Study: NCT03640221

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Ertugliflozin
Description: The sodium-glucose cotransporter 2 (SGLT2) inhibitors are an exciting new class of antidiabetic drugs that cause a modest reduction in high blood pressure and large reductions in the risk of cardiovascular disease (CVD) outcomes and renal outcomes in patients with advanced type 2 diabetes and very high CVD risk. However, the mechanistic underpinning of these CVD benefits is not well understood. this arm will allow us to test our hypothesis.

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Hydrochlorothiazide 12.5mg
Description: comparator arm allow us to mimic the mild anti hypertensive effect seen with the SGLT-2 inhibitors in order to enable us to differentiate whether the cardiovascular protection seen with the SGLT-2 inhibitors is secondary to its antihypertensive effects vs the potential decrease in sympathetics.

Intervention type: DEVICE
Group type: ACTIVE_COMPARATOR
Intervention: Microneurography
Description: Multiunit recordings of postganglionic sympathetic nerve activity will be obtained with unipolar tungsten microelectrodes inserted selectively into skeletal muscle nerve fascicles of the peroneal nerve. The nerve signals are amplified, filtered (bandwidth 700-2000 Hz), rectified and integrated to obtain a mean voltage display of sympathetic nerve activity. Sympathetic bursts are counted by inspection of the neurograms. A deflection on the mean voltage display is counted as a burst if it has a minimal signal to noise ratio of 2:1. The interobserver and intraobserver variations in identifying bursts are \<10% and \< 5%, respectively.

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: Microneurography
Description: Multiunit recordings of postganglionic sympathetic nerve activity will be obtained with unipolar tungsten microelectrodes inserted selectively into skeletal muscle nerve fascicles of the peroneal nerve. The nerve signals are amplified, filtered (bandwidth 700-2000 Hz), rectified and integrated to obtain a mean voltage display of sympathetic nerve activity. Sympathetic bursts are counted by inspection of the neurograms. A deflection on the mean voltage display is counted as a burst if it has a minimal signal to noise ratio of 2:1. The interobserver and intraobserver variations in identifying bursts are \<10% and \< 5%, respectively.

Intervention type: OTHER
Group type: ACTIVE_COMPARATOR
Intervention: SKNA recordings
Description: SKNA recordings will be captured by placing ECG electrodes on the chest wall. Recordings will be obtained simultaneously with microneurographic recording. The two techniques will undergo identical filtering and processing of the neurophysiologic inputs which are then displayed simultaneously using identical output functions.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: SKNA recordings
Description: SKNA recordings will be captured by placing ECG electrodes on the chest wall. Recordings will be obtained simultaneously with microneurographic recording. The two techniques will undergo identical filtering and processing of the neurophysiologic inputs which are then displayed simultaneously using identical output functions.

Intervention type: OTHER
Group type: ACTIVE_COMPARATOR
Intervention: Static Handgrip
Description: Subjects will perform static handgrip at 33% MVC for 2 minutes, using a Stoelting recording handgrip dynamometer. Force output will be recorded continuously and displayed on the computer screen in real time to provide the subject with visual feedback. MVC will be determined for each subject at the beginning of each experiment. Subjects will be instructed to avoid straining maneuvers, changes in breathing, and contraction of non-exercising muscles during the experimental protocols. Ratings of perceived exertion (RPE) will be obtained at the end of each exercise by using a 6- to 20-unit Borg scale. Static handgrip at 33% MVC is accompanied by reflex increases in muscle sympathetic nerve activity caused by activation of the acid-sensing unmyelinated muscle afferents.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Static Handgrip
Description: Subjects will perform static handgrip at 33% MVC for 2 minutes, using a Stoelting recording handgrip dynamometer. Force output will be recorded continuously and displayed on the computer screen in real time to provide the subject with visual feedback. MVC will be determined for each subject at the beginning of each experiment. Subjects will be instructed to avoid straining maneuvers, changes in breathing, and contraction of non-exercising muscles during the experimental protocols. Ratings of perceived exertion (RPE) will be obtained at the end of each exercise by using a 6- to 20-unit Borg scale. Static handgrip at 33% MVC is accompanied by reflex increases in muscle sympathetic nerve activity caused by activation of the acid-sensing unmyelinated muscle afferents.

Intervention type: OTHER
Group type: ACTIVE_COMPARATOR
Intervention: Post-handgrip forearm vascular occlusion
Description: This will be performed by inflating a pneumatic cuff on the upper exercising arm to suprasystolic pressure (220 mmHg) beginning 10 seconds before the subject stops gripping and ending 2 minutes into the post-exercise period. The vascular occlusion maintains intramuscular acidosis and thus the stimulation of acid-sensing unmyelinated skeletal muscle afferents and their reflex increase in muscle sympathetic nerve activity and BP, while the muscular relaxation eliminates central command and the attendant increase in heart rate (which returns to the baseline level). As soon as the cuff is release and the forearm circulation is restored, muscle sympathetic nerve activity quickly returns to the baseline level and BP soon follows.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Post-handgrip forearm vascular occlusion
Description: This will be performed by inflating a pneumatic cuff on the upper exercising arm to suprasystolic pressure (220 mmHg) beginning 10 seconds before the subject stops gripping and ending 2 minutes into the post-exercise period. The vascular occlusion maintains intramuscular acidosis and thus the stimulation of acid-sensing unmyelinated skeletal muscle afferents and their reflex increase in muscle sympathetic nerve activity and BP, while the muscular relaxation eliminates central command and the attendant increase in heart rate (which returns to the baseline level). As soon as the cuff is release and the forearm circulation is restored, muscle sympathetic nerve activity quickly returns to the baseline level and BP soon follows.

Intervention type: OTHER
Group type: ACTIVE_COMPARATOR
Intervention: Testing of the Arterial Baroreflex Function
Description: We will compare effects of Ertugliflozin vs. low-dose HCTZ on sinoaortic baroreflex function in hypertensive diabetic subjects during both spontaneous fluctuations in arterial pressure and during decreases and increases in arterial pressure induced by the Valsalva maneuver. The aim of this protocol is to determine if the sympathetic nerve, as well as the heart rate, component of the sinoaortic baroreflex can be augmented by the SGLT2 inhibitor. After obtaining stable baseline recordings, arterial pressure, heart rate, and muscle sympathetic nerve activity will recorded during spontaneous fluctuations in BP over 5 minutes and during both decreases in BP during phase III of the Valsavla maneuver and during the phase IV overshoot in BP upon its release. Frequent accurate measurement of arterial pressure will be obtained with a highly-rated oscillometric arm monitor that records 6 BP readings per minute (Welch Allyn Vital Signs Monitor).

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Testing of the Arterial Baroreflex Function
Description: We will compare effects of Ertugliflozin vs. low-dose HCTZ on sinoaortic baroreflex function in hypertensive diabetic subjects during both spontaneous fluctuations in arterial pressure and during decreases and increases in arterial pressure induced by the Valsalva maneuver. The aim of this protocol is to determine if the sympathetic nerve, as well as the heart rate, component of the sinoaortic baroreflex can be augmented by the SGLT2 inhibitor. After obtaining stable baseline recordings, arterial pressure, heart rate, and muscle sympathetic nerve activity will recorded during spontaneous fluctuations in BP over 5 minutes and during both decreases in BP during phase III of the Valsavla maneuver and during the phase IV overshoot in BP upon its release. Frequent accurate measurement of arterial pressure will be obtained with a highly-rated oscillometric arm monitor that records 6 BP readings per minute (Welch Allyn Vital Signs Monitor).