BsmI polymorphism in the vitamin D receptor gene is associated with leg extensor muscle strength in elderly men.
OBJECTIVE
Sarcopenia is defined as a reduction in skeletal muscle mass, strength, and endurance observed with advancing age. Although Vitamin D receptor (VDR) polymorphism is reported to be associated with muscle mass and strength, evidence for this is limited and conflicting. In this study, we examined the association between the polymorphisms of VDR gene BsmI, TaqI and FokI and muscular mass and strength in elderly men.


METHODS
This is a cross-sectional study conducted in a university hospital. One hundred and twenty men over 65 years of age participated, all participants were active men living independently in Istanbul, who were followed as outpatients in geriatric polyclinics. Most common diagnoses were hypertension, hyperlipidemia, and mild to moderate osteoarthritis. Morbid obese patients were not included in the study. Genomic DNA was extracted from peripheral blood, and VDR genotypes were determined by the polymerase chain reaction. The peak torque of the knee flexors and extensors was measured on a Cybex 350 dynamometer. Body muscle mass was calculated by using bioelectric impedance analysis.


RESULTS
The extensor strength of the knee was higher in BB homozygotic men than in the Bb/bb group. No significant association was found with TaqI and FokI haplotypes. There was no significant association between muscle mass and strength, or between muscle mass and VDR genotype.


CONCLUSIONS
Our data suggest that VDR gene BsmI polymorphism is associated with muscular strength in elderly men.
Bahat
Gulistan
G
Department of Internal Medicine, Istanbul Medical School, Istanbul University, Istanbul, Turkey. gbahatozturk@yahoo.com
Saka
Bulent
B
Erten
Nilgun
N
Ozbek
Ugur
U
Coskunpinar
Ender
E
Yildiz
Safinaz
S
Sahinkaya
Turker
T
Karan
Mehmet Akif
MA
D000368:Aged; D000375:Aging / Q000235:genetics* / Q000502:physiology; D001823:Body Composition; D003430:Cross-Sectional Studies; D005838:Genotype; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D053580:Muscle Strength / Q000235:genetics*; D010807:Physical Endurance / Q000502:physiology; D011110:Polymorphism, Genetic; D018167:Receptors, Calcitriol / Q000235:genetics*; D055948:Sarcopenia / Q000235:genetics* / Q000503:physiopathology
D018167:Receptors, Calcitriol