Introduction: Prediabetes, a stage between normal glycemia and type 2 diabetes, often shows no symptoms but can damage vital organs. Traditional Chinese medicine uses body constitution and meridians to assess health and predict disease risk. Studies on the link between traditional Chinese medicine and prediabetes risk are scarce. This study aimed to examine the association between body constitution and meridian energy in individuals with prediabetes versus matched healthy controls. materials and methods: We conducted a matched case–control study from January to December 2019. Participants were recruited from an outpatient clinic and health examination center at a teaching hospital in northern Taiwan. The study involved 30 adults with prediabetes and 30 healthy controls matched for age and sex. 2.2. Ethics This study received approval from the Institutional Review Board of our hospital (approval number: IRB 07-XD-082). The study was conducted in accordance with the tenets of the Declaration of Helsinki, and written informed consent was obtained from all participants. 2.3. Sampling We used convenience sampling, with the following inclusion criteria: (a) previous diagnosis of prediabetes with a hemoglobin A1c (HbA1c) level of 5.7%–6.4% and a fasting plasma glucose (FPG) level of 100–125 mg/dL; (b) age ≥ 20 years; and (c) provided informed consent. Healthy individuals whose FPG levels were below 100 mg/dL in at least two blood tests in the past 6 months were included as controls. The exclusion criteria were as follows: (a) use of a hypoglycemic agent within the past 3 months; (b) self-reported catastrophic illness in the last 6 months; (c) pregnancy or lactation; and (d) presence of a pacemaker. 2.4. Measurements The study variables included patient demographic characteristics (age, sex, marital status, education level, and employment status), clinical characteristics (health and medical history), and health behaviors such as smoking habit (yes or no) and alcohol consumption (yes or no). Physiological indicators included body mass index (BMI) and FPG, HbA1c, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels. Weight and height were measured while the participants wore light clothing and no shoes, and then, the BMI (kg/m2) was calculated. FPG, HbA1c, HDL-C, and LDL-C were quantified by the same laboratory technician who measured the weight and height using standardizedprocedures of the teaching hospital. In this study, data were collected using the scales and devices introduced below. 2.5. Body Constitution The body constitution of the participants was measured using the BCQ, which measures the state of deviation in body constitution during the past month and consists of 44 items rated on a 5-point Likert scale. The items were organized into three summative subscales: 19 items for yang deficiency (BCQ+), 19 items for yin deficiency (BCQ−), and 16 items for phlegm stasis (BCQs). Body constitution was considered to be yang deficient if the BCQ+ score was ≥ 30.5, yin was considered to be deficient if the BCQ score was ≥ 29.5, and phlegm stasis was considered to exist if the BCQ score was ≥ 26.5. The BCQ was established using the Delphi process with a content validity index of ≥ 0.7. The Cronbach alpha and intraclass correlation coefficient values for each subscale were as follows: BCQ+, 0.88 and 0.91; BCQ–, 0.85 and 0.91; and BCQs, 0.88 and 0.91, respectively (J. D. Lin et al., 2012; J. S. Lin et al., 2012; Su et al., 2008). 2.6. Meridian Energy The Aetoscan meridian energy detection device (MED; Aeto Technology Co. Ltd., Taipei City, Taiwan) uses a low-voltage electrical current (3.7V, 200 μA) to detect 12 meridian energy levels in 24 representative measuring points (RMPs) on the skin of wrists and ankles. The Aetoscan MED analysis report includes the body and balance energy (Lee et al., 2018). Body energy was defined as the average value of 24 RMPs with a normal range of 25–55. Balance energy was measured using metabolic, musculoskeletal, circulatory, mental health, and autonomic nervous system status ratios. The normal range for metabolism, musculoskeletal and circulatory systems, and mental health was set at 0.8–1.2, while that for the autonomic nervous system was 1.5–2.0. All participants were required to rest in a room for 15 min before measurements using the Aetoscan MED and were asked to remove their shoes, socks, and any metal objects that could interfere with the measurements. A skilled operator handled the Aetoscan MED to ensure consistency and reliability following the manufacturer’s recommendations. 2.7. Cohort Size Estimation and Statistical Analysis Various sample size guidelines recommend a cohort size of 30 for both correlational designs (Onwuegbuzie & Collins, 2007). Statistical analyses were performed using Statistical Package for Social Sciences software for Windows (version 23.0; IBM, Armonk, NY, USA). Analyses of descriptive statistics, including frequency, percentage, mean, and standard deviation, were performed. Differences in the results between individuals with prediabetes and healthy controls were compared using an independent t-test for continuous variables and the Fisher exact test for categorical variables. Variables that were significant in the univariate analysis were subsequently included in the multivariate regression analysis. The associations among body constitution, meridian energy, and prediabetes risk were examined using binary logistic regression analyses. For all analyses, results with P-values < 0.05 were considered statistically significant. 2.8 Theoretical Framework and Calculation This study is grounded in TCM theory, which postulates that imbalances in body constitution and disruptions in meridian energy flow contribute fundamentally to susceptibility to diseases, including metabolic dysregulation such as...