Considerably decreased risk of cardiovascular disease with combined reductions in HbA1c, blood pressure and blood lipids in type 2 diabetes: Report from the Swedish National Diabetes Register

Abstract

Objectives: Assess the effect of risk factors changes on risk for cardiovascular disease and mortality in patients with type 2 diabetes selected from the Swedish National Diabetes Register.

Methods: Observational study of 13,477 females and males aged 30-75 years, with baseline HbA1c 41-67 mmol/mol, systolic blood pressure 122-154 mmHg and ratio non-HDL:HDL 1.7-4.1, followed for mean 6.5 years until 2012. Four groups were created: a reference group (n = 6757) with increasing final versus baseline HbA1c, systolic blood pressure and non-HDL:HDL cholesterol during the study period, and three groups with decreasing HbA1c (n = 1925), HbA1c and systolic blood pressure (n = 2050) or HbA1c and systolic blood pressure and non-HDL:HDL (n = 2745).

Results: Relative risk reduction for fatal/nonfatal cardiovascular disease was 35% with decrease in HbA1c only (mean 6 to final 49 mmol/mol), 56% with decrease in HbA1c and systolic blood pressure (mean 12 to final 128 mmHg) and 75% with combined decreases in HbA1c, systolic blood pressure and non-HDL:HDL (mean 0.8 to final 2.1), all p < 0.001 adjusting for clinical characteristics, other risk factors, treatments and previous cardiovascular disease. Similar risk reductions were found for fatal/nonfatal coronary heart disease, fatal cardiovascular disease, all-cause mortality and also in a subgroup of 3038 patients with albuminuria.

Conclusion: Considerable risk reductions for cardiovascular disease and mortality were seen with combined long-term risk factor improvement.

Keywords: Blood lipids; HbA1c; blood pressure; cardiovascular diseases; diabetes mellitus.