title: Human mitochondrial haplogroup H: the highest VO2max consumer--is it a paradox?
abstract: Mitochondrial background has been demonstrated to influence maximal oxygen uptake (VO(2max), in mLkg(-1)min(-1)), but this genetic influence can be compensated for by regular exercise. A positive correlation among electron transport chain (ETC) coupling, ATP and reactive oxygen species (ROS) production has been established, and mitochondrial variants have been reported to show differences in their ETC performance. In this study, we examined in detail the VO(2max) differences found among mitochondrial haplogroups. We recruited 81 healthy male Spanish Caucasian individuals and determined their mitochondrial haplogroup. Their VO(2max) was determined using incremental cycling exercise (ICE). VO(2max) was lower in J than in non-J haplogroup individuals (P=0.04). The H haplogroup was responsible for this difference (VO(2max); J vs. H; P=0.008) and this group also had significantly higher mitochondrial oxidative damage (mtOD) than the J haplogroup (P=0.04). In agreement with these results, VO(2max) and mtOD were positively correlated (P=0.01). Given that ROS production is the major contributor to mtOD and consumes four times more oxygen per electron than the ETC, our results strongly suggest that ROS production is responsible for the higher VO(2max) found in the H variant. These findings not only contribute to a better understanding of the mechanisms underneath VO(2max), but also help to explain some reported associations between mitochondrial haplogroups and mtOD with longevity, sperm motility, premature aging and susceptibility to different pathologies.
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza y CIBER de Enfermedades Raras (CIBERER), Universidad de Zaragoza, Spain.
authors.forename: Diana
authors.initials: D
authors.lastname: Martínez-Redondo
authors.forename: Ana
authors.initials: A
authors.lastname: Marcuello
authors.forename: José A
authors.initials: JA
authors.lastname: Casajús
authors.forename: Ignacio
authors.initials: I
authors.lastname: Ara
authors.forename: Yahya
authors.initials: Y
authors.lastname: Dahmani
authors.forename: Julio
authors.initials: J
authors.lastname: Montoya
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ruiz-Pesini
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: López-Pérez
authors.forename: Carmen
authors.initials: C
authors.lastname: Díez-Sánchez
mesh_terms: D004249:DNA Damage; D015444:Exercise; D006239:Haplotypes; D006801:Humans; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism*; D010101:Oxygen Consumption; D017382:Reactive Oxygen Species / Q000378:metabolism; D013030:Spain; D044465:White People
chemical_list: D017382:Reactive Oxygen Species