Monocyte to HDL ratio: a novel marker of resistant hypertension in CKD patients

Background: Inflammation, oxidative stress (OS), atherosclerosis and resistant hypertension (RH) are common features of chronic kidney disease (CKD) leading to a higher risk of death from cardiovascular disease. These effects seem to be modulated by impaired anti-oxidant, anti-inflammatory and reverse cholesterol transport actions of high-density lipoprotein cholesterol (HDL). HDL prevents and reverses monocyte recruitment and activation into the arterial wall and impairs endothelial adhesion molecule expression. Recently, monocyte count to HDL-cholesterol ratio (MHR) has emerged as a potential marker of inflammation and OS, demonstrating to be relevant in CKD. Our research was aimed to assess, for the first time, its reliability in RH. Methods: We performed a retrospective study on 214 patients with CKD and arterial hypertension who were admitted between January and June 2019 to our Department, 72 of whom were diagnosed with RH. Results: MHR appeared inversely related to eGFR (ρ = - 0.163; P = 0.0172). MHR was significantly higher among RH patients compared to non-RH ones (12.39 [IQR 10.67-16.05] versus 7.30 [5.49-9.06]; P < 0.0001). Moreover, MHR was significantly different according to the number of anti-hypertensive drugs per patient in the whole study cohort (F = 46.723; P < 0.001) as well as in the non-RH group (F = 14.191; P < 0.001). Moreover, MHR positively correlates with diabetes mellitus (ρ = 0.253; P = 0.0002), white blood cells (ρ = 0.664; P < 0.0001) and C-reactive protein (ρ = 0.563; P < 0.0001). Conclusions: MHR may be a reliable biomarker due to the connection between HDL and monocytes. Our study suggests that MHR is linked with the use of multiple anti-hypertensive therapy and resistant hypertension in CKD patients, and can be a useful ratio to implement appropriate treatment strategies.