Effect of tight control of HbA1c and blood pressure on cardiovascular diseases in type 2 diabetes: An observational study from the Swedish National Diabetes Register (NDR)

Cederholm, Jan; Zethelius, Björn; Nilsson, Peter M.; Eeg-Olofsson, Katarina; Eliasson, Björn; Gudbjörnsdottir, Soffia; on behalf of the Swedish National Diabetes Register,

doi:10.1016/j.diabres.2009.07.003

« Previous Next »Diabetes Research and Clinical Practice
Volume 86, Issue 1 , Pages 74-81, October 2009

Effect of tight control of HbA1c and blood pressure on cardiovascular diseases in type 2 diabetes: An observational study from the Swedish National Diabetes Register (NDR)

Jan Cederholm
- Department of Public Health and Caring Sciences/Family Medicine and Clinical Epidemiology, Uppsala University, Uppsala, Sweden
- Corresponding author at: Family Medicine and Clinical Epidemiology Section, Department of Public Health and Caring Sciences, Uppsala University, Uppsala Science Center, Dag Hammarskjölds väg 14B, S-751 85 Uppsala, Sweden. Tel.: +46 0709 507850; fax: +46 18 541097.
Björn Zethelius
- Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Uppsala, Sweden
Peter M. Nilsson
- Department of Clinical Sciences, Lund University, University Hospital, Malmö, Sweden
Katarina Eeg-Olofsson
- Department of Medicine, Sahlgrenska University Hospital, Göteborg University, Göteborg, Sweden
Björn Eliasson
- Department of Medicine, Sahlgrenska University Hospital, Göteborg University, Göteborg, Sweden
Soffia Gudbjörnsdottir
- Department of Medicine, Sahlgrenska University Hospital, Göteborg University, Göteborg, Sweden
on behalf of the Swedish National Diabetes Register

Received 10 March 2009; received in revised form 22 June 2009; accepted 13 July 2009. published online 13 August 2009.

Abstract

Aim

To estimate hazard ratio (HR) of first incident fatal/non-fatal cardiovascular diseases (CVD) in female/male type 2 diabetic patients, with tight versus adverse control of HbA1c and blood pressure (BP) at baseline, age 30–70 years, no baseline CVD, followed for mean 5.7 years.

Methods

2593 patients with tight control of HbA1c <7.5% and BP ≤140/90mmHg (median 6.5%/130/80mmHg), and 2160 patients with adverse control 7.5–9.0%/141–190/91–110mmHg (median 8.1%/155/85mmHg).

Results

The hazard ratio (HR) for CVD with tight/adverse control was 0.67 (0.55–0.80; p<0.001), adjusting for age, sex, duration, hypoglycaemic treatment, smoking, BMI, lipid-lowering drugs, antihypertensive drugs, microalbuminuria. Adjusted HR for myocardial infarction, coronary heart disease, stroke and total mortality were 0.72 (0.56–0.92; p=0.01), 0.69 (0.55–0.86; p<0.001), 0.62 (0.45–0.84; p<0.001), 1.00 (0.72–1.39). The partial population-attributable risk percent for myocardial infarction, stroke and CVD was 23%, 33%, 29% if adverse HbA1c/BP control could be avoided, while 43%, 38%, 39% with overweight and smoking also avoided. Baseline lower BMI and absence of microalbuminuria were associated with tight control.

Conclusion

Median difference of HbA1c/BP 1.6%/25/5mmHg between tight and adverse control considerably reduced the risk of cardiovascular diseases. The findings call for a multi-factorial approach to improve HbA1c, BP, obesity, smoking, and microalbuminuria.

Keywords: Diabetes, Blood pressure, Cardiovascular diseases, Myocardial infarction, Stroke