Trial Outcomes & Findings for QT Interval Abnormalities in Sulfonylurea Treated Type 2 Diabetes: Relationship to Treatment Induced Hypoglycaemia (NCT NCT02298803)

NCT ID: NCT02298803

Last Updated: 2018-02-28

Results Overview

The nocturnal time period for the study spanned from 11 pm in the evening until 7 am the following morning on two consecutive days. The change in the corrected QT interval during nocturnal hypoglycemia was determined by calculating the difference between the average QTc interval length during periods of hypoglycemia (blood glucose level \<3.5 mmol/L) and the average QTc interval length during periods of normoglycemia (blood glucose level \>3.5 mmol/L) for the nocturnal time period. The average QTc interval was calculated using an individually optimised correction formula. If the result of average QTc (hypoglycemia) - average QTc (normoglycemia) was positive, the participant experienced QTc prolongation during hypoglycemia. If the result of average QTc (hypoglycemia) - average QTc (normoglycemia) was negative, the participant experienced QTc shortening during hypoglycemia.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

30 participants

Primary outcome timeframe

Nocturnal time period (2300-0700) during the 48 hours of Holter monitoring

Results posted on

2018-02-28

Participant Flow

Patients with type 2 diabetes attending the Diabetes Centre, Royal Prince Alfred Hospital who fulfilled the entry criteria were approached to participate. The requirements of the study were discussed and participants were given a copy of the Participant Information Sheet and Consent Form to read. 30 individuals were recruited in 2015.

30 participants were screened and enrolled. Data from all 30 participants was included in the analysis.

Participant milestones

Participant milestones
Measure
Holter and Glucose Monitoring
In this study all participants underwent simultaneous monitoring of glucose and QT interval via a subcutaneous continuous glucose monitor and a Hoter monitor, respectively. Holter and Glucose monitoring: (i) Continuous Glucose Monitoring A sterile disposable glucose-sensing sensor was inserted into the subcutaneous tissue in the abdomen of the patient. This sensor automatically measured the average glucose concentration in interstitial fluid every 5 minutes. The monitor was worn for 48 hours. (ii)Holter Monitoring The Holter monitor was worn for the same period as the continuous glucose monitor. QT intervals were extracted using proprietary software. Study participants were encouraged to perform regular daily activities during monitoring.
Overall Study
STARTED
30
Overall Study
COMPLETED
30
Overall Study
NOT COMPLETED
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Males and Females analysed separately

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Hypoglycemic Group
n=9 Participants
N=9; these participants experienced at least one episode of hypoglycaemia (blood glucose level \<3.5mmol/L) during the monitoring period.
Normoglycemic Group
n=21 Participants
N=21; these participants experienced no episodes of hypoglycaemia during the monitoring period.
Total
n=30 Participants
Total of all reporting groups
Age, Continuous
62.8 years
STANDARD_DEVIATION 10.2 • n=9 Participants
68.3 years
STANDARD_DEVIATION 7.4 • n=21 Participants
66.7 years
STANDARD_DEVIATION 8.6 • n=30 Participants
Sex: Female, Male
Female
3 Participants
n=9 Participants
9 Participants
n=21 Participants
12 Participants
n=30 Participants
Sex: Female, Male
Male
6 Participants
n=9 Participants
12 Participants
n=21 Participants
18 Participants
n=30 Participants
Region of Enrollment
Australia
9 participants
n=9 Participants
21 participants
n=21 Participants
30 participants
n=30 Participants
Ethnicity: Caucasian, Non-Caucasian
Caucasian
7 Participants
n=9 Participants
17 Participants
n=21 Participants
24 Participants
n=30 Participants
Ethnicity: Caucasian, Non-Caucasian
Non-Caucasian
2 Participants
n=9 Participants
4 Participants
n=21 Participants
6 Participants
n=30 Participants
Diabetes duration
15.0 years
n=9 Participants
14.0 years
n=21 Participants
14.5 years
n=30 Participants
Diabetes Treatment: Mono or dual therapy, Triple or quadruple therapy
Mono or dual therapy
5 Participants
n=9 Participants
9 Participants
n=21 Participants
14 Participants
n=30 Participants
Diabetes Treatment: Mono or dual therapy, Triple or quadruple therapy
Triple or quadruple therapy
4 Participants
n=9 Participants
12 Participants
n=21 Participants
16 Participants
n=30 Participants
HbA1c
6.6 %
STANDARD_DEVIATION 0.8 • n=9 Participants
7.0 %
STANDARD_DEVIATION 0.9 • n=21 Participants
6.9 %
STANDARD_DEVIATION 0.9 • n=30 Participants
Body Mass Index
31.8 kg/m2
STANDARD_DEVIATION 6.3 • n=9 Participants
31.2 kg/m2
STANDARD_DEVIATION 5.0 • n=21 Participants
31.3 kg/m2
STANDARD_DEVIATION 5.4 • n=30 Participants
Waist circumference
Male
113 cm
STANDARD_DEVIATION 13 • n=6 Participants • Males and Females analysed separately
107 cm
STANDARD_DEVIATION 11 • n=12 Participants • Males and Females analysed separately
109 cm
STANDARD_DEVIATION 13 • n=18 Participants • Males and Females analysed separately
Waist circumference
Female
108 cm
STANDARD_DEVIATION 10 • n=3 Participants • Males and Females analysed separately
108 cm
STANDARD_DEVIATION 11 • n=9 Participants • Males and Females analysed separately
108 cm
STANDARD_DEVIATION 10 • n=12 Participants • Males and Females analysed separately
Systolic Blood Pressure
122 mmHg
STANDARD_DEVIATION 10 • n=9 Participants
131 mmHg
STANDARD_DEVIATION 10 • n=21 Participants
128 mmHg
STANDARD_DEVIATION 11 • n=30 Participants
Smoking Status: Current, Former, Lifelong non-smoker
Current
2 Participants
n=9 Participants
0 Participants
n=21 Participants
2 Participants
n=30 Participants
Smoking Status: Current, Former, Lifelong non-smoker
Former
4 Participants
n=9 Participants
6 Participants
n=21 Participants
10 Participants
n=30 Participants
Smoking Status: Current, Former, Lifelong non-smoker
Lifelong non-smoker
3 Participants
n=9 Participants
15 Participants
n=21 Participants
18 Participants
n=30 Participants
Alcohol consumption status: Consumer, Abstainer
Consumer
5 Participants
n=9 Participants
17 Participants
n=21 Participants
22 Participants
n=30 Participants
Alcohol consumption status: Consumer, Abstainer
Abstainer
4 Participants
n=9 Participants
4 Participants
n=21 Participants
8 Participants
n=30 Participants
Microvascular Complication Status: Present, Absent
Present
1 Participants
n=9 Participants
8 Participants
n=21 Participants
9 Participants
n=30 Participants
Microvascular Complication Status: Present, Absent
Absent
8 Participants
n=9 Participants
13 Participants
n=21 Participants
21 Participants
n=30 Participants

PRIMARY outcome

Timeframe: Nocturnal time period (2300-0700) during the 48 hours of Holter monitoring

The nocturnal time period for the study spanned from 11 pm in the evening until 7 am the following morning on two consecutive days. The change in the corrected QT interval during nocturnal hypoglycemia was determined by calculating the difference between the average QTc interval length during periods of hypoglycemia (blood glucose level \<3.5 mmol/L) and the average QTc interval length during periods of normoglycemia (blood glucose level \>3.5 mmol/L) for the nocturnal time period. The average QTc interval was calculated using an individually optimised correction formula. If the result of average QTc (hypoglycemia) - average QTc (normoglycemia) was positive, the participant experienced QTc prolongation during hypoglycemia. If the result of average QTc (hypoglycemia) - average QTc (normoglycemia) was negative, the participant experienced QTc shortening during hypoglycemia.

Outcome measures

Outcome measures
Measure
Hypoglycemia Group
n=8 Participants
While there were nine study participants who experienced hypoglycemia during the entire study period, only eight of those participants experienced hypoglycemia during the nocturnal time period (2300-0700). Six study participants experienced isolated nocturnal hypoglycemia; two study participants experienced both nocturnal and day time hypoglycemia. Hypoglycemia during monitoring was defined as a blood glucose level \<3.5mmol/L that was sustained for a minimum of 20 consecutive minutes.
Change in the Corrected QT-interval During Nocturnal Hypoglycemia
QTc shortening during hypoglycemia
5 Participants
Change in the Corrected QT-interval During Nocturnal Hypoglycemia
QTc prolongation during hypoglycemia
3 Participants

PRIMARY outcome

Timeframe: Day time period (0700-2300) during the 48 hours of Holter monitoring

The day time period for the study spanned from 7 am in the morning until 11 pm in the evening on two consecutive days. The change in the corrected QT interval during day time hypoglycemia was determined by calculating the difference between the average QTc interval length during periods of hypoglycemia (blood glucose level \<3.5 mmol/L) and the average QTc interval length during periods of normoglycemia (blood glucose level \>3.5 mmol/L) for the day time period. The average QTc interval was calculated using an individually optimised correction formula. If the result of average QTc (hypoglycemia) - average QTc (normoglycemia) was positive, the participant experienced QTc prolongation during hypoglycemia. If the result of average QTc (hypoglycemia) - average QTc (normoglycemia) was negative, the participant experienced QTc shortening during hypoglycemia.

Outcome measures

Outcome measures
Measure
Hypoglycemia Group
n=3 Participants
While there were nine study participants who experienced hypoglycemia during the entire study period, only eight of those participants experienced hypoglycemia during the nocturnal time period (2300-0700). Six study participants experienced isolated nocturnal hypoglycemia; two study participants experienced both nocturnal and day time hypoglycemia. Hypoglycemia during monitoring was defined as a blood glucose level \<3.5mmol/L that was sustained for a minimum of 20 consecutive minutes.
Change in Corrected QT Interval During Day Time Hypoglycaemia
Experienced QTc prolongation during hypoglycemia
2 Participants
Change in Corrected QT Interval During Day Time Hypoglycaemia
Experienced QTc shortening during hypoglycemia
1 Participants

SECONDARY outcome

Timeframe: Nocturnal time period (2300-0700) during the 48 hours of Holter monitoring

Population: The eight study participants who experienced nocturnal hypoglycemia are included in the analysis population.

MAGE, a commonly used index of glucose variability, was calculated using data obtained during continuous glucose monitoring. Analysis of correlation between MAGE and delta QTc was undertaken. Please note delta QTc represents the difference between average QTc length during hypoglycemia and average QTc length during normoglycemia.

Outcome measures

Outcome measures
Measure
Hypoglycemia Group
n=8 Participants
While there were nine study participants who experienced hypoglycemia during the entire study period, only eight of those participants experienced hypoglycemia during the nocturnal time period (2300-0700). Six study participants experienced isolated nocturnal hypoglycemia; two study participants experienced both nocturnal and day time hypoglycemia. Hypoglycemia during monitoring was defined as a blood glucose level \<3.5mmol/L that was sustained for a minimum of 20 consecutive minutes.
Pearson's Correlation Coefficient of Delta QTc and a Measure of Glucose Variability, MAGE (Mean Amplitude of Glycemic Excursion).
0.09 Correlation coefficient

SECONDARY outcome

Timeframe: 48 hours of continuous glucose monitoring

Population: Only those participants who experienced nocturnal hypoglycemia (BGL \<3.5 mmol/L for \>20 minutes) are included in the analysis population

The MAGE results (in mmol/L) for the eight participants who experienced nocturnal hypoglycemia are included in the table below.

Outcome measures

Outcome measures
Measure
Hypoglycemia Group
n=8 Participants
While there were nine study participants who experienced hypoglycemia during the entire study period, only eight of those participants experienced hypoglycemia during the nocturnal time period (2300-0700). Six study participants experienced isolated nocturnal hypoglycemia; two study participants experienced both nocturnal and day time hypoglycemia. Hypoglycemia during monitoring was defined as a blood glucose level \<3.5mmol/L that was sustained for a minimum of 20 consecutive minutes.
Mean Amplitude of Glycemic Excursion (MAGE)
Participant 1
3.9 mmol/L
Mean Amplitude of Glycemic Excursion (MAGE)
Participant 24
4.3 mmol/L
Mean Amplitude of Glycemic Excursion (MAGE)
Participant 4
4.7 mmol/L
Mean Amplitude of Glycemic Excursion (MAGE)
Participant 5
3.0 mmol/L
Mean Amplitude of Glycemic Excursion (MAGE)
Participant 10
3.9 mmol/L
Mean Amplitude of Glycemic Excursion (MAGE)
Participant 15
1.8 mmol/L
Mean Amplitude of Glycemic Excursion (MAGE)
Participant 16
3.6 mmol/L
Mean Amplitude of Glycemic Excursion (MAGE)
Participant 19
5.7 mmol/L

SECONDARY outcome

Timeframe: Nocturnal time period (2300-0700) during the 48 hours of Holter monitoring

deltaQTc is the difference in QTc observed during periods of hypoglycemia and periods of normoglycemia (for those participants who experienced nocturnal hypoglycemia)

Outcome measures

Outcome measures
Measure
Hypoglycemia Group
n=8 Participants
While there were nine study participants who experienced hypoglycemia during the entire study period, only eight of those participants experienced hypoglycemia during the nocturnal time period (2300-0700). Six study participants experienced isolated nocturnal hypoglycemia; two study participants experienced both nocturnal and day time hypoglycemia. Hypoglycemia during monitoring was defined as a blood glucose level \<3.5mmol/L that was sustained for a minimum of 20 consecutive minutes.
deltaQTc
Participant 1
10 milliseconds
deltaQTc
Participant 4
4 milliseconds
deltaQTc
Participant 5
-2 milliseconds
deltaQTc
Participant 10
-6 milliseconds
deltaQTc
Participant 15
-4 milliseconds
deltaQTc
Participant 16
-1 milliseconds
deltaQTc
Participant 19
-8 milliseconds
deltaQTc
Participant 24
15 milliseconds

Adverse Events

Hypoglycemic Group

Serious events: 0 serious events
Other events: 9 other events
Deaths: 0 deaths

Normoglycemic Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Hypoglycemic Group
n=9 participants at risk
N=9; these participants experienced at least one episode of hypoglycaemia (blood glucose level \<3.5mmol/L) during the monitoring period.
Normoglycemic Group
n=21 participants at risk
N=21; these participants experienced no episodes of hypoglycaemia during the monitoring period.
Endocrine disorders
Hypoglycemia
100.0%
9/9 • Number of events 15
0.00%
0/21

Additional Information

Dr Ted Wu

Diabetes Centre, Royal Prince Alfred Hospital

Phone: 61295155888

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place