Real World Impact of Blood Pressure Changes on Morbidity and Mortality in Type 2 Diabetes

Abstract

Objective:To assess the impact of BP changes on the risk of cardiovascular events and mortality in type 2 diabetes.Design and method:The sample was selected using the HER of the Valencian Community. Type 2 diabetics were selected through ICD codes and retrospectively evaluated from January 2012 to December 2016. To evaluate BP changes, the follow-up time was divided in six-month blocks and the average of BP for each interval was considered. SBP was categorized: < 120 mmHg; 120–129 mmHg (reference); 130–139 mmHg; 140–149 mmHg; > 150 mmHg. To evaluate the influence of DBP, the population was stratified according to categories of average DBP: < 60 mmHg; 60–69 mmHg; 70–79 mmHg; > 80 mmHg. Information about cardiovascular events, including Stroke and Acute Coronary Syndrome (ACS) was extracted from the ICD codes. Total mortality was determined by matching records and death certificates. Time-varying Cox regression for SBP stratified by DBP categories was used to assess the risk associated with changes of SBP. The models were adjusted by age, sex, HBA1c, KDIGO, previous cardiovascular events and use of cardiovascular drugs.Results:156 363 type 2 diabetics patients were included (mean age 69.5(11.5), 48.7% females, mean glycated Hb 7.05 (1.35%) 21% in secondary prevention, 21.4% under insulin treatment). The average number of BP measurements was 14. During an average follow-up of 4.18 y, there were 13399 deaths, 15100 strokes and 6295 ACS. In the fully adjusted time-varying Cox regression, having a SBP< 120 mmHg was a significant risk factor for death across all categories of DBP, whereas SBP> 130 mmHg conferred protection. For the case of ACS and stroke, a J-curve phenomenon was observed with significantly higher risk for those with SBP> 150 mmHg or < 120 mmHg across categories with DBP> 60 mmHg. This J-curve phenomenon was also observed graphically using restricted cubic splines (Figure).Conclusions:Although difficult to achieve in clinical practice, lower boundaries for BP goals in diabetics have to be taking into account.