Abstract-Little is known about the clinical significance of isolated ambulatory hypertension, a condition characterized by low office but elevated ambulatory blood pressure. This study aimed to investigate the prevalence and the predictive value of isolated ambulatory hypertension diagnosed after 3 months of observation for the development of sustained hypertension within a cohort of 871 never-treated stage-1 hypertensive subjects. The study end point was progression to more severe hypertension and need of antihypertensive medication. In 244 subjects (28%), clinic blood pressure declined to Ͻ140/90 mm Hg after 3 months. Of these, 124 (14.2% of total) had low clinic and ambulatory blood pressures after 3 months (nonhypertensive subjects), whereas 120 subjects (13.8% of total) showed low clinic but elevated ambulatory blood pressure (isolated ambulatory hypertension). During the 6 years of observation, the number of end points based on multiple clinic blood pressure readings progressively increased from the nonhypertensive subjects (19%) to the subjects with isolated ambulatory hypertension (35%) and to the subjects with high clinic and high ambulatory blood pressures (65%, PϽ0.0001). In an adjusted proportional hazard model, isolated ambulatory hypertension status was associated with a 2.2 (Pϭ0.02) increase in the risk of reaching the end point in comparison with the nonhypertensive subjects. Final ambulatory systolic blood pressure was also higher in the former than the latter (Pϭ0.03). Our results indicate that among subjects screened for stage 1 hypertension, individuals with isolated ambulatory hypertension after 3 months of observation have increased risk of developing sustained hypertension in later life compared with subjects in whom both clinic and ambulatory blood pressures are normal.

Subjects with increased WCE have an exaggerated response also to psycho-social stimuli. Average daytime BP, which incorporates the BP reactions to many psycho-social triggers can, thus, not be taken as the basal BP of an individual. This helps explain why DeltaC-D does not reflect the true WCE.

It has been suggested that the insertion(I) allele of the I/deletion(D) polymorphism of the angiotensin converting enzyme (ACE) gene is associated with endurance exercise and increased physical conditioning in response to this type of exercise. To investigate the association between the ACE I/D polymorphism and physical activity status in 355 never treated, stage I hypertensives (265 men, 90 women, mean age: 33 +/- 9 years), in whom power exercise is contraindicated, participants of the HARVEST study. Physical activity was assessed using a standardized questionnaire. BMI and age did not vary among genotypes. None of active subjects performed power oriented exercises. ACE I/D frequencies (II-18%, ID-55%, DD-27%) were in Hardy-Weinberg equilibrium. Sedentary lifestyle was more common among DD than II hypertensives (76% in DD, and 48% in II, Chi(2) = 13.9, P = 0.001). In stepwise MANOVA using age, marital status, profession, sex, and ACE genotype as predictors of physical activity, marital status (F = 24.4, P < 0.0001) and ACE genotype (F = 16.03, P < 0.0001) contributed to more than 50% of the variance in physical activity status of the population. Our results suggest that the ACE I/D polymorphism may be a specific genetic factor associated with physical activity levels in free-living borderline and mild hypertensive subjects.

These data indicate that a condition characterized by sympathetic predominance may favour the development of sustained hypertension and hypercholesterolemia early in life, and lead to increased susceptibility to vascular complications. They further indicate that the increased white-coat effect is not an innocent phenomenon.