A Challenging Interaction of Chronic Kidney Disease With Other Metabolic Disorders: Paradoxes in Cardiometabolic Risk Factors.

INTRODUCTION: Controversial findings are reported on the risk of cardiovascular disease in chronic kidney disease (CKD). There are some interactions between CKD and other metabolic disorders including metabolic syndrome (MS) and obesity regarding coronary heart disease (CHD) outcomes.

MATERIALS AND METHODS: A total of 2823 men and 3684 women aged 30 years and older, without cardiovascular disease, were followed for 10 years. Multivariable adjusted hazard ratio of CHD was estimated for those who developed CKD, MS or both by sex and body mass index levels below and above 27 kg/m2. The interaction term of CKD and MS and also CKD-MS components were assessed in the Cox proportional hazard models as well.

RESULTS: Chronic kidney disease without MS, showed a significant effect on CHD only in participants with low body mass index (hazard ratio, 2.06; 95% confidence interval, 1.28 to 3.31 in the men and hazard ratio, 2.56; 95% confidence interval, 1.04 to 6.31 in the women). The joint effect of CKD and MS decreased to one-third of their multiplicative effect in this subgroup, indicating a negative interaction between CKD, MS, and Obesity. The same interaction was observed between CKD and hypertension in both sexes and CKD and type 2 diabetes mellitus in the men.

CONCLUSIONS: Our results showed that CKD was an independent risk factor for CHD only in nonobese individuals; however, its risk was wiped out when joined to MS. Following the concept of "obesity paradox," the term of "risk factors paradox" also needs more attention.