title: Hypovitaminosis D is associated with a reduction in upper and lower limb muscle strength and physical performance in post-menopausal women: a retrospective study.
abstract: BACKGROUND
  Elderly people experience a gradual loss of muscle strength and a reduction of serum levels of vitamin D and of vitamin D receptor expression in skeletal muscle cells.
  
  
  OBJECTIVE
  The aim of our study was to evaluate the association among serum levels of 25-hydroxy-vitamin D [25(OH)D3], muscle strength, and physical performance in post-menopausal women.
  
  
  METHODS
  In our retrospective case-control study, we analyzed data from medical records of post-menopausal women aged ≥ 50 years. We compared subjects with hypovitaminosis D [25(OH)D3 <30 ng/ml] vs. those with normal levels [25(OH)D3 ≥ 30 ng/ml]. Outcome measures were: Hand Grip Strength Test (HGS) and Knee Extension Strength Test (KES) to evaluate upper and lower limb muscle strength, respectively; Short Physical Performance Battery (SPPB) and usual 4-m gait speed (4 MGS) to evaluate physical performance.
  
  
  RESULTS
  We examined 80 patients (mean aged 65.92 ± 7.69 years): forty-six subjects with hypovitaminosis D (mean aged 66.09 ± 7.71 years) and 34 with normal levels of vitamin D (mean aged 65.71 ± 7.78 years). There was a statistically significant difference between hypovitaminosis D group and subjects with normal levels of vitamin D in HGS (12.13 ± 4.34 vs. 19.14 ± 5.59; p < 0.001), KES (11.99 ± 4.04 vs. 16.98 ± 8.43; p = 0.003), SPPB score [8 (5.75-10.25) vs. 12 (10-12); p < 0.001], and proportion of patients with usual 4 MGS ≤ 0.8 m/s [29 (63.0%) vs. 9 (26.5%); p = 0.002].
  
  
  CONCLUSIONS
  In literature, there is no agreement on the association among serum vitamin D levels and muscle function. Our data showed that post-menopausal women with hypovitaminosis D had worse upper and lower limb muscle strength and physical performance than subjects with normal levels of 25(OH)D3.
  
  
  CONCLUSIONS
  Our results support the hypothesis that there is a significant positive association among serum 25(OH)D3 levels and upper and lower limb muscle functioning.
authors.affiliation: Department of Medical and Surgical Specialties and Dentistry, Second University of Naples, Naples, Italy. giovanni.iolascon@gmail.com.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Iolascon
authors.affiliation: Department of Medical and Surgical Specialties and Dentistry, Second University of Naples, Naples, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: de Sire
authors.affiliation: Department of Medical and Surgical Specialties and Dentistry, Second University of Naples, Naples, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Calafiore
authors.affiliation: Department of Medical and Surgical Specialties and Dentistry, Second University of Naples, Naples, Italy.
authors.forename: Antimo
authors.initials: A
authors.lastname: Moretti
authors.affiliation: Department of Medical and Surgical Specialties and Dentistry, Second University of Naples, Naples, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Gimigliano
authors.affiliation: Department of Mental and Physical Health and Preventive Medicine, Second University of Naples, Naples, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Gimigliano
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005684:Gait; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D035002:Lower Extremity / Q000502:physiology / Q000503:physiopathology; D008875:Middle Aged; D018908:Muscle Weakness / Q000097:blood / Q000175:diagnosis / Q000517:prevention & control; D010809:Physical Fitness / Q000502:physiology*; D017698:Postmenopause / Q000378:metabolism*; D012189:Retrospective Studies; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000175:diagnosis
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Hypovitaminosis D; Muscle strength; Physical performance; Skeletal muscle; Vitamin D