Chronic Kidney Diseases, Cognitive Decline
Conditions
Brief summary
The proposed research is clinical study evaluating the therapeutic benefits of curcumin on vascular function in patients with chronic kidney disease (CKD). The study aims to establish that curcumin will improve endothelial function and reduce large artery stiffness by reducing oxidative stress and in conjunction with lowering markers of inflammation and oxidative stress. In addition, the study will evaluate the potential benefit of curcumin on cognitive function in patients with CKD.
Detailed description
Patients with chronic kidney disease (CKD) are at increased risk of death from cardiovascular disease (CVD). Inflammation, oxidative stress and vascular dysfunction (impaired endothelial function and increased large elastic artery stiffness), are highly prevalent in CKD and contribute to the high incidence of CVD in this patient population. In addition, patients with CKD suffer from high rates of cognitive decline for which we lack effective therapies. Thus, therapeutic interventions targeting inflammation, oxidative stress, vascular dysfunction, and cognitive impairment in CKD are a biomedical priority. Curcumin is a natural polyphenol with anti-inflammatory and antioxidant characteristics. It is safe and widely-available. Preliminary data in old mice and healthy middle-aged (MA)/older adult humans indicate that curcumin administration improves endothelial dysfunction and large artery stiffness by reducing oxidative stress and inflammation. Additionally, 12 weeks of curcumin supplementation improves episodic memory in MA/older adults. The primary goal of this R01 application is to extend previous findings in healthy MA/older adults to patients with CKD, a growing clinical population with extensive baseline vascular dysfunction and cognitive impairment who presently have few treatment options. The hypothesis is that curcumin improves vascular endothelial function and large elastic artery stiffness in MA/older adults with stage IIIb and IV CKD (estimated GFR 15-45 mL/min/1.73m2). The possible mechanisms by which curcumin improves vascular function will be evaluated as well as whether curcumin improves cognitive function in these patients. Specific aim 1a will determine if 12 months of curcumin supplementation will improve brachial artery-flow mediated dilation (BA-FMD) (endothelial function) and aortic pulse wave velocity (aPWV) (arterial stiffness) compared to placebo (randomized placebo-controlled double-blind study). Specific aim 1b will evaluate whether the curcumin-induced improvements in BA-FMD and aPWV are mediated by reduced oxidative stress, and will evaluate the effects of curcumin on systemic and endothelial cell markers of inflammation and oxidative stress. Importantly, specific aim 2 will evaluate the effects of curcumin supplementation on cognitive function, an important complication of CKD, using the NIH Cognitive Toolbox Battery.
Interventions
Oral supplement for 12 months
Oral placebo for 12 months
Sponsors
Study design
Masking description
Patient, providers, and the investigative team will all be blinded to the randomization.
Intervention model description
Randomized Double-Blind Placebo-Controlled Clinical Trial
Eligibility
Inclusion criteria
* CKD stage IIIB and IV * BMI\<35 kg/m2 * Able to give informed consent
Exclusion criteria
* Consuming a diet rich in curcumin or taking curcumin supplements in the past 12 months * Life expectancy \<1 year * Pregnant, breastfeeding, or unwilling to use adequate birth control * Uncontrolled hypertension * Severe liver disease * Severe congestive heart failure * Hospitalization within the last 3 months * Active infection or antibiotic therapy * Immunosuppressive therapy within the last year
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Vascular Endothelial Function at 12 Months | 12 months | Brachial artery flow-mediated dilation, changed in diameter in brachial artery in response to shear stress |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Large Artery Stiffness | 12 months | Aortic pulse wave velocity |
| Cognitive Function | 12 months | NIH toolbox battery- Executive Function Age-Corrected Standard Score is reported (T-score): This score compares the score of the test-taker to those in the NIH Toolbox nationally representative normative sample at the same age, where a score of 100 indicates performance that was at the national average for the test-taking participant's age. Age-corrected standard scores were derived separately for children (ages 3-17) and adults (ages 18-85). A score of 115 or 85, for example, would indicate that the participant's performance is 1 SD above or below the national average, respectively, when compared with like-aged participants. Higher scores indicate better performance. |
Countries
United States
Participant flow
Recruitment details
Study participants were recruited between June 2018 and February 2022 from the Renal Clinics at the University of Iowa Hospital and Clinics (UIHC) and the Iowa City Veterans Affairs Health Care System (VA HCS). All procedures were approved by the University of Iowa and the Iowa City VA HCS Institutional Review Boards and conducted in accordance with the Declaration of Helsinki. All participants provided written documentation of the informed consent process before study participation.
Participants by arm
| Arm | Count |
|---|---|
| Curcumin Patients will receive curcumin (Lonvida) 2000 mg PO once a day
Curcumin: Oral supplement for 12 months | 45 |
| Placebo Patients will receive placebo pill identical in appearance and taste to the supplement
Placebo: Oral placebo for 12 months | 43 |
| Total | 88 |
Baseline characteristics
| Characteristic | Curcumin | Placebo | Total |
|---|---|---|---|
| Age, Continuous | 66 years STANDARD_DEVIATION 8 | 65 years STANDARD_DEVIATION 8 | 66 years STANDARD_DEVIATION 8 |
| Brachial artery flow-mediated dilation | 2.8 % change | 2.6 % change | 2.7 % change |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 1 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 45 Participants | 42 Participants | 87 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 4 Participants | 1 Participants | 5 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) White | 41 Participants | 40 Participants | 81 Participants |
| Region of Enrollment United States | 45 participants | 43 participants | 88 participants |
| Sex: Female, Male Female | 10 Participants | 12 Participants | 22 Participants |
| Sex: Female, Male Male | 35 Participants | 31 Participants | 66 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 1 / 45 | 0 / 43 |
| other Total, other adverse events | 27 / 45 | 21 / 43 |
| serious Total, serious adverse events | 0 / 45 | 0 / 43 |
Outcome results
Change in Vascular Endothelial Function at 12 Months
Brachial artery flow-mediated dilation, changed in diameter in brachial artery in response to shear stress
Time frame: 12 months
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Curcumin | Change in Vascular Endothelial Function at 12 Months | -0.1 %change |
| Placebo | Change in Vascular Endothelial Function at 12 Months | -0.7 %change |
Cognitive Function
NIH toolbox battery- Executive Function Age-Corrected Standard Score is reported (T-score): This score compares the score of the test-taker to those in the NIH Toolbox nationally representative normative sample at the same age, where a score of 100 indicates performance that was at the national average for the test-taking participant's age. Age-corrected standard scores were derived separately for children (ages 3-17) and adults (ages 18-85). A score of 115 or 85, for example, would indicate that the participant's performance is 1 SD above or below the national average, respectively, when compared with like-aged participants. Higher scores indicate better performance.
Time frame: 12 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Curcumin | Cognitive Function | 2.62 age-adjusted T-score | Standard Deviation 9 |
| Placebo | Cognitive Function | 2.25 age-adjusted T-score | Standard Deviation 9.5 |
Large Artery Stiffness
Aortic pulse wave velocity
Time frame: 12 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Curcumin | Large Artery Stiffness | 0.28 m/s | Standard Deviation 2.4 |
| Placebo | Large Artery Stiffness | 0.36 m/s | Standard Deviation 4.2 |