BACKGROUND: Seasonal variation of flow-mediated vasodilation (FMD) remains controversial. A large cohort study showing that FMD was highest in summer and lowest in winter has been performed in a cross-sectional manner on different populations in different seasons, and the results for the same population were not compared. METHODS: FMD was compared between the cool season (14.4 ± 4.4°C) and warm season (28.8 ± 1.0°C) in the same 27 outpatients with hypertension, diabetes mellitus and/or hyperlipidemia. RESULTS: The mean resting brachial artery diameter was significantly larger in the warm season than in the cool season. The maximal post-deflation brachial artery diameter was also significantly larger in the warm season than in the cool season. FMD, which was calculated from the resting diameter and the maximal diameter, was significantly higher in the warm season than in the cool season even when expressed as the relative value (4.74 ± 2.15 vs. 5.71 ± 2.17%, p=0.03) or absolute value (0.18 ± 0.08 vs, 0.23 ± 0.07 mm, p=0.008). CONCLUSIONS: FMD was significantly higher in the warm season than in the cool season when the measurements were performed on the same subjects and a paired comparison was made.
BACKGROUND: Seasonal variation of flow-mediated vasodilation (FMD) remains controversial. A large cohort study showing that FMD was highest in summer and lowest in winter has been performed in a cross-sectional manner on different populations in different seasons, and the results for the same population were not compared. METHODS:FMD was compared between the cool season (14.4 ± 4.4°C) and warm season (28.8 ± 1.0°C) in the same 27 outpatients with hypertension, diabetes mellitus and/or hyperlipidemia. RESULTS: The mean resting brachial artery diameter was significantly larger in the warm season than in the cool season. The maximal post-deflation brachial artery diameter was also significantly larger in the warm season than in the cool season. FMD, which was calculated from the resting diameter and the maximal diameter, was significantly higher in the warm season than in the cool season even when expressed as the relative value (4.74 ± 2.15 vs. 5.71 ± 2.17%, p=0.03) or absolute value (0.18 ± 0.08 vs, 0.23 ± 0.07 mm, p=0.008). CONCLUSIONS:FMD was significantly higher in the warm season than in the cool season when the measurements were performed on the same subjects and a paired comparison was made.
Authors: Dick H J Thijssen; Mark A Black; Kyra E Pyke; Jaume Padilla; Greg Atkinson; Ryan A Harris; Beth Parker; Michael E Widlansky; Michael E Tschakovsky; Daniel J Green Journal: Am J Physiol Heart Circ Physiol Date: 2010-10-15 Impact factor: 4.733
Authors: D S Celermajer; K E Sorensen; V M Gooch; D J Spiegelhalter; O I Miller; I D Sullivan; J K Lloyd; J E Deanfield Journal: Lancet Date: 1992-11-07 Impact factor: 79.321
Authors: Michael E Widlansky; Joseph A Vita; Michelle J Keyes; Martin G Larson; Naomi M Hamburg; Daniel Levy; Gary F Mitchell; Ewa W Osypiuk; Ramachandran S Vasan; Emelia J Benjamin Journal: Am J Cardiol Date: 2007-06-18 Impact factor: 2.778
Authors: Chinedu Ejike; Lu Wang; Mochuan Liu; Wei Wang; Masako Morishita; Robert L Bard; Wei Huang; Jack Harkema; Sanjay Rajagopalan; Robert D Brook Journal: J Am Soc Hypertens Date: 2017-09-28