Biomedical subjects

S Berthouze

Publications and source records attributed to S Berthouze.

3 recordsLinked to original sources

PubMed2002

[Relation between physical activity, muscle function and IGF-1, testosterone and DHEAS concentrations in the elderly].

OBJECTIVE: Lower amounts of circulating anabolic hormones are thought to accelerate the age related decline in muscle mass and function. Replacement therapies are promising interventions but there are problems with these therapies. Thus alternative strategies should be developed. The age related changes in hormonal status may be probably influenced by exercise. The purpose of this study was: a) to confirm with other methods, more adapted for elderly people, the results of a previous study that has shown relationship between physical activity (PA) and quadriceps muscle function with dehydroepiandrosterone sulphate (DHEAS), insulin like growth factor-1 (IGF-1). Quadriceps muscle power (Pmax) is measured in this new work with a recently developed leg extensor machine and, b) to complete the results of the first study examining simultaneously the relationship between PA, Pmax and cardiorespiratory fitness (VO2max) with DHEAS, IGF-1 and testosterone in a group of healthy elderly people. METHODS: Fifty independent, community dwelling elderly subjects (25 mens and 25 womens) aged from 66 to 84 volunteered to participate in the study. PA was evaluated by the questionnaire and expressed using two activity indices: mean habitual daily energy expenditure (MHDEE) and the daily energy expenditure corresponding to leisure time sports activities (Sports Activity). Pmax and optimal shortening velocity (vopt) were measured on a Ergopower dynamometer. The Pmax was expressed relative to body mass, Pmax/kg (W kg-1), and relative to the mass of the two quadriceps muscles, Pmax/Quadr (W.kgQuadr-1). VO2max has been measured during a maximal treadmill exercise. RESULTS: In women, IGF-1 correlated significantly with MHDEE (r = 0.54, P = 0.004), Pmax/kg (r = 0.54, P = 0.004) and Pmax/Quadr (r = 0.46, P = 0.02), whereas DHEAS with MHDEE (r = 0.54, P = 0.004), Sports Activity (r = 0.65, P < 0.001), VO2max (r = 0.46, P = 0.02), Pmax/kg (r = 0.46, P = 0.02) and Pmax/Quadr (r = 0.55, P = 0.004). No such correlation was found in men. CONCLUSION: These findings confirm that in healthy elderly women physical activity, cardiorespiratory fitness and quadriceps muscle function are similarly related to levels of circulating DHEAS and IGF-1 suggesting a favourable influence of exercise on anabolic hormonal production in the elderly.

Aged↗

PubMed1998

Nutritional status and physical fitness of elderly sportsmen.

The nutritional status of elderly sportsmen has not been reported on, neither has the nutritional balance nor the precise relationship between nutritional status and physical fitness been detailed for this population. Thus, group of 18 sportsmen [age 63 (SD 4.5) years] was monitored by weighing their food during a 6-day period. Macro nutrient, mineral and vitamin content was derived from tables. Daily energy expenditure (DEE) and sport activity (DSA) were quantified over a 7-day period using a questionnaire. Physical fitness was assessed by maximal oxygen uptake (VO2max) measurements. The DEE was 11429 (SD 1890) kJ x day(-1). The DSA corresponded to 38% of DEE and VO2max to 35.9 (SD 6.1) ml x min(-1) x kg(-1). When compared with French recommended dietary allowances (RDA) intakes were higher for energy (+ 24%), macro nutrients, and most minerals and vitamins. Despite high energy intakes, some subjects had mineral and vitamin deficits. Energy intakes were significantly related to intakes of magnesium, phosphorus, iron, vitamins B2, B6, C and to VO2max, but not to age. Stepwise regressions indicated that vitamin C intake was the only determinant to have a relationship with VO2max. Thus, most elderly sportsmen had higher nutritional status than RDA, although some had mineral and vitamin deficits. It is therefore suggested that elderly sportsmen should be encouraged to consume food with higher mineral and vitamin contents.

Aged↗

PubMed1992

A comparative study of the muscle strength and mass of the arm flexors and extensors in paraplegic and in non paraplegic basketball players.

OBJECTIVES: to study the changes in the strength of the elbow flexors and extensors in paraplegic subjects, and the agonist/antagonist mass and strength ratio in paraplegic wheelchair users. METHOD: 10 paraplegic wheelchair basketball players were compared with 10 healthy basketball players. The 20 subjects underwent a clinical and dynamometric isokinetic assessment, and a CT scan measurement of the muscle cross-sectional surface area of the flexor and extensor muscles of the elbows. RESULTS: there was an increase in muscle strength in paraplegic subjects. There was no significant difference in the agonist/antagonist ratio between the dominant and non dominant upper limb in paraplegics whereas such a difference was found in healthy subjects. The muscle mass was increased in the paraplegics, but a correlation between muscle mass and strength was only found in the healthy subjects.

Adult↗