Roxana Valdés-Ramos

The effect of exercise on cardiovascular risk markers in Mexican school-aged children: comparison between two structured group routines

OBJECTIVE To assess the effects of two groups of exercise routines on cardiovascular disease risk markers. MATERIAL AND METHODS An intervention study was conducted with 319 Mexican school-aged children in which routines were implemented Monday through Friday for 12 weeks. Routine A was the reference group, with 20 min of less intense activity and routine B was the new group with 40 min of aerobic exercises. Body mass index (BMI), waist circumference, fat mass percentage (FM%), systolic and diastolic blood pressure, lipids, lipoproteins, glucose and insulin were measured before and after the intervention. RESULTS Routine A had an effect on diastolic pressure, while routine B had an effect on BMI, FM%, blood pressure and triglycerides. Routine B had a greater effect on blood pressure than routine A. The prevalence of obesity, high blood pressure and hypertriglyceridemia decreased in both groups. CONCLUSION Aerobic exercise is an effective health promotion strategy to reduce some cardiovascular disease risk markers.

Type 2 diabetes, PUFAs, and vitamin D: their relation to inflammation.

Chronic diseases have become one of the most important public health problems, due to their high costs for treatment and prevention. Until now, researchers have considered that the etiology of Type 2 diabetes mellitus (T2DM) is multifactorial. Recently, the study of the innate immune system has offered an explanation model of the pathogenesis of T2DM. On the other hand, there is evidence about the beneficial effect of polyunsaturated fatty acids (PUFA) n-3 and n-6 in patients with chronic inflammatory diseases including diabetes. Furthermore, high vitamin D plasmatic concentrations have been associated with the best performance of pancreatic β cells and the improving of this disease. In conclusion, certain fatty acids in the adequate proportion as well as 25-hydroxivitamin D can modulate the inflammatory response in diabetic people, modifying the evolution of this disease.

Activated Umbilical Cord Blood Cells from Pre-term and Term Neonates Express CD69 and Synthesize IL-2 but Are Unable to Produce IFN-γ

BACKGROUND The immune response exhibits quantitative and qualitative differences throughout human development. Both phenotypical and functional immaturity of newborn immune cellular components have been reported. We aimed to analyze possible differences in cellular activation assessed by expression of surface CD69 and cytokine production in mononuclear peripheral blood cells from premature (<37) and term (>37 weeks of gestation) neonates compared to adult donors. METHODS Ten persons from each group were selected; none was infected, immunodepressed, under medical treatment, or had any congenital abnormalities. Blood was obtained from umbilical cord of term and pre-term donors and vein punction of adults. All samples were collected in heparin and subsequently activated with PHA-L or PMA plus ionomycin at 37 degrees C for 4 h. After incubation, cells were labeled to determine CD69 expression on CD3+CD4+, CD3+CD8+, CD19+, and CD16+56+ subpopulations. Intracellular staining was performed to analyze IFN-gamma, IL-2, and CD69 in CD3+ cells. After staining, cells were analyzed by flow cytometry. RESULTS We first found a substantially higher number of CD3+CD4+CD69+ cells in premature and term neonates than in adults. Secondly, percentage of CD3+CD8+, CD56+, and CD19+ cells expressing CD69 was similar among the three groups. Thirdly, expression of CD69 was higher in CD19+ cells than in CD16+56+ cells of all three groups. Regarding cytokine production, IFN-gamma was detected only in cells from adults and was consistent in all individuals analyzed. In sharp contrast, IL-2 and intracellular CD69 (iCD69) were detected in all three groups, with no significant differences among them. Induction of IL-2 and iCD69 showed that lack of response with IFN-gamma was restricted to pre-term and newborn populations. CONCLUSIONS In summary, our results showed that a) CD69 is an early activation marker of both mononuclear umbilical cord and peripheral blood cells activated by a mitogenic stimulus, and b) newborn CD3+ cells probably lack conditions required to progress through the activation process that leads to IFN-gamma production. These conditions are still unknown but certainly constitute an interesting issue for further studies.

Diet, exercise and gut mucosal immunity.

Diet and exercise are primary strategies recommended for the control of the obesity epidemic. Considerable attention is being paid to the effect of both on the immune system. However, little research has been done on the effect of diet, nutrients or exercise on the mucosal immune system. The gastrointestinal tract (gut) is not only responsible for the entry of nutrients into the organism, but also for triggering the primary immune response to orally ingested antigens. The gut-associated lymphoid tissue contains a large amount of immune cells, disseminated all along the intestine in Peyers patches and lamina propria. Specific nutrients or their combinations, as well as the microflora, are capable of modulating the immune system through cell activation, production of signalling molecules or gene expression. We have observed an increase in T-cells as well as a decrease in B-cells from Peyers patches, induced by diets high in fats or carbohydrates in Balb/c mice. It has also been demonstrated that exercise modulates the immune system, where moderate levels may improve its function by increasing the proliferation of lymphocytes from various sites, including gut-associated lymphoid tissue, whereas exhaustive acute exercise may cause immunosuppression. High-fat diets combined with exercise are able to induce an increase in CD3+ lymphocytes due to increased CD8+ cells and a decrease in B-cells. Explanations and consequences of the effects of diet and exercise on the gut mucosal immunity are still being explored.

Evaluating concordance with the 1997 World Cancer Research Fund/American Institute of Cancer Research cancer prevention guidelines: challenges for the research community

Diet, nutritional status and lifestyle practices are significant determinants of the risk of certain cancers. In 1997 The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) developed a series of evidence-based recommendations to help reduce the population and individual risk of cancer. However, guidance for evaluating concordance or compliance with these recommendations is limited. To illustrate the challenges in evaluation, four publications were reviewed that explored the task of creating operative criteria from which to assess concordance with the tenets of the WCRF/AICR recommendations. Three documents dealt with secondary analysis, whereas one was a prospective inquiry, with procedures and instruments designed to obtain responses to WCRF/AICR cancer-prevention specification. One considered only population-goal criteria, and two dealt implicitly or explicitly with criteria at both population and individual levels. The assessment approaches used by the authors were compared with alternative semantic and conceptual interpretations of the WCRF/AICR population goals and individual guidelines. Attempts to develop operative criteria for assessment of concordance (reflecting either a more superficial or more in-depth parsing of recommendations) have been inconsistent. The results indicate that the language of the WCRF/AICR leaves a certain degree of semantic ambiguity for evaluation purposes. Future design of prospective studies for analyses of behaviours and relevant exposures (including those reported in the 2007 WCRF/AICR report) should carefully consider evaluation criteria and fully document detailed methodology.

Iron zinc and vitamin C nutritional status is not related to weight gain in pregnant women.

Abstract To evaluate if the pregestational body mass index (BMI) and weight gain during pregnancy permits the identification of cases with high risk of developing specific nutrient deficiencies (iron, zinc, vitamin C), a follow-up study was done on a group of apparently healthy pregnant women, evaluated at weeks 16, 24 and 34. Pregestational weight was recalled by the women, while gestational weight and height were measured. Hemoglobin, leukocyte vitamin C and serum zinc and ferritin were determined from venous blood samples. The sample was divided for analysis according to BMI and gestational weight gain. A total of 82 women was evaluated. All women showing hemoglobin ≤ 125 g/L were supplemented with ferrous sulfate. Hemoglobin and zinc concentrations remained relatively constant during the whole period, while ferritin and vitamin C tended to decrease. Weight gain during pregnancy tended to compensate for pregestational weight, with no significant differences. The prevalence of nutrition deficiencies was between 60–90% for hemoglobin and ferritin, 15–35% for zinc and 64–88% for vitamin C. The classification according to pregestational BMI and weight gain during pregnancy did not discriminate between those women with low or high concentrations of any of the nutrients evaluated. The results of the present study suggest that a biochemical evaluation of nutritional status should be done systematically during pregnancy to detect specific nutrient deficiencies according to prevalence of specific deficiencies in the studied population, as pregestational BMI and weight gain during pregnancy lack the sensitivity to detect the risk for some of these deficiencies.

Effect of n-3 Polyunsaturated Fatty Acid Supplementation on Metabolic and Inflammatory Biomarkers in Type 2 Diabetes Mellitus Patients

Background: Type 2 diabetes mellitus (T2DM) is accompanied by chronic low-grade inflammation, with an imbalance in the secretion of adipokines and, worsening insulin resistance. Supplementation with n-3 PUFA in T2DM decreases inflammatory markers, the purpose of the study was to investigate the effect of n-3 PUFA supplementation on adipokines, metabolic control, and lipid profile in T2DM Mexican adults. Methods: In a randomized, single-blind, placebo-controlled pilot study, 54 patients with T2DM received 520 mg of DHA + EPA-enriched fish-oil (FOG) or a placebo (PG) daily. Baseline and 24-week anthropometric and biochemical measurements included glucose, insulin, glycosylated hemoglobin (Hb1Ac), leptin, adiponectin, resistin, and lipid profile; n-3 PUFA intake was calculated in g/day. Results: Waist circumference and blood glucose showed significant reductions in the FOG group (p = 0.001 and p = 0.011, respectively). Hb1Ac (p = 0.009 and p = 0.004), leptin (p < 0.000 and p < 0.000), and leptin/adiponectin ratio (p < 0.000 and p < 0.000) decreased significantly in both groups after 24 weeks (FOG and PG respectively). Serum resistin (FOG p < 0.000 and PG p = 0.001), insulin (FOG p < 0.000 and PG p < 0.000), and HOMA-IR (FOG p = 0.000 and PG p < 0.000) increased significantly in both groups. FOG had an overall improvement in the lipid profile with a significant decrease in triacylgycerols (p = 0.002) and atherogenic index (p = 0.031); in contrast, the PG group had increased total cholesterol (p < 0.000), non-HDL cholesterol (p < 0.000), and atherogenic index (p = 0.017). Conclusions: We found a beneficial effect of n-3 PUFA supplementation on waist circumference, glucose, Hb1Ac, leptin, leptin/adiponectin ratio, and lipid profile, without significant changes in adiponectin, and increases in resistin, insulin, and HOMA-IR in both groups.

Concordance with dietary and lifestyle population goals for cancer prevention in Dutch, Scottish, Mexican, and Guatemalan population samples

OBJECTIVES We assessed concordance with selected population goal components of the 1997 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) diet and lifestyle recommendations to decrease cancer risk across four population samples. METHODS This was a prospectively designed survey examining concordance with the population goals of the WCRF/AICR recommendations using target criteria across sites. Population samples were from the Netherlands, Scotland, Mexico, and Guatemala. A total of 3564 men and women aged 18 to 70 y were recruited in equal proportions by site and gender. RESULTS None of the four pooled samples met the target population average criteria for body mass index or refined sugar intake. The Guatemalan sample had concordance with the largest number of recommended cancer-prevention goals (10 of 12 selected WCRF/AICR components). Successively, Mexican, Scottish, and Dutch samples were concordant with seven, four, and three selected components, respectively. CONCLUSIONS A prospectively designed research instrument and exhaustive prior examination of operative criteria allow for the assessment of group-level concordance with cancer-prevention goals. To the extent that the study samples reflect the respective national situations, geographic variance in concordance exists, with conditions and behaviors in Guatemala bringing that nation into more general compliance with the 1997 WCRF/AICR goals.

Retinol sérico en mujeres mexicanas urbanas durante el periodo perinatal

Objective. To establish the prevalence of vitamin A deficiency during pregnancy and lactation in a group of urban Mexican women. Material and methods. A group of pregnant women who attended a prenatal care program were invited to participate. Subjects had no added pathologies and were less than 20 weeks pregnant. Evaluations were performed 3 times during pregnancy until 24 weeks postpartum. Vitamin A levels were determined in serum by high performance liquid chromatography (HPLC). The cut-off point to consider retinol deficiency was < 1.05 μmol/L. Results. During the 3 gestational evaluations, vitamin A levels were 2.34±0.70, 2.41±1.03 and 1.86±0.66 μmol/L, respectively, which shows a significant decrease. However, only 1/30 was situated below the accepted cut-off point to consider risk of deficiency, and none for deficiency. During post-partum , concentrations remained relatively constant, approximately 2.10 μmol/L. Lactation had no impact on serum retinol levels, while weight loss did. Conclusions. No cases of vitamin A deficiency were found in the studied population during the perinatal period. Maternal weight loss affects post-partum retinol levels.

Cord blood retinol and retinol-binding protein in preterm and term neonates

Abstract Vitamin A deficiency causes abnormalities in cellular replication, affecting the functional and structural integrity of epithelial cells. Based on the fact that vitamin A is transferred to the fetus in the last trimester of pregnancy, and the preterm baby may have low concentrations of this nutrient, we decided to study two groups of newborns during a six month period, evaluating their serum retinol and retinol-binding protein concentrations from cord blood samples. Group I consisted of 41 neonates with gestational age ≥ 37 weeks and group II of 58 newborns with gestational age at birth ≤ 36.6 weeks. Results showed suboptimal concentrations of retinol in the preterm group (