Isolated increases in in-office pressure account for a significant proportion of nurse-derived blood pressure-target organ relations

Relations between white coat effect of blood pressure and arterial stiffness

The aim of this study was to analyze the relationship between brachial-ankle pulse wave velocity (b-a PWV) and white coat effect (WCE), that is the difference between the elevated office blood pressure (BP) and the lower mean daytime pressure of ambulatory BP, in a mixed population of normotention, untreated sustained hypertension, sustained controlled hypertension, sustained uncontrolled hypertension, white coat hypertension, white coat uncontrolled hypertension. A total of 444 patients with WCE for systolic BP (54.1% female, age 61.86 ± 13.3 years) were enrolled in the study. Patients were separated into low WCE (<9.5 mm Hg) and high WCE (≥9.5 mm Hg) according to the median of WCE. The subjects with a high WCE showed a greater degree of arterial stiffness than those with a low WCE for systolic BP values (P < .05). The b-a PWV were 17.2 ± 3.3 m/s and 18.4 ± 3.4 m/s in low WCE and high WCE, respectively. The b-a PWV increased with the increase of WCE, showing a positive correlation between them (P > .05 for non-linearity). The significant association between the high WCE and the b-a PWV was confirmed by the results of multiple regression analysis after adjusting for confounding factors (β = .78, 95% Cl .25-1.31, P = . 004). Similar results were observed in subgroups. In conclusion, WCE is significantly associated with arterial stiffness. More research is needed to determine the WCE and target organ damage.

Twenty-four hour ambulatory blood pressure reference values in Africans

OBJECTIVE

We aimed to establish reference values for 24 h ambulatory blood pressure (ABP) monitoring in an African community.

PATIENTS AND METHODS

We randomly recruited 1219 participants of African ancestry from Soweto, a township in Johannesburg. Twenty-four hour ABP was measured using ABP monitors (model 90207; Spacelab). Complete 24 h ABP measurements from 530 healthy participants with a mean age of 38 were used to determine thresholds.

RESULTS

Twenty-four hour, daytime and night-time systolic and diastolic BP increased significantly with age. The 95th prediction bands of this relation at age 38 years were ∼135/85 mmHg for 24 h, 140/90 mmHg for daytime and 130/80 mmHg for night-time ABP values, respectively. These thresholds and absolute ABP values are similar to those observed in individuals of other demographics. These thresholds increase with age by an average of 1.5 mmHg with each decade's increase in age.

CONCLUSION

Pending authentication in prospective outcome-based studies, these values might be considered preliminary thresholds to diagnose hypertension in individuals of African descent.

Intrafamilial aggregation and heritability of left ventricular geometric remodeling is independent of cardiac mass in families of African ancestry

BACKGROUND

Whether left ventricular (LV) geometric remodeling, as indexed by relative wall thickness (RWT), aggregates in families and is inherited independent of LV mass (LVM) and additional confounders is uncertain.

METHODS

We determined whether RWT as assessed from 2D targeted M-mode echocardiography shows intrafamilial aggregation and heritability independent of LVM in 181 nuclear families (73 spouse pairs, 403 parent-child pairs, and 177 sibling-sibling pairs) with 16 families including 3 generations from an urban developing community of black Africans. Intrafamilial aggregation and heritability estimates (S.A.G.E. software) were assessed independent of confounders, including central aortic systolic blood pressure (SBPc) (radial applanation tonometry and SphygmoCor software).

RESULTS

Independent of confounders including SBPc, LV RWT was correlated in parent-child (r = 0.32, P < 0.0001) and sibling-sibling (r = 0.29, P < 0.0001), but not in spouse (r = 0.11, P = 0.33) pairs. The relationships between parent-child (r = 0.28, P < 0.0001) and sibling-sibling (r = 0.24, P < 0.001) pairs persisted with further adjustments for LVM or LVM indexed to height(2.7) (LVMI). Similarly, independent of confounders, LV RWT showed significant heritability (h(2) ± SEM = 0.56 ± 0.09, P < 0.0001) and this persisted with further adjustments for LVM (h(2) ± SEM = 0.48 ± 0.09, P < 0.0001) or LVMI (h(2) ± SEM = 0.49 ± 0.09, P < 0.0001).

CONCLUSIONS

In a group of African ancestry, independent of LVM, LV geometric remodeling shows significant intrafamilial aggregation and heritability. Genetic factors may in-part determine the LV geometric remodeling process independent of the extent of cardiac hypertrophy.