Lifestyle intervention might easily improve blood pressure in hypertensive men with the C genotype of angiotensin II type 2 receptor gene

BACKGROUND/OBJECTIVES: Recent studies have reported an association of the angiotensin II type 2 receptor (AT2R) 3123Cytosine/Adenine (3123C/A) polymorphism with essential hypertension and cardiovascular diseases. The purpose of the study was to investigate whether the AT2R 3123C/A polymorphism affects blood pressure for free-living hypertensive men during a 5-month intervention period. SUBJECTS/METHODS: The subjects were free-living hypertensive Japanese men aged 40 to 75 years who agreed to intervention in the period from 2004 to 2011. Detection of the AT2R 3123C/A polymorphism was determined by polymerase chain reaction. The dietary intervention was designed to decrease salt level and to increase potassium level through cooking instructions and self-monitoring of the diet. The exercise session consisted of activities such as stretching, resistance training, and walking. Blood pressure, urinary sodium and potassium excretion, dietary and lifestyle data, and non-fasting venous blood sample were collected at baseline and after the intervention period. RESULTS: Thirty nine subjects were eligible for participation and the follow-up rate was 97.4%. The C allele proportion was 57.9%. AT2R 3123C/A polymorphism was X-chromosome-linked, therefore we analyzed the C and A genotypes. At baseline, no significant differences were observed between the genotype groups. After the intervention, there were no significant differences in lifestyle habit between the groups. Nevertheless, the estimated salt excretion (g/day) was significantly decreased only in the C genotype (13.0-10.3, P = 0.031). No significant change was observed in systolic blood pressure (SBP) (mmHg) in the A genotype, but a significant decrease was observed in the C genotype (150.0-141.5, P = 0.024). CONCLUSTIONS: In the C genotype, it might be easy to improve SBP through lifestyle intervention in free-living hypertensive Japanese men, however generalization could not be achieved by the small sample size.

Possibility of the novel myokine SPARC: A mechanistic approach to colon cancer prevention by physical exercise / 体力科学

Growing evidence has shown that skeletal muscle secretes several bioactive proteins from the cell into extracellular fluid. The secretion of several proteins, whose levels increase in response to exercise, can regulate the functions of several organs via autocrine, paracrine, and endocrine actions, and mediate exercise-induced benefits such as metabolic improvement, anti-inflammation, and muscle building; this is known as the myokine theory. These secretory proteins may be biomarkers that reflect muscular function and beneficial adaptation achieved by exercise training, and could estimate adequate condition of exercise to obtain its beneficial effects. Recently, we found a novel myokine, secreted protein acidic and rich in cysteine (SPARC), a secreted matricellular glycoprotein. In a colon cancer mouse model, regular exercise reduced the formation of the precursor lesions of colon adenocarcinoma in wild-type mice but not SPARC-null mice. Furthermore, regular exercise enhanced apoptosis in colon mucosal cells and increased the cleaved form of caspase in wild-type mice but not SPARC-null mice. The muscle-secreted protein SPARC can support underlying mechanisms of epidemiological studies that suggest that regular exercise prevents the incidence of colon cancer.