Evidence That Women With Polycystic Ovary Syndrome Exhibit Altered Vascular Function To High-intensity Exercise

Abstract

PURPOSE: Women with Polycystic Ovary Syndrome (PCOS) have an increased risk of cardiovascular disease (CVD). The link between PCOS and CVD is believed to be related to vascular dysfunction. An integral component of the management and prevention of CVD is high-intensity (HI) exercise, which has been shown to improve vascular function. However, there is currently a lack of evidence regarding the vascular response following an acute HI exercise bout in PCOS. Therefore, we assessed vascular function via brachial artery flow-mediated dilation (FMD) in response to an acute HI treadmill exercise bout in women with PCOS and healthy controls (CON). METHODS: 8 PCOS (age: 26 ± 4 y; height 166 ± 5 cm; weight 66 ± 11 kg) and 10 CON (age: 28 ± 6 y; height 166 ± 7 cm; weight 59 ± 12 kg) were studied. All participants performed a maximal incremental treadmill test to determine peak oxygen uptake (V̇O2peak). On a separate day, subjects performed a 30min constant-load HI treadmill test at 75% of their individual V̇O2peak. FMD was measured at baseline (pre-HI) and immediately after (post-HI) exercise. A two-way group (PCOS vs CON) by time (pre-HI vs post-HI) analysis of variance was conducted. RESULTS: V̇O2peak was similar between groups (PCOS: 2.78 ± 0.42; CON: 2.41 ± 0.48 L·min-1, p = 0.118). The reduction in FMD post-HI was similar (p = 0.985) in PCOS (-0.66 ± 1.26 %) and CON (-0.47 ± 0.79 %). SRAUC increased (p = 0.035) in PCOS post-HI (4167 ± 6239 cm·s-1), whereas a reduction (p = 0.048) was observed in CON (-4133 ± 7462 cm·s-1). When FMD was normalized for shear rate, as defined by the area under the curve (SRAUC) following hyperaemia, the FMD:SRAUC ratio decreased (p = 0.020) to a greater extent in PCOS (-0.90 ± 0.84) compared with CON (0.03 ± 0.10) post-HI. CONCLUSIONS: Despite being young and active individuals, we provide new evidence that, for a given shear stress evoked by HI exercise, the impairment in vasodilatory function is worse in women with PCOS compared with CON. Whether this alteration in exercise-induced changes in vascular function plays a role in the elevated risk of developing CVD in this population is presently unclear. Further investigation into the underlying mechanisms of the altered vascular response to HI exercise in women with PCOS is warranted.