Hypertension in Middle-Aged Adults in Libreville, Gabon: Epidemiological, Clinical and Therapeutic Features

Abstract

Introduction: Hypertension (HTN) in middle-aged adults represents a major but poorly documented challenge in sub-Saharan Africa. In Gabon, no study has specifically characterised the HTN profile in adults aged 40-59 years. Aim: This study describes the epidemiological, clinical and therapeutic features of hypertensive patients in this age group at the University Hospital of Libreville. Methods: A retrospective, cross-sectional descriptive study was conducted from January 2019 to January 2023 in the Cardiology Department of the CHU de Libreville. All patients aged 40-59 years with known or newly diagnosed HTN were included. Categorical variables were compared using the Chi-square test; continuous non-normally distributed variables by the Mann-Whitney U test. Statistical significance was set at p < 0.05. Results: Among 807 hypertensive patients, 411 (50.9%) were middle-aged adults, with a median age of 51 years [IQR 46-56] and a female predominance (65.9%). Grade III HTN was observed in 30.2% of patients. Systolo-diastolic HTN predominated (63.3%). At least one target organ damage was documented in 17.8% of patients: stroke in 9.2%, heart failure in 5.4%, and renal failure in 4.9%. Calcium channel blockers (52.1%), ACE inhibitors (46.5%) and thiazide diuretics (40.6%) were the most frequently prescribed drugs; dual therapy was the predominant regimen (41.1%). Therapeutic rupture was recorded in 25.8% and was significantly associated with HTN grade (p < 0.001), reaching 39.5% in grade III patients. Conclusion: Middle-aged adults constitute the largest group of hypertensives in Libreville (50.9%), with severe HTN in nearly one-third and significant target organ damage in nearly one-fifth. The high rate of therapeutic rupture, disproportionately concentrated in grade III patients, underscores the urgent need for structured adherence programmes in this professionally active population.