Differential Post-Exercise Blood Pressure Responses between Blacks and Caucasians

Post-exercise hypotension (PEH) is widely observed in Caucasians (CA) and is associated with histamine receptors 1- and 2- (H1R and H2R) mediated post-exercise vasodilation. However, it appears that blacks (BL) may not exhibit PEH following aerobic exercise. Hence, this study sought to determine the extent to which BL develop PEH, and the contri- bution of histamine receptors to PEH (or lack thereof) in this population. Forty-nine (22 BL, 27 CA) young and healthy subjects completed the study. Subjects were randomly assigned to take either a combined H1R and H2R antagonist (fexofenadine and ranitidine) or a con- trol placebo. Supine blood pressure (BP), cardiac output and peripheral vascular resistance measurements were obtained at baseline, as well as at 30 min, 60 min and 90 min after 45 min of treadmill exercise at 70% heart rate reserve. Exercise increased diastolic BP in young BL but not in CA. Post-exercise diastolic BP was also elevated in BL after exercise with histamine receptor blockade. Moreover, H1R and H2R blockade elicited differential responses in stroke volume between BL and CA at rest, and the difference remained follow- ing exercise. Our findings show differential BP responses following exercise in BL and CA, and a potential role of histamine receptors in mediating basal and post-exercise stroke vol- ume in BL. The heightened BP and vascular responses to exercise stimulus is consistent with the greater CVD risk in BL

Differential Post-Exercise Blood Pressure Responses between Blacks and Caucasians

Post-exercise hypotension (PEH) is widely observed in Caucasians (CA) and is associated with histamine receptors 1- and 2- (H1R and H2R) mediated post-exercise vasodilation. However, it appears that blacks (BL) may not exhibit PEH following aerobic exercise. Hence, this study sought to determine the extent to which BL develop PEH, and the contri- bution of histamine receptors to PEH (or lack thereof) in this population. Forty-nine (22 BL, 27 CA) young and healthy subjects completed the study. Subjects were randomly assigned to take either a combined H1R and H2R antagonist (fexofenadine and ranitidine) or a con- trol placebo. Supine blood pressure (BP), cardiac output and peripheral vascular resistance measurements were obtained at baseline, as well as at 30 min, 60 min and 90 min after 45 min of treadmill exercise at 70% heart rate reserve. Exercise increased diastolic BP in young BL but not in CA. Post-exercise diastolic BP was also elevated in BL after exercise with histamine receptor blockade. Moreover, H1R and H2R blockade elicited differential responses in stroke volume between BL and CA at rest, and the difference remained follow- ing exercise. Our findings show differential BP responses following exercise in BL and CA, and a potential role of histamine receptors in mediating basal and post-exercise stroke vol- ume in BL. The heightened BP and vascular responses to exercise stimulus is consistent with the greater CVD risk in BL

Peer-Led Diabetes Self-Management Program for Patients With Glycated Hemoglobin Values Greater Than 7%

INTRODUCTION: Type II diabetes mellitus is the 7th leading cause of death in Kalamazoo County. Glycated hemoglobin (HbA1c) is a biomarker used to evaluate blood glucose control spanning a 3-month period; a value \u3e7% indicates poorly controlled diabetes over the past 3 months. PURPOSE: To determine the effectiveness of a free diabetes self-management program when implemented in Kalamazoo County. METHODS: Nineteen individuals (5 males, 14 females, average age 58 years, range 39 to 82 years) with type II diabetes mellitus and a self-reported HbA1c \u3e7% enrolled in the study. These individuals began a 6-week diabetes self-management program, during which participants met in small groups for 2.5 hours each week. The focus of this program was for participants to build skills that enabled them to better manage their chronic disease by improving problem solving, nutrition, blood glucose monitoring, and working with healthcare providers. HbA1c values were obtained via medical records prior to program completion (baseline) and 3-months post-program. Surveys that evaluated subjective information were also obtained at baseline and 3-months post-program. RESULTS: Nearly 950 members of the Kalamazoo community with type II diabetes mellitus were contacted to participate in this free self-management program. Recruitment was a challenge as only 99 verbally agreed they would attend the program, of which 48 attended the first session and 19 of those enrolled in the study. Five participants were excluded due to medical-record-documented HbA1c values \u3c7%, 6 did not complete the program, and 1 was lost to follow-up. Of the 7 participants who completed their 3-month follow-up, most variables exhibited desirable trends from baseline to 3-months post-program, and those that remained unchanged were already within a desirable range at baseline. The variables closest to significance were an increase in median self-efficacy score (49 to 78 using a 0-80 scale, p = 0.062) and a decrease in median HbA1c (10.2% to 8.5%, p = 0.31). DISCUSSION: Despite limited statistical power due to small sample size, this program provided valuable education to many community members who may be considered underserved and have HbA1c values as high as 14%. Future work is needed to analyze the healthcare barriers these individuals endure and how they may be overcome. Facilitation of healthcare provider referral to the program may be an option that encourages both participant adherence and expansion of this low-cost diabetes education model throughout the community

Exercise hemodynamic and water intake.

<p>Exercise hemodynamic and water intake.</p

Subject characteristics.

<p>Subject characteristics.</p

A schematic of the study design showing the procedures for each visit.

<p>Subjects underwent testing to determine peak oxygen uptake (VO_2peak) and a blood draw prior to randomization to placebo or histamine blockade (Visit 1). The order in which the blockade/placebo (visits 2 or 3) were administered was randomized. During study visits 2 and 3, cardiovascular (CV) measurements were obtained at rest and at 30 min, 60 min and 90 min post-exercise (during recovery).</p

Systemic vascular conductance (SVC) at baseline and at 30 min, 60 min and 90 min following aerobic exercise in the control condition (A) and H₁R and H₂R blockade condition (B).

<p>* Significant blockade by time interaction. § Significant main effect of time (p<0.05). ‡ BL had significantly lower SVC compared to CA at PRE in the blockade condition (p<0.05).</p