Hypertension is the Main Determinant Behind the Association Between Metabolic Syndrome and Chronic kidney Disease in Subjects with Different Degrees of Glucose Tolerance

Background: Chronic kidney disease (CKD) is a significant public health problem. It is still controversial if the metabolic syndrome (MS) is associated with CKD. Methods: Cross-sectional study of individuals at high risk of developing diabetes at the endocrine outpatient clinic of Hospital de Clinicas de Porto Alegre. Fasting and 2h-plasma glucose levels, A1c, insulin, cholesterol, triglycerides, creatinine, and urinary albumin excretion were measured. MS was defined as the presence of three out of five of the following factors: hypertension, low HDL-cholesterol, high triglyceride levels, elevated plasma glucose, and high waist circumference. Glomerular filtration rate (GFR) was estimated by the Modified Diet in Renal Disease (MDRD) equation and insulin resistance was measure using the Homeostasis Model of Assessment - Insulin Resistance (HOMA-IR). Correlation analyses were performed between each MS components and the GFR. Results: CKD was present in 20.9% of the subjects. GFR was lower in subjects with MS compared with those without MS (p = 0.019). Estimated GFR decreased with the increasing number of MS criteria (mean ± SD; zero or one criterion 103.09 ± 9.5 vs. two criteria 99.14 ± 21.2 vs. three criteria 90.9 ± 21.1 vs. four criteria 91.0 ± 19.4 vs. five criteria 80.9 ± 23.5 mL/min per 1.73m 2 ; p = 0.053). Only systolic arterial blood pressure was related to eGFR (r = 0.280; p = 0.003). Discussion: According to our data, the previously described association between MS and decreased renal function was confirmed, mostly determined by the hypertension criterion. Conclusion: These data suggest that the relationship between MS and CKD is driven mostly by abnormalities in blood pressure homeostasis.