Alcoholic myopathy: vitamin D deficiency is related to muscle fibre atrophy in a murine model.
OBJECTIVE
Chronic myopathy has been described in alcoholics, characterized by atrophy of type II fibres, and vitamin D deficiency. Low serum vitamin D levels are frequent in alcoholics. The possibility exists that serum vitamin D levels are related to muscle changes in a murine experimental model.


METHODS
Histological analysis of the right gastrocnemius muscle was performed in four groups of adult Sprague-Dawley rats, sacrificed after 5 weeks of treatment following the Lieber-DeCarli model. We studied the association between muscle histological changes and the activity of glutathione peroxidase (GPX), superoxide dismutase (SOD) and lipid peroxidation products (malondialdehyde); parathyroid hormone (PTH), insulin-like growth factor 1 (IGF-1), free testosterone, 1,25 dihydroxyvitamin D3 (vitamin D) and corticosterone; and serum calcium and magnesium.


RESULTS
Alcoholic animals showed type IIa and IIb fibre atrophy, especially the low-protein-fed ones, an effect dependent on protein deficiency. A significant relationship was observed between serum vitamin D levels and IIa fibre area (rho = 0.56, P = 0.002), and also, as a trend, between vitamin D and type IIb fibre area (rho = 0.39, p = 0.053); between vitamin D and muscle GPX (rho = 0.40, P = 0.025) and SOD activities (rho = 0.43, P = 0.012). Muscle GPX activity was significantly related with type I fibre area (rho = 0.49, P = 0.01) and muscle SOD, with type IIa fibre area (rho = 0.38, P = 0.045). Serum testosterone was also related with type IIa fibre area (rho = 0.61, P < 0.001). No relation was observed between serum PTH, corticosterone, or IGF-1 and fibre area PTH and antioxidant systems. Multiple regression analysis disclosed that the only parameter independently related with type IIa fibre area was serum vitamin D.


CONCLUSIONS
Low vitamin D levels are related to muscle fibre atrophy, and altered levels of muscle antioxidant enzymes could play a role in alcoholic myopathy.
González-Reimers
E
E
Departamento de Medicina Interna, Hospital Universitario, Ofra s/n 38320 La Laguna, Tenerife, Canary Islands, Spain. egonrey@ull.es
Durán-Castellón
M C
MC
López-Lirola
A
A
Santolaria-Fernández
F
F
Abreu-González
P
P
Alvisa-Negrín
J
J
Sánchez-Pérez
M J
MJ
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001284:Atrophy; D002118:Calcium / Q000097:blood; D002492:Central Nervous System Depressants / Q000633:toxicity*; D000431:Ethanol / Q000633:toxicity*; D005979:Glutathione Peroxidase / Q000378:metabolism; D006728:Hormones / Q000097:blood; D008274:Magnesium / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D018656:Muscle Fibers, Fast-Twitch / Q000473:pathology; D018485:Muscle Fibers, Skeletal / Q000473:pathology*; D018482:Muscle, Skeletal / Q000473:pathology; D009135:Muscular Diseases / Q000139:chemically induced* / Q000473:pathology*; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D012709:Serum Albumin / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014807:Vitamin D / Q000378:metabolism; D014808:Vitamin D Deficiency / Q000473:pathology*
D000975:Antioxidants; D002492:Central Nervous System Depressants; D006728:Hormones; D012709:Serum Albumin; D014807:Vitamin D; D000431:Ethanol; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D008274:Magnesium; D002118:Calcium