The Link Between Plant-based Diet Indices With Biochemical Markers of Bone Turn Over, Inflammation and Insulin in Iranian Older Adults

Background: The association of plant base diets and biomarkers of bone, insulin, and inflammation is still unclear. Objectives: We investigated the associations between biomarkers of bone, insulin, and inflammation and three plant-based diet indices: an overall plant-based diet index (PDI); a healty plant-based diet index (hPDI); and an unhealthy plant-based diet index (uPDI).Methods: We included 178 elderly subjects who referred to health centers in Tehran. Blood and urine samples were collected to measure osteocalcin, The Human C-telopeptide of type Ⅰ collagen (u-CTX-I), highly sensitive C-reactive protein (hs-CRP) Parathyroid hormone (PTH), 25(OH) D and insulin resistance and sensitivity. We created an overall PDI, hPDI and uPDI from semi quantitative food-frequency questionnaire (FFQ) data. Results: Dietary groups of Vegetables (r=0.15, P=0.03), nuts (r=0.16, P=0.03), dairy (r=0.25, P=0.001), eggs (r=0.27, P<0.001), red meat and animal products (r=0.25, P=0.001) were directly correlated with osteocalcin. Refined grains were also had positive association with serum insulin concentration (r=0.14, P=0.04). PTH levels are inversely associated with PDI score (β=-0.18, P=0.01). Also serum insulin concentration was negatively associated with PDI score (β=-0.10, P=0.04). Urine CTX-1 levels was significantly associated with hPDI score (β=-0.06, P=0.04). u-CTX-1 levels are inversely associated with uPDI score. This significance did not change with the adjustment of the confounders (β=-0.28, P<0.001). Conclusions: more adherence to PDI and hPDI and less in uPDI may have beneficial effect on biomarkers of bone, inflammation, and insulin thus preserving chronic diseases.

The Effect of 8-Week Resistance Training and Leucine Supplementation on Protein Synthesis Among Elderly Men With Sarcopenia

Introduction: The aim of present study was to determine the effect of eight weeks resistance training and the supplementation of leucine on protein synthesis in the elderly men with sarcopenia. Methods: A total of 40 elderly men residing in the elderly nursing center were randomly chosen and divided into four groups including Resistance Training and Leucine Supplement (RTLS=10), Resistance Training (RT=10), Leucine Supplement (LS=10), and Control (C=10). Resistance training was performed 8 weeks with intensity training %35-70 of one repetition maximum (1RM) for 20-45 minutes. The group supplement consumed 3 grams of leucine amino acid in every meal. The serum insulin concentration, urine nitrogen, muscle mass, and muscle strength were measured one day before the protocol and 72 hours after the last training session. Ancova was analyzed within and between group changes. Bonferroni post hoc test was used to determine the difference between every two groups. Results: Results showed that Urine nitrogen and muscle mass levels increased significantly after 8 weeks of RT compared to the C group (p<0.05). Serum insulin concentration increased significantly in the RT group compared with the C group (p<0.05). There was a significant increase in muscle strength in the RT and S group compared to the C group (p<0.05). Conclusion: The results of this study revealed that the muscle protein synthesis increased after resistance training in skeletal muscle. This indicates that the rate of sarcopenia reduced as a result of resistance training. In addition, resistance training along with consuming leucine supplement was effective in improving muscle strength.

Interaction of Dietary Zinc and Vitamin A Influences the Zinc Deposition and some Enzymes` Activity in Broilers

576 broilers are experimented on with 6 × 2 (Zn × vitamin A) repetitive experiment in attempt to study the influence of different dietary zinc levels (40,80 ,120 ,160 ,200 and 320 mg/ kg) and dietary vitamin A levels (2700 and 8800 IU/ kg) on vitamin A metabolism, zinc concentration in liver and tibia, zinc apparent deposition rate, serum ALK activity, CuZn-SOD activity in liver and serum, and serum insulin concentration. Results showed that vitamin A concentration in serum increased with the increasing of zinc level in the diet, and that in livers decreased accordingly, which means that zinc can mobilize vitamin A of liver into serum. When dietary zinc level was 320 mg/kg, vitamin A concentration in serum, liver and kidney increased at the same time, perhaps higher dietary zinc level promoted vitamin A absorption except for mobilizing it into serum. Higher dietary vitamin A level (8800 IU/kg) increased zinc concentration in liver and tibia slightly. Zinc apparent deposition rate increased with the increasing of dietary zinc level within certain range and then decreased.；dietary Zinc level has a prominent influence on CuZn – SOD in serum when P < 0. 01; and the result also shows that dietary zinc level, vitamin A level and their interaction has a respectively prominent influence on ALK, serum insulin concentration is also apparently affected.

A threshold exists for the stimulatory effect of insulin on plasma l-carnitine clearance in humans

Maintaining hyperinsulinemia (∼160 mU/l) during steady-state hypercarnitinemia (∼550 μmol/l) increases skeletal muscle total carnitine (TC) content by ∼15% within 5 h. The aim of the present study was to further examine the relationship between serum insulin concentration and skeletal muscle carnitine accumulation by attempting to identify the serum insulin concentration at which this stimulatory effect of insulin on carnitine retention becomes apparent. On four randomized experimental visits, eight healthy men (body mass index 23.8 ± 0.9 kg/m2) underwent a 6-h euglycemic insulin clamp of 5, 30, 55, or 105 mU·m−2·min−1 accompanied by a 5-h iv infusion of l-carnitine (15 mg/kg bolus followed by 10 mg·kg−1·h−1). The clamps produced steady-state serum insulin concentrations of 10.1 ± 0.5, 48.8 ± 1.0, 88.9 ± 2.8, and 173.9 ± 6.5 mU/l, respectively. During l-carnitine infusion, plasma TC concentration remained above 450 μmol/l during all four visits. However, there was a significant treatment effect of insulin ( P < 0.001), such that by the end of infusion the plasma TC concentration in the 55- and 105-mU clamps was lower than that seen in the 5- ( P < 0.05 and P < 0.01, respectively) and 30-mU ( P < 0.01) clamps. The findings demonstrate that only high circulating serum insulin concentrations (≥90 mU/l) are capable of stimulating skeletal muscle carnitine accumulation. This is of relevance to athletes, and the treatment of obesity and type 2 diabetes, where increasing skeletal muscle carnitine content may be used as tool to modify skeletal muscle energy metabolism.