Scholars@Duke
Crystal Cenell Tyson

Crystal Cenell Tyson

Assistant Professor of Medicine
Medicine, Nephrology
crystal.simpson@duke.edu
2727 Erwin Road, Suite 605, Durham, NC 27705
Office hours

Selected Publications

Longitudinal Pilot Evaluation of the Gut Microbiota Comparing Patients With and Without Chronic Kidney Disease.

Journal Article J Ren Nutr · July 2024 OBJECTIVE: The gut microbiota contributes to metabolic diseases, such as diabetes and hypertension, but is poorly characterized in chronic kidney disease (CKD). DESIGN AND METHODS: We enrolled 24 adults within household pairs, in which at least one member ... Full text Link to item Cite

Effects of Lifestyle Modification on Psychosocial Function in Patients With Resistant Hypertension: SECONDARY OUTCOMES FROM THE TRIUMPH RANDOMIZED CLINICAL TRIAL.

Journal Article J Cardiopulm Rehabil Prev · January 1, 2024 PURPOSE: In a secondary analysis of the TRIUMPH clinical trial, psychological outcomes in patients with resistant hypertension (RH) receiving a diet and exercise intervention delivered in a cardiac rehabilitation setting were compared with those receiving ... Full text Link to item Cite

Sociodemographic predictors of successful screening and subsequent randomization in a digital health hypertension intervention.

Journal Article Digit Health · 2024 INTRODUCTION: Clinical trials often enroll nonrepresentative participant samples, limiting generalizability of trial findings. The current analysis explores the influences of remote recruitment and screening protocols on participation in a digital health i ... Full text Link to item Cite

Safety and Efficacy of Renal Denervation in Patients Taking Antihypertensive Medications.

Journal Article J Am Coll Cardiol · November 7, 2023 BACKGROUND: Renal denervation (RDN) reduces blood pressure (BP) in patients with uncontrolled hypertension in the absence of antihypertensive medications. OBJECTIVES: This trial assessed the safety and efficacy of RDN in the presence of antihypertensive me ... Full text Link to item Cite

Self-Perceived Barriers and Facilitators to Dietary Approaches to Stop Hypertension Diet Adherence Among Black Americans With Chronic Kidney Disease: A Qualitative Study.

Journal Article J Ren Nutr · January 2023 OBJECTIVE: The Dietary Approaches to Stop Hypertension (DASH) eating plan improves hypertension in Black individuals and is associated with favorable chronic kidney disease (CKD) outcomes. Yet, adherence to DASH is low among US adults in general, particula ... Full text Link to item Cite

Inflammation moderates the effects of lifestyle modification on neurocognition among individuals with resistant hypertension.

Journal Article J Clin Hypertens (Greenwich) · January 2023 Individuals with resistant hypertension (RH) have the greatest risk of cerebrovascular disease and cognitive impairment among individuals with hypertension. Elevated levels of pro-inflammatory cytokines may represent a critical yet unexamined factor influe ... Full text Link to item Cite

Implementation of an At-home Blood Pressure Measurement Protocol in a Hypertension Management Clinical Trial During the COVID-19 Pandemic.

Journal Article J Cardiovasc Nurs · September 2022 BACKGROUND: The Dietary Approaches to Stop Hypertension eating plan is an evidence-based treatment of hypertension; however, adherence to the Dietary Approaches to Stop Hypertension is low. To improve adherence to the Dietary Approaches to Stop Hypertensio ... Full text Link to item Cite

Lifestyle modification and cognitive function among individuals with resistant hypertension: cognitive outcomes from the TRIUMPH trial.

Journal Article J Hypertens · July 1, 2022 BACKGROUND: Resistant hypertension is associated with increased risk of cognitive decline, stroke, and dementia. Lifestyle modification has been suggested to improve cognitive function through its salutary effects on vascular function. METHODS: Participant ... Full text Link to item Cite

Cerebrovascular Function, Vascular Risk, and Lifestyle Patterns in Resistant Hypertension.

Journal Article J Alzheimers Dis · 2022 BACKGROUND: Impaired cerebrovascular reactivity (CVR) and blunted cerebral hemodynamic recruitment are thought to be important mechanisms linking hypertension to cerebrovascular and cognitive outcomes. Few studies have examined cardiovascular or dietary co ... Full text Link to item Cite

Psychosocial determinants of cardiovascular events among black Americans with chronic kidney disease or associated risk factors in the Jackson heart study.

Journal Article BMC Nephrol · November 11, 2021 BACKGROUND: Individuals with chronic kidney disease (CKD), hypertension (HTN), or diabetes mellitus (DM) are at increased risk for cardiovascular disease (CVD). The extent to which psychosocial factors are associated with increased CVD risk within these in ... Full text Link to item Cite

Effects of Lifestyle Modification on Patients With Resistant Hypertension: Results of the TRIUMPH Randomized Clinical Trial.

Journal Article Circulation · October 12, 2021 BACKGROUND: Although lifestyle modifications generally are effective in lowering blood pressure (BP) among patients with unmedicated hypertension and in those treated with 1 or 2 antihypertensive agents, the value of exercise and diet for lowering BP in pa ... Full text Link to item Cite

Retrospective cohort study of changes in estimated glomerular filtration rate for patients prescribed a low carb diet.

Journal Article Curr Opin Endocrinol Diabetes Obes · October 1, 2021 PURPOSE OF REVIEW: Obesity and diabetes contribute to chronic kidney disease (CKD) and accelerate the loss of kidney function. Low carbohydrate diets (LCDs) are associated with weight loss and improved diabetes control. Compared to the typical Western diet ... Full text Open Access Link to item Cite

The Nourish Protocol: A digital health randomized controlled trial to promote the DASH eating pattern among adults with hypertension.

Journal Article Contemp Clin Trials · October 2021 INTRODUCTION: Over 100 million adults in the United States have hypertension. The DASH (Dietary Approaches to Stop Hypertension) eating pattern is an evidence-based first-line treatment option for hypertension; however, adherence to the DASH eating pattern ... Full text Link to item Cite

Effect of Bicarbonate on Net Acid Excretion, Blood Pressure, and Metabolism in Patients With and Without CKD: The Acid Base Compensation in CKD Study.

Journal Article Am J Kidney Dis · July 2021 RATIONALE & OBJECTIVE: Patients with CKD are at elevated risk of metabolic acidosis due to impaired net acid excretion (NAE). Identifying early markers of acidosis may guide prevention in chronic kidney disease (CKD). This study compared NAE in participant ... Full text Link to item Cite

Urine and Plasma Metabolome of Healthy Adults Consuming the DASH (Dietary Approaches to Stop Hypertension) Diet: A Randomized Pilot Feeding Study.

Journal Article Nutrients · May 22, 2021 We aimed to identify plasma and urine metabolites altered by the Dietary Approaches to Stop Hypertension (DASH) diet in a post-hoc analysis of a pilot feeding trial. Twenty adult participants with un-medicated hypertension consumed a Control diet for one w ... Full text Link to item Cite

DASH Diet and Blood Pressure Among Black Americans With and Without CKD: The Jackson Heart Study.

Journal Article Am J Hypertens · September 24, 2019 BACKGROUND: The Dietary Approaches to Stop Hypertension (DASH) diet lowers blood pressure (BP) more effectively in blacks compared to other US racial subgroups. Considering chronic kidney disease (CKD) raises BP through complex mechanisms, DASH may affect ... Full text Link to item Cite

Association of functional and structural social support with chronic kidney disease among African Americans: the Jackson Heart Study.

Journal Article BMC Nephrol · July 15, 2019 BACKGROUND: There is limited evidence on the relationship between social support and renal outcomes in African Americans. We sought to determine the association of social support with prevalent chronic kidney disease (CKD) and kidney function decline in an ... Full text Link to item Cite

Ambulatory heart rate reduction after catheter-based renal denervation in hypertensive patients not receiving anti-hypertensive medications: data from SPYRAL HTN-OFF MED, a randomized, sham-controlled, proof-of-concept trial.

Journal Article Eur Heart J · March 1, 2019 AIMS: The randomized sham-controlled SPYRAL HTN-OFF MED trial demonstrated that renal denervation (RDN) using a multi-electrode catheter lowers ambulatory blood pressure (BP) in non-medicated hypertensive patients. The current report describes the effects ... Full text Link to item Cite

Low use of routine medical care among African Americans with high CKD risk: the Jackson Heart Study.

Journal Article BMC Nephrol · January 10, 2019 BACKGROUND: Use of routine medical care (RMC) is advocated to address ethnic/racial disparities in chronic kidney disease (CKD) risks, but use is less frequent among African Americans. Factors associated with low RMC use among African Americans at risk of ... Full text Open Access Link to item Cite

Dietary Phosphorus and Ambulatory Blood Pressure in African Americans: The Jackson Heart Study.

Journal Article Am J Hypertens · January 1, 2019 BACKGROUND: Higher dietary phosphorus is associated with left ventricular hypertrophy and mortality, which are blood pressure (BP)-related outcomes. For this reason, we hypothesized that dietary phosphorus may be associated with adverse clinic and ambulato ... Full text Link to item Cite

The Association Between Engagement and Weight Loss Through Personal Coaching and Cell Phone Interventions in Young Adults: Randomized Controlled Trial.

Journal Article JMIR Mhealth Uhealth · October 18, 2018 BACKGROUND: Understanding how engagement in mobile health (mHealth) weight loss interventions relates to weight change may help develop effective intervention strategies. OBJECTIVE: This study aims to examine the (1) patterns of participant engagement over ... Full text Open Access Link to item Cite

Obesity and synergistic risk factors for chronic kidney disease in African American adults: the Jackson Heart Study.

Journal Article Nephrol Dial Transplant · June 1, 2018 BACKGROUND: African Americans are at high risk for chronic kidney disease (CKD). Obesity may increase the risk for CKD by exacerbating features of the metabolic syndrome and promoting glomerular hyperfiltration. Whether other factors also affecting these p ... Full text Link to item Cite

Nondepressive Psychosocial Factors and CKD Outcomes in Black Americans.

Journal Article Clin J Am Soc Nephrol · February 7, 2018 BACKGROUND AND OBJECTIVES: Established risk factors for CKD do not fully account for risk of CKD in black Americans. We studied the association of nondepressive psychosocial factors with risk of CKD in the Jackson Heart Study. DESIGN, SETTING, PARTICIPANTS ... Full text Link to item Cite

Ambulatory blood pressure in the dash diet trial: Effects of race and albuminuria.

Journal Article J Clin Hypertens (Greenwich) · February 2018 We evaluated whether low-grade albuminuria or black race modulates ambulatory blood pressure (BP) or nocturnal BP response to the DASH diet. Among 202 adults enrolled in the DASH multicenter trial who were fed the DASH or control diet for 8 weeks, reductio ... Full text Link to item Cite

Association between normal or mildly reduced kidney function, cardiovascular risk and biomarkers for atherosclerosis: results from the ENCORE trial.

Journal Article Clin Kidney J · October 2017 BACKGROUND: Moderate-to-severe kidney dysfunction is associated with atherosclerotic cardiovascular disease (ASCVD). Gradations of normal or mildly reduced kidney function may also associate with ASCVD risk. METHODS: We conducted a secondary analysis using ... Full text Link to item Cite

In the Wake of Systolic Blood Pressure Intervention Trial: New Targets for Improving Hypertension Management in Chronic Kidney Disease?

Journal Article Nephron · 2017 Systolic Blood Pressure Intervention Trial (SPRINT) was a multicenter randomized controlled trial showing the significant benefit of intensive reduction of blood pressure to a target of 120 mm Hg in individuals with hypertension and elevated cardiovascular ... Full text Link to item Cite

Nutrition, lifestyle, and hypertension

Chapter · January 1, 2017 Hypertension is a major risk factor for coronary heart disease, stroke, and premature death and a leading risk factor for global disease burden. Prevalence for those 18 years and older in the United States has remained around 29% since 1999 with little imp ... Full text Cite

Influence of Kidney Function on Blood Pressure Response to Lifestyle Modifications: Secondary Analysis From the Exercise and Nutritional Interventions for Cardiovascular Health (ENCORE) Trial.

Journal Article J Clin Hypertens (Greenwich) · December 2016 The kidney is an important regulator of blood pressure (BP). To determine whether BP response to lifestyle modification varies across normal ranges of kidney function, the authors examined the moderating role of estimated glomerular filtration rate (eGFR) ... Full text Link to item Cite

Short-term effects of the DASH diet in adults with moderate chronic kidney disease: a pilot feeding study.

Journal Article Clin Kidney J · August 2016 BACKGROUND: Although the Dietary Approaches to Stop Hypertension (DASH) diet lowers blood pressure (BP) for adults with normal kidney function, evidence is lacking regarding its safety and efficacy in chronic kidney disease (CKD). We aimed to test the effe ... Full text Open Access Link to item Cite

The impact of continued intervention on weight: Five-year results from the weight loss maintenance trial.

Journal Article Obesity (Silver Spring) · May 2016 OBJECTIVE: In the Weight Loss Maintenance (WLM) Trial, a personal contact (PC) intervention sustained greater weight loss relative to a self-directed (SD) group over 30 months. This study investigated the effects of continued intervention over an additiona ... Full text Link to item Cite

Adaptive intervention design in mobile health: Intervention design and development in the Cell Phone Intervention for You trial.

Journal Article Clin Trials · December 2015 BACKGROUND/AIMS: The obesity epidemic has spread to young adults, and obesity is a significant risk factor for cardiovascular disease. The prominence and increasing functionality of mobile phones may provide an opportunity to deliver longitudinal and scala ... Full text Open Access Link to item Cite

Lifestyle modification for resistant hypertension: The TRIUMPH randomized clinical trial.

Journal Article Am Heart J · November 2015 BACKGROUND: Resistant hypertension (RH) is a growing health burden in this country affecting as many as 1 in 5 adults being treated for hypertension. Resistant hypertension is associated with increased risk of adverse cardiovascular disease (CVD) events an ... Full text Link to item Cite

Cell phone intervention for you (CITY): A randomized, controlled trial of behavioral weight loss intervention for young adults using mobile technology.

Journal Article Obesity (Silver Spring) · November 2015 OBJECTIVE: To determine the effect on weight of two mobile technology-based (mHealth) behavioral weight loss interventions in young adults. METHODS: Randomized, controlled comparative effectiveness trial in 18- to 35-year-olds with BMI ≥ 25 kg/m(2) (overwe ... Full text Open Access Link to item Cite

Application of Latent Class Analysis to Identify Behavioral Patterns of Response to Behavioral Lifestyle Interventions in Overweight and Obese Adults.

Journal Article Int J Behav Med · August 2015 BACKGROUND: Examining responders and non-responders to behavioral lifestyle interventions among overweight/obese adults with additional comorbidities may aid in refining and tailoring obesity treatment. PURPOSE: The purpose of this study is to demonstrate ... Full text Open Access Link to item Cite

Apparent treatment-resistant hypertension and chronic kidney disease: another cardiovascular-renal syndrome?

Journal Article Adv Chronic Kidney Dis · November 2014 To identify patients at increased risk of cardiovascular (CV) outcomes, apparent treatment-resistant hypertension (aTRH) is defined as having a blood pressure above goal despite the use of 3 or more antihypertensive therapies of different classes at maxima ... Full text Open Access Link to item Cite

Weight loss intervention for young adults using mobile technology: design and rationale of a randomized controlled trial - Cell Phone Intervention for You (CITY).

Journal Article Contemp Clin Trials · March 2014 BACKGROUND: The obesity epidemic has spread to young adults, leading to significant public health implications later in adulthood. Intervention in early adulthood may be an effective public health strategy for reducing the long-term health impact of the ep ... Full text Open Access Link to item Cite

Impact of Kidney Function on Effects of the Dietary Approaches to Stop Hypertension (Dash) Diet.

Journal Article J Hypertens (Los Angel) · 2014 OBJECTIVES: Although the Dietary Approaches to Stop Hypertension (DASH) diet lowers blood pressure in adults with hypertension, how kidney function impacts this effect is not known. We evaluated whether Estimated Glomerular Filtration Rate (eGFR) modifies ... Full text Open Access Link to item Cite

Association of a reduction in central obesity and phosphorus intake with changes in urinary albumin excretion: the PREMIER study.

Journal Article Am J Kidney Dis · November 2013 BACKGROUND: Excess adiposity and dietary factors may be important determinants of urinary albumin excretion (UAE). STUDY DESIGN: Observational analysis of PREMIER, a randomized trial designed to lower blood pressure using behavioral interventions (counseli ... Full text Open Access Link to item Cite

Recruiting young adults into a weight loss trial: report of protocol development and recruitment results.

Journal Article Contemp Clin Trials · July 2013 Obesity has spread to all segments of the U.S. population. Young adults, aged 18-35 years, are rarely represented in clinical weight loss trials. We conducted a qualitative study to identify factors that may facilitate recruitment of young adults into a we ... Full text Open Access Link to item Cite

Impact of 5-year weight change on blood pressure: results from the Weight Loss Maintenance trial.

Journal Article J Clin Hypertens (Greenwich) · July 2013 In this secondary analysis of the Weight Loss Maintenance trial, the authors assessed the relationship between blood pressure (BP) change and weight change in overweight and obese adults with hypertension and/or dyslipidemia who were randomized to 1 of 3 w ... Full text Open Access Link to item Cite

The Dietary Approaches to Stop Hypertension (DASH) eating pattern in special populations.

Journal Article Curr Hypertens Rep · October 2012 The Dietary Approaches to Stop Hypertension (DASH) trial showed that a diet rich in fruits, vegetables, low-fat dairy products with reduced total and saturated fat, cholesterol, and sugar-sweetened products effectively lowers blood pressure in individuals ... Full text Open Access Link to item Cite