Borderline Hypokalemia Clinical Trial
Official title:
The Effects of Potassium on Glucose Metabolism in African Americans
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.
n/a
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Treatment