Magnesium, insulin resistance and body composition in healthy postmenopausal women

Objective: This study was conducted to determine the association between magnesium (Mg), body composition and insulin resistance in 136 sedentary postmenopausal women, 50 to 77 years of age. Methods: Diabetics, hypertensives and women on hormonal replacement therapy were excluded and the remaining 74 were divided according to BMI≥25 (obese: OG) and BMI<25 kg/m2 (non-obese: NOG). Nutritional data disclosed that intakes were high for protein and saturated fat, low for carbohydrates, polyunsaturated fat and Mg and normal for the other nutrients, according to recommended dietary allowances (RDA). Mg values in red blood cells (RBC-Mg) and plasma (P-Mg), were determined, as were fasting glucose, and insulin levels, Homeostasis Model Assessment (HOMA), body mass index (BMI), body fat percent (BF %), abdominal fat (AF) and free fat mass (FFM). Results: RBC-Mg values were low in both groups when compared with normal values. There were significant differences in body composition parameters, HOMA and insulin levels, with higher basal insulin levels in OG. RBC-Mg was directly correlated with insulin, HOMA and FFM in both groups, according to Pearson correlations. HOMA in OG was also directly correlated with BMI, FFM and AF. In NOG, HOMA was only correlated with FFM. The low RBC-Mg levels observed were probably due to low Mg intake and to deregulation of factors that control Mg homeostasis during menopause. Conclusions: Both Mg deficit and obesity may independently lead to a higher risk for insulin resistance and cardiovascular disease

Differences in the genotype frequencies of genes related to blood pressure regulation - a comparative study between South-West Europe and Peri-equatorial Africa

Background: Since the emergence of the genus Homo, hominids have occupied a wide variety of environments, facing different selective pressures. Objectives: The aim this study is to compare genotype frequencies between South-West Europe and Peri-equatorial Africa in genes potentially modulators of blood pressure. Methods: The analyzed sample consisted of 325 individuals from Portugal and 226 individuals from Africa (48 from Mo zambique and 178 from São Tomé and Príncipe). The following genetic variants were analyzed: intron 4 VNTR in eNOS, rs1050829 in G6PD, -3.7kb α-thalassemic deletion in HBA, rs1800457 in CYB5R3, Hp 1/2 genotype/phenotype in Hp and intron 16 I/D in ACE. Results: Frequencies of genotypes with the 4a allele in eNOS (p<0.001), the G allele in G6PD (p<0.001), the α-3.7 kb in HBA (p <0.001), the C allele in the CYB5R3 (p<0.001) were higher in Peri-equatorial Africa. The Hp 1.1 genotype of Hp has a higher frequency in Peri-equatorial Africa (p=0.002). ACE shows no significant differences. Conclusion: Results show differences in five genetic variants. Conditions of extreme heat and humidity, characteristic of Peri-equatorial Africa, have been associated with increased sodium loss. This study suggests that selected compensatory mechanisms printed in the genome, are nowadays risk factors for hypertension in Peri-equatorial Africa.Financial support - Instituto de Investigação Científica Bento da Rocha Cabralinfo:eu-repo/semantics/publishedVersio

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Comparison of immunohematological profile between endurance- and power-oriented elite athletes

There is general perception that elite athletes are highly susceptible to changes in immunohematological profile. The objective of this study was to compare immunohematological parameters of elite athletes of different aerobic and muscular strength sports and analyze changes over 2 months. Sixteen judoists and 14 swimmers were evaluated 2 months before (M1) and immediately prior to competition (M2). Hemogram and lymphocytes subpopulations were assessed with automatic counter and flow cytometry, respectively. Judoists had higher neutrophils and lower monocytes and eosinophils percentages than swimmers at M1 and M2. At M2 judoists had lower red blood cells (RBC), hemoglobin, and hematocrit than swimmers. At M2 judoists' hematocrit and CD16 decreased while swimmers' hemoglobin and hematocrit increased. In conclusion, neither sports characteristics nor intense training seem to displace the athletes' immunohematological profile out of the clinical range, despite the possibility of occurrence of microlesions that may stimulate production of leukocytes and reduction of RBC in judoists.Les athlètes d’élite seraient, selon l’impression générale, très prédisposés aux changements du profil immunohématologique. Cette étude a pour objectif de comparer les paramètres immunohématologiques d’athlètes d’élite de divers sports a` dominante aérobie et de force musculaire et d’analyser les changements en deux mois. On évalue 16 judokas et 14 nageurs 2 mois avant (M1) et immédiatement avant la compétition (M2). On évalue l’hémogramme et les sous-populations de lymphocytes par comptage automatique et cytométrie en flux, respectivement. À M1 et M2, les judokas présentent un plus haut pourcentage de neutrophiles et un plus faible pourcentage de monocytes et d’éosinophiles que les nageurs. À M2, les judokas ont moins de globules rouges, d’hémoglobine et un plus faible hématocrite que les nageurs. À M2, l’hématocrite et le nombre de CD16 des judokas diminuent alors que, chez les nageurs, l’hémoglobine et l’hématocrite augmentent. En conclusion, les caractéristiques du sport et l’entraînement intensif ne semblent pas déplacer le profil immunohématologique des athlètes a` l’écart des valeurs cliniques, et ce, malgré la possibilité de l’occurrence de microlésions pouvant stimuler la production de leucocytes et la diminution des globules rouges chez les judokas. [Traduit par la Rédaction]José P. Morgado and Catarina N. Matias were supported by the Portuguese Foundation for Science and Technology (SFRH/BD/48211/2008 and SFRH/BD/61520/2009, respectively).info:eu-repo/semantics/publishedVersio