The aim now is to perform a large, prospective trial to test Twizzlers® as a cost effective
glucola alternative in a gravid population to determine its sensitivity, specificity, PPV
(positive predictive value) and NPV (negative predictive value) alongside ROC (receiver
operating curve) from a population-based cohort.
Participants will be enrolled among the pregnant patients in the Harris Health System
Obstetrics Clinics who are either due for the standard glucola GCT (glucose challenge test)
or who have had their glucola screening but have not had the 3 hour GTT (glucose tolerance
test). These women will be offered the opportunity to consume the Twizzler equivalent of the
50 gm glucola beverage (10 strawberry flavored Twizzlers) and to have their venous blood
glucose checked 1 hour post consumption. This will all be done while the patient is in clinic
and will not necessitate any extra clinic visits on their behalf. They will then go on to be
scheduled for their confirmatory 3 hour glucose tolerance tests if indicated by any
abnormality in either their glucola GCT or their Twizzlers challenge. The efficacy of
Twizzlers will then be compared to the 50 gm glucola beverage as a screen for gestational
diabetes. Specifically, the sensitivity, specificity, PPV, NPV, NNT (number needed to treat),
ROC, and referral rates for each mode of screening will be calculated.
For the Twizzler portion of the study, the subjects will consume 10 strawberry Twizzlers
within 5 minutes. One hour after consumption begins each participant will have a blood draw
to check a serum glucose level. Within the same day, the samples will be delivered to Dr.
Morey Haymond's lab for analysis.
Serum glucose and insulin levels will be tested on each sample. The amount of each blood
sample will be approximately 10 ml of blood (2 teaspoons). Sample collection (blood draws;
venipuncture) will allow for testing the serum glucose levels of subjects after consumption
of Twizzlers. These values will be used for analysis to determine if Twizzlers are truly
equivalent to the Glucola beverage. Ultimately, the patient's will only undergo 1 extra
venipuncture than what they would have had as part of their routine prenatal care if both
screening tests are normal. There is a possibility of undergoing a 3 hour GTT that would not
have otherwise been performed if the subjects Twizzlers screen is elevated but glucola was
normal.
Participants will receive a phone call to report any abnormal values on their GCT as per
standard clinical operating measures, and will have their GTT scheduled with the nursing
staff. Based on prior studies, a notable rate of false-positives is not anticipated with the
Twizzler GCT. In the rare occasion that such occurs (i.e., screen positive by Twizzler but
not by glucola beverage) they will be informed of the need for a 3 hour GTT. This will be
covered by the study costs, and their insurance will not be charged.
Pregnancy outcomes data for subjects will be collected, including gestational age at
delivery, mode of delivery and any complications, maternal weight gain, and infant
birthweight. This will all be acquired as data abstraction from the EMR and maintained in a
secure coded database.
Otherwise, there will be no further contact or requirements of the subject.