Date Published: July 17, 2017
Publisher: Public Library of Science
Author(s): Jong Wook Choi, Il Hwan Oh, Chang Hwa Lee, Joon-Sung Park, Tatsuo Shimosawa.
Central obesity and related metabolic components are important risks for microalbuminuria. To describe the effects of interactions between central obesity and related metabolic components on microalbuminuria, we conducted a nation-wide, population-based interaction analysis using cardio-metabolic index (CMI) as a candidate indicator of central obesity and related abnormal lipid metabolism. We recruited native Koreans aged 20 years or older with no medical illness. A total of 5398 participants were divided into quintiles according to CMI with sex as a covariate factor. Participants in the highest CMI quintile had elevated blood pressure (BP), increased glycemic exposure, poor lipid profile, and increased urine albumin-to-creatinine ratio compared to other lower quintiles. Multiple logistic regression models adjusted for age, sex, systolic BP, and diastolic BP showed that CMI had an independent association with increased glycemic exposure and increased urine albumin-to-creatinine ratio. Our interaction analysis revealed a significant interaction between the highest CMI quintile and prediabetes with an increased risk of microalbuminuria (adjusted RERI = 0.473, 95% CI = 0.464–0.482; adjusted AP = 0.276, 95% CI = 0.156–0.395; adjusted SI = 2.952, 95% CI = 1.234–4.670). Our findings suggest a significant association between central obesity-related abnormal lipid metabolism and prediabetes, and their interaction may exert a synergistic effect on renal vascular endothelial dysfunction even before the appearance of full-blown diabetes mellitus. To confirm these findings, large population-based prospective studies are needed.
Central obesity and related abnormal lipid metabolism are main components of metabolic syndrome, which is a major public health and economic problem on the global scale . Accumulating evidence indicates that the copious release of free fatty acids and various pro-inflammatory cytokines/adipokines from dysfunctional adipose tissue plays a central role in the development of low-grade systemic inflammation and metabolic complications in patients with visceral obesity . Accurate measurement of central obesity is critical to assess the severity of its metabolic disturbances and to prevent irreversible metabolic disorders. Recently, the cardio-metabolic index (CMI), simply calculated as the product of waist-to-height ratio (WHtR) and triglycerides (TG) to high-density lipoprotein (HDL) cholesterol ratio, was introduced as a possible clinical indicator reflecting central obesity and related abnormal lipid metabolism; CMI has been shown to describe the risk of diabetes in the general population and also had an association with progression of atherosclerosis in patients with peripheral arterial disease [3, 4], suggesting that CMI may be a useful marker for endovascular damage. However, little is known about its role in estimating the negative effects of central obesity-related abnormal lipid metabolism on kidney function.
This study provides comprehensive information on the performance of CMI as a surrogate indicator for central obesity-related abnormal lipid metabolism with respect to kidney function. We demonstrated that there is a positive synergistic interactive relationship between CMI and mild hyperglycemia on the risk of microalbuminuria in the general population. These results indicate that central obesity-related abnormal lipid metabolism and its metabolic interaction with glycemic exposure may be one of the leading causes of vascular endothelial dysfunction and kidney disease, even before the diagnosis of diabetes and hypertension.