@article{3151503,
    title = "Gender variation of exercise-induced anti-arrhythmic protection: the
Ikaria Study",
    author = "Oikonomou, E. and Chrysohoou, C. and Tsiachris, D. and Vogiatzi, G. and and Gialafos, E. and Marinos, G. and Tsitsinakis, G. and Dimitriadis, K. and and Tousoulis, D. and Pitsavos, C. and Stefanadis, C.",
    journal = "QJM: An International Journal of Medicine",
    year = "2011",
    volume = "104",
    number = "12",
    pages = "1035-1043",
    publisher = "Oxford University Press",
    issn = "1460-2725, 1460-2393",
    doi = "10.1093/qjmed/hcr112",
    abstract = "Methods: In a cross-sectional survey 1071 inhabitants of Ikaria Island
(65 +/- 13 years, 47% males) were enrolled. PA was estimated by means
of IPAQ classifying the participants into low, moderate and vigorous
group. QT duration was measured from a surface electrocardiogram; while
using Bazett’s formula the heart-rate-corrected QT (QTc) was calculated.
Results: Among participants, 85% reported at least moderate PA levels.
Women in the ‘vigorous’ and ‘moderate’ PA level compared to those in the
‘low’ PA level had significantly shorter QTc (408 +/- 2 ms vs. 411 +/- 1
ms vs. 419 +/- 2 ms, P = 0.001, respectively). In contrast, no
significant difference in QTc according to PA levels was observed in men
(P = 0.053). Linear regression analysis revealed that PA level was
significantly associated with shorter QTc in women after adjustment for
established confounders; while no such association was evident in men.
Furthermore, compared to the ‘low’ PA group, women in the ‘vigorous’ PA
group were 5.5-times less likely to have QTc interval above 450 ms (P =
0.031).
Conclusion: Increased PA is associated with shorter QTc interval only in
middle-aged and elderly women of Ikaria Island irrespectively of
participant’s habits or medical conditions, illustrating gender
differences in the cardioprotective effect of habitual exercise."
}