Q-Score: development of a new metric for continuous glucose monitoring that enables stratification of antihyperglycaemic therapies.
BACKGROUND
Continuous glucose monitoring (CGM) has revolutionised diabetes management. CGM enables complete visualisation of the glucose profile, and the uncovering of metabolic 'weak points'. A standardised procedure to evaluate the complex data acquired by CGM, and to create patient-tailored recommendations has not yet been developed. We aimed to develop a new patient-tailored approach for the routine clinical evaluation of CGM profiles. We developed a metric allowing screening for profiles that require therapeutic action and a method to identify the individual CGM parameters with improvement potential.


METHODS
Fifteen parameters frequently used to assess CGM profiles were calculated for 1,562 historic CGM profiles from subjects with type 1 or type 2 diabetes. Factor analysis and varimax rotation was performed to identify factors that accounted for the quality of the profiles.


RESULTS
We identified five primary factors that determined CGM profiles (central tendency, hyperglycaemia, hypoglycaemia, intra- and inter-daily variations). One parameter from each factor was selected for constructing the formula for the screening metric, (the 'Q-Score'). To derive Q-Score classifications, three diabetes specialists independently categorised 766 CGM profiles into groups of 'very good', 'good', 'satisfactory', 'fair', and 'poor' metabolic control. The Q-Score was then calculated for all profiles, and limits were defined based on the categorised groups (<4.0, very good; 4.0-5.9, good; 6.0-8.4, satisfactory; 8.5-11.9, fair; and ≥12.0, poor). Q-Scores increased significantly (P <0.01) with increasing antihyperglycaemic therapy complexity. Accordingly, the percentage of fair and poor profiles was higher in insulin-treated compared with diet-treated subjects (58.4% vs. 9.3%). In total, 90% of profiles categorised as fair or poor had at least three parameters that could potentially be optimised. The improvement potential of those parameters can be categorised as 'low', 'moderate' and 'high'.


CONCLUSIONS
The Q-Score is a new metric suitable to screen for CGM profiles that require therapeutic action. Moreover, because single components of the Q-Score formula respond to individual weak points in glycaemic control, parameters with improvement potential can be identified and used as targets for optimising patient-tailored therapies.
Institute for Diabetes "Gerhardt Katsch" Karlsburg, Greifswalder Str. 11e, 17495, Karlsburg, Germany. info@diabetes-karlsburg.de.
Petra
P
Augstein
Institute for Diabetes "Gerhardt Katsch" Karlsburg, Greifswalder Str. 11e, 17495, Karlsburg, Germany. heinke@diabetes-karlsburg.de.
Peter
P
Heinke
Diabetes Service Center Karlsburg, Greifswalder Str. 11e, 17495, Karlsburg, Germany. vogt@diabetes-service-center.de.
Lutz
L
Vogt
Ernst-Moritz-Arndt Universität Greifswald, Domstraße 11, 17487, Greifswald, Germany. rvogt@ibvnet.de.
Roberto
R
Vogt
Institute for Diabetes "Gerhardt Katsch" Karlsburg, Greifswalder Str. 11e, 17495, Karlsburg, Germany. ch.rackow@web.de.
Christine
C
Rackow
Institute for Diabetes "Gerhardt Katsch" Karlsburg, Greifswalder Str. 11e, 17495, Karlsburg, Germany. kohnert@diabetes-karlsburg.de.
Klaus-Dieter
KD
Kohnert
Institute for Diabetes "Gerhardt Katsch" Karlsburg, Greifswalder Str. 11e, 17495, Karlsburg, Germany. salzsied@diabetes-karlsburg.de.
Eckhard
E
Salzsieder
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015190:Blood Glucose Self-Monitoring / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000175:diagnosis*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007206:Individuality; D008297:Male; D008875:Middle Aged; D057285:Precision Medicine / Q000379:methods; D011379:Prognosis; D012107:Research Design
D007004:Hypoglycemic Agents