Depressive Symptoms and 24-Hour Ambulatory Blood Pressure in Africans: The SABPA Study

Epidemiology of depressive disorders in people living with hypertension in Africa: a systematic review and meta-analysis

OBJECTIVES

Better knowledge of epidemiology of depressive disorders in people living with hypertension can help to implement pertinent strategies to address its burden. The objective was to estimate the prevalence of depressive disorders and symptoms in people living with hypertension in Africa.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, EMBASE, African Index Medicus, African Journals OnLine were searched up to 31 January 2020, regardless of the language of publication.

ELIGIBILITY CRITERIA

We included studies conducted among adult patients with hypertension (≥18 years) living in Africa and reporting the prevalence of depressive disorders and symptoms.

DATA EXTRACTION AND SYNTHESIS

Two independent investigators selected studies, extracted data and assessed the methodological quality of included studies by using the tools developed by Joanna Briggs Institute. Multivariate random-effects meta-analysis served to pool data by considering the variability between diagnostic tools used to identify patients with depressive disorders or symptoms.

RESULTS

We included 11 studies with 5299 adults with hypertension. Data were collected between 2002 and 2017, from South Africa, Nigeria, Ghana, Ethiopia and Burkina Faso. The mean age varied between 50.3 years and 59.6 years. The proportion of men ranged from 28% to 54%. The adjusted prevalence of depressive disorders taking into account the variance between diagnostic tools was 17.9% (95% CI 13.0% to 23.4%). The prevalence of depressive symptoms and major depressive symptoms was 33.3% (95% CI 9.9% to 61.6%) and 7.8% (95% CI 3.0% to 14.5%), respectively. There was heterogeneity attributable to the diagnostic tools for depressive disorders and symptoms. There was no publication bias.

CONCLUSION

Notwithstanding the representativeness lack of some (sub) regions of Africa, weakening the generalisability of findings to the entire region; depressive disorders and symptoms are prevalent in people living with hypertension in Africa, indicating that strategies from clinicians, researchers and public health makers are needed to reduce its burden in the region.

Ambulatory blood pressure monitoring and morning surge in blood pressure in adult black and white South Africans

We examined whether there were differences in the circadian variation in blood pressure and the morning surge in blood pressure between black and white Africans. Clinic and ambulatory blood pressure data obtained from the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was examined (n = 406; 49% black African). Ambulatory blood pressure readings were fitted to a six-parameter double logistic equation to determine the power and rate of the morning surge in blood pressure. Multiple linear regression analysis was used to examine differences in blood pressure between black and white participants. Clinic and ambulatory blood pressure were higher in black participants throughout the day and night. In those taking medications, blood pressure was less well controlled in black subjects. Despite the higher systolic blood pressure, the day-night difference estimated by the logistic function was similar in black and white participants. However, the rate of rise and power in the morning surge in blood pressure was lower in black participants. We conclude that black participants of the SABPA study present with higher blood pressure throughout the day and night but have a lower power of the morning surge in blood pressure due to a slower morning rate of increase. Moreover, they had an increased prevalence of undiagnosed hypertension and, in those taking medication, were less likely to have their blood pressure controlled than their white counterparts.

Predictors of depression in black women with hypertension

Black women have the highest prevalence of hypertension in the world, and depression is associated with both hypertension and lack of health promoting behaviors. Thus, it is important to identify factors that may contribute to depression in hypertensive women. This cross-sectional study was conducted with a convenience sample of 80 black women ages 18-60 who were prescribed anti-hypertensive medication. Data were collected using self-report instruments. The study showed that lower income level, greater number of comorbidities, lower active coping scores, and poorer medication adherence were significantly associated with higher depression scores. These findings have important implications for the development of screening protocols and interventions for black women.

Sympathetic vasomotor tone is associated with depressive symptoms in young females: a potential link between depression and cardiovascular disease

BACKGROUND

Although increased sympathetic nervous system (SNS) activity is commonly associated with major depressive disorder (MDD) and cardiovascular disease (CVD), a biomarker linking these two entities remains elusive. We therefore evaluated the relationship between depressive symptoms and cardiovascular modulation by heart rate variability (HRV), brachial blood pressure (BP), ambulatory BP (ABP), and low frequency component of systolic BP variability (LFSBP), a surrogate of sympathetic vasomotor tone. We hypothesized that LFSBP would be the strongest predictor of depressive symptoms compared with HRV and BP measurements.

METHODS

Eighty young healthy female subjects (20.51 ± 2.82 years) were evaluated for depressive symptoms using the Center for Epidemiologic Studies Depression Scale (CES-D). Data collection was conducted after a 10-minute resting period. Beat-to-beat BPs were recorded for 5-minute at baseline (BASE) followed by a 3-minute cold pressor test (CPT). ABP was obtained for 24 hours.

RESULTS

Hierarchical multiple regression analyses indicated that LFSBP at BASE was a stronger predictor of CES-D variance than BP and HRV indices, with LFSBP uniquely accounting for 8.1% of variance in CES-D scores during laboratory beat-by-beat BP assessments and 44.7% in ABP assessments. Individuals with acute depression scores (n = 12; CES-D ≥ 16) had significantly higher (P < 0.001) mean LFSBP values (6.66 ± 2.54 mm Hg(2)) than the remaining sample (3.32 ± 2.2 mm Hg(2)), whereas no other significant differences were detected in any of the other cardiovascular variables. Cardiovascular responses to CPT did not predict CES-D scores.

CONCLUSIONS

These findings suggest that LFSBP could be a biomarker of neurovascular functioning with potential clinical implications for understanding the interaction between MDD and CVD.