Non-adherence to antihypertensive pharmacotherapy in Buea, Cameroon: a cross-sectional community-based study

Background

Hypertension is a challenging public health problem with a huge burden in the developing countries. Non-adherence to antihypertensive treatment is a big obstacle in blood pressure (BP) control and favours disease progression to complications. Our objectives were to determine the rate of non-adherence to antihypertensive pharmacotherapy, investigate factors associated with non-adherence, and to assess the association between non-adherence and BP control in the Buea Health District (BHD), Cameroon.

Methods

A community-based cross-sectional study using stratified cluster sampling was conducted in the BHD from November 2013 – March 2014. Eligible consenting adult participants had their BP measured and classified using the Joint National Committee VII criteria. The Morisky medication adherence scale was used to assess adherence to BP lowering medication. Multivariable logistic regression models were used to predict non-adherence.

Results

One hundred and eighty-three participants were recruited with mean age of 55.9 years. Overall, 67.7% (95% CI: 59.8–73.6%) of participants were non-adherent to their medications. After adjusting for age, sex and other covariates, forgetfulness (aOR = 7.9, 95%CI: 3.0–20.8), multiple daily doses (aOR = 2.5, 95%CI: 1.2–5.6), financial constraints (aOR = 2.8, 95%CI: 1.1–6.9) and adverse drug effects (aOR = 7.6, 95%CI: 1.7–33.0) independently predicted non-adherence to anti-hypertensive medication. BP was controlled in only 21.3% of participants and was better in those who were adherent to medication (47.5% versus 8.2%, p <  0.01).

Conclusion

At least two of every three hypertensive patients in the Buea Health District are non-adherent to treatment. Forgetfulness, multiple daily doses of medication, financial constraints and medication adverse effects are the major predictors of non-adherence in hypertensive patients. These factors should be targeted to improve adherence and BP control, which will contribute to stem hypertension-related morbidity and mortality.

Knowledge of Hypertension and Compliance with Therapy Among Hypertensive Patients in the Bamenda Health District of Cameroon: A Cross-sectional Study

INTRODUCTION

The prevalence of hypertension has continued to increase and is now a great burden for health care providers. Obtaining information on the factors affecting compliance to antihypertensive drugs is thus important. The aim of this study was to assess knowledge of hypertension and to determine factors affecting the compliance of hypertensive patients to their antihypertensive drugs.

METHODS

This was a cross-sectional study involving 221 hypertensive patients in the Bamenda Health District. Validated questionnaires were used. From December 2014 to March 2015, knowledge of hypertension was assessed using a 15-item scale, while compliance was assessed using the 8-item Morisky Medication Adherence Scale. Statistical analysis was performed using SPSS version 20.

RESULTS

14.0%, 53.4%, and 32.6% of participants had adequate, average, and poor knowledge of hypertension, respectively. The antihypertensive compliance rate was 43.9%. Independent predictors of noncompliance were forgetfulness (OR = 0.011, 95% CI = 0.002-0.063), lack of motivation due to the incurable nature of the disease (OR = 0.068, 95% CI = 0.017-0.274), and lack of symptoms of the disease (OR = 0.019, 95% CI = 0.02-0.23). There was a significant association between compliance and blood pressure control (p < 0.001).

CONCLUSION

Knowledge of hypertension was poor. Compliance rate to treatment was low. Some medication-related, patient attitude, and health care provider factors affected compliance. Knowledge positively affected compliance, and good compliance was associated with good blood pressure control. Emphasis should be placed on patient education and reminders to patients to take their drugs.

Prevalence and Determinants of Chronic Kidney Disease Among Hypertensive Cameroonians According to Three Common Estimators of the Glomerular Filtration Rate

Hypertension is a risk factor for renal diseases, which, in turn, are precursors of hypertension. The authors assessed the prevalence and determinants of chronic kidney disease (CKD) among 336 hypertensive adult Cameroonians (mean age, 60.9±11.3 years; 63.4% women) at Yaoundé. Any participant with an estimated glomerular filtration rate <60 mL/min/1.73 m(2) regardless of the equation used (Cockcroft-Gault [CG], Modification of Diet in Renal Disease [MDRD], and Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) and/or dipstick proteinuria was reviewed 3 months later. Participants presented a high prevalence of diabetes (18.5%), dyslipidemia (17.6%), gout/hyperuricemia (10.7%), overweight/obesity (68.8%), self-medication (37.5%), and alcohol consumption (33.3%). Hypertension was uncontrolled in 265 patients (78.9%). The prevalence of CKD was 49.7%, 50.0%, and 52.1% according to MDRD, CKD-EPI, and CG equations, respectively. Advanced age, adiposity, and severity of hypertension were determinants of CKD. Nearly half of the hypertensive patients had CKD regardless of the estimators used, predicted by well-known risk factors.

Current diagnostic and treatment strategies for Lutembacher syndrome: the pivotal role of echocardiography

Lutembacher syndrome (LS) is a rare cardiac abnormality characterized by any combination of a congenital or iatrogenic atrial septal defect (ASD) and a congenital or acquired mitral stenosis (MS). Clinical features and hemodynamic effects of LS depend on the balance of effects of the MS and the ASD. Prognosis is influenced by several factors [pulmonary vascular resistance, right ventricle (RV) compliance, size of ASD and MS severity] but the occurrence of secondary pulmonary hypertension and congestive heart failure is commonly associated with poor outcome. Echocardiography remains the gold standard for diagnosis and evaluation of LS. Timely diagnosis is critical for modifying the natural course, by allowing patients to benefit from currently available percutaneous trans-catheter therapies with favorable effects on the outcomes. This article is a review of published literature on the current diagnostic and therapeutic modalities for LS, focusing on the pivotal role of echocardiography as the key diagnostic tool. Clinical suspicion of LS should prompt extensive investigation with non-invasive and where possible, invasive technics. Multicenter registers have a potential to assist the evaluation of long term outcomes of percutaneous trans-catheter therapies in patients with LS.

Ambulatory blood pressure measurement in the main cities of Cameroon: prevalence of masked and white coat hypertension, and influence of body mass index

Introduction

Identifying White Coat Hypertension (WCH) may avoid inappropriate commitment of individuals to lifelong and costly blood pressure (BP) lowering medications’. We assessed the prevalence and determinants of WCH in urban clinical settings in Cameroon.

Methods

Participants were a consecutive sample of adults, who underwent ambulatory BP measurements (ABPM) for the diagnosis of hypertension and evaluation of treatmentin three referral cardiac clinics in the cities of Yaounde and Douala, between January 2006 and July 2011. WCH was defined as an office-based systolic (or diastolic) BP ≥ 140(90) mmHg together with an average day time ambulatory systolic (and diastolic) BP < 135(85) mmHg.

Results

Of the 500 participants included, 188 (37.6%) were women, 230 (46%) were nonsmokers and 53 (10.6%) had diabetes mellitus. The mean age was 51.6±10.2years. The ABPM readings were higher in men than in women (p<0.05).The prevalence of WCH was 26.4% overall, 39.3% in women and22.4% in men (p=0.01).In multivariable analysis, body mass index was the only significant determinant of WCH (Odds ratio= 1.15(95% confidence intervals: 1.00-1.43), p<0.05).

Conclusion

The prevalence of WCH was high in our study population and was correlated only with BMI. Accurate measurement of BP and appropriate diagnosis of hypertension using ABPM in this setting may help limiting the consequences of over estimating hypertension severity on individuals, families and health systems.

Prevalence, awareness, treatment and control of hypertension in a self-selected sub-Saharan African urban population: a cross-sectional study

OBJECTIVES

Hypertension has been established as a major public health problem in Africa, but its specific contributions to disease burden are still incompletely understood. We report the prevalence and determinants of hypertension, detection, treatment and control rates among adults in major cities in Cameroon.

DESIGN

Cross-sectional study.

SETTINGS

Community-based multicentre study in major cities in Cameroon.

PARTICIPANTS

Participants were self-selected urban dwellers from the Center, Littoral, North-West and West Regions, who attended on 17 May 2011 a screening campaign advertised through mass media. PRIMARY AND SECONDARY OUTCOMES MEASURES: Hypertension defined as systolic (and/or diastolic) blood pressure (BP)≥ 140 (90) mm Hg, or ongoing BP-lowering medications.

RESULTS

In all, 2120 participants (1003 women) were included. Among them, 1007 (prevalence rate 47.5%) had hypertension, including 319 (awareness rate 31.7%) who were aware of their status. The prevalence of hypertension increased with age overall and by sex and region. Among aware hypertensive participants, 191 (treatment rate 59.9%) were on regular BP-lowering medication, and among those treated, 47 (controlled rate 24.6%) were at target BP levels (ie, systolic (and diastolic) BP<140 (90) mm Hg). In multivariable logistic regression analysis, male gender, advanced age, parental history of hypertension, diabetes mellitus, elevated waist and elevated body mass index (BMI) were the significant predictors of hypertension. Likewise, male gender, high BMI and physical inactivity were associated with poor control.

CONCLUSIONS

High prevalence of hypertension with low awareness, treatment and control were found in this urban population; these findings are significant and alarming with consideration to the various improvements in the access to healthcare and the continuing efforts to educate communities over the last few decades.

Left ventricular mass and systolic function in African diabetic patients: association with microalbuminuria

OBJECTIVE

To assess echocardiographic evidence of cardiomyopathy and its association with microalbuminuria in type 2 normotensive non-proteinuric diabetic patients.

MATERIAL AND METHODS

Forty consecutive normotensive non-proteinuric type 2 diabetic patients were studied. Body mass index, blood pressure, urinary albumin excretion, ECG at rest and after exercise, left ventricular mass, and shortening fraction using two-dimensional and M-mode echocardiography were measured in every patient.

RESULTS

Among the 40 patients studied, 17 (42.5%) presented with microalbuminuria, 16 (40.0%) with left ventricular hypertrophy, 22 (55.0%) with systolic dysfunction and 3 (7.5%) with ECG changes compatible with cardiac ischaemia. No significant difference existed between normoalbuminuric and microalbuminuric patients for age, known duration of diabetes, body mass index, systolic and diastolic blood pressure. Ventricular mass correlated to urinary albumin excretion rate (r=0.34; p=0.04) and shortening fraction to diastolic blood pressure (r = - 0.40; p=0.01).

CONCLUSION

Left ventricular structure and function might be altered in African type 2 diabetic patients in the absence of hypertension, and microalbuminuria may be an early biochemical marker of these abnormalities.

[Diastolic function of the left ventricle in a North-African patient with homozygous sickle-cell anemia]

AIM

The aim of this study was to investigate left ventricular diastolic function in a group of homozygous Black African patients with sickle-cell disease via echocardiography-Doppler, and to describe the possible hemodynamic implications of these findings.

PATIENTS AND METHODS

Fifty patients with sickle-cell anemia from two hematology departments in Yaoundé volunteered to participate in the study, carried out between May-October 1995. The presence of any other associated pathology (cardiovascular disorder, acute drepanocytic anemia, pregnancy) was excluded following a clinical, hematological and echocardiographic examination. A sex- and age-matched control group consisting of 50 healthy subjects was selected after the same examination criteria had been met. Mitral flow recorded by pulsed Doppler was measured, and the amplitudes of the E and A waves of the proto- and telediastolic flow, the E/A ratio, the decrease over time (DT) for the E wave, and the left ventricular isovolumetric relaxation time were also calculated. The limits of the confidence interval for the mean DT of the control group were used as the criterion to determine the following in the patient population: i) relaxation disorder profile, with DT > 154 ms; ii) restrictive disorder profile, with DT < 137 ms.

RESULTS

The dimensions of the cardiac cavities and the left ventricular mass were higher in the patient population; 34 cases of left auricular dilatation (68%) and 33 cases of left ventricular dilatation 8 66%) were observed. In only two patients was a systolic dysfunction noted. The amplitudes of the mitral flow E and A waves were increased, and the DT was longer in the sickle-cell group. Forty patients (80%) had abnormal diastolic function, with a marked predominance of the 'relaxation disorder' profile (60%). The restrictive disorder profile was only observed in ten sickle-cell patients (20%), while ten others displayed a normal profile (20%). The means of the various clinical and echocardiographic parameters of the three categories of sickle-cell patients (based on their diastolic profile, i.e., normal, relaxation disorder, restrictive disorder) were compared. The clinical parameters could be superimposed in the 3 categories. The dimensions of the left auricle and the telesystolic diameter of the left ventricle were significantly larger in the restrictive disorder category. The latter category appeared to be more symptomatic, and included the two isolated cases of systolic dysfunction.

CONCLUSION

Left ventricular diastolic dysfunction is commonly encountered in sickle-cell cases in the Cameroon. The restrictive disorder profile is less frequently observed, but appears to be more harmful at the hemodynamic level. The present results suggest that the study of diastolic function in patients with sickle-cell anemia could help identify hemodynamically at-risk subjects who require more specific cardiovascular care, even before a noticeable alteration in systolic function has taken place.

Microalbuminuria and retinopathy in a diabetic population of Cameroon

Microalbuminuria and retinopathy was studied in a non-proteinuric diabetic population of Cameroon. Patients were enrolled on a consecutive basis in two referral hospitals in Yaoundé. Retinopathy was evaluated by direct ophthalmoscopy and biomicroscopy, and controlled by mydriatic fundus photography. Detection of microalbuminuria was carried out on an overnight urine sample using Micral II test (Boehringer Mannheim). Anthropometric and blood pressure measurements were done using validated methods. In 64 non-proteinuric diabetic patients (9 IDDM and 55 NIDDM) aged 19-70 years with known duration of diabetes of 1-23 years, the prevalence of retinopathy was 37.5%. Microalbuminuria was detected in 53.1% of patients. Microalbuminuria correlated with duration of diabetes, and blood pressure, retinopathy was positively correlated with age, and blood pressure. Retinopathy was not significantly associated with the known duration of diabetes. Retinopathy was found to be independently associated with microalbuminuria (P < 0.001) and microalbuminuria appeared to be a sensitive marker of retinopathy. The prevalence of retinopathy and microalbuminuria in this population was high. Microalbuminuria and non-proliferative retinopathy are independently associated, and are both associated with increased blood pressure levels in the study population. As shown in previous studies microalbuminuria may also be a sensitive marker of early diabetic retinopathy in African diabetic patients.

[Screening of hepatocellular carcinoma in the middle of a high risk population in Cameroon]

We undertook a prospective study of cancerous lesions of the liver in 163 patients (136 males and 27 females) considered to be on high risk. These patients were, healthy carriers of HBs Antigen (n = 70), had chronic hepatitis (n = 45) or cirrhosis (n = 48). The screening was done from two main tests: liver ultrasound and blood alphafoetoprotein. Amongst the 163 patients, malignancy was diagnosed in 29 (22 males and 7 females) giving a prevalence of 17.8 percent: 9 cancers were diagnosed in the group with chronic hepatitis (20 percent), 20 in the group with cirrhosis (41.6 percent) and none in the group of healthy carriers. These results show that in Cameroun, cirrhosis is the most frequent abnormality associated with development of hepatocarcinoma. Thus the strategy against liver cancer should be oriented towards two main objectives; vaccination of children after eliminating healthy carriers and a regular follow-up of patients at risk.

[Chronic pancreatitis in Cameroon. Analysis of etiological and clinical aspects]

In a collection of 3,571 patient's files admitted in the University Teaching Hospital and the Yaounde General Hospital, we studied 27 patients suspected of chronic pancreatitis. 20 patients with calcified chronic pancreatitis benefited from a detailed history, physical examination and a complete paraclinical work-up. From the data collected, chronic alcoholism seemed to have been the main aetiology. Industrial beer from barley alone and/or associated with other traditional liquors was most consumed. The majority of patients were heavy alcoholics and daily consumption varied from 75 to 124 g of pure alcohol. The natural history of the disease and physical examination were identical to that observed in the western countries. Associated pathology was observed in 10% of the patients. This included peptic ulcer disease, cirrhosis and bile stones. Complications included diabetics, obstructive jaundice, and malabsorption syndrome. As a conclusion, chronic pancreatitis is a pathology whose prevalence seems to be progressing constantly.