Self-monitoring of blood glucose in type 2 diabetes and long-term outcome: an epidemiological cohort study.
OBJECTIVE
The aim of this study was to obtain epidemiological data on self-monitoring of blood glucose (SMBG) in type 2 diabetes and to investigate the relationship of SMBG with disease-related morbidity and mortality.


METHODS
The German multicentre Retrolective Study 'Self-monitoring of Blood Glucose and Outcome in Patients with Type 2 Diabetes' (ROSSO) followed 3,268 patients from diagnosis of type 2 diabetes between 1995 and 1999 until the end of 2003. Endpoints were diabetes-related morbidity (non-fatal myocardial infarction, stroke, foot amputation, blindness or haemodialysis) and all-cause mortality. SMBG was defined as self-measurement of blood glucose for at least 1 year.


RESULTS
During a mean follow-up period of 6.5 years, 1,479 patients (45.3%) began SMBG prior to an endpoint and an additional 64 patients started SMBG after a non-fatal endpoint. Interestingly, many patients used SMBG while being treated with diet or oral hypoglycaemic drugs (808 of 2,515, 32%). At baseline, the SMBG cohort had higher mean fasting blood glucose levels than the non-SMBG cohort (p<0.001), suggesting that insufficient metabolic control was one reason for initiating SMBG. This was associated with a higher rate of microvascular endpoints. However, the total rate of non-fatal events, micro- and macrovascular, was lower in the SMBG group than in the non-SMBG group (7.2 vs 10.4%, p=0.002). A similar difference was found for the rate of fatal events (2.7 vs 4.6%, p=0.004). Cox regression analysis identified SMBG as an independent predictor of morbidity and mortality, with adjusted hazard ratios of 0.68 (95% CI 0.51-0.91, p=0.009) and 0.49 (95% CI 0.31-0.78, p=0.003), respectively. A better outcome for both endpoints was also observed in the SMBG cohort when only those patients who were not receiving insulin were analysed.


CONCLUSIONS
SMBG was associated with decreased diabetes-related morbidity and all-cause mortality in type 2 diabetes, and this association remained in a subgroup of patients who were not receiving insulin therapy. SMBG may be associated with a healthier lifestyle and/or better disease management.
Martin
S
S
German Diabetes Clinic, German Diabetes Centre at the Heinrich-Heine-University, Dusseldorf, Auf'm Hennekamp 65, 40225 Dusseldorf, Germany. martin@ddz.uni-duesseldorf.de
Schneider
B
B
Heinemann
L
L
Lodwig
V
V
Kurth
H-J
HJ
Kolb
H
H
Scherbaum
W A
WA
D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D015190:Blood Glucose Self-Monitoring / Q000706:statistics & numerical data*; D015331:Cohort Studies; D048909:Diabetes Complications / Q000453:epidemiology / Q000401:mortality; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology* / Q000401:mortality; D019468:Disease Management; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012044:Regression Analysis; D012189:Retrospective Studies; D016019:Survival Analysis
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin