Risk factors for chronic kidney disease progression over 20 years for primary prevention in Japanese individuals at a preventive medicine research center: Focus on the influence of plasma glucose levels.

AIMS/INTRODUCTION: Chronic kidney disease (CKD) is a very important issue globally because of the risk of its progressing to end-stage renal disease. We aimed to identify factors contributing to long-term estimated glomerular filtration rate (eGFR) decline to determine an early diagnosis and prevent CKD progression. MATERIALS AND METHODS: From January 2003 to December 2006, 5,507 individuals underwent health checkups at our hospital's Preventive Medicine Research Center. We ultimately enrolled 2,175 individuals. The eGFR was ≥60 mL/min/1.73 m2 at the start of observation period, which was 20 years. The event onset time was the day that the eGFR became <30 mL/min during the 20-year period. Baseline risk factors - in particular, the effect of plasma glucose levels on the eGFR - were extracted and evaluated by using Fine and Gray analysis. RESULTS: During the 20-year observation, the hazard ratio (HR) of CKD progression was examined. A fasting plasma glucose (FPG) level ≥105 mg/dL was significantly associated with the risk of CKD progressing to an eGFR <30 mL/min. This trend was similar in the slope of eGFR. An FPG ≥105 mg/dL or an glycated hemoglobin level ≥6.5% was useful for intervening in CKD progression. Multivariate analysis showed that independent risk factors were an FPG level ≥105 mg/dL (HR 1.9; P < 0.001), age ≥60 years (HR 3.86; P < 0.001), obesity (HR 1.61; P < 0.01) and urinary protein (HR 1.55; P < 0.01). CONCLUSIONS: For early intervention against a reduction in the eGFR, detecting mild increases in FPG ≥105 mg/dL in patients with CKD with or without diabetes is useful.

Hyperferritinemia Is a Predictor of Onset of Diabetes in Japanese Males Independently of Decreased Renal Function and Fatty Liver: A Fifteen-Year Follow-Up Study.

BACKGROUND: Type 2 diabetes is an important health concern worldwide. The disease etiology may depend on multiple environmental and genetic factors that cause insulin resistance, including dysregulation of iron storage. The goal of this study was to examine the relationship of the serum ferritin concentration with onset of diabetes over a long period. METHODS: Correlations of serum ferritin and metabolic markers with onset of diabetes mellitus were examined over 15 years in 150 males participating in a health screening program. RESULTS: HOMA-ß showed a gradual significant decrease in the first 4 years in subjects with ferritin > 190 ng/mL (group H) compared to those with ferritin ≤ 190 ng/mL, but there was no difference in HOMA-R between these groups. A significant number of cases with onset of diabetes was observed over 15 years (hazard ratio (HR): 3.97), and obesity, fasting blood glucose level, hemoglobin A1c (HbA1c), HOMA-R, fasting immunoreactive insulin (IRI) and C-peptide immunoreactivity (CPR) were all significant in univariate comparison between non-diabetes and diabetes-onset groups. In multivariate analysis, ferritin in group H (HR: 3.25), fatty liver (HR: 3.38), estimated glomerular filtration rate (eGFR) < 70 mL/min/1.73 m2 (HR: 3.48) and high-density lipoprotein (HDL) < 40 mg/dL (HR: 2.61) were significant predictive factors for onset of type 2 diabetes mellitus. CONCLUSIONS: These results suggest that the serum ferritin level is an important index for priority intervention in preventive medicine for reduction of onset of diabetes.