Nonalcoholic fatty liver disease is independently associated with an increased incidence of chronic kidney disease in patients with type 1 diabetes.
OBJECTIVE
There is no information about the role of nonalcoholic fatty liver disease (NAFLD) in predicting the development of chronic kidney disease (CKD) in type 1 diabetes.


METHODS
We studied 261 type 1 diabetic adults with preserved kidney function and with no macroalbuminuria at baseline, who were followed for a mean period of 5.2 years for the occurrence of incident CKD (defined as estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2 and/or macroalbuminuria). NAFLD was diagnosed by ultrasonography.


RESULTS
At baseline, patients had a mean eGFR of 92 ± 23 mL/min/1.73 m2; 234 (89.7%) of them had normoalbuminuria and 27 (10.3%) microalbuminuria. NAFLD was present in 131 (50.2%) patients. During follow-up, 61 subjects developed incident CKD. NAFLD was associated with an increased risk of incident CKD (hazard ratio [HR] 2.85 [95% CI 1.59-5.10]; P < 0.001). Adjustments for age, sex, duration of diabetes, hypertension, A1C, and baseline eGFR did not appreciably attenuate this association (adjusted HR 2.03 [1.10-3.77], P < 0.01). Results remained unchanged after excluding those who had microalbuminuria at baseline (adjusted HR 1.85 [1.03-3.27]; P < 0.05). Addition of NAFLD to traditional risk factors for CKD significantly improved the discriminatory capability of the regression models for predicting CKD (e.g., with NAFLD c statistic 0.79 [95% CI 0.73-0.86] vs. 0.76 [0.71-0.84] without NAFLD, P = 0.002).


CONCLUSIONS
This is the first study to demonstrate that NAFLD is strongly associated with an increased incidence of CKD. Measurement of NAFLD improves risk prediction for CKD, independently of traditional cardio-renal risk factors, in patients with type 1 diabetes.
Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy giovanni.targher@univr.it.
Giovanni
G
Targher
Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
Alessandro
A
Mantovani
Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
Isabella
I
Pichiri
Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
Lucia
L
Mingolla
Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
Valentina
V
Cavalieri
Department of Public Health and Community Medicine, University of Verona, Verona, ItalyDepartment of Prevention, Public Health Trust, Trento, Italy.
William
W
Mantovani
Department of Public Health and Community Medicine, University of Verona, Verona, ItalyDepartment of Prevention, Public Health Trust, Trento, Italy.
Serena
S
Pancheri
Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
Maddalena
M
Trombetta
Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
Giacomo
G
Zoppini
Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO.
Michel
M
Chonchol
Nutrition and Metabolism, Faculty of Medicine, University of Southampton, Southampton, U.K.
Christopher D
CD
Byrne
Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.
Enzo
E
Bonora
D000328:Adult; D000419:Albuminuria / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D048909:Diabetes Complications / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000503:physiopathology*; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D012189:Retrospective Studies; D012307:Risk Factors