Carbohydrate nutrition is associated with the 5-year incidence of chronic kidney disease.

It has been shown that dietary glycemic index (GI) and fiber could have a role in the development of chronic diseases; however, the link between carbohydrate nutrition and development of chronic kidney disease (CKD) is unclear. We aimed to determine whether cross-sectional and longitudinal associations exist between carbohydrate nutrition (mean dietary GI, dietary intakes of carbohydrate, sugar, starch, and fiber) and CKD. Data included 2600 Blue Mountains Eye Study (1997-1999) participants aged ≥50 y. Baseline biochemistry including serum creatinine was measured. Moderate CKD was defined as estimated glomerular filtration rate (eGFR) < 60 mL·min(-1)·1.73 m(-2). Dietary data were collected in a semiquantitative FFQ. Cross-sectionally, participants in the 4th quartile of mean dietary GI intake compared with those in the first quartile (reference) had a 55% increased likelihood of having eGFR < 60 mL·min(-1)·1.73 m(-2) [multivariable-adjusted OR = 1.55 (95% CI = 1.07-2.26); P-trend = 0.01]. After multivariable adjustment, participants in the 4th quartile of dietary cereal fiber intake compared with those in the first quartile (reference) had a 50% reduced risk of incident moderate CKD (P-trend = 0.03). Higher baseline consumption of energy-dense, nutrient-poor sources of carbohydrate (e.g. cookies) yielded a 3-fold higher risk of incident CKD (P-trend = 0.01). In summary, we observed a novel link between high cereal fiber intake and reduced incidence of moderate CKD and this was supported by the cross-sectional association with dietary GI. Conversely, our data suggest that higher intake of energy-dense, nutrient-poor sources of carbohydrate, potentially through acute hyperglycemia, could impair renal function.