Genomic scan for exercise blood pressure in the Health, Risk Factors, Exercise Training and Genetics (HERITAGE) family study

A genome-wide linkage scan was performed for genes affecting submaxinial ex ercise systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the sedentary state and their responses to a standardized endurance trainin g program. A total of 344 polymorphic markers were used, and 344 pairs of s iblings from 99 white nuclear families and 102 sibling pairs from 105 black family units were available for the study. All subjects were healthy but s edentary at baseline. SBP and DBP were measured during exercise tests at 2 different intensities: 50 W (SBP50 and DBP50) and 80% of maximal oxygen con sumption (SBP80 and DBP80). Baseline blood pressure phenotypes were adjuste d for age, gender, and body mass index, and the training responses (after t raining minus baseline \ Delta \) were adjusted for age, gender, baseline b ody mass index, and baseline blood pressure. Two analytical strategies were used: a multipoint variance-components linkage analysis using all the fami ly data and a single-point linkage analysis using pairs of siblings. In whi tes, promising linkages (lod score > 1.75) were detected for baseline SBP80 oil 10q23-q24 and for Delta SBP50 on 8q21. In addition, several chromosoma l regions with suggestive evidence of linkage (lod score 1.0 to 1.75) were observed for SBP50 (22q11.2-q13), DBP50 (6q23-q27), SBP80 (2p24, 2q21, 14q1 1.1-q12, and 16q21), DBP80 (6q13-q21), Delta SBP50 (7p12-p13), and Delta DB P50 (5q31-q32). In blacks, DBP50, DBP80, and Delta DBP80 showed promising q uantitative trait loci on 18p11.2, 11q13-q21, and 10q21-q23, respectively. Suggestive linkages were evident for DBP50 on 2p22-p25, 11p15.5, and 18q21. 1; for SBP80 on 6q21-q21, 6q31-q36, 12q12-q13, 15q12-q13, and 17q11-q12, an d for DBP80 on 8q24, 10q21-q24, and 12p13. All the detected chromosomal reg ions include several potential candidate genes and therefore warrant furthe r studies in the Health, Risk Factors, Exercise Training and Genetics (HERI TAGE) cohort and other studies.