title: Lower skeletal muscle capillarization in hypertensive elderly men.
abstract: Aging strongly affects the skeletal muscle and is associated with microvascular dysfunctions. Age is also a primary risk factor for the metabolic syndrome, which is a cluster of metabolic and cardiovascular symptoms. Among the metabolic syndrome components, hypertension is the most prevalent in elderly subjects and has a central role in vascular alterations. Despite critical clinical outcomes, the effects of hypertension and metabolic syndrome on skeletal muscle capillarization have poorly been investigated during aging. In the present study, muscle biopsies from normotensive young (YO) and elderly (ELc) men, and elderly men with hypertension (EL-HT) or metabolic syndrome (EL-MS) were assessed for the number of capillaries around a fiber (CAF), capillary-to-fiber perimeter exchange (CFPE), length of contact to perimeter of fiber ratio (LC/PF), capillary tortuosity, and for extracellular matrix (ECM) embedding capillaries. As capillarization and muscle mitochondrial oxidative capacity may be associated, we also investigated cytochrome c oxidase (COX) content. Our findings indicate that capillarization and COX did not change between normotensive adult and old individuals. They further reveal that hypertension in elderly men is associated with reduced CAF (ELc: 5.2 ± 0.4, EL-HT: 4.1 ± 0.2, P<0.02 for type I fibers; ELc: 4.1 ± 0.2, EL-HT: 3.1 ± 0.3, P<0.03 for type IIA fibers), CFPE (ELc: 7.9 ± 0.7, EL-HT: 6.4 ± 0.4 capillaries/1000 μm, P<0.03 for type I fibers; ELc: 6.5 ± 0.4, EL-HT: 5.2 ± 0.4 capillaries/1000 μm, P<0.03 for type IIA fibers), LC/PF (ELc: 23.3 ± 1.2, EL-HT: 17.8 ± 0.6%, P<0.01 for type I fibers; ELc: 19.8 ± 1.1, EL-HT: 15.6 ± 0.8%, P<0.01 for type IIA fibers) and capillary tortuosity, and with ECM endomysium fibrosis. Capillary rarefaction also correlated with lower COX content in the old hypertensive muscle. No further modification occurred with metabolic syndrome in elderly men. Collectively, our results suggest that hypertension plays a central role in muscle capillarization during aging, and that the other components of metabolic syndrome do not make major additional changes in the aged skeletal muscle capillary network.
authors.affiliation: INRA, UMR1019, Unité de Nutrition Humaine, CRNH Auvergne, F-63122 Saint-Genès Champanelle, France; Clermont Université, Université d'Auvergne, F-63000 Clermont-Ferrand, France.
authors.forename: Marine
authors.initials: M
authors.lastname: Gueugneau
authors.affiliation: INRA, UMR1019, Unité de Nutrition Humaine, CRNH Auvergne, F-63122 Saint-Genès Champanelle, France; Clermont Université, Université d'Auvergne, F-63000 Clermont-Ferrand, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Coudy-Gandilhon
authors.affiliation: INRA-VetAgro Sup, UMR1213, F-63122 Saint-Genès Champanelle, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Meunier
authors.affiliation: INRA, UMR1019, Unité de Nutrition Humaine, CRNH Auvergne, F-63122 Saint-Genès Champanelle, France; Clermont Université, Université d'Auvergne, F-63000 Clermont-Ferrand, France.
authors.forename: Lydie
authors.initials: L
authors.lastname: Combaret
authors.affiliation: INRA, UMR1019, Unité de Nutrition Humaine, CRNH Auvergne, F-63122 Saint-Genès Champanelle, France; Clermont Université, Université d'Auvergne, F-63000 Clermont-Ferrand, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Taillandier
authors.affiliation: INRA, UMR1019, Unité de Nutrition Humaine, CRNH Auvergne, F-63122 Saint-Genès Champanelle, France; Clermont Université, Université d'Auvergne, F-63000 Clermont-Ferrand, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Polge
authors.affiliation: INRA, UMR1019, Unité de Nutrition Humaine, CRNH Auvergne, F-63122 Saint-Genès Champanelle, France; Clermont Université, Université d'Auvergne, F-63000 Clermont-Ferrand, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Attaix
authors.affiliation: Service de Physiologie Clinique et de l'Exercice, CHU Nord, Faculté de Médecine Jacques Lisfranc, PRES de Lyon, Université Jean Monnet, F-42055 Saint-Etienne, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Roche
authors.affiliation: Unité de Myologie, Centre Référent Maladies Neuromusculaires Rares Rhône-Alpes, CHU de Saint-Etienne F-42055, France; Laboratoire de Physiologie de l'Exercice EA4338, Université Jean Monnet, Saint-Etienne F-42023, Université de Lyon, France; Université de Lyon, France.
authors.forename: Léonard
authors.initials: L
authors.lastname: Féasson
authors.affiliation: Service de Physiologie Clinique et de l'Exercice, CHU Nord, Faculté de Médecine Jacques Lisfranc, PRES de Lyon, Université Jean Monnet, F-42055 Saint-Etienne, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Barthélémy
authors.affiliation: INRA, UMR1019, Unité de Nutrition Humaine, CRNH Auvergne, F-63122 Saint-Genès Champanelle, France; Clermont Université, Université d'Auvergne, F-63000 Clermont-Ferrand, France. Electronic address: daniel.bechet@clermont.inra.fr.
authors.forename: Daniel
authors.initials: D
authors.lastname: Béchet
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging / Q000473:pathology; D001706:Biopsy; D002196:Capillaries / Q000473:pathology / Q000503:physiopathology*; D003576:Electron Transport Complex IV / Q000032:analysis; D005109:Extracellular Matrix / Q000473:pathology; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D035002:Lower Extremity; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D018482:Muscle, Skeletal / Q000098:blood supply*; D018919:Neovascularization, Physiologic; D012737:Sex Factors; D055815:Young Adult
chemical_list: D003576:Electron Transport Complex IV
keywords: Aging; Capillary; Hypertension; Metabolic syndrome; Muscle fiber; Sarcopenia