Effects of Amylopectin Chromium Blend on Whole-Body Protein Kinetics and Glucose in Peri/Post-Menopausal Women

This randomized, double-blind, placebo-controlled clinical trial will evaluate the effects of two dosage forms of an amylopectin-chromium blend on whole-body protein balance in peri- and post-menopausal women. The study will employ a stable isotope tracer methodology to quantify acute changes in protein synthesis and breakdown following a standardized resistance exercise bout and protein ingestion. Continuous glucose monitoring will assess the impact of the supplement on glycemic control over a 24-hour period.

Approximately 60 apparently healthy women, aged 40-65 years, will be enrolled at a single clinical site (The Center for Applied Health Sciences, Canfield, OH). Participants will complete four in-person visits over a 2-3-week period: one screening visit and three testing visits. Following screening and baseline assessments (including clinical chemistry, complete blood count, lipid panel, vital signs, and body composition via bioimpedance analysis), eligible participants will be randomly assigned to one of three groups:

1. Amylopectin-chromium blend, 2 g co-ingested with 20 g of protein from yogurt, 2. Concentrated Amylopectin-chromium blend, 100 mg, co-ingested with 20 g of protein from yogurt, or 3. Placebo (2 g amylopectin) co-ingested with 20 g of protein from yogurt.

Each participant will receive only one product dose during the study. Group assignment will be randomized and blinded to both participants and investigators.

Prior to dosing, participants will undergo exercise familiarization and 5-repetition-maximum testing for leg press and leg extensions. At Visit 3 (Day 5), participants will ingest a single oral dose of ¹⁵N-alanine (2 g) as a metabolic tracer, and then will perform a standardized resistance exercise protocol (3 × 12-15 repetitions each of leg press and leg extension at 60-65 % of estimated 1RM, with 2-minute rest intervals). Immediately following exercise, the assigned study product with yogurt protein will be ingested. A second 20 g yogurt protein serving will be consumed with the evening meal to maintain uniform post-exercise protein intake.

Urinary nitrogen enrichment (¹⁵N-urea) will be measured from 24-hour urine collections (0-12 h and 12-24 h) to determine protein turnover rates. Blood samples obtained at multiple time points will assess biochemical responses, including blood urea nitrogen and isotope enrichment. Whole-body protein synthesis and breakdown will be calculated from tracer kinetics. Continuous glucose monitoring will capture interstitial glucose fluctuations.