2.1 Settings
This 12-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group trial was conducted at two hospital sites in the Republic of Korea. The study protocol (versionV1.0, June 24th, 2021) complied with the Declaration of Helsinki and was approved by the Institutional Review Board of the conducting institutions (Yongin Severance Hospital; 9-2021-0085, Myongji Hospital; 2021-07-035). The study is registered in the Clinical Research Information Service. Osong (Chungcheongbuk-do): Korea Centers for Disease Control and Prevention, Ministry of Health and Welfare (Republic of Korea); 2010; 14/09/2023; KCT0008797; A 12-week, multicenter, randomized, double-blind, placebo-controlled human application study to evaluate the efficacy and safety of SHCog™ on cognitive function improvement in mild cognitive decline.
2.2 Study Subject
One hundred study subjects were recruited through advertisements. Overall healthy subjects who experienced cognitive decline were tested for aMCI by a certified clinician using neurocognitive tests. Exclusion of dementia were carried out through evaluation by psychiatrists. The inclusion criteria were participants aged between 55 and 85 years old and a decline of 1.0 standard deviation or more in either memory scores (Word List Memory of Word List Recall or Word List Recognition) on the Korean version of the neuropsychological assessment developed by the Consortium to Establish a Registry for Alzheimer’s Disease, or on the Seoul Verbal Learning Test (SVLT) of the Seoul neuropsychological screening battery.
The exclusion criteria were as follows: 1) patients with concurrent neurodegenerative conditions, such as AD or Parkinson's disease; 2) current mental disorders (e.g., major depressive disorder, schizophrenia, alcohol use disorder)according to DSM-5 criteria; 3) patients who had taken medications known to affect cognitive function within 4 weeks before the initial visit (all types of psychotropics including antidepressants, nootropics, supplements for brain function) 4) ongoing treatment for severe immune, respiratory, gastrointestinal/hepatic/biliary, renal/urinary, neurological, musculoskeletal, and infectious diseases or malignancies; 5) a history of head trauma with loss of consciousness within 6 months before the initial visit; 6) a history of cardiovascular disease within 6 months before the initial visit; 7) vitamin E supplementation exceeding 400 IU per day or anticipated inability to reduce the dosage; 8) use of estrogen replacement therapy (excluding local applications) within 2 months before the initial visit; 9) use of dietary supplement related to cognitive improvement within 2 months before the initial visit; 10) thyroid disease with thyroid-stimulating hormone (TSH) levels below 0.1 µIU/mL or above 10 µIU/mL; 11) creatinine levels exceeding twice the normal upper limit; 12) aspartate transaminase (AST) or alanine aminotransferase (ALT) levels exceeding three times the normal upper limit; 13) uncontrolled hypertension and diabetes; 14) sensitivity or allergy to the ingredients of the investigational product; 15) pregnancy, breastfeeding, or planning to get pregnant during the study period; 16) participation in any other interventional clinical trial (including clinical trials other than the current study) within 3 months before the initial visit, or planned participation in any other clinical trial (including clinical trials other than the current study) after the start of the current study. All enrolled subjects were provided written informed consent after receiving a complete description of the study protocol.
2.3 Randomization and blinding
A block randomization method was used for randomization. To ensure balanced randomization between the αGPC group and the placebo group, the ratio of participants in each group was set to 1:1. The randomization table was generated using the SAS software randomization program, which applied a permutation of random numbers to the sequential test subject numbers, starting from number one. Drug labeling was performed according to the randomization table, and the labeled drugs were supplied to the institutions before the start of the trial.
To maintain blinding, the assignment details (information about blinding) for each group were securely managed by the trial coordinator. Except in cases where it was necessary because of significant adverse drug reactions, the blinding codes were not disclosed until the end of the trial. The investigators administered the randomly assigned drug corresponding to the allocated blinding code to the eligible participants during the treatment phase human application phase of the trial. To maintain blinding, reserves (specific to each unique code) were used in cases of shortage or damage to the drugs. Throughout the study, there were no occurrences of unblinding during the trial period.
2.4 Raw Material
SHCog™ is a branded α-GPC (HS Bio, Republic of Korea), prepared from Soybean lecithin and is highly viscose, as it absorbs moisture up to 14 ~ 18.5%. Materials used for the manufacturing process and residual solvent standards comply with food regulations of Korea. The raw materials were stored at room temperature until test product is prepared as a soft capsule format.
2.5 Interventions
Enrolled subjects were administered αGPC or placebo once daily with adequate water for a duration of 12 weeks. Based on the choline dosage recommended by the National Academies Press, and considering previous studies, a single dose of the drug was determined to contain 727 mg of SHCog™, which is equivalent to 600 mg of aGPC (HSBio, Republic of Korea). Enrolled subjects were allowed to continue taking medications and dietary supplements that were deemed unlikely to affect the interpretation of the results. However, the following medications were prohibited during the trial because of their potential to influence the interpretation of the results: 1) medications that affect cognitive function (e.g., antipsychotics, tricyclic antidepressant, neurodegenerative disease drugs, nootropics) 2) vitamin E supplementation exceeding 400 IU per day, 3) estrogen replacement therapy (excluding local applications), and 4) dietary supplements associated with cognitive improvement.
2.6 Outcome assessments
The primary outcome was a change in the total score Alzheimer’s Disease Assessment Scale–cognitive subscale (ADAS-cog score). The Alzheimer Disease Assessment Scale (ADAS) consists of cognitive and noncognitive sections. ADAS-Cog, which is cognitive section of ADAS, aims to assess various cognitive domains in dementia patients, including memory, language abilities, and executive function, among others [17, 18]. We additionally assess concentration abilities through an item in noncognitive section. The secondary outcome assessment included the Korean version of the Montreal Cognitive Assessment (MoCA-K) [19], the Visual Continuous Performance Test (Visual C.P.T) [20], the Korean-Color Word Stroop Test (K-CWST) [21], Seoul-Instrumental Activities of Daily Living (S-IADL) [22], Subjective Cognitive Decline Questionnaire (SCD-Q) [23], and the Korean version of the Short Form Geriatric Depression Scale (SGDS-K) [24]. These outcomes were assessed at baseline and 12 weeks after baseline.
2.7 Safety assessment
Safety assessments included monitoring of AEs, clinical laboratory tests (hematological/blood chemistry and urinalysis), vital signs (blood pressure and pulse rate), and physical measurements (body weight). These assessments were conducted at screening (2 weeks before baseline), baseline, 6 weeks after baseline, and 12 weeks after baseline.
2.8 Sample size and power analysis
A sample size of 35 per treatment group was estimated to assess the effectiveness of αGPC, compared with that of placebo, using primary efficacy variables (ADAS-cog score), with 80% power at a significance level of 0.05. To account for a potential dropout rate of 30%, we enrolled 50 participants in each group, resulting in a total enrollment of 100 individuals across both treatment groups.
2.9 Statistical Analysis
Outcome analysis was carried out based on an intention-to-treat (ITT) dataset, defined as the subset of participants who received at least one dose of medication after randomization. The statistical analysis was conducted using SAS® software (Version 9.4, SAS Institute, Cary, North Carolina, USA).
To evaluate efficacy variables, including the ADAS-cog score, MoCA-K, visual C.P.T, K-CWST, S-IADL, SCD-Q, and SGDS-K, intra-group comparisons of pre- and post-intake changes were performed using paired t-test. The difference in extent of changes between the αGPC group and the placebo group at each time point was assessed using two sample t-test or Wilcoxon rank-sum test. Demographics and results of biological tests (Laboratory examination, measuring vital signs and body weight) were analyzed using a two-sample t-test or the Wilcoxon rank-sum test. Chi-square or Fisher's exact test was used to analyze categorical data.