Effect of GenF20 Plus on serum IGF-1 levels in healthy adults: a randomized controlled study

摘要

Background: Aging is related to a reduction of growth hormones, resulting in physiological derailment and affects overall wellbeing. GenF20 Plus is a dietary supplement postulated to naturally stimulate the secretion of human growth hormone (HGH) through the anterior pituitary. This study sought to evaluate the effect of GenF20 Plus in enhancing the levels of insulin-like growth factor-1 (IGF-1), which is a marker of HGH levels. Methods: Seventy subjects aged 35–65 years visiting outpatient departments at five study centers across India, presenting with at least two of the following age-related complaints: decreased memory, decreased libido, low energy levels, or poor quality of sleep were randomly assigned to either GenF20 Plus (n=35) or placebo (n=35) for a period of 12 weeks (84 days). Randomization was carried out using computerized software. The primary outcome measure was serum IGF-1 levels. Changes in waist circumference, body mass index, body fat percentage, lean muscle mass, and scores for memory, libido, energy levels, and quality of sleep were also assessed. Trial registration: CTRI/2011/06/001784. Results: Sixty-one subjects completed the study as per protocol and were analyzed. The mean increase (mean ± standard deviation) in IGF-1 levels at day 84 in the GenF20 Plus group was 13.46±36.12 ng/mL and in the placebo group was 6.35±36.56 ng/mL, which was not statistically significantly different (P>0.05) when compared across the groups. In the ≥40 years subgroup, the mean increase in IGF-1 in the GenF20 Plus group (14.59±40.08 ng/mL) was not statistically significantly different when compared to the placebo group (3.17±16.09 ng/mL) using analysis of variance (ANOVA; P>0.05). However, when this change was analyzed using analysis of covariance (ANCOVA) considering baseline values as the covariates, it was found to be statistically significantly different (GenF20 Plus: 22.69±40.62 ng/mL, placebo: -4.31±16.79 ng/mL; P<0.05). The changes in IGF-1 values in the <40 years subgroup were not found to be statistically significant. No statistically significant difference over placebo was seen for the other variables. Conclusion: GenF20 Plus increased serum IGF-1 levels in subjects ≥40 years of age who physiologically have reduced IGF-1 levels. However, significant changes in other parameters were not seen, probably due to the short duration of treatment. Further studies with longer treatment duration and large sample size are warranted to understand the clinical benefits of GenF20 Plus, especially in adults above 40 years of age.