Elevated Blood Pressure Increases Pneumonia Risk: Epidemiological Association and Mendelian Randomization in the UK Biobank.

BACKGROUND: Small studies have correlated hypertension with pneumonia risk; whether this is recapitulated in larger prospective studies, and represents a causal association, is unclear. METHODS: We estimated the risk for prevalent hypertension with incident respiratory diseases over mean follow-up of 8 years among 377,143 British participants in the UK Biobank. Mendelian randomization of blood pressure on pneumonia was implemented using 75 independent, genome-wide significant variants associated with systolic and diastolic blood pressures among 299,024 individuals not in the UK Biobank. Secondary analyses with pulmonary function tests were performed. FINDINGS: In total, 107,310 participants (30%) had hypertension at UK Biobank enrollment, and 9,969 (3%) developed pneumonia during follow-up. Prevalent hypertension was independently associated with increased risk for incident pneumonia (HR: 1.36; 95% CI: 1.29-1.43; p < 0.001), as well as other incident respiratory diseases. Genetic predisposition to a 5 mm Hg increase in blood pressure was associated with increased risk for incident pneumonia for systolic blood pressure (HR: 1.08; 95% CI: 1.04-1.13; p < 0.001) and diastolic blood pressure (HR: 1.11; 95% CI: 1.03-1.20; p = 0.005). Additionally, consistent with epidemiologic associations, increased blood pressure genetic risk was significantly associated with reduced performance on pulmonary function tests (p < 0.001). CONCLUSIONS: These results suggest that elevated blood pressure increases risk for pneumonia. Maintaining adequate blood pressure control, in addition to other measures, may reduce risk for pneumonia. FUNDING: S.M.Z. (1F30HL149180-01), M.H. (T32HL094301-07), and P.N. (R01HL1427, R01HL148565, and R01HL148050) are supported by the National Institutes of Health. J.P. is supported by the John S. LaDue Memorial Fellowship.