Borderline Hypokalemia Clinical Trial
Official title:
The Effects of Potassium on Glucose Metabolism in African Americans
| Verified date | September 2016 |
| Source | Duke University |
| Contact | n/a |
| Is FDA regulated | No |
| Health authority | United States: Institutional Review Board |
| Study type | Interventional |
African Americans suffer a disproportionately high risk of diabetes compared to other
Americans. Reasons for race disparities in diabetes incidence are not completely understood.
Although a difference in prevalence of obesity does explain a significant portion of the
racial disparity in diabetes risk, it does not explain all of this disparity. Strategies to
control the diabetes epidemic and reduce its racial disparity often overlook preventive
measures. Currently, the most powerful known strategy for preventing diabetes is weight loss
in the overweight/obese. However, because weight loss is often difficult to achieve and
maintain, other opportunities to prevent diabetes should be identified, particularly in
African Americans. Among potential novel opportunities is correction of low or low-normal
potassium levels (hypokalemia). In secondary analyses, we have found low-normal potassium
(K) to be a novel risk factor for diabetes; and we have found that this association between
low-K and diabetes risk may be stronger in African Americans compared to whites. Therefore,
a previously unrecognized alternative or adjunct strategy for preventing diabetes,
particularly in African Americans, may involve correction of low or low-normal K levels
(hypokalemia). Large-scale, adequately-powered, randomized controlled trials are needed to
establish the effectiveness of this approach. However, prior to those trials, the
pathophysiology of the association between low K and poor glucose metabolism must be
understood. This pilot clinical trial will begin to determine the effect of K
supplementation on measures of glucose metabolism in African Americans.
In this pilot clinical trial, 30 African Americans with prediabetes and a low-normal serum K
(<4.0 mEq/L) will be randomized to K-supplements, 20mEq (2-10mEq tablets) twice daily or a
matching placebo capsules twice daily. Prior to randomization, baseline measures will be
taken including measures of glucose metabolism with a 3-hour oral glucose tolerance test
(OGTT), baseline chemistries and a baseline 24-hour urinary potassium measurement. Patients
will take the intervention daily and will undergo repeat testing of all of these measures at
the end of a 3 month period. The primary endpoint will be change in glucose tolerance, as
measured by change in glucose area-under-the-curve (AUC) of a 3-hour oral glucose tolerance
test (OGTT). Secondary endpoints will include changes in fasting, 1-hour, and 2-hour
post-challenge glucose levels, as well as measurements of insulin secretion and insulin
sensitivity as measures by the oral glucose minimal model method.(1) The baseline data from
this trial will allow us to quantify abnormalities in glucose metabolism in African
Americans with prediabetes/early diabetes and low-normal serum K. The post-intervention data
will provide estimates of the impact of K-supplements compared to no supplements on these
abnormalities. Data derived from the pilot study will be used in the design of a larger
scale, adequately powered clinical trial. This trial will also help to assess the
feasibility of recruiting this target population.
With this pilot trial, we will begin to determine whether or not K-supplements, an
inexpensive, well-tolerated, and simple intervention, could help to reduce diabetes risk
among African Americans.
ON 1/31/2016 we stopped consenting/enrolling subjects. We consented a total of 61 subjects
of which 29 screened in and 32 screened out.
| Status | Completed |
| Enrollment | 61 |
| Est. completion date | February 2016 |
| Est. primary completion date | February 2016 |
| Accepts healthy volunteers | No |
| Gender | Both |
| Age group | 30 Years and older |
| Eligibility |
Inclusion Criteria: To be eligible for inclusion in the study the following enrollment criteria must be met: 1. Participants must be 30 years of age or older. 2. They must have a diagnosis of prediabetes defined as a hemoglobin A1c between 5.7-6.5% measured at the initial screening visit. 3. They must have a serum K+ of 3.3-4.0 mEq/L on 2 occasions, within a 18 month period, including at initial screening visit. If subject is just outsdie range for inclusion, PI may offer the subject the option to repeat their screening serum K+ measurement. 4. The participant must be willing and capable of providing written informed consent. 5. The participant must be available for follow-up and must at minimum have telephone access. 6. Participants must be able to readn/understand English. Exclusion Criteria: - Participants must not have any of the following: 1. Participants must not have evidence of chronic kidney disease with an estimated GFR < 60ml/min. All patients will be screened for eGFR at the enrollment visit. 2. Participants must not have evidence of diabetes mellitus requiring treatment with medications prior to screening visit. The cannot have a random or post-challenge glucose = 200mg/dl (from prior labs), A1c level = 6.5% (from prior labs), prior physician diagnosis, or use of anti-diabetic medications. If participants have glucose levels in the diabetic range at screening visit, they will be eligible to continue in study as long as glucose levels are not > 200 mg/dl. 3. Participants must not have a history of endoscopy-verified peptic ulcer disease with past history of either gastric or duodenal ulcer. 4. Participants must not have evidence of cardiac arrhythmias, unstable angina or cardiac event within 6 months, congestive heart failure, or other conditions that might impact follow-up, based on the discretion of the principal investigator. 5. Participants must not be pregnant or intend to get pregnant during the study period. The study intervention is safe for pregnant women, so serum pregnancy screening is not indicated; however, pregnant women are excluded because pregnancy affects glucose homeostasis, which will bias primary outcome measurement and damage scientific validity of the study. |
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Treatment
| Country | Name | City | State |
|---|---|---|---|
| United States | Duke University Medical Center | Durham | North Carolina |
| Lead Sponsor | Collaborator |
|---|---|
| Duke University |
United States,
| Type | Measure | Description | Time frame | Safety issue |
|---|---|---|---|---|
| Primary | Change in Glucose Tolerance | Change in glucose tolerance, as measured by change in glucose area-under-the-curve (AUC) of a 3-hour oral glucose tolerance test (OGTT). | 3 months | No |
| Secondary | Changes in fasting, 1-hour, and 2-hour post-challenge glucose levels | Changes in fasting, 1-hour, and 2-hour post-challenge glucose levels | 3 months | No |
| Secondary | Changes in Insulin Secretion | Changes in insulin secretion as measured by OGTT Minimal Model Analyses Method of Cobelli et al, Diabetes 63: 1203-1213, 2014, using plasma c-peptide & insulin values obtained at 0, 10, 20, 30, 60, 90, 120, 180 minutes after a standard 75 gram oral glucose challenge. | 3 months | No |
| Secondary | Changes in Insulin Sensitivity | Changes in insulin sensitivity by Oral glucose tolerance test Minimal Model analyses of Cobelli et al., Diabetes 63: 1203-1213, 2014 | 3 months | No |