Association of Systolic Blood Pressure and Complications of Type 2 Diabetes

In the UKDPS study 1 the incidence of diabetic complications was recorded in relation to mean of blood pressure measurements. 3 642 patients were included in analyses of relative risk. The analyses were adjusted for age at diagnosis, sex, ethnic group, smoking, albuminuria, HbA1c level, HDL and LDL cholesterol, and triglycerides. There was a nearly linear association between systolic blood pressure and myocardial infarction, stroke, amputations, and microvascular complications (need for retinal photocoagulation). Each 10 mmHg reduction in updated mean systolic blood pressure was associated with a reduction in risk of 12% for any end point related to diabetes (95% CI 10% to 14%), 15% for deaths related to diabetes (95% CI 12% to 18%), 11% for myocardial infarction (95% CI 7% to 14%), and 13% for microvascular complications (95% CI 10% to 16%). No threshold of risk was observed for any endpoint.

A retrospective cohort study 2 (Veterans Affairs electronic medical records) of 53 120 patients with T2DM compared the risk of microvascular and macrovascular complications and mortality, across 4 cohorts: triple-goal, dual-goal, single-goal, and no-goal achievers (achieving targets of blood glucose, blood pressure and blood lipids). During the follow-up period of 4 years, triple-goal achievement was associated with risk reductions of complications and all-cause mortality when compared to all other groups of achieving dual or single-goal. Across different combinations of dual-goal achievement, the cohort with LDL-C goal achievement had lower risk of complication.

A retrospective longitudinal study 3 included a total of 124 651 patients with T2DM, with mean of 6.7 follow-up years. In the general population, to achieve the lowest risk of microvascular and macrovascular complication, the optimal goals were HbA1c 6.81%, LDL-C=109.10 mg/dL; and A1C=6.76%, LDL-C=111.65 mg/dL, systolic blood pressure (SBP)=130.60 mmHg, respectively. The optimal goals differed between age and racial subgroups. Lower SBP for younger patients was associated with better health outcomes.

Comment: The quality of evidence is upgraded by large magnitude of effect.

References

• Adler AI, Stratton IM, Neil HA, Yudkin JS, Matthews DR, Cull CA, Wright AD, Turner RC, Holman RR. Association of systolic blood pressure with macrovascular and microvascular complications of type 2 diabetes (UKPDS 36): prospective observational study. BMJ 2000 Aug 12;321(7258):412-9. [PubMed]
• Shi Q, Liu S, Krousel-Wood M et al. Long-term Outcomes Associated with Triple-Goal Achievement in Patients with Type 2 Diabetes Mellitus (T2DM). Diabetes Res Clin Pract 2018. [PubMed]
• Shi Q, Lin Y, Fonseca VA, ym. Optimizing treatment goals for long-term health outcomes among patients with type 2 diabetes mellitus. BMJ Open Diabetes Res Care 2021;9(1): [PubMed]