A new analysis of data from the Chronic Renal Insufficiency Cohort (CRIC) study finds an increased incidence of type 2 diabetes at long-term follow-up in CKD patients who were initially free of diabetes. The findings support the need for greater vigilance for type 2 diabetes in the CKD population, the authors reported in the American Journal of Kidney Diseases.
The analysis included 1713 participants from the prospective CRIC study. All had reduced kidney function at baseline, with a median eGFR of 47.3 mL/min/1.73 m2. About 51% were white, 36% black, and 8% Hispanic. The participants’ median age was 59 years. Based on blood glucose levels, HbA1c, and/or use of oral hypoglycemic medications, 81.8% of patients had diabetes at baseline.
The incidence of type 2 diabetes was assessed over a median follow-up of 7.69 years. A wide range of potential risk factors for developing diabetes were analyzed, including baseline measures of renal function and damage; HbA1c; homeostatic model assessment of insulin resistance (HOMA-IR); demographic factors; family history of diabetes, smoking, blood pressure- and lipid-lowering medications; systolic blood pressure; lipid profile; body mass index; and physical activity.
In this sample of participants who had reduced eGFR but were initially free of diabetes, 11.85% developed type 2 diabetes during follow-up. The diabetes incidence rate was 17.81 cases per 1000 person-years overall. Broken down, the diabetes incidence rate was 12.17 per 1000 for patients with a baseline fasting blood glucose of less than 100 mg/dL, and 46.55 per 1000 for those with a fasting blood glucose greater than 100 mg/dL. There was low concordance between fasting blood glucose and HbA1c.
On multivariable analysis, fasting blood glucose level and family history of diabetes were independent risk factors for incident type 2 diabetes. Measures of renal function and kidney damage were not significantly associated with type 2 diabetes incidence, nor did the investigators find that these measures improved the ability of models to predict diabetes risk. On adjusted analysis, the association of HOMA-IR with type 2 diabetes was similar to that of fasting blood glucose, while HbA1c was not a significant factor.
Measures of glycemic control and family history of diabetes are independently associated with incident diabetes, while measures of kidney function and damage are not, the authors noted. Yet previous models of type 2 diabetes risk incorporating measures of kidney function and damage have not included individuals with CKD before the occurrence of end stage renal disease. The study’s findings demonstrated that because of their common risk factors, CKD may increase the risk of developing type 2 diabetes.
Jepson C, et al. Incident type 2 diabetes among individuals with CKD: findings from the Chronic Renal Insufficiency Cohort (CRIC) Study. Am J Kidney Dis 2018; DOI: 10.1053/j.ajkd.2018.06.017].