Determinants of decline in glomerular filtration rate in nonproteinuric subjects with or without diabetes and hypertension.
OBJECTIVE
This study investigated whether the slope of estimated GFR is different between nonproteinuric subjects with and without diabetes, and what clinical factors are associated with the GFR slope.


METHODS
An observational cohort study was performed in 923 subjects, and the predictive value of baseline variables on the GFR slope was investigated.


RESULTS
On the basis of the median 3-yr follow-up and 7 measurements of GFR, GFR slope (%/yr, median and interquartile range) was significantly larger in subjects with diabetes (-2.39 (-4.86 to 0.15), n=729) than in those without diabetes (-1.02 (-4.28 to 1.37), n=194), and this difference remained significant with or without presence of hypertension. After adjustments for confounding factors, predictors of GFR decline were found to be baseline high values of glycosylated hemoglobin A1C(HbA1C), GFR, systolic blood pressure, and low plasma total protein in subjects with diabetes, whereas only the latter two were significant in subjects without diabetes. In subjects with diabetes, the high GFR was accounted for by high HbA1C at baseline, and the predictors of GFR decline differed between those with and without hypertension, or with high and low baseline GFR. Any combination of the predictors showed increased risk for GFR decline.


CONCLUSIONS
GFR slope is substantially affected by multiple factors at various stages. The degree of chronic hyperglycemia is likely to play a crucial role in elevating GFR and accelerating the decline in patients with type 2 diabetes even from the normoalbuminuric stage.
Yokoyama
Hiroki
H
Jiyugaoka Medical Clinic, Internal Medicine, Obihiro 080-0016, Japan. hiroki@m2.octv.ne.jp
Kanno
Sakiko
S
Takahashi
Suguho
S
Yamada
Daishiro
D
Itoh
Hiroshi
H
Saito
Kazumi
K
Sone
Hirohito
H
Haneda
Masakazu
M
D000368:Aged; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D001798:Blood Proteins / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D003928:Diabetic Nephropathies / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
D015415:Biomarkers; D001786:Blood Glucose; D001798:Blood Proteins; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human