Tai chi diminishes oxidative stress in Mexican older adults.

OBJECTIVE: To determine the effect of Tai Chi on oxidative stress in a population of elderly Mexican subjects. DESIGN: It was carried out a quasi-experimental study with a sample of 55 healthy subjects randomly divided into two age-matched groups: (i) a control group with 23 subjects and (ii) an experimental group with 32 subjects. The experimental group received daily training in Tai Chi for 50 min. MEASUREMENTS: It was measured before and after 6-month of exercise period: thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), superoxide dismutase (SOD), and glutathione peroxidase (GPx). RESULTS: It was found that the experimental group exhibited a statistically significant decrease in glucose levels, total cholesterol, low-density lipoprotein cholesterol (LDLC), and systolic blood pressure, as well as an increase in SOD and GPx activity and TAS compared with the control group (p < 0.05). CONCLUSIONS: Our findings suggest that the daily practice of Tai Chi is useful for reducing OxS in healthy older adults.

Supplementation of ascorbic acid and alpha-tocopherol is useful to preventing bone loss linked to oxidative stress in elderly.

OBJECTIVE: To determine the effect of ascorbic acid and alpha-tocopherol on oxidative stress and bone mineral density (BMD) in elderly people. DESIGN: A double-blind, controlled clinical assay was carried out in a sample of 90 elderly subjects divided into three age-paired random groups with 30 subjects in each group. Group Tx0 received placebo, group Tx1 received 500 mg of ascorbic acid and 400 IU of alpha-tocopherol, whereas group Tx2 received 1,000 mg of ascorbic acid and 400 IU of alpha-tocopherol, for a 12-month period. MEASUREMENTS: We measured thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), superoxide dismutase (SOD), and glutation peroxidase (GPx); BMD was obtained on DXA of hip and spine before and after the 12-month treatment period with supplementation of vitamins C and E. RESULTS: We found a positive correlation between hip-BMD and SOD (r = 0.298, p < 0.05) and GPx (r = 0.214, p < 0.05). Also, a significantly lower decrease of LPO (p < 0.05) was observed as linked with hip bone loss in the Tx2 group than in the Tx0 group. CONCLUSIONS: Our findings suggest that that administration of 1,000 mg of ascorbic acid together with 400 IU of alpha-tocopherol could be useful in preventing or aiding in the treatment of age-related osteoporosis.

Effect of a self-care program on oxidative stress and cognitive function in an older Mexican urban-dwelling population.

OBJECTIVE: To determine the effect of a self-care program on oxidative stress (OxS) and cognitive function in an older, Mexican, urban-dwelling population. DESIGN: A longitudinal and pre-experimental study was carried out in a sample of 79 older healthy, urban-dwelling individuals residing in Mexico City, (62 females and 17 males), of which 71 of them (59 women and 12 males) complied with the entire self-care program. MEASUREMENTS: We measured OxS, cognitive function, the Nagi Disability Scale of physical task functioning, and Instrumental Activities of Daily Living (IADL) prior to and after 2 years of intervention with an active aging program. RESULTS: All older persons adopted healthy, self-care-based lifestyles according to the active aging program to which they were trained, which was associated with a statistically significant improvement of OxS and cognitive function markers on comparing pre- and post-community intervention data. CONCLUSIONS: Our findings suggest that self-care-based healthy lifestyles programs can improve the oxidative stress and cognitive function in urban-dwelling elderly population.

Influence of the placebo effect on oxidative stress in healthy older adults of Mexico City.

BACKGROUND: The placebo effect has been widely recognized in the randomized clinical trials; nevertheless, this effect has not been evaluated in terms of antioxidant therapy on oxidative stress (OxS). OBJECTIVE: The objective of this study was to determine the influence of the placebo effect on OxS in healthy older adults of Mexico City. METHODS: We carried out a double-blind controlled clinical assay with the participation of 75 healthy older adults residents for the past 10 years of Mexico City; randomly distributed into three groups of 25 subjects each after previous informed consent; control group not received any treatment, placebo group received a placebo with a pharmaceutical presentation similar to that of the treatment, whereas treatment group were administered 1000 mg of ascorbic acid and 400 IU of alpha-tocopherol. All subjects ingested the treatment daily according to study group for 12 months. We measured before and after 12 months of treatment, lipoperoxides levels (LPO), erythrocyte superoxide dismutase, glutathione peroxidase and total plasma antioxidant status with Randox Laboratories Ltd kits. The concentration of ascorbic acid and alpha-tocopherol were measured using high-performance liquid chromatography. RESULTS: The placebo group subjects showed a statistically significant decrease in LPO concentration, in the same way as the treatment group subjects (P < 0.01), both in comparison with a control group. CONCLUSION: Our findings suggest that the placebo has a significant effect on OxS.

Total antioxidant levels, gender, and age as risk factors for DNA damage in lymphocytes of the elderly.

During past years, the association of oxidative stress with DNA damage and its possible clinical translation into chronic degenerative illnesses, such as atherosclerosis, cancer, diabetes mellitus and Alzheimer's disease, has been demonstrated. In addition, it has been pointed out that age and gender are factors that influence the generation of DNA damage; however, this is still controversial. We have previously reported the results of a study of 88 subjects older than 60 years of age in whom DNA damage is related with serum levels of total antioxidants. The results of this study demonstrate a greater frequency of DNA damage in elderly persons with normal levels of antioxidants, in addition to males, and in the younger group of subjects, i.e., 60-69 years. In this work, we enlarged our study sample to 160 elderly subjects; in this way, we were able to evaluate the consistency of the influence of total antioxidants, age, and gender on the magnitude and grade of DNA damage in lymphocytes of the elderly. The results demonstrated that 45% of the subjects showed DNA damage, measured by an alkaline unicellular electrophoresis technique (comet assay). Similarly, 62% of the subjects presented low levels of total antioxidant levels measured by a colorimetric method (Randox Kit). A greater percentage of DNA damage was observed in subjects with normal levels of antioxidants (48%) compared with subjects with low levels (43%), although the difference was not statistically significant. The group of subjects 70 years of age or older showed a greater percentage of DNA damage (50%) than the group of subjects of 60-69 years of age (41%). However, the difference was again not statistically significant (P>0.05). With respect to gender, 64% of males and 38% of females had DNA damage with an odds ratio (OR) of 2.86 and a 95% confidence interval (CI) of 1.31-6.32 (P<0.05). In the logistic regression analysis, the interaction of the male sex variables with low antioxidants had an OR of 2.5 (CI 95%, 1.33-4.68; P<0.01). We conclude that the interaction of male sex factors-low levels of antioxidants would justify the indication of antioxidant dietetic supplements.

Serum leptin levels and blood pressure in the overweight elderly.

BACKGROUND: Leptin is a protein produced by adipocytes that reduces reflex appetite by blocking the Y neuropeptide, thus causing body weight loss. A large percentage of elderly people are reported to exhibit obesity, which may be caused by low leptin serum levels. However, hypertension is a highly prevalent condition in old age. Obesity under these circumstances is an added risk factor due to the presence and severity of hypertension and thus can be related with leptin serum levels. Our objective was to determine the relationship between leptin serum levels and hypertension in obese elderly persons. METHODS: A comparative transverse study was done in a random sample of 61 elderly persons-36 obese and 25 non-obese. Their blood pressure and their leptin serum levels by RIA were measured. RESULTS: Leptin serum levels showed a statistically significant difference (p <0.05) in elderly obese individuals (12.8 +/- 4.4 microg/L vs. 9.8 +/- 4.2 microg/L). Likewise, 45% of obese elderly individuals and 20% of the non-obese were hypertensive with a predominant elevation of the systolic pressure. CONCLUSIONS: The higher serum leptin levels in obese elderly individuals suggests that aging is associated with resistance to leptin and/or to a decrease of receptors for this hormone. The high incidence of hypertension during the aging process is the result of associated obesity (OR = 3.2, CI 0.88-13.14).

DNA damage in lymphocytes of elderly patients in relation with total antioxidant levels.

DNA damage may occur as a result of an imbalance between the production and removal of free radicals, a process in which age plays an outstanding role. The purpose of this study was to analyze the relationship between total antioxidants and DNA damage in a sample of old age people in Mexico City. The sample included a total of 88 subjects, 15 males and 69 females, with a mean age of 65.5 years old (range between 60 and 79 years old), all of whom had lived in Mexico City during the last 10 years and had been diagnosed as clinically healthy. Results showed that 52% of the subjects presented DNA damage in peripheral blood lymphocytes which was assessed through an alkaline unicellular electrophoresis procedure (Comet Test), regardless of total antioxidant serum levels quantified through a colorimetric method (Randox Kit). Higher non-damage occurrences were observed in subjects with low antioxidant levels, a difference that was statistically significant (P < 0.05). Furthermore, the highest incidence of damaged cells was observed in subjects belonging to the 70-years-old-and-above group (P < 0.05). As to the magnitude and intensity of the damage associated to total antioxidant concentrations, a trend toward greater DNA damage in subjects with low serum levels was observed. It is concluded that low antioxidant levels are not always indicative of oxidative strain and therefore should not be considered as predictors of DNA damage in this population.

[Model of a program of clinical investigation at the first level of medical care]. / Modelo de un programa de investigación clínica en el primer nivel de atención médica.

A major commitment of educational institutions in the health field is to train professionals capable of meeting the needs of society. In order to achieve this goal it is necessary to develop research programs related to field service and thoroughly integrated to the teaching-learning process. In this regard, we propose a model for the implementation and development of a clinical research program for the primary level of health care. This model can be adapted or modified according to the particular needs of the community, leading to the establishment of a dynamic and continuous system based on feedback obtained from scientific data. On the other hand, it assures the delivery of high quality health care services to the community.