Abstract
Elevated blood pressure is a major cause of premature death, but there is little direct evidence demonstrating this association in studies of Hispanic populations. To assess the association between blood pressure and cause-specific mortality in a large cohort of Mexican adults with a high prevalence of uncontrolled diabetes. A total of 159 755 adults aged 35 years or older from 2 districts in Mexico City were recruited to this cohort study between April 1998 and September 2004 and followed up until January 2018. The present analyses focused on 133 613 participants who were aged 35 to 74 years and had no history of chronic disease besides diabetes. Blood pressure. Cox regression, adjusted for confounders, yielded mortality rate ratios (RRs) for deaths of participants occurring between ages 35 and 74 years. Of the 133 613 participants (43 263 [32.4%] men; mean [SD] age, 50 [11] years), 16 911 (12.7%) had self-reported previously diagnosed diabetes (including 8435 [6.3%] with uncontrolled diabetes, defined as hemoglobin A1c ≥9%) and 6548 (4.9%) had undiagnosed diabetes. Systolic blood pressure (SBP) was associated with vascular mortality between ages 35 to 74 years, with each 20 mm Hg lower usual SBP associated with 35% lower vascular mortality (RR, 0.65; 95% CI, 0.61-0.68), including 48% lower stroke mortality (RR, 0.52; 95% CI, 0.47-0.59) and 32% lower ischemic heart disease mortality (RR, 0.68; 95% CI, 0.63-0.74). These RRs were broadly similar in those with and without diabetes. Compared with those without diabetes and SBP less than 135 mm Hg at recruitment, the vascular mortality RR was 2.8 (95% CI, 2.4-3.3) for those without diabetes and SBP of 155 mm Hg or greater, 4.7 (95% CI, 4.1-5.4) for those with uncontrolled diabetes and SBP less than 135 mm Hg, and 8.9 (95% CI, 7.2-11.1) for those with uncontrolled diabetes and SBP of 155 mm Hg or greater. Lower SBP was also associated with decreased kidney-related mortality (RR per 20 mm Hg lower usual SBP, 0.69; 95% CI, 0.64-0.74), decreased mortality from infection (RR, 0.81; 95% CI, 0.71-0.91), and decreased mortality from hepatobiliary disease (RR, 0.87; 95% CI, 0.78-0.98), but not decreased neoplastic or respiratory mortality. SBP was more informative for vascular mortality than other blood pressure measures (eg, compared with SBP, diastolic blood pressure was only two-thirds as informative). Blood pressure was most strongly associated with vascular and kidney-related mortality in this Mexican population, with particularly high absolute excess mortality rates among individuals with diabetes. The findings reinforce the need for more widespread use of blood pressure-lowering medication in Mexico, particularly among those with diabetes.
Highlights
Elevated blood pressure is a major cause of death and disability
Systolic blood pressure (SBP) was associated with vascular mortality between ages 35 to 74 years, with each 20 mm Hg lower usual systolic blood pressure (SBP) associated with 35% lower vascular mortality (RR, 0.65; 95% CI, 0.61-0.68), including 48% lower stroke mortality (RR, 0.52; 95% CI, 0.47-0.59) and 32% lower ischemic heart disease mortality (RR, 0.68; 95% CI, 0.63-0.74)
Lower SBP was associated with decreased kidney-related mortality (RR per 20 mm Hg lower usual SBP, 0.69; 95% CI, 0.64-0.74), decreased mortality from infection (RR, 0.81; 95% CI, 0.71-0.91), and decreased mortality from hepatobiliary disease (RR, 0.87; 95% CI, 0.78-0.98), but not decreased neoplastic or respiratory mortality
Summary
Elevated blood pressure is a major cause of death and disability. Using evidence from 2 large metaanalyses of prospective studies[1,2] and 1 large health-record linkage study in the UK,[3] the 2017 Global Burden of Disease Collaborators estimated that elevated systolic blood pressure (SBP), defined as SBP higher than 110 to 115 mm Hg, was the leading cause of disability-adjusted life-years lost among women, and the second-leading cause among men (behind only tobacco use).[4] In a 2002 metaanalysis of data from 61 cohorts involving 1 million people,[1] each 20 mm Hg lower SBP was associated with at least a halving in the death rates from ischemic heart disease, stroke, and other vascular causes between ages 40 and 69 years. Among 150 000 Mexican adults recruited into a prospective study between 1998 and 2004, diabetes was more strongly associated with mortality than was expected based on studies done in other populations.[7,8] Using updated data from the Mexico City Prospective Study, the main aim of this study was to assess the association between blood pressure and 16-year cause-specific mortality in this Mexican population and in particular to examine how the association differed among those with and without diabetes
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have