Clinical Research Directory

Dose-Response Impact of Geranylgeraniol (GG) Supplementation on Muscle Health

This study will evaluate the effects of daily geranylgeraniol (GG) supplementation on muscular strength, body composition, and aerobic capacity in healthy, physically active men and women. Approximately 60 participants aged 30-60 years will be enrolled in a randomized, double-blind, placebo-controlled, parallel-group trial lasting 8 weeks. Participants will be assigned to receive either placebo, 150 mg GG, or 300 mg GG daily. Outcome measures will be assessed at baseline, week 4, and week 8 and include maximal strength (1RM bench press and leg press), fat-free mass, muscular endurance, aerobic capacity (VO2peak), and circulating biomarkers related to metabolism and health.

Diet Synergy in Muscle Protein Synthesis

In the present semi-crossover randomized design, 15 recreationally active young adults (19-40 y) will receive stable isotope tracer infusions and perform a single bout of resistance exercise. Immediately after exercise, participants will ingest either 1 medium russet potato with skins and 2 ounce-equivalent lean ground beef combination (274 kcals, 19.3 g protein, 5 g fat, 37 g carbohydrates, and 4 g fiber), 2 slices of white bread and beef combination (262 kcals, 19.8 g protein, 6.8 g fat, 28 g carbohydrates, and 1.8 g fiber) or 2 ounce-equivalent beef (93% lean meat/7% fat; 110 kcals, 14.8 g protein, and 5 g fat). Repeated blood and muscle biopsies will be collected to determine whole body leucine kinetics, amino acid concentrations, anabolic signaling and myofibrillar protein synthesis rates during the trials.

Bone and Muscle Health Following Sleeve Gastrectomy in Men, Premenopausal and Postmenopausal Women

Background: Bariatric surgery is gaining in popularity. While it's health benefits are undisputed, the older malabsorptive bariatric procedures (Roux-in-Y gastric bypass - RYGB and biliopancreatic diversion - BPD) are associated with an increased risk of fractures and falls as early as 3-5 years after surgery. Sleeve gastrectomy - SG is now the most performed bariatric procedure. Although SG does not cause malabsorption, it is predicted to result in bone and muscle loss via weight loss and weight loss-independent mechanisms. Primary aim: to compare the changes in spine volumetric bone mineral density (vBMD) by quantitative computed tomography (QCT) and muscle mass at mid-femur by computed tomography (CT) at 3 years in the 3 groups of: 1) men; 2) premenopausal women; 3) postmenopausal women after SG versus their respective non-surgical peers who did not undergo SG in the 3-year period following recruitment. Secondary aims: to compare the changes in vBMD by QCT at skeletal sites other than the spine and in areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA), whole-body muscle mass by DXA, muscle quality by CT at mid-femur and muscle strength as well as in selected physical performance and capacity tests shown to predict falls and fractures between 0-1 and 1-3 years after SG in the same 3 groups after SG vs. in the respective non-surgical groups.