Association of Metabolic Syndrome with Urinary Albumin Excretion, Low-grade Inflammation, and Low Glomerular Filtration Rate among Non-diabetic Japanese Subjects

Objective Several studies have reported a significant association of metabolic syndrome with urinary albumin excretion, high-sensitivity C-reactive protein, or chronic kidney disease; however, no study has investigated the association of metabolic syndrome with these 3 factors together in the same individual. Therefore, we conducted the present study to obtain more information on this association. Methods We enrolled 712 Japanese subjects without diabetes, macroalbuminuria, or medications, who entered our hospitalized health check-up program (180 women and 532 men; mean age, 53.2 years; mean body mass index, 24.1 kg/m(2)). Metabolic syndrome was diagnosed by 4 major definitions. Low glomerular filtration rate was defined as an estimated glomerular filtration rate of <60 mL/min/1.73 m(2). Results Both urinary albumin excretion and high-sensitivity C-reactive protein were significantly higher in those with metabolic syndrome than without, and metabolic syndrome was an independent determinant of both. In contrast, estimated glomerular filtration rate and the prevalence of low glomerular filtration rate did not differ significantly between those with and without metabolic syndrome. Among the 5 components of metabolic syndrome and other clinical variables, systolic blood pressure was an independent determinant of urinary albumin excretion; the 5 components and low-density lipoprotein cholesterol were all independent determinants of high-sensitivity C-reactive protein; systolic blood pressure was an independent determinant of low glomerular filtration rate. Conclusion Metabolic syndrome is associated with vascular dysfunction and low-grade inflammation and the latter association is strong, whereas the association of metabolic syndrome with low glomerular filtration rate may be less apparent among those without diabetes, macroalbuminuria, and medications.