Principles and frequency of self-adjustment of insulin dose in people with diabetes mellitus type 1 and correlation with markers of metabolic control.
OBJECTIVE
Insulin dose self-adjustment (ISA) to different blood glucose levels, carbohydrate intake, exercise or illness is a core element of structured education programmes for people with diabetes mellitus type 1 (DM1). The aim of this study was to register the patients' current principles and frequency of ISA and to check the ability for correct adjustments.


METHODS
117 people with DM1 (mean HbA1c 7.1%, diabetes duration 24y) were interviewed in a tertiary care centre. The number of ISA was drawn from the last 28days of the patients' diary. The ability to find the correct insulin dose was assessed using five different calculation examples. All patients had participated in a structured education programme.


RESULTS
Mean frequency of ISA was 72.1±29.4 per 28days. ISA by adjustment rules was used in 48% (56/117) and by personal experience or feeling in 44% (52/117). Patients adjusting by feeling were older, did less ISA and had lower social status. There were no differences in HbA1c (feeling 7.2±0.8 vs. rules 7.0±0.9, p=0.403), non severe hypoglycaemia (feeling 1.7±1.8 vs. rules 1.9±1.9, p=0.132) and comprehensibility of ISA between both groups. Overall, the participants answered on average 2.8±2.3 of the five calculation examples correctly.


CONCLUSIONS
Although all people were trained to use a factor for correction for ISA in case of high premeal blood glucose levels, only half of the patients adjusted their insulin dosage using the complex rules from the treatment and education programme. Patients, who performed their ISA based upon feeling, did not show worse metabolic control.
Dept. Internal Medicine III, Jena University Hospital, Germany. Electronic address: guido.kramer@med.uni-jena.de.
Guido
G
Kramer
Dept. Internal Medicine III, Jena University Hospital, Germany.
Nadine
N
Kuniss
Dept. Internal Medicine III, Jena University Hospital, Germany.
Christof
C
Kloos
Institute of Medical Statistics, Computer Sciences and Documentation, Jena University Hospital, Germany.
Thomas
T
Lehmann
Dept. Internal Medicine III, Jena University Hospital, Germany.
Nicolle
N
Müller
Dept. Internal Medicine III, Jena University Hospital, Germany.
Gunter
G
Wolf
Institute of Nutrition, Friedrich-Schiller-University Jena, Germany; Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD), Halle-Jena-Leipzig, Germany.
Stefan
S
Lorkowski
Dept. Internal Medicine III, Jena University Hospital, Germany.
Ulrich A
UA
Müller
D000328:Adult; D000368:Aged; D015415:Biomarkers; D001786:Blood Glucose; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy*; D054796:Drug Dosage Calculations; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007003:Hypoglycemia / Q000188:drug therapy; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012648:Self Care / Q000379:methods*
D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; C517652:hemoglobin A1c protein, human
Diabetes mellitus type 1; Self-adjustment of insulin dose