Vasomotor Symptoms, Cardiovascular Risk and the Role of Physical Activity in Midlife Women

Sammanfattning: Background: The menopausal transition is, for most women, accompanied by hot flushes and night sweats (i.e., vasomotor symptoms, VMS). VMS has been associated with a worsened cardiovascular risk profile, but whether VMS constitutes an independent risk marker for developing subclinical atherosclerotic cardiovascular disease (ASCVD) is still uncertain. Visceral adipose tissue (VAT) contributes more to systemic low-grade inflammation than abdominal subcutaneous adipose tissue (ASAT), enhancing atherosclerosis development. Physical activity is an effective behavioral strategy to maintain and improve cardiovascular health. Whether a resistance training intervention (RTI) could reduce low-grade inflammation and VAT volume in postmenopausal women with VMS remains unclear, and whether the RTI-associated effects could be maintained over time requires further investigation.Material and Methods: This thesis is based on three studies. Study 1 was conducted on a subset of participants from the cross-sectional population-based Swedish CArdioPulmonary BioImage Study (SCAPIS), including women 50-64 years of age. The women underwent comprehensive cardiovascular assessments and completed an extensive female-specific questionnaire. VMS was assessed on a 4-point scale. Subclinical ASCVD was detected via coronary computed tomography angiography (CCTA), computed tomography (CT), and carotid ultrasound. Study 2 is a sub-study of 65 postmenopausal women with VMS and low physical activity, randomized to either three days/week of an RTI or unchanged physical activity for 15 weeks. Women underwent anthropometric measurements, magnetic resonance imaging (MRI), and blood sampling at baseline and after 15 weeks. During the last followup contact in Study 2 after two years, 35 women agreed to attend an additional clinic visit to reevaluate cardiovascular risk markers, marking the inception of Study 3.Results: Of 2995 women included in Study 1, 14.2% reported severe VMS (n = 425), 18.1% moderate VMS (n = 543), and 67.7% no or mild VMS (n = 2027). Current or previous severe VMS, but not moderate VMS, was significantly associated with CCTA-detected coronary atherosclerosis, with odds ratio (OR) before and after multivariable adjustment 1.36, 95% confidence interval (CI) 1.08 – 1.72 and 1.33, 95% CI 1.02 – 1.72, respectively. This association was only present for >5 years durations of severe VMS or when the onset of severe VMS occurred before menopause. Adjustment for menopausal hormone therapy strengthened the association for women with severe VMS >5 years (OR 1.67, 95% CI 1.16 – 2.40). Women compliant with an RTI had compared to a control group (CG), decreased adiponectin (p < 0.01), ASAT (p < 0.01), VAT (p < 0.01), total abdominal adipose tissue (TAAT) (p < 0.01) and fat ratio (p <0.001). Furthermore, an RTI reduced moderate to severe VMS frequency to six months post-intervention compared to a CG, but did neither contribute to preserved cardiovascular health markers nor improved health-related quality of life (HRQoL) after two years compared to a CG.Conclusions: There is a need for extra vigilance regarding cardiovascular risk factors in the group of women suffering from severe VMS. Implementing a 15-week RTI in these women could counteract the VAT redistribution and alter the frequency of moderate to severe VMS with maintained effects up to six months.