Menopause Effects on Cortico-reticular Functioning

Ten double-pulse transcranial magnetic stimulations delivered with 3 ms inter-stimulus interval. The conditioning pulse delivered at 80% of active motor threshold and the test pulse delivered at 120% of active motor threshold. Motor-evoked potential amplitude compared to single-pulse responses at 120% of active motor threshold.

Ten transcranial magentic stimulations (single-pulse) at 100%, 120%, 140%, 160%, 180% and 200% of active motor threshold. Calculations of I50 and area-under-the-recruitment-curve to be performed offline.

Twenty single-pulse transcranial magnetic stimulations delivered using 120% of active motor threshold. Ten stimulations without sound and ten stimulations conditioned by a loud sound (120 dB, 50 Hz) delivered 50 ms prior to TMS discharge.

Ten double-pulse transcranial magnetic stimulations delivered with 15 ms inter-stimulus interval. The conditioning pulse delivered at 80% of active motor threshold and the test pulse delivered at 120% of active motor threshold. Motor-evoked potential amplitude compared to single-pulse responses at 120% of active motor threshold.

Ten double-pulse transcranial magnetic stimulations delivered with 50 ms inter-stimulus interval. The conditioning pulse delivered at 120% of active motor threshold and the test pulse delivered at 120% of active motor threshold. Motor-evoked potential amplitude of the test pulse compared to the amplitude of the conditioning pulse.

The TMS coil is rotated 180 degrees to induce the opposite direction current within the cortex. A new active motor threshold for this coil orientation is first attained and then ten stimulations with 120% and 140% of active motor threshold are delivered. Motor-evoked potential amplitude is analysed offline.

Reaction test where the participant contracts the biceps brachii upon seeing a flashing white LED light 1 m in front. Ten flashes occur without accompanying sound. Ten flashes occur accompanied by a quiet sound (80 dB, 50 Hz). Ten flashes occur accompanied by a loud sound (120 dB, 50 Hz). The order of the conditions presented is randomized and separated by approximately 8 s. Reaction time is analysed from the presentations of the flash to the beginning (7 SD above baseline) of the voluntary electromyogram burst. The difference in the reactions times between conditions are calculated. Further analyses regarding rate of force development and voluntary EMG amplitude over 0-50 ms from each contraction are assessed.

Testing is performed under controlled pre-test conditions (10-12 h fast, no vigorous physical activity in the prior 24 h), seated in a thermoneutral room. The participant performs 3-5 isometric elbow flexion actions by maximally contracting the biceps brachii muscle while seated in an electromechanical dynamometer. Force and electromyography (EMG) activity are recorded during the contractions.

Measured by Indirect Calorimetry Resting energy expenditure (REE) is measured by indirect calorimetry (ventilated hood; overnight fast 10-12 h; supine, thermoneutral room). After stabilization, VO2 and VCO2 are recorded for ≥20-30 min; a steady-state segment (e.g., ≥5 min with CV <10% and physiologic RQ) is used to compute REE (kcal/day) via the Weir equation, higher values

= higher energy expenditure. Outcome is change from baseline to follow-up (follow-up - baseline); higher positive values = higher increase in energy expenditure. Procedures/quality criteria follow the device manual and the Statistical Analysis Plan (SAP). Per SAP, supportive analyses may adjust for body composition (FFM/FM) or express REE relative to FFM; these do not replace the prespecified analysis of this primary outcome.

Total fat mass (FM) will be measured by bioelectrical impedance analysis (BIA; InBody) under standardized conditions, including a 10-12 h fast before assessment. FM is reported in kg; higher values indicate higher fat mass. The outcome is the change from baseline to the specified follow-up (follow-up - baseline).

Fat-free mass (FFM) will be measured by bioelectrical impedance analysis (BIA; InBody) under standardized conditions, including a 10-12 h fast before assessment. FFM is reported in kg; higher values indicate higher fat-free mass.

Aortic pulse wave velocity (PWV) will be measured using an oscillometric Arteriograph device under standardized resting conditions, including a 10-12 h fast and avoidance of vigorous physical activity during the previous 24 h.

Measurements are taken supine in a quiet, thermoneutral room. PWV is reported in m/s; higher values indicate greater arterial stiffness.

Augmentation Index (AIx) will be measured using the Arteriograph under the same standardized resting conditions, including a 10-12 h fast and avoidance of vigorous physical activity during the preceding 24 h. AIx is expressed in %; higher values indicate greater arterial wave reflection.

Reflection time measured by Arteriograph in standardized rest (as above). ms; shorter RT = faster wave return.

Resting cutaneous microvascular perfusion measured at the forearm using Laser Doppler under standardized resting conditions (10-12 h fast, no vigorous physical activity in prior 24 h, supine, thermoneutral). Perfusion units (PU); higher = higher resting microvascular flow.

Endothelium-dependent vasodilatory response measured at the forearm using Laser Doppler during standardized forearm occlusion to induce a controlled ischemic stimulus under resting conditions (as above). % change from baseline; higher = better endothelial function.

Post-occlusive reactive hyperemia measured at the forearm with Laser Doppler under standardized rest (as above). % increase; higher = better microvascular reactivity.

Near-Infrared Spectroscopy (NIRS)-derived quadriceps StO2 at rest under standardized conditions (10-12 h fast, no vigorous PA in prior 24 h, supine, thermoneutral). %; higher = higher oxygenation.

NIRS-derived tHb signal (during rest). Arbitrary units; marker of local microvascular blood volume.