Traditionally, the retina has been considered as the easiest accessible window to study the state of the systemic microcirculation, 1 even if the choroid is the most important vascular layer of the eye, which thinning may be due to microvascular damage, reflecting the local expression of a more generalized vascular injury. [2][3][4] Recent studies have associated changes in the thickness of the choroid with

No abstract

Objective: Metabolic acidosis is a common complication of advanced CKD and it has been associated with an increased risk of death and faster renal function decline. Diabetes mellitus is one of the most crucial cause of CKD. The dysregulation of glucose homeostasis may lead to many acid–base balance disorders. Our study was aimed to compare the acid-base status in diabetic patients with severe CKD with non diabetic CKD subjects. Design and method: Study population included 143 consecutive CKD hypertensive subjects attending our Nephrology unit with advanced renal failure. To be included on the study, patients were required to have an estimated eGFR of less than 30 mL/min, no intake of alkali within the previous 30 days, and the absence of pulmonary diseases and other clinical conditions at the time of the study that could explain an acute imbalance of the acid-base status, such as heart failure, hemorrhage, or sepsis. Patients were divided into two groups on the basis of the presence (n = 73) or the absence of Type 2 diabetes mellitus (n = 70) Arterial blood samples were drawn in all the subjects. Results: Age, sex distribution, serum creatinine, eGFR and proteinuria were not different in the two groups. Blood pH [7.406 (7.35–7.43) vs 7.384 (7.32–7.41), p = 0.02], bicarbonate levels [22 (19.1–23.7) vs 20.5 (17.4–23.1); p = 0.05] were higher and the prevalence of metabolic alkalosis (16.8 vs 8.4 %) was greater in diabetic patients as compared to non diabetic ones. The positive associations between diabetes and pH values (beta: 0.186; p = 0.02) and between diabetes and metabolic alkalosis (odds ratio 2.68; p < 0.05), were confirmed respectively in linear multiple regression analyses and in logistic multivariate models even after adjustment for potential confounders. Conclusions: Our results, in agreement with those obtained in a previous study (Caracava F et al, Am J Kidney Dis 1999), seem to suggest that metabolic alkalosis is more common than metabolic acidosis in diabetic patients with severe CKD. Further studies are needed in order to provide the pathophysiological explanations of these findings.