Primacy of lowered baseline glomerular filtration rate as a risk for incident chronic kidney disease: A longitudinal study in Japanese subjects

Renal functional impairment in the elderly, the importance of fasting plasma glucose: the Northern Shanghai Study

BACKGROUND

Chronic kidney disease is a global health problem that is closely related to the aging population. Although plasma glucose levels have been shown to be related to renal dysfunction, risk factors for renal functional impairment in the geriatric population are unknown. The authors therefore aimed to investigate the determinants of renal functional impairment in an elderly population.

METHODS

From June 2014 to August 2015, 912 participants (aged > 65 years) were recruited. Renal function was assessed at baseline; follow-up was conducted in 2016. Within the framework of comprehensive cardiovascular examinations, all conventional cardiovascular risk factors, fasting plasma glucose (FPG), and renal function were assessed. Renal function was evaluated by the estimated glomerular filtration rate (e-GFR) using a modified Modification of Diet in Renal Disease formula. Rapid decline in e-GFR was defined as an e-GFR slope > 5 mL/min per 1.73 m² per year.

RESULTS

We observed that FPG levels were significantly higher in participants with (6.15 ± 2.76 mmol/L) than in those without (5.56 ± 1.61 mmol/L) a rapid decline in e-GFR (p = 0.02). The average decline in e-GFR was 0.149 mL/min/1.73m² per year in this elderly population, and the increasing risk of having rapid decline in e-GFR was 0.44-fold each year. In the full adjustment model, decline in e-GFR (p = 0.02) and rapid decline in e-GFR (OR1.33, 95% CI 1.03-1.72) were significantly associated with FPG, independent of other conventional cardiovascular risk factors. Using the same models, decline in e-GFR (p = 0.04) and rapid decline in e-GFR (OR 1.57, 95% CI 1.05-2.35) were also significantly associated with FPG in diabetic population, but they were not in non-diabetic population.

CONCLUSIONS

In community-dwelling elderly Chinese, the average decline in e-GFR was 0.149 mL/min/1.73m² per year. FPG control is important for delaying renal functional impairment in elderly population. Trial registration NSS, NCT02368938.

Elevated haemoglobin A1c but not fasting plasma glucose conveys risk of chronic kidney disease in non-diabetic individuals

AIMS

To compare impact of elevated HbA1c and fasting plasma glucose (FPG) on incident chronic kidney disease (CKD) in a non-diabetic cohort.

METHODS

Data from diabetes- and CKD-free 25,109 health examinees were retrospectively analysed with a mean observation period of 5.3 years. Prediabetes was diagnosed by the ADA and WHO criteria, and CKD by estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² and/or dipstick proteinuria. Cox proportional hazards model was applied with sex, age, insulin sensitivity, systolic blood pressure, eGFR and serum alanine aminotransferase level as covariates.

RESULTS

For incident CKD (n = 2483), high HbA1c but not FPG was an independent risk: adjusted hazard ratio (AHR, 95%CI) for HbA1c 1% and FPG 1 mmol/L, 1.91 (1.70-2.16) and 0.85 (0.60-1.20), respectively. Prediabetes by the ADA and WHO criteria were both risk for CKD with AHR (95%CI), 1.21 (1.12-1.32) and 1.31 (1.16-1.48), respectively. Prediabetes diagnosed by 'elevated HbA1c irrespective of FPG', either by the ADA and the WHO definition, was a risk with AHR (95%CI), 1.48 (1.36-1.61) and 1.51 (1.31-1.74), respectively. In contrast, prediabetes diagnosed by 'raised FPG irrespective of HbA1c' was not a CKD risk.

CONCLUSIONS

Elevated HbA1c, but not FPG, identified CKD risk in non-diabetic individuals.