Both insulin resistance and metabolic syndrome accelerate the progression of chronic kidney disease among Chinese adults: results from a 3-year follow-up study.

BACKGROUND: Metabolic syndrome (MetS) has been found to be associated with an increased risk for chronic kidney disease (CKD). However, the relationship between insulin resistance (IR), which is believed to play a central role in the pathogenesis of MetS, and CKD is still unclear in Chinese adults and needs further investigation.
METHODS: This 3-year follow-up study included 3237 middle-aged and elderly Chinese without CKD at baseline. Estimated glomerular filtration rate (eGFR) 60-90 mL/min/1.73 m2 was defined as the mildly reduced eGFR; CKD was defined as eGFR < 60 mL/min/1.73 m2. MetS was defined based on the China guideline for type 2 diabetes. IR was measured by the homeostatic model assessment of IR (HOMA-IR). Incidences of mildly reduced eGFR and CKD from normal eGFR were calculated. The roles of MetS and IR in predicting the progression of CKD were estimated using multiple logistic regression models.
RESULTS: The incidences of CKD and mildly reduced eGFR for the entire cohort were 20.08 and 33.28 per 1000 person-years, respectively. A large proportion [13.1% (182/1394)] of patients with mildly reduced eGFR progressed to CKD in 3 years. After accounting for age, gender, five components of MetS and HOMA-IR in multiple logistic regression model, only IR presented increased OR (1.119, 95% CI 1.052-1.189, p < 0.001) for CKD. When we included MetS instead of its five components in model, both MetS (OR 1.420, 95% CI 1.020-1.977, p = 0.038) and HOMA-IR (OR 1.118, 95% CI 1.055-1.186, p < 0.001) showed increased risk for CKD progression.
CONCLUSIONS: Both IR and MetS accelerate the progression of CKD among Chinese adults. Single metabolic abnormality did not have enough potency to induce the occurrence of CKD in 3 years.