Left ventricular hypertrophy (LVH) and abnormal LV geometry are important markers of cardiovascular risk in hypertensive as well as chronic kidney disease (CKD) patients [1] [2] . They are associated with increased cardiovascular morbidity due to progressive ischaemic compromise, systolic and/or diastolic dysfunction, arrhythmias and sudden cardiac death [3] . LVH in hypertension is also associated with increased prothrombotic state, microalbuminuria, higher systolic hypertension, increased body mass index, fasting serum lipids and blood sugar levels [4] . Adaptation of the LV to increasing wall tension, pressure and volume changes in hypertension may result in four LV geometric patterns (normal, concentric remodeling, eccentric hypertrophy and concentric hy- pertrophy) based on relative wall thickness and LV mass [1] [2] . These patterns bear potential significant impact on systolic and/or diastolic function of the left ventricle [1] [2] and hence, could help to identify subjects at high risk for cardiovascular disease (CVD) who can benefit from preventive measures [5] .

In the Democratic Republic of the Congo (DRC), the prevalence of hypertension and CKD has been estimated to be of 30% and 12%, respectively [6] -[8] . LVH and CKD are target organ damage (TOD) commonly seen in hypertensive patients [9] [10] . While LVH and its geometric patterns have already been described in type 2 diabetic patients with CKD [11] , the exploration has not yet been done among hypertensive patients with CKD. Therefore, the aim of the present work was to study the pattern and clinical correlates of LVH and geometry among hypertensive patients with reduced kidney function (RKF).

Treated and naïve consecutive hypertensive patients (n = 155; 51% females) referred for echocardiography to the Division of Cardiology of the University of Kinshasa Hospital between January 6, 2012 and January 10, 2013 were enrolled in the present study. We collected information on age, gender, duration of hypertension, lifestyle habits (alcohol intake, smoking, physical activity), history of diabetes and, current medication for chronic diseases and measured body weight, height, waist circumference and seated blood pressure. Blood pressure was recorded using an electronic device (Zydus, Andon Health Co, Tianjin, China) with appropriate cuff secured on the left arm after at least five minutes at rest. Hypertension was systolic/diastolic blood pressure ≥ 140/90 mmHg on two separate hospital visits at one week interval or use of antihypertensive therapy [12] . Hypertension duration was the time elapsed from diagnosis to the present procedure. We calculated body mass index (BMI) as weight (in Kg) divided by the square of height (in m) and defined overweight and obesity as BMI ≥ 25 and ≥ 30 Kg/m², respectively [13] . We obtained measurements of blood hemoglobin, hematocrit, fasting plasma glucose (FPG), lipids and serum creatinine and a dipistick qualitative proteinuria. Anemia was blood hemoglobin <12 g/dl in men or < 11 g/dl in women [14] . Diabetes was fasting plasma glucose ≥ 126 mg/dl or use of antidiabetic drugs [15] . We estimated the glomerular filtration rate (GFR, ml/min/1.73 m²) using the abbreviated Modification of Diet in Renal Disease equation (MDRD) [16] . Reduced kidney function (RKF) was defined as GFR < 60 ml/min/1.73 or dipstick proteinuria ≥ 1+ and was stratified according to Kidney Disease Outcome Quality Initiative (KDOQI) [17] . We used NCEP-ATP III criteria to define metabolic syndrome (MetS) [18] .

With the patient in the left lateral decubitus position, we performed a transthoracic two-dimensional guided M-mode echocardiography in the parasternal view using a 3.5-Hz transducer equipped cardiac ultrasound machine (Acuson Corporation, Mountain View, California, USA). LV measurements were obtained at end-diastole and end-systole following the recommendations of the American Society of Echocardiography (ASE) [19] . LV internal diameters in systole (LVIDs) and in diastole (LVIDd), interventricular septal thickness (IVSTd) and posterior wall thickness (PWTd) were obtained only in diastole. These measurements were the average of three cardiac cycles [20] . LV mass (LVM) was calculated using the modified Devereux formula: LV mass (g) = 0.8 [1.04 (IVSTd + PWTd + LVIDd)³ - LVIDd³]+ 0.6] [21] and was indexed (LVMI) to body surface area and by the allometric power of height for lean and obese patients, respectively [22] . LVH was considered present when LVMI was > 125 g/m² for men and > 110 g/m² for women or > 51 g/m^2.7 for both sexes [12] [23] . The relative wall thickness (RWT) was double the ratio of PWTd to LVIDd; a RWT > 0.42 was considered as high [23] . Four LV geometric patterns were derived from the combination of LVMI and RWT as follows: normal geometry (both LVMI and RWT normal); concentric remodeling (RWT increased, LVMI normal); eccentric hypertrophy (LVMI increased, RWT normal) and concentric hypertrophy (both RWT and LVMI increased) [24] . End- diastolic and end-systolic LV volumes by Teichholz method were used to compute LV ejection (EF) and shortening (SF) fractions¹; the LV systolic dysfunction was EF < 50% or SF < 28% [1] .

Data are presented as means ± SD for normally distributed variables, median and interquartile range (IQR) for skewed variables and frequencies and percentages for categorical variables. Student t test and Mann Whitney Wilcoxon test were used to compare continuous variables in patients with and without RKF and one-way analysis of variance (ANOVA) in patients at different stages of RKF. Comparison of categorical variables was done using Chi square test. P value < 0.05 defined the level of statistical significance.

Main clinical and biological characteristics of the study population and difference according to renal function status are shown in Table 1 and Table 2. RKF was observed in 74 hypertensive patients (53% females, mean age 59 ± 12 years), 34 (46%), 27 (36%) and 13 (18%) of whom being on stage 3, 4 and 5, respectively. Compared to patients with relatively normal kidney function (NKF), those with RKF had a longer duration of hypertension [8 (4 - 12) vs 6 (1 - 13) years; p = 0.004), a greater BMI (27 vs 25 Kg/m²; p = 0.04) and WC (95 ± 14 vs 95 ± 14 cm; p = 0.03). The proportions of RKF patients receiving one, two or more antihypertensive drugs, amounted to 45 (61%), 20 (27%) and 4 (5%) patients, respectively. Uncontrolled hypertension predominated among patients with RKF (77 vs 62%; p = 0.04) who also had higher FPG [101 (86 - 126) mg/dl], uric acid (7.4 ± 2.8 vs 5.5 ± 2.2 mg/dl; p < 0.001) but lower hemoglobin (11 ± 2 vs 13 ± 2 g/dl; p < 0.001) or hematocrit (35% vs 40%; p < 0.001). Patients with RKF had a higher proportion of subjects with global obesity (30% vs 10%; p = 0.002), central obesity (55% vs 39%; p = 0.04), diabetes (38% vs 6%; p < 0.001), hyperuricemia (54% vs 21%;