The influence of the Korean traditional Chungkookjang on variables of metabolic syndrome in overweight/obese subjects: study protocol

Back et al. BMC Complementary and Alternative Medicine 2013, 13:297 http://www.biomedcentral.com/1472-6882/13/297 STUDY PROTOCOL Open Access The influence of the Korean traditional Chungkookjang on variables of metabolic syndrome in overweight/obese subjects: study protocol Hyang-Im Back1,2, Ki-Chan Ha1,2, Hye-Mi Kim1,2, Min-Gul Kim3, Ok-Kyeong Yu4,5, Moon-Sun Byun4,5, Do-Youn Jeong6, Seong-Yeop Jeong6, Youn-Soo Cha4,5* and Tae-Sun Park3,5,7* Abstract Background: Metabolic syndrome is a set of disorders that increases the risk of developing cardiovascular disease. The primary target of treatment of patients with metabolic syndrome is therapeutic lifestyle change. Numerous preclinical study have reported positive effects of chungkookjang in in vivo models of diabetes and obesity, but there is a paucity of controlled clinical trials on variables of metabolic syndrome in obese subjects. Thus, the objective of this trial is to examine the effect of chungkookjang compared to placebo on variables of metabolic syndrome in overweight/obese subjects. Methods: This double-blind randomized controlled crossover trial will be conducted on 120 overweight/obese subjects; aged 19–29 years. Subjects will be recruited from the Chonbuk National University, Jeonju, South Korea. Enrolled subjects will be randomly assigned to two groups of equal number; one group received 35 g of chungkookjang (n = 60) and the other group received placebo (n = 60) on a regular daily basis for 12 weeks. After a 12-week washout period, the groups will be crossed over. In addition to anthropometric measures and blood pressure, glucose parameter, lipid profile, adipocytokine, and carnitine assay will be determined at baseline and 12 week. Also, safety will be assessing by measuring total bilirubin, alkaline phosphatase, alanine transaminase, aspartate aminotransferase, total protein, albumin, blood urea nitrogen, creatinine, and creatine kinase at baseline and 12 weeks. 24-hour dietary recalls were collected at the baseline and at the end of the trial. Discussion: This trial will evaluate the effects of chungkookjang on variables of metabolic syndrome in overweight/obese subjects. The results of this study may contribute to the reduction of risk factor for metabolic syndrome caused by obesity. Trial registration: Clinical trials NCT01811511. Keywords: Chungkookjang, Metabolic syndrome, Overweight, Obesity, Diabetes * Correspondence: ; 4 Department of Food Science and Human Nutrition, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 561-756, Republic of Korea 3 Clinical Trial Center, Chonbuk National University Hospital, 20 Geonji-ro, Deokjin-gu, Jeonju, Jeonbuk 561-712, Republic of Korea Full list of author information is available at the end of the article © 2013 Back et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Back et al. BMC Complementary and Alternative Medicine 2013, 13:297 http://www.biomedcentral.com/1472-6882/13/297 Page 2 of 6 Background The prevalence of obesity has increased worldwide over the past decades [1,2], although more recent data suggest a slowing of this trend. The rising rates of obesity in children and adults have been accompanied by an increase in the co-occurrence of obesity-associated metabolic abnormalities known as the metabolic syndrome (Met-S). The prevalence of Met-S is increasing; it currently affects 22.1% of men and 27.8% of women in Korea [3,4]. The clustering of major components of the syndrome, including obesity, dyslipidemia, hypertension, and insulin resistance, has been demonstrated in youth [5,6], and clustering of these risk factors has also been shown to track into early adulthood. These obese youth are a high-risk population to target for screening, prevention, and intervention for Met-S [5,6]. Conclusions in nutritional intervention studies are frequently drawn from epidemiological studies, but there are affected by many possible confounding factors. Unlike laboratory animals, human beings cannot be fed over a long time; thus most nutritional intervention studies are short to medium term and focus on surrogate parameters. On the other hand, although the preferred treatment for Met-S is lifestyle modification including exercise and nutrition therapy [7,8], the challenge is the multitude of risk factors and the high prevalence of obesity. But there are difficult to approach in typically clinic visits. Furthermore, in the large scale trials, subjects often struggle with adopting lifestyle changes to derive siginificant results, but it is difficult to control the subjects by physician or investigators. Soybeans contain various nutritious and functional components such as isoflavonoids besides soy protein which are helpful in protecting against metabolic diseases such as obesity and type 2 diabetes [9]. Fermenting soybean such as chungkookjang (CKJ) may be enhance the functionality of soybeans to protect against metabolic disease. Korean traditional CKJ is a good fermented soybean product for use as a functional food. However, traditional CKJ did not recognized as a functional food in Korea. Currently, the non-clinical data on effects of CKJ have been reported from in vivo and in vitro studies [10-18] but there is paucity the controlled clinical trials on variables of Met-S. Our previous study have revealed that traditionally made CKJ from Sunchang district of Jeolla province, Korea showed potential anti-atherosclerotic effects in overweight/obese subjects [19]. It has also been reported that traditional CKJ (made from Sunchang district of Jeolla province, Korea) improves insulinotropic action and hepatic insulin sensitivity in diabetic rats [16,17]. However, CKJ intake in Korean youth is gradually decreased due to distinctive flavor of CKJ. Therefore, the present study will be conducted by the easy-to-eat freeze-dried CKJ pills. The CKJ shows distinctive flavor characteristics. For this reason, we used cinnamon as flavoring agent to make it palatable. The purpose of this study is to evaluate the effect of CKJ compared to placebo on variables of Met-S in overweight/obese subjects. Methods and design Objective The objectives of this RCT are to study whether the CKJ can improve the Met-S in overweight/obese subjects. Primary objective To evaluate the efficacy of the CKJ on anthropometric parameter in overweight/obese subjects after 12 weeks of consumption. Secondary objectives To evaluate the following factors in overweight or obese subjects after 12 weeks of consumption on: A) blood pressure (...truncated)