ABSTRACT
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
ABSTRACT
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.
Subject(s)
Humans , alpha-2-HS-Glycoprotein , Blood Glucose , Body Mass Index , Case-Control Studies , Compliance , Diet , Eating , Fasting , Healthy Volunteers , Homeostasis , Insulin Resistance , Lipoproteins , Motor Activity , Nutrition Policy , Transferases , Triglycerides , Waist CircumferenceABSTRACT
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.
Subject(s)
Humans , alpha-2-HS-Glycoprotein , Blood Glucose , Body Mass Index , Case-Control Studies , Compliance , Diet , Eating , Fasting , Healthy Volunteers , Homeostasis , Insulin Resistance , Lipoproteins , Motor Activity , Nutrition Policy , Transferases , Triglycerides , Waist CircumferenceABSTRACT
Appetite lowering characteristics of dairy have attracted scientists to look for its effect on energy intake particularly among children. In the present study, we tried to assess the effect of low-fat milk on total and short-term energy intake among obese boys in a randomized three-way cross-over clinical trial. A total of 34 obese 10-12-year-old boys were randomized to consume three beverages [low-fat milk, apple juice, or water] with a fixed energy breakfast for two consecutive days, 1 week apart. Ad libitumlunch was provided for subjects 5 h later. The energy intake from breakfast till lunch and total energy intake on intervention days, and 2 days after intervention were compared. Generalized linear model repeated measures procedure in which test beverages were considered as repeated factors. Energy intake from breakfast till lunch was lower when low-fat milk consumption was included in the breakfast compared with water and apple juice [adjusted mean +/- standard error: Low-fat milk = 1484.33 +/- 15.30 Kcal, apple juice = 1543.39 +/- 20.70 Kcal, water = 1606.6 +/- 19.94 Kcal; P < 0.05]. The energy intake on a day before interventions, total energy intake on intervention days, and 2 days after intervention was not statistically different between intervention periods [P > 0.05]. One serving of low-fat milk might affect the energy intake in a short-term period. The possible effect of frequent consumption of dairy products on long-term energy intake among children is needed to be examined