The AGT M235T variant and renin–angiotensin–aldosterone system parameters in a predominantly hypertensive elderly black South African cohort: a hypothesis-generating descriptive case series

Background Hypertension (HTN) is a key cardiovascular risk factor, with its pathogenesis remaining incompletely understood. Blood pressure (BP) regulation involves the Renin–Angiotensin–Aldosterone System (RAAS), including the Angiotensin-converting enzyme (ACE), Angiotensin I (Ang I) and Angiotensin II (Ang II). The rs699 variant (M235T) may influence BP via the RAAS. Aim This study aimed to evaluate the relationships between the rs699 genotypes, RAAS parameters, BP, Body mass index (BMI) and gender in a black elderly population. Methods Data were collected from 48 participants aged ≥60 years, using World Health Organization (WHO) obesity guidelines and South African Hypertension Society (SAHS) 2019 standards for HTN categories. Statistical analysis was performed using IBM SPSS version 27 and Python 3.14. Results Most participants possessed the rs699 variant (GG: 93.8%, AG: 4.2%). ACE levels were low in 64.6%, while Ang II was elevated in the same percentage. The majority were classified as hypertensive and obese. No significant associations were found between the rs699 variant and ACE, Ang I, Ang II, HTN, BMI or gender, though BMI showed sex-related differences in females. Conclusion Our findings suggest no significant association of the rs699 variant on RAAS or cardiometabolic parameters within the study population, warranting cautious interpretation. These findings require validation in larger and more diverse populations, as meaningful statistical inferences cannot be drawn from the current data.