putative effects of D-Aspartic acid on blood testosterone levels: a systematic review

Background: D-Aspartic acid [D-Asp] is in invertebrate and vertebrate neuroendocrine tissues, where it carries out important physiological functions. Recently, it has been reported that D-Asp is involved in the synthesis and release of testosterone and is assumed can be used as a testosterone booster for infertile men, and by athletes to increase muscle mass and strength

Objective: The aim of this review is to summarize available evidence related to the effects of D-Asp on serum testosterone levels.Materials and Methods: We conducted a systematic review of all type studies, which evaluated the effect of the D-Asp on blood testosterone including published papers until October 2015, using PubMed, ISI Web of Science, ProQuest and Scopus database

Results: With 396 retrieved records, 23 animal studies and 4 human studies were included. In vivo and in vitro animal studies revealed the effect of D-Asp depending on species, sex and organ-specific. Our results showed that exogenous D-Asp enhances testosterone levels in male animal's studies, whereas studies in human yielded inconsistent results. The evidence for this association in man is still sparse, mostly because of limited number and poor quality studies

Conclusion: There is an urgent need for more and well-designed human clinical trials with larger sample sizes and longe

Association between Healthy Eating Index-2010 and Fetuin-A Levels in Patients with Type 2 Diabetes: a Case-Control Study

The Healthy Eating Index-2010 (HEI-2010) assesses compliance with the 2010 Dietary Guidelines for Americans. Studies suggest that adherence to the HEI-2010 is related to lower the risk of type 2 diabetes (T2D). Fetuin-A, a novel biomarker for T2D, may play a linking role in the inverse association between HEI-2010 and T2D. Thus, a case-control analysis involving 107 patients with T2D and107 healthy subjects was conducted to determine the association between HEI-2010 and serum fetuin-A levels. The results of simple regression analysis showed that fetuin-A levels were positively associated with full name of body mass index (BMI) (p < 0.001), waist circumference (WC) (p < 0.001), fasting blood glucose (FBG) (p < 0.001), triglycerides (TG) (p = 0.003), gamma-glutamyl transferase (GGT) (p < 0.001), and homeostasis model assessment of insulin resistance (HOMA-IR) (p =0.001) and negatively associated with physical activity (PA) (p < 0.001), high-density lipoprotein (HDL) (p = 0.022), and HEI-2010 (p < 0.001) in all subjects. After controlling for confounders, the inverse association between fetuin-A and HEI-2010 remained significant in the subjects with T2D (β = −0.386; p < 0.001), 107 healthy controls (β = −0.237; p = 0.028), and all subjects (β = −0.298; p < 0.001). In conclusion, the present results suggested that higher quality diet assessed by HEI-2010 associates with lower serum fetuin-A levels in people with and without T2D. More studies are needed to confirm these findings.

Association between Healthy Eating Index-2010 and Fetuin-A Levels in Patients with Type 2 Diabetes: a Case-Control Study

The Healthy Eating Index-2010 (HEI-2010) assesses compliance with the 2010 Dietary Guidelines for Americans. Studies suggest that adherence to the HEI-2010 is related to lower the risk of type 2 diabetes (T2D). Fetuin-A, a novel biomarker for T2D, may play a linking role in the inverse association between HEI-2010 and T2D. Thus, a case-control analysis involving 107 patients with T2D and107 healthy subjects was conducted to determine the association between HEI-2010 and serum fetuin-A levels. The results of simple regression analysis showed that fetuin-A levels were positively associated with full name of body mass index (BMI) (p < 0.001), waist circumference (WC) (p < 0.001), fasting blood glucose (FBG) (p < 0.001), triglycerides (TG) (p = 0.003), gamma-glutamyl transferase (GGT) (p < 0.001), and homeostasis model assessment of insulin resistance (HOMA-IR) (p =0.001) and negatively associated with physical activity (PA) (p < 0.001), high-density lipoprotein (HDL) (p = 0.022), and HEI-2010 (p < 0.001) in all subjects. After controlling for confounders, the inverse association between fetuin-A and HEI-2010 remained significant in the subjects with T2D (β = −0.386; p < 0.001), 107 healthy controls (β = −0.237; p = 0.028), and all subjects (β = −0.298; p < 0.001). In conclusion, the present results suggested that higher quality diet assessed by HEI-2010 associates with lower serum fetuin-A levels in people with and without T2D. More studies are needed to confirm these findings.