Blood Pressure, Kidney Function, and Kidney Mortality Among Mexican Adults

Chronic kidney disease (CKD) is a major cause of death in Mexico, and blood pressure (BP) may be an important contributor. This study investigated the associations of BP with CKD, albuminuria, and death from kidney failure.

Prospective cohort study.

133,470 adults aged ≥35 to <85 years without CKD or other chronic disease (except diabetes), recruited from 2 districts of Mexico City between 1998 and 2004, and who had survived ≥5 years after recruitment. A random subset of 9,198 underwent additional evaluation from 2015 to 2019.

Systolic BP (SBP), diastolic BP (DBP) and hypertension (defined as participant report, taking BP-lowering medication, and/or BP ≥ 140/90 mm Hg).

Kidney failure mortality during follow-up, and CKD (self-report and/or estimated glomerular filtration rate < 60 mL/min/1.73 m²) and albuminuria at the time of repeat clinical evaluation.

Multivariable Cox regression for the association of BP with kidney failure mortality and multivariable logistic regression for the association of baseline BP with CKD and albuminuria at the time of re-evaluation.

Among all participants, SBP showed a continuous log-linear association with kidney failure mortality; each 20 mm Hg lower SBP was associated with a 24% lower risk at ages 40-84 years (kidney failure death HR, 0.76 [95% CI, 0.69-0.84]). The association was stronger among those without diabetes (HR, 0.54 [95% CI, 0.45-0.69]) than with diabetes (HR, 0.90 [95% CI, 0.80-1.01]), but the absolute excess risk associated with higher BP was similar in these subgroups. Hypertension accounted for 9% of kidney failure deaths. Among those re-evaluated, 6% had developed CKD, and 25% had albuminuria. A 20 mm Hg lower baseline SBP was associated with 24% lower odds of both CKD (OR, 0.76 [95% CI, 0.68-0.85]) and albuminuria (OR, 0.76 [95% CI, 0.68-0.84]) at the time of re-evaluation. The results were similar for DBP.

Baseline urine samples were unavailable, and kidney function trends over time could not be assessed.

This large prospective study in Mexican adults highlights elevated BP as a major modifiable risk factor for kidney failure mortality, CKD, and albuminuria.

Kidney disease is a major cause of death in Mexico, and high blood pressure may play an important role. The Mexico City Prospective Study followed approximately 150,000 Mexican adults aged 35 years or older for approximately 20 years, tracking causes of death over time. These analyses found that lower blood pressure was linked to a lower risk of dying from kidney failure. For every 20 mm Hg lower systolic blood pressure, the risk of dying from kidney failure was lower by approximately one quarter. High blood pressure accounted for 9% of all deaths from kidney failure. Lower blood pressure also was associated with better kidney function-as measured by blood tests, participant questionnaires, and urine protein levels-some years later. These analyses suggest that reducing high blood pressure is likely to prevent kidney disease and deaths related to kidney disease in Mexico.