitutional perspective of various forms of traditional Asian medicine through the ancient, middle, and modern eras, particularly the holistic approach of Sasang constitutional medicine (SCM), may provide a novel framework for creating tailored medicine. This article aims to review the theoretical development of traditional Chinese medicine and the initiation of SCM in addition to summarizing current evidence on the genetic basis, bio-physiological features, and risk of disease of different SCM phenotypes. We also suggest that the patho-physiological principle and scientific evidence underlying SCM, particularly for the TaeEum type, can be effective in dealing with obesity-linked disease, which is a predominant disease in today's society.