Ann-Katrin Grotle

• PhD
• Associate professor at Western Norway University of Applied Sciences

Type 2 diabetes mellitus (T2DM) patients have exaggerated sympathetic activity and blood pressure responses to exercise. However, the underlying mechanisms for these responses, as well as how these responses change throughout disease progression, are not completely understood. For this study, we examined the effect of the progression of T2DM on the...

Autonomic alterations at the onset of exercise are critical to redistribute cardiac output towards the contracting muscles while preventing a fall in arterial pressure due to excessive vasodilation within the contracting muscles. Neural mechanisms responsible for these adjustments include central command, the exercise pressor reflex, and arterial a...

Emerging evidence suggests that type 2 diabetes (T2D) may impair the ability to properly adjust the circulation during exercise with augmented blood pressure (BP) and an attenuated contracting skeletal muscle blood flow (BF) response being reported. This review provides a brief overview of the current understanding of these altered exercise respons...

The prevalence of major depressive disorder (MDD) is highest in young adulthood, an effect that has been magnified by the COVID-19 pandemic. Importantly, individuals with MDD are at a greater risk of developing cardiovascular disease (CVD). Accumulating evidence supports immune system dysregulation as a major contributor to the elevated CVD risk in...

Recent findings suggest that COVID-19 causes vascular dysfunction during the acute phase of the illness in otherwise healthy young adults. To date, no studies have investigated the longer-term effects of COVID-19 on vascular function. Herein, we hypothesized that young, otherwise healthy adults who are past the acute phase of COVID-19 would exhibit...

Autonomic adjustments of the cardiovascular system are critical for initiating and sustaining exercise by facilitating the redistribution of blood flow and oxygen delivery to meet the metabolic demands of the active skeletal muscle. Afferent feedback from active skeletal muscles evokes reflex increases in sympathetic nerve activity and blood pressu...

Background Insufficient physical activity (PA) is a significant public health challenge, with a drastic decline in activity levels observed in young adulthood likely contributing to increases in cardiometabolic risk factors with age. Recent research suggests that health literacy (HL) may be an important modifiable factor associated with reduced phy...

Background: Major Depressive Disorder (MDD) is increasingly prevalent in young adults and is a significant contributor to disease burden worldwide. Previously we have shown that young adults with MDD produce greater T cell mitochondrial ROS compared to their heathy non-depressed counterparts. Because evidence from rodent models of stress-related mo...

Aging is the most important and predictable risk factor for cardiovascular diseases, the major hallmarks of which are hypertension, arterial stiffness and impaired endothelial function. CCL5, a chemokine also called RANTES (Regulated upon Activation, Normal T-cell Expressed and Presumably Secreted) is expressed in T-cells and monocytes. Immune cell...

Background: Chronic kidney disease (CKD) affects more than 37 million US adults and is associated with a 3-5-fold increased risk of stroke. An attenuated cerebrovascular function may contribute to an increased risk of stroke in patients with CKD. However, our understanding of cerebrovascular function in CKD has mainly been limited to patients with...

Background: Black (BL) individuals living in the United States are more likely to develop hypertension and cardiovascular disease compared to their White (WH) counterparts. However, studies investigating racial differences in blood pressure regulation and baroreflex sensitivity (BRS) are limited and have reported equivocal results. Furthermore, des...

Cardiovascular disease is a leading cause of death in chronic kidney disease (CKD), yet the mechanisms remain unclear. Asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) are endogenous nitric oxide synthase inhibitors shown to be independent risk markers for cardiovascular disease. Previous research has predominantly focused o...

Many individuals who had COVID-19 develop detrimental persistent symptoms; a condition known as post-acute sequelae of COVID-19 (PASC). Despite the elevated risk of cardiovascular disease following COVID-19, limited studies have examined vascular function in PASC with equivocal results reported. Moreover, the role of PASC symptom burden on vascular...

Exaggerated cardiovascular responses to exercise increase the risk of myocardial infarction and stroke in individuals with type 1 diabetes (T1D); however, the underlying mechanisms remain largely elusive. This review provides an overview of the altered exercise pressor reflex in T1D, with an emphasis on the mechanical component of the reflex.Summar...

Introduction: Studies in humans and animals have found that type 2 diabetes mellitus (T2DM) exaggerates the blood pressure (BP) response to exercise, which increases the risk of adverse cardiovascular events such as heart attack and stroke. T2DM is a chronic disease that, without appropriate management, progresses in severity as individuals grow ol...

Emerging evidence suggests COVID-19 may affect cardiac autonomic function; however, the limited findings in young adults with COVID-19 have been equivocal. Notably, symptomology and time since diagnosis appear to influence vascular health following COVID-19, but this has not been explored in the context of cardiac autonomic regulation. Therefore, w...

Previous studies have reported detrimental effects of COVID-19 on the peripheral vasculature. However, reports on blood pressure (BP) are inconsistent and measurements made only in the laboratory setting. To date, no studies have measured ambulatory BP. Additionally, in previous studies, time since COVID-19 diagnosis among participants varied acros...

We and others have previously shown that COVID-19 results in vascular and autonomic impairments in young adults. However, the newest variant of COVID-19 (Omicron) appears to have less severe complications. Therefore, we investigated whether recent breakthrough infection with COVID-19 during the Omicron wave impacts cardiovascular health in young ad...

Background: Major depressive disorder (MDD) is prevalent in young adults and projected to rise further with the COVID pandemic. Notably, MDD is associated with an increased risk of cardiovascular disease (CVD) and mortality. Although the mechanisms are unclear, evidence supports chronic systemic inflammation as a major contributor to CVD risk in o...

Background: COVID-19 has been shown to cause impairments in vascular function and elevations in resting sympathetic nerve activity in young otherwise healthy adults. Notably, our laboratory recently reported that persistence of COVID-19 symptoms beyond the acute phase of the illness (i.e., beyond 4 weeks) was accompanied by macro- and micro- vascu...

Background: The COVID-19 pandemic has evolved into an unprecedented public health crisis, with over 255 million cases and over 5 million deaths worldwide. Emerging evidence indicates that many previously healthy young adults diagnosed with COVID-19 experience persistent symptoms beyond the acute phase of the illness, a phenomenon coined "long-COVI...

Background: The prevalence of hypertension (HTN) is highest in the non-Hispanic Black (BL) population. Notably, BL women have an equal or greater HTN prevalence compared to BL men; however, limited studies have included women. Heightened sympathetic nervous system reactivity has been proposed as a potential mediator of elevated HTN risk in the BL...

Vascular dysfunction and inflammation are precursors to cardiovascular disease (CVD). Notably, young adults who were symptomatic from COVID-19 during the acute phase of illness (within 4 weeks from diagnosis) have shown to exhibit peripheral vascular dysfunction. Importantly, many young adults report persistent symptoms from COVID-19 for several mo...

Emerging evidence suggests the exercise pressor reflex is exaggerated in early-stage type 1 diabetes mellitus (T1DM). Piezo channels may play a role in this exaggeration since blocking these channels attenuates the exaggerated pressor response to tendon stretch in T1DM rats. However, tendon stretch constitutes a different mechanical and physiologic...

The exercise pressor reflex is exaggerated in type 2 diabetes mellitus (T2DM). Hyperglycemia, a main characteristic of T2DM, likely contributes to this exaggerated response. However, the isolated effect of acute hyperglycemia, independent of T2DM, on the exercise pressor reflex is not known. Therefore, the purpose of this study was to determine the...

Studies have shown that early-stage type 1 diabetes mellitus (T1DM) leads to an exaggerated reflex pressor response to both static muscle contraction and tendon stretch. However, whether similar responses are present during dynamic exercise (i.e., intermittent contraction) is not known. Therefore, the purpose of this study was to determine whether...

Both the exercise pressor reflex and mechanoreflex are exaggerated after the development of T2DM in UCD‐T2DM rats. Whether the pressor reflex is also exaggerated before UCD‐T2DM rats developed diabetes is not known. Therefore, the purpose of this study was to determine if both the exercise pressor reflex and mechanoreflex are exaggerated in the UCD...

The exercise pressor reflex and the mechanoreflex are exaggerated in type 1 diabetes mellitus (T1DM) rats. Studies using GsMTx‐4, which has high potency for Piezo channels, have suggested that Piezo channels play a significant role in evoking this exaggerated response. However, studies have also reported that GsMTx‐4 may block TRPC1 and TRPC6 chann...

Type 2 diabetes mellitus (T2DM) leads to exaggerated cardiovascular responses to exercise, in part due to an exaggerated exercise pressor reflex. Accumulating data suggest excessive oxidative stress contributes to an exaggerated exercise pressor reflex in cardiovascular-related diseases. Excessive oxidative stress is also a primary underlying mecha...

The exercise pressor reflex was evoked in unanesthesized, decerebrate rats by intermittently contracting the hindlimb muscles while simultaneously measuring popliteal arterial blood flow. The pressor and blood flow response to muscle contraction was compared between type 1 diabetic rats and healthy controls.

Type 1 diabetes mellitus (T1DM) is associated with an impaired regulation of autonomic and cardiovascular responses during exercise, an effect attributable, in part, to the exercise pressor reflex. Previously, we have found that the pressor responses to both static muscle contraction and to tendon stretch are exaggerated in the early stage of T1DM....

Type 1 diabetes mellitus (T1DM) is a metabolic disease in which chronic hyperglycemia increases the risk of developing peripheral neuropathy. A common early symptom of peripheral neuropathy is mechanical allodynia, which is characterized as painful sensation to a normally non‐painful stimulus. However, whether the expression of mechanical allodynia...

Previous work has shown that the exercise pressor reflex is exaggerated in type 2 diabetic rats that present with hyperglycemia. Although it is likely that chronic hyperglycemia plays a role, no studies have isolated the acute effects of high blood glucose levels on this reflex. Therefore, the purpose of the current study was to determine the acute...

Recent findings have shown that muscle contraction evokes an exaggerated pressor response in type 1 diabetes mellitus (T1DM) rats; however, it is not known whether the mechanoreflex, which is commonly stimulated by stretching the Achilles tendon, contributes to this abnormal response. Furthermore, the role of mechano-gated Piezo channels, found on...

Type 1 diabetes (T1DM) is known to cause both peripheral and autonomic neuropathy through mechanisms affecting thinly myelinated afferents. These same afferents may also play a role in the exercise pressor reflex suggesting that T1DM could alter this reflex as well. The purpose of this study was to establish the effects of type 1 diabetes on the pr...

Type 1 diabetes (T1DM) pathophysiology and prevalence differ in males as do the mechanisms of cardiovascular related diseases. The purpose of this study was to establish whether the pressor and cardioaccelerator responses evoked by static contraction or tendon stretch differ by sex in T1DM rats. We injected (i.p) 50 mg/kg of Streptozotocin (STZ) or...

Studies have shown that type 1 diabetic (T1DM) rats develop mechanical allodynia as early as four days post streptozotocin (STZ) injection. This is thought to occur through mechanisms affecting the same thin fiber afferents that evoke the mechanoreflex. In this study we attempted to determine the effects of T1DM on the mechanoreflex at two differen...

ACSM Abstract Augmented Mechanoreflex in Type 2 Diabetic Rats: Piezo channels, an Important Part of the Puzzle? Ann-Katrin Grotle1, Yu Huo1, James Graham2, Kimber L. Stanhope2, Peter J. Havel2, and Audrey J. Stone1 1TheUniversity of Texas at Austin, Austin, TX, 2The University of California Davis, Davis, CA A recent study demonstrated that type...

In this study we show that the mechanoreflex is exaggerated in type 2 diabetic rats and that Piezo channels play an important role in this exaggeration. This poster was selected as the winner of the President cup (best overall) and PhD category winner at TACSM, as well as the Texas representative at the national ACSM president cup competition in...

Type 2 diabetes (T2DM) is a metabolic disorder that can lead to many neuropathic complications such as mechanical allodynia, which is perceived pain caused by a normally non‐painful stimulus. T2DM is also associated with exaggerated pressor and cardioaccelerator responses to skeletal muscle contraction, namely the exercise pressor reflex. The mecha...

Type 2 diabetes Mellitus (T2DM) patients have an augmented sympathetic activity and cardiovascular response to exercise. The exercise pressor reflex, which is evoked by mechanical and metabolic stimuli arising from contracting muscle, and results in an increase in mean arterial pressure and heart rate, may contribute to this augmented response. Stu...

Aging, type 2 diabetes mellitus (T2DM), and cardiovascular disease are all associated with systematic low grade inflammation. Accordingly, these conditions alter circulating concentrations of cytokines involved in inflammation and vascular function. Recent studies suggest that these same cytokines may contribute to the sensitization of group III an...

Previous studies have shown that diabetic peripheral neuropathy affects both unmyelinated and myelinated afferents, similar to those evoking the exercise pressor reflex. However, the effect of type 1 diabetes (T1DM) on this reflex is not known. We examined, in decerebrate male and female T1DM [streptozotocin (STZ)] and healthy control (CTL) rats, p...