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Objective: To investigate the relationship of muscle mass and muscle function with age.Methods and Study Design: The study including 415 participants (aged 60-99 years). Upper (UMM) and lower (LMM) limbs muscle mass and whole body fat free mass (FFM) were measured by bioelectrical impedance analysis. The appendicular skeletal muscle mass (ASM) index (ASM/height2) was calculated. Muscle function was assessed by measuring hand grip strength (HGS) and gait speed.Results: Using ASM index cutoff values we found that higher prevalence of sarcopenia in women than in men (33.5% vs 23.6%, p=0.025). In the upper limb, HGS (β=-0.809) declined more rapidly with age than did UMM (β=-0.592) in men, but not in women (β=-0.389 and β=-0.486 respectively). In the lower limb, gait speed declined more rapidly than LMM in both men (β=-0.683 vs β=-0.442) and women (β=-1.00 vs β=-0.461). The variance of UMM explained 28-29% of the variance of HGS, and LMM explained 7-8% of the variance of gait speed in women and men respectively. In addition to the common predictors (BMI and age), the specific predictors were smoking, exercise and education for FFM and ASM, and smoking, drinking and exercise for HGS (p<0.05).Conclusions: Loss of muscle function is greater than the decline of muscle mass particularly in the upper limbs in men. However, women are more prone to have low muscle mass than the men. Exercise programs need to be designed gender specifically. [ABSTRACT FROM AUTHOR]

The lifelong exposure of antigens and stressors results in chronic oxidative stress situation in the organism. The free radicals and reactive oxygen species (ROS) with high reactivity produced by our cells under oxidative stress will cause oxidative damage in biomolecules. The oxidative damage leads to the releases of both damage-associated-molecular patterns (DAMPs) and intracellular cytokines. DAMPs activate pathogen recognition receptors (PRRs) and non-PRRs. Intracellular cytokines activate signalling pathways downstream of PRRs. Activation of these receptors results in the upregulation of cytokines and chemokines, which are released to recruit and activate additional inflammatory cells and cause the systemic and chronic sterile inflammation. The regulatory system, especially immune systems play an important role in homeostasis maintenance in the organism. The cells of immune systems are very vulnerable to oxidative damage. Once the homeostasis is destroyed, an imbalance between inflammatory and anti-inflammatory networks will occur. Genetic factor also is an important factor of oxi-inflamm-aging and age-related diseases. Many genes are involved in oxidative stress, inflammation process, and the genomic variations within most of these genes might produce different effects on oxi-inflamm-aging. The polymorphism of ApoE genes can affect the antioxidant and immunomodulatory/anti-inflammatory properties of the organism. ApoE genotype-phenotype is associated with the progress and prognosis of oxi-inflamm-aging, age-related diseases as well. Anti-inflammation together with regulation of the expression of ApoE might be an efficient method against oxi-inflamm-aging. Based on our previous studies, the progresses in these areas are reviewed.

Nonhuman primate rhesus monkey is a ideal model for human aging and aging intervention. Same with human aging, rehesus monkey demonstrates age-related aging and diseases in endocrine, neural, immune and cardiovascular system. Coloric restriction can slow down the primary and secondry aging efficently. The mechanism may be to suppress the oxidative stress-inflammaging-DNA damage by mediating the nutrient sensitive metablic signal pathways, and activate damaged DNA repair. However, the differeces of study design, husbandry and diet composition may differently affect CR against the the primary and secondry effects in a long-lived nonhuman primate. Optimization in protocol design, control of the experimetal variables, and shortening the experimental period will be advantageous to understand the mechanistic questions about the anti-aging effects of CR.