Relationship between different protein intake recommendations with muscle mass and muscle strength.

OBJECTIVE: The purpose of the present study was to examine the relationship between two different levels of protein intake (0.8 vs.1.2 g/kg body weight/day) with muscle mass and muscle strength. METHOD: Seventy-two postmenopausal women were recruited. Body composition (bioelectrical impedance analysis), muscle strength (dynamometer), energy metabolism (indirect calorimetry) and dietary intake (dietary journal) were measured. We divided the women into two groups. Women with a protein intake of ≥ 1.2 g/kg body weight/day were placed in the Protein ≥ 1.2 group (n = 35), whereas women with a protein intake of 0.8-1.19 g/kg body weight/day were categorized in the Protein 0.8-1.19 group (n = 32). RESULTS: No significant difference was observed between groups for age, height, skeletal muscle mass, resting energy expenditure, total energy expenditure, carbohydrate and lipid intake. Significant differences between groups were observed for body mass index (p < 0.001), fat mass (p < 0.001) and muscle strength (hand grip and knee extensors) (p < 0.001). More specifically, the Protein ≥ 1.2 group presented a higher muscle strength as well as a lower body mass index and fat mass compared to the Protein 0.8-1.19 group. In addition, the group with a protein intake of ≥ 1.2 g/kg body weight/day presented significantly higher energy intake (p = 0.002), and essential (p < 0.001) and non-essential (p < 0.001) amino acid intake. Interestingly, when muscle strength was adjusted for essential or non-essential amino acids, differences in muscle strength persisted. CONCLUSION: The present study indicates higher levels of muscle strength in postmenopausal women with a protein intake of ≥ 1.2 g/kg body weight/day compared to 0.8-1.19 g/kg body weight/day despite no differences in muscle mass.

Relationship between the Level of Education and Functional Capacity in Active Elderly Adults.

BACKGROUND: Both the level of education and functional capacity seems to be associated with the level of physical activity in the elderly. However, the relationship between the level of education and functional capacity in active elderly adults is poorly understood. OBJECTIVE: To examine the association between the level of education and the functional capacity profile of active elderly adults. DESIGN: Cross-sectional. PARTICIPANTS: One hundred and four elderly men and 198 postmenauposal women (mean age: 62.7 ± 7.6 years old) were recruited among registered members of the YMCAs of Montreal who practiced at least one hour of structured physical activity per week. Participants were then divided in two groups based on their level of education (the cut-off point was the high-school diploma). MEASUREMENTS: Body composition (DXA), muscle strength (knee extensors, handgrip), estimated maximal oxygen consumption (2-km walk test), perceived health (SF-36) and functional capacity (timed up and go, alternate step and one-leg stance tests) were measured. The level of education of the participants was assessed by questionnaire. RESULTS: Body composition was similar between groups. We observed that all functional capacity tests as well as the global functional capacity score were significantly higher in the most educated group compared to the least educated group (p<0.05). In addition, the most educated group had significantly higher levels of knee extensors strength, estimated maximal oxygen consumption and perception of physical functioning. CONCLUSIONS: A higher level of education was associated with a favourable functional capacity profile in our cohort of active elderly adults. However, the mechanism(s) which could mediate this association remain(s) unknown.

Relationship between protein intake and dynapenia in postmenopausal women.

OBJECTIVE: The purpose of this study was to investigate the relationship between protein intake and dynapenia. DESIGN: A cross-sectional/observational study. SETTING: Department of Kinanthropology at the University of Quebec at Montreal. PARTICIPANTS: Seventy-two non-frail postmenopausal women aged between 50 to 75 years were recruited. MEASUREMENTS: Body weight (BW), lean body mass (LBM; %) and skeletal muscle mass (bio-electrical impedancemetry analysis), maximum voluntary handgrip strength (using hand dynamometer), aerobic capacity (VO2peak) and dietary intake were measured. Women were divided according to dynapenia criteria. RESULTS: The strongest correlation between muscle strength and protein intake was observed when we express the amount of protein in g/d/BW. No differences for age, BMI, status of menopause, fat mass and VO2peak were observed between non-dynapenic, type I dynapenic and type II dynapenic women, independently of the criteria used. We observed significant differences in protein intake (g/d/BW) between non-dynapenic and type II dynapenic (p<0.01) as well as between type I dynapenic and type II dynapenic (p<0.01) when dynapenia was expressed in kg/BW and in kg/LBM, respectively. It should be noted that no differences in LBM between the three groups were observed when dynapenia was expressed in kg/BW and kg/LBM. Protein intake for all groups respected the RDA of 0.8 to 1.2 g/d/BW (non-dynapenic: 1.44/1.38; type I dynapenic: 1.30/1.33; type II dynapenic: 1.05/1.08 g/d/BW). CONCLUSIONS: Protein intake seems to play a role in the development of dynapenia particularly at the level of type II dynapenia. Therefore, an increase in the recommended daily allowance for protein intake may be warranted.

How to assess functional status: a new muscle quality index.

Aging is associated with decreases in muscle mass, muscle strength and muscle power, with muscle strength declining at a higher rate than muscle mass, but at a lower rate than muscle power. This progressive mismatch suggests a deterioration of muscle "quality" that may lead to functional incapacities. Although it may be difficult to synthesize the concept of muscle quality, the aim of the present paper was to propose a clinical definition of muscle quality in regard to the functional status. Accordingly, the muscle strength or muscle power per unit of muscle mass ratios appear to be clinically relevant markers of muscle quality. Several mechanisms susceptible to influence these ratios have been described, among which age, gender, sex hormones, obesity, physical activity and fibrosis. Various methods to assess muscle quality in both the clinical and research fields have also been listed, with a particular interest for the tests used to measure muscle power. Finally, we proposed a clinical screening tool to detect individuals at risk of functional incapacities. Briefly, the muscle quality score is based on handgrip strength assessment by hand dynamometer, muscle mass measurement by bioelectrical analysis, and leg muscle power estimation using a chair stand test.

ANALYSIS OF TWO POPULATIONS OF THE URUGUAYAN CANINE BREED CIMARRON (Canis familiaris) USING RAPD MARKERS / ANÁLISIS DE DOS POBLACIONES DE CANINOS (Canis familiaris) DE LA RAZA CIMARRÓN URUGUAYO UTILIZANDO RAPDs COMO MARCADORES MOLECULARES

Objective. To analyze the genetic variability in two populations of the native canine breed "Uruguayan Cimarron" from different areas of the country. Materials and methods. DNA was isolated from 40 animals of the Cimarron breed. Using PCR, 11 RAPD (random amplified polymorphism of DNA) molecular markers were analyzed. Results. 14.9% of loci were polymorphic. We found an index of shared bands of 0.91, a genetic distance of 0.16 and a Nei's average diversity index of 0.08. Conclusions. Both populations present a high homogeneity and genetic identity for these markers suggesting that they belong to a common genetic nucleus.

Objetivo. Analizar la variabilidad genética en dos poblaciones de caninos de la raza autóctona "Cimarrón uruguayo" provenientes de distintas zonas del País. Materiales y métodos. Se aisló ADN de 40 animales de la raza Cimarrón. Mediante la técnica de PCR se analizaron 11 marcadores moleculares RAPD (amplificación al azar de ADN polimórfico). Resultados. Se detectó un 14.9% de loci polimórficos. Se obtuvo un índice de bandas compartidas de 0.91, una distancia genética de 0.16 e índice promedio de diversidad de Nei's de 0.08. Conclusiones. Ambas poblaciones presentan una alta homogeneidad e identidad genética para estos marcadores y pertenecerían a un núcleo genético común.

Association of aromatase (CYP 19) gene variation with features of hyperandrogenism in two populations of young women.

BACKGROUND: Aromatase catalyses the conversion of androgens to estrogens and thus variation in the aromatase gene could contribute to female syndromes of androgen excess, such as precocious pubarche (PP) and polycystic ovarian syndrome (PCOS). METHODS: Two groups, one case-control containing girls from Barcelona, Spain with PP (n = 186) or healthy controls (n = 71), and the other a population study of young women from Oxford, UK, who volunteered for a study of normal women's health (n = 109), were genotyped at four aromatase gene haplotype-tag single nucleotide polymorphisms (SNP). Clinical features and hormone concentrations relevant to hyperandrogenism were compared across haplotypes or genotypes. RESULTS: Distributions of aromatase haplotypes (P < 0.0001) and aromatase SNP_50 genotype (P = 0.001) were significantly different between PP girls and Spanish controls. The AGGG haplotype was associated with an odds ratio (95% confidence interval) of 0.5 (0.3-0.9) (P = 0.005) for the presence of PP compared to GAGG. In 84 post-pubertal PP girls, aromatase haplotype was associated with functional ovarian hyperandrogenism (P < 0.05), independently of insulin sensitivity. In the Oxford population, SNP_50 was associated with variation in PCOS symptom score (P = 0.008) and circulating testosterone concentrations (P = 0.02). CONCLUSIONS: This study suggests that common variation at the aromatase gene (and not just rare loss-of-function mutations) is associated with androgen excess in girls and young women.