Stress and CKD Among African Americans

The goal of this study is to determine whether experiencing stress from discrimination may increase chronic kidney disease (CKD) progression in African Americans. Study participation occurs over the course of 2 days, and participant time burden is expected to be about 4.5 hours, plus a 24-hour period of wearing a blood pressure monitor.

On Day 1, the project coordinator will explain the study to participants and answer any questions he/she may have. Those who agree to participate in the study will provide consent at the clinic and will also be asked to complete a questionnaire on an iPad in a small, private room at the clinic. The participant will complete the questionnaire alone, however, the project coordinator will read questions aloud if the participant chooses. Before leaving on Day 1, participants will fitted with a blood pressure monitor to be worn for the next 24 hours. The clinical intervention portion of the study occurs during the morning of Day 2 (between 9:00 AM and 11:00 AM). Participants will be instructed to bring the blood pressure monitor and a list of current medications (or the actual medications) with them. First, participants will provide a urine sample and undergo blood pressure testing. A research nurse will insert a catheter (a small thin tube) into the participant's vein, and allow a 30-minute resting period so that the participant gets used to the catheter, and then take a baseline blood draw. Participants will judge how distressed they feel in that moment using a standard scale and tell the project coordinator his/her rating. Next, participants will be randomized to one of two study arms such that half will recall the racial experience and half will recall the non-racialized stressful event. An audience of two observers of same race will wear white coats and watch as the participants recall the stressful events. The research nurse will draw blood and take blood pressure measurements at multiple time points during both recall experiences. Immediately before and after each recall task, the participant will again judge how distressed he/she is feeling in that moment using the same scale as before. The project coordinator will explain the purpose of the story recall and common ways that individuals may respond to the task (such as feeling anxious after the task). A total of 100 people will take part in this study.

Of the 100 participants recruited, 80 will have a diagnosis of chronic kidney disease (CKD) and 20 will not. Participants will be randomized such that half will recall the racial experience and half will recall the non-racialized stressful event. Each participant will have an equal chance of being placed in the racialized or non-racialized experience group.

Participants will undergo a moderate psychological stress adapted from the Trier Social Stress Test (TSST) where they will be asked to recall a stressful, real-life, race-related event. After instructions are provided, participants will be given two minutes to prepare their statement, and three minutes to deliver their statement. There will be an 'audience' present at each participant's speaking task which will include two observers who are of same race as the participant (African American), to heighten stress responses.

Participants will undergo a moderate psychological stress adapted from the Trier Social Stress Test (TSST) where they will be asked to recall a stressful, real-life, event unrelated to race. After instructions are provided, participants will be given two minutes to prepare their statement, and three minutes to deliver their statement. There will be an 'audience' present at each participant's speaking task which will include two observers who are of same race as the participant (African American), to heighten stress responses.

Level of distress will be measured with the Subjective Units of Distress Scale (SUDS). Participants rate their distress on a linear scale from 0 to 100, where 0 = No distress; totally relaxed, 50 = Moderate anxiety/distress; uncomfortable, but can continue to function, 100 = Highest anxiety/distress ever felt. The SUDS will be administered at baseline and after the first stress task. The change in SUDS scores is presented here. Scores above zero mean that the participants experienced an increase in distress following the stress task.

Participants will report their level of stress directly related to reliving the stressful experience using an adapted version of Cooper's Racism Recall Scale. Participants reported their level of distress at the time of the event and currently while thinking about the event, on a linear scale from 0 to 10 where higher values indicate higher distress. Values presented here are the change from baseline and values greater than 0 mean that stress increased from before (baseline) and after the stressful event recall.

Monocyte Chemoattractant Protein-1 (MCP-1) is an inflammatory marker that is sensitive to acute stress induction and is associated with chronic kidney disease (CKD). Blood will be drawn three times, at 30 minutes after the IV catheter is inserted (prior to the stressful event recall) and after each 45 minute recovery period following the stress tests, in order to compare MCP-1 levels at before and after the study intervention. Increased MCP-1 indicates an increased inflammatory response. MCP-1 levels will be quantitated by the MesoScale system (MSD Rockville, Maryland) according to the protocols supplied by the manufacturer, which uses electrochemiluminescence for high sensitivity with a dynamic range of 0.09-375 pg/mL. Values presented here are the difference between the baseline and post-intervention blood draws and values greater than 0 indicate that there is an increase in inflammatory response post-intervention.

Interleukin-6 (IL-6) is an inflammatory marker that is sensitive to acute stress induction and is associated with CKD. Blood will be drawn three times, at 30 minutes after the IV catheter is inserted (prior to the intervention) and after each 45 minute recovery period following the stress tests, in order to compare IL-6 levels at before and after the study intervention. IL-6 is influenced by a variety of factors and increases in IL-6 indicate an increased inflammatory response. IL-6 levels will be quantitated by the MesoScale system (MSD Rockville, Maryland) according to the protocols supplied by the manufacturer, which uses electrochemiluminescence for high sensitivity with a dynamic range of 0.06-488 pg/mL. Values presented here are the difference between the baseline and post-intervention blood draws and values greater than 0 indicate that there is an increase in inflammatory response post-intervention.

Soluble urokinase-type plasminogen activator receptor (suPAR) is an inflammatory marker that is sensitive to acute stress induction and is associated with CKD. Blood will be drawn three times at 30 minutes after the IV catheter is inserted (prior to the intervention) and after each 45 minute recovery period following the stress tests, in order to compare suPAR levels at before and after the study intervention. Increases in suPAR indicate an increased inflammatory response. suPAR will be measured with the Virogates (CEDARLANE Laboratories, Burlington, NC) suPARnostic® ELISA, according to the protocols supplied by the manufacturer. This assay has a high sensitivity (0.1 ng/mL) giving consistently quantitative results in plasma samples. Values presented here are the difference between the baseline and post-intervention blood draws and values greater than 0 indicate that there is an increase in inflammatory response post-intervention.

Blood pressure readings will be taken at baseline and every 5 minutes during the experimental manipulation, except during the recall task when blood pressure will be measured every 1 minute. Mean systolic blood pressure scores for rest, recall task, and recovery will be calculated by averaging the readings taken during each period. Blood pressure reactivity will be a change score, calculated as the mean of the scores during the recall task minus the mean of the scores during rest, designed to represent the change in systolic blood pressure induced by the recall task. Values greater than 0 are the mean increase in systolic blood pressure following the intervention, compared to the baseline time period.

Blood pressure readings will be taken at baseline and every 5 minutes during the experimental manipulation, except during the recall task when blood pressure will be measured every 1 minute. Mean diastolic blood pressure scores for rest, recall task, and recovery will be calculated by averaging the readings taken during each period. Blood pressure reactivity will be a change score, calculated as the mean of the scores during the recall task minus the mean of the scores during rest, designed to represent the change in diastolic blood pressure induced by the recall task. Values greater than 0 are the mean increase in diastolic blood pressure following the intervention, compared to the baseline time period.

Inclusion Criteria: Patient at Emory University Hospital Midtown Self-identify as African American or Black Estimated glomerular filtration rate (eGFR) ≥ 15, or <90 Exclusion Criteria: Mental disorder that prevents the completion of the Computer Assisted Personal Interview (CAPI) and the stressful recall manipulation Currently on maintenance dialysis Unable or unwilling to undergo intravenous catheterization

Arriola KJ, Lewis TT, Pearce B, Cobb J, Weldon B, Valentin MIZ, Lea J, Vaccarino V. A randomized trial of race-related stress among African Americans with chronic kidney disease. Psychoneuroendocrinology. 2021 Sep;131:105339. doi: 10.1016/j.psyneuen.2021.105339. Epub 2021 Jun 18.