Predictors of mortality in patients with type 2 diabetes with or without diabetic nephropathy: a follow-up study.
OBJECTIVE
To evaluate the prognostic significance of cardiovascular risk factors including 24-h ambulatory blood pressure level and rhythm for all-cause mortality in type 2 diabetic patients.


METHODS
In a prospective observational study, 104 patients with type 2 diabetes were followed: 51 patients with diabetic nephropathy and 53 patients with persistent normoalbuminuria. At baseline, 24-h ambulatory blood pressure, left ventricular hypertrophy, glomerular filtration rate and cardiac autonomic neuropathy were measured. Blood samples were taken and patients answered a World Health Organization questionnaire. Dipping was calculated as the average nocturnal reduction in systolic and diastolic blood pressure.


RESULTS
Mean follow-up was 9.2 years (range 0.5-12.9). During follow-up, 54 of 104 patients died. Sixteen patients (15%) had higher blood pressure at night than during the day (reversed pattern); 14 of these patients died (88%), compared to 40 of 88 patients (45%) with reduced dipping or normal dipping; log rank P = 0.001. In a Cox regression analysis, predictors of all-cause mortality were: age, male sex, presence of left ventricular hypertrophy, glycated haemoglobin A1c (HbA1c), daytime systolic blood pressure, cardiac autonomic neuropathy, glomerular filtration rate and dipping (1% increase; hazard ratio 0.97, 95% confidence interval 0.94-0.998, P = 0.033).


CONCLUSIONS
Type 2 diabetes patients with non-dipping of night blood pressure were at higher risk of death as compared to dippers, independent of known cardiovascular risk factors. Since non-dipping has a high prevalence in patients with diabetic nephropathy, 24-h ambulatory blood pressure should be used to assess a full risk profile and blood pressure-lowering therapy in these patients.
Astrup
Anne Sofie
AS
Steno Diabetes Center, Gentofte, Denmark. ansa@steno.dk
Nielsen
Flemming S
FS
Rossing
Peter
P
Ali
Samir
S
Kastrup
Jens
J
Smidt
Ulla Meng
UM
Parving
Hans-Henrik
HH
D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure / Q000502:physiology; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm / Q000502:physiology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000401:mortality* / Q000503:physiopathology; D003928:Diabetic Nephropathies / Q000150:complications* / Q000401:mortality* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
D000959:Antihypertensive Agents