The Association Between Kidney Disease and Diabetes Remission in Bariatric Surgery Patients With Type 2 Diabetes

RATIONALE & OBJECTIVE: The association between bariatric surgery, type 2 diabetes, and chronic kidney disease (CKD) is poorly understood. We studied whether remission of type 2 diabetes induced by bariatric surgery influences markers of kidney disease, if CKD is associated with remission of diabetes after bariatric surgery, and if baseline levels of gut hormones and peptides modify these associations. STUDY DESIGN: Prospective observational study. STUDY PARTICIPANTS: 737 bariatric surgery patients with type 2 diabetes who participated in a multicenter cohort study for up to 5 years. PREDICTORS: Demographics, blood pressure, medications, type of bariatric surgery, anthropometrics, markers of kidney disease, and circulating levels of gut hormones and peptides. OUTCOMES: Estimated glomerular filtration rate (eGFR), urinary albumin excretion, prognostic risk for CKD, and remission of diabetes. ANALYTICAL APPROACH: Linear mixed models for eGFR; generalized linear mixed models with logit link for albuminuria, prognostic risk for CKD, and diabetes remission. RESULTS: Remission of diabetes at 5 years post-bariatric surgery was not independently associated with eGFR but was associated with lower risk for moderate/severe increase in albuminuria (risk ratio, 0.66; 95% CI, 0.48-0.90) and stabilization in prognostic risk for CKD. These findings were modified by baseline ghrelin level. Lower preoperative eGFR and greater prognostic risk for CKD were independently associated with reduced likelihood of diabetes remission. The association with preoperative GFR was modified by C-peptide level. Higher baseline circulating ghrelin level was independently associated with a lower prognostic risk for CKD. LIMITATIONS: A minority of participants had baseline CKD; lack of comparison group; no information on duration of diabetes, other clinical end points, or kidney biopsy results. CONCLUSIONS: Remission of type 2 diabetes 5 years after bariatric surgery was associated with improvements in albuminuria and stabilized prognostic risk for CKD, but not with eGFR. Lower kidney function and greater prognostic risk at the time of bariatric surgery was linked to a lower likelihood of diabetes remission. These results highlight the need to identify the mechanisms through which bariatric surgery may delay the long-term progression of CKD in type 2 diabetes.