title: Muscle strength in obese elderly women: effect of recreational physical activity in a cross-sectional study.
abstract: BACKGROUND
  Muscle strength (MS) may be impaired in obese persons, and this impairment may be a consequence of both obesity and low physical fitness.
  
  
  OBJECTIVE
  We investigated whether MS differed between obese [body mass index (BMI; in kg/m2 > 29], normal-weight (BMI = 24-29), and lean (BMI < 24) elderly subjects and compared the MS of sedentary and active subjects according to their BMI group.
  
  
  METHODS
  The study included 215 obese [ (+/- SD) age: 80.0 +/- 3.5 y; BMI: 31.9 +/- 2.6], 630 normal-weight (age: 80.2 +/- 3.7 y; BMI: 26.3 +/- 1.4), and 598 lean (age: 80.7 +/- 3.5 y; BMI: 21.6 +/- 1.8) women with good functional ability. A cross-sectional design was used. Anthropometric measures (weight, height); measures of appendicular skeletal muscle mass (by dual-energy X-ray absorptiometry), isometric knee and elbow extension (by statergometer), and isometric handgrip strength (by dynamometer); and data on health status and self-reported recreational physical activity (RPA: walking, gymnastics, cycling, swimming, gardening) were collected.
  
  
  RESULTS
  Absolute (unadjusted) MS was higher in obese than in lean women (P < 0.01), except for handgrip strength (P > 0.05). When adjusted for age, height, RPA, pain, depression, and appendicular skeletal muscle mass, MS did not differ significantly between obese, normal-weight, and lean subjects, except for knee extension (significant interaction effect with RPA; P = 0.01). With increasing BMI, lower limb strength did not change in the sedentary women but increased in active (> or = 1 h/wk in > or = 1 RPA for > or = 1 mo) women. All adjusted MS measures in active participants were significantly higher (P < 0.001) than those in their sedentary peers.
  
  
  CONCLUSIONS
  The adjusted MS of elderly women is not associated with obesity but is higher in active subjects than in sedentary ones, especially in the lower limbs of obese subjects.
authors.affiliation: Service de Médecine Interne et de Gérontologie Clinique, Hôpital La Grave-Casselardit, Toulouse, France. yves.rolland@9online.fr
authors.forename: Yves
authors.initials: Y
authors.lastname: Rolland
authors.forename: Valérie
authors.initials: V
authors.lastname: Lauwers-Cances
authors.forename: Marco
authors.initials: M
authors.lastname: Pahor
authors.forename: Judith
authors.initials: J
authors.lastname: Fillaux
authors.forename: Hélène
authors.initials: H
authors.lastname: Grandjean
authors.forename: Bruno
authors.initials: B
authors.lastname: Vellas
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D005602:France; D015577:Geriatric Assessment; D018737:Hand Strength; D006801:Humans; D009765:Obesity; D010809:Physical Fitness; D011446:Prospective Studies