Specific genetic influences on nighttime blood pressure.

Georgia Prevention Center, Institute of Prevention and Public Health, Georgia Regents University, Augusta, Georgia; College of Nursing, Medical University of South Carolina, Charleston, South Carolina; Department for Human Genetics, University Hospital Gasthuisberg, KU Leuven, Leuven, Belgium; Hypertension and Cardiovascular Rehabilitation Unit, Department of Cardiovascular Diseases, KU Leuven, Leuven, Belgium; Research School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands; Cluster of Genetics and Cell Biology, Department of Complex Genetics, Maastricht University Medical Centre, Maastricht, The Netherlands; Medical Research Council Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom; Department of Biomedical Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, University Hospital Gasthuisberg, KU Leuven, Leuven, Belgium; Genetics of Obesity and Related Metabolic Traits Program, Institute for Personalized Medicine, Child Health and Development Institute, Department of Preventive Medicine, Mount Sinai School of Medicine, New York; Unit of Genetic Epidemiology and Bioinformatics, Department of Epidemiology, University of Groningen, University Medical Center Groningen, The Netherlands. Georgia Prevention Center, Institute of Prevention and Public Health, Georgia Regents University, Augusta, Georgia; xwang@gru.edu.

American journal of hypertension. 2015;(4):440-3

Abstract

OBJECTIVES Nighttime blood pressure (BP) has been shown to be superior to daytime BP in predicting hypertension related target organ damage and cardiac mortality. In our Georgia Cardiovascular Twin Study, we showed that apart from the genes that also influence daytime BP, specific genetic determinants explained 44% and 67% of the nighttime systolic BP (SBP) and diastolic BP (DBP) heritabilities, respectively. Here, we determined whether these results could be confirmed in a much larger twin cohort of young adults with 24-hour ambulatory BP measurements. METHODS Ambulatory BP was available in 703 white twins (308 pairs and 87 singletons, aged 18-34 years, 50% males) from the Prenatal Programming Twin Study. A bivariate quantitative genetic twin model was used to analyze daytime and nighttime BP. We conducted a meta-analysis to compare and integrate results from the 2 twin cohorts. RESULTS Model fitting showed no sex differences for any of the measures. Heritabilities were 0.60 and 0.51 for SBP and 0.54 and 0.46 for DBP at daytime and nighttime. The specific heritability due to novel genetic effects emerging during the nighttime was 0.21 for SBP and 0.26 for DBP, which comprised 41% and 57% of the total nighttime heritability for SBP and DBP, respectively. Meta-analysis confirmed absence of cohort differences with very similar combined results. CONCLUSIONS In addition to genes that influence both daytime and nighttime BP, a large part of the heritability is explained by genes that specifically influence BP at night.

Methodological quality

Publication Type : Meta-Analysis

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