Renin–angiotensin–aldosterone system gender differences in an Afro-Caribbean population

Abstract

Hypothesis / Introduction Prior studies have denoted gender differences in the expression and therapeutic benefits of hypertension treatment and clinical outcomes. This study documents for the first time gender differences in the expression of blood and urine angiotensin peptides in a normotensive Afro-Caribbean Barbadians (25 males; 26 females). Materials and Methods Participants provided clinical anthropometric measurements, 24 ambulatory blood pressure and urine collections, and a blood sample for measurements of angiotensin peptides. Results Plasma renin activity ranged between 0.00 – 3.00 ng/mL/h. Plasma and urinary Ang II were comparable in both genders while urinary Ang-(1–7) was greater in females (p<0.05). Urinary Ang-(1–7) and office systolic blood pressure correlated significantly in females only (p<0.01) while plasma Ang-(1–7) and Ang II correlated significantly in both genders (p>0.05). Conclusions A shift in the balance between Ang II and Ang-(1–7) and their respective pressor and depressor axes might be markers of the cardio-renal protective mechanisms that may be present in females of Afro-Caribbean descent.

Hypertension is associated with increased mortality and severity of disease in COVID-19 pneumonia: A systematic review, meta-analysis and meta-regression

“…Oestrogen is postulated in bringing the predisposition towards 'good' RAS in females. 49 Although we did not have data concerning the menopausal status of the women in the included studies, the majority of subjects included in the studies were in older age groups. This could explain why the association between hypertension and outcome was stronger in studies with a lower percentage of male patients.…”

Gender difference in the response to valsartan/amlodipine single-pill combination in essential hypertension (China Status II): An observational study

“…Notably, gender-related differences also exist in the RAS, due to differential modulation by sex hormones. 25 , 26 In our study, most patients were aged > 55 years (6601/11,312 (58%)); and of these, 46% (3058/6601) of them were women. Given that the mean post-menopausal age is 56 years in China, 27 quite a few women in our study were in the post-menopausal period.…”

Is hypertension in African-descent populations contributed to by an imbalance in the activities of the ACE2/Ang-(1-7)/Mas and the ACE/Ang II/AT1 axes?

“…The sample of participants was determined using data gathered in a previous study in which a significant difference in Ang- (1)(2)(3)(4)(5)(6)(7) was found between normotensive male and female counterparts of an Afro-Caribbean population 4 ( Table 1). A statistically significant difference in the levels of an Ang peptide level was found in normotensive participants so it is anticipated that a greater difference may be found between normotensive and hypertensive Afro-Caribbean persons visiting the polyclinics.…”

“…This concept is supported by low Ang-(1-7) expression observed in untreated essential hypertensive non-black subjects 16 and the increased Ang-(1-7) levels found in females of Afro-Caribbean descent in a genetically unmixed normotensive population of Afro-Caribbean in Barbados (Table 1). 4,28 Although sexual dimorphism in RAAS peptides has been found in Afro-Caribbean normotensives, 4 the activities of the counter axes of RAAS in Afro-Caribbean normotensive and naïve hypertensive Afro-Caribbean persons remain unknown. We intend to resolve this lack of knowledge through the following: (a) identifying a representative sample of normotensive and hypertensive Afro-Caribbean participants over a 2-year period in Barbados; (b) collecting demographic data, biological samples and other relevant study data from the participants; (c) analysing biological samples by radioimmunoassay (RIA) to assess the expression of peptides from both pressor and depressor axis of the RAAS; and (d) making inferences from the analysed data on the relative balance shift of the peptides from both axes of the RAAS and disseminating findings to community interest groups.…”

“…Our previous study remains the only attempt to identify RAAS sex differences in the expression of RAAS peptides in an Afro-Caribbean population. 4 The analyses in that study were carried out at Wake Forest University and the analysis of the RAAS peptides from the current study will be done in the same laboratory. Past studies from Dr. Ferrario have demonstrated: (a) reduced urinary Ang-(1-7) expression and content in untreated essential hypertensive subjects; 16 (b) chronic normalization of arterial pressure in essential hypertensive subjects treated with either captopril 20 or the dual inhibitor of ACE and neprilysin (Omapatrilat) 29 was also associated with increases in Ang-(1-7); (c) prehypertension, chronic kidney disease and diabetes are associated with reduced ACE2 activity; and (d) increased circulating Ang II and serum aldosterone in untreated hypertensive women.…”