title: Renal hyperfiltration in prediabetes confirmed by fasting plasma glucose and hemoglobin A1c.
abstract: BACKGROUND
  The aim of the study was to confirm that glomerular hyperfiltration, an early and reversible stage of kidney damage, is associated in patients with prediabetes and prehypertension.
  
  
  METHODS
  In total, 5003 people aged between 35 and 69 years who had participated in the Shizuoka part of the Japan Multi-Institutional Collaborative Cohort (J-MICC) study took part in the study. Prevalence of hyperfiltration [the estimated glomerular filtration rate (eGFR) above the age- /sex-specific 95th percentile] was compared among different stages of prediabetes [fasting plasma glucose (FPG) < 100, 100-109, 110-125, and ≥126 mg/dL; and/or hemoglobin A1c (HbA1c) < 5.7, 5.7-6.0, 6.1-6.4 and ≥6.5% for no prediabetes, stage 1 prediabetes, stage 2 prediabetes, and overt diabetes, respectively] and prehypertension (blood pressure <120/80, 120-129/80-84, 130-139/85-89, and ≥140/90 mmHg for no prehypertension, stage 1 prehypertension, stage 2 prehypertension, and overt hypertension, respectively).
  
  
  RESULTS
  The prevalence of hyperfiltration increased with increasing stages of prediabetes (odds ratios: 1.25, 1.68, and 2.37 using FPG, and 1.26, 2.15, and 2.45 using HbA1c for stage 1 prediabetes, stage 2 prediabetes, and diabetes, respectively, relative to no prediabetes). Prehypertension, however, was not associated with hyperfiltration.
  
  
  CONCLUSIONS
  The results confirmed that the prevalence of glomerular hyperfiltration increased with increasing stages (i.e., worsening) of prediabetes. Because both FPG and HbA1c showed similar association with hyperfiltration, either of these can be used to identify subjects who are at increased risk of nephropathy. Therefore, the functioning of kidneys should be monitored in subjects with prediabetes. Prompt treatment of hyperglycemia is necessary in subjects with hyperfiltration to prevent it to cause nephropathy.
authors.affiliation: Department of Preventive Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Rieko
authors.initials: R
authors.lastname: Okada
authors.forename: Kenji
authors.initials: K
authors.lastname: Wakai
authors.forename: Mariko
authors.initials: M
authors.lastname: Naito
authors.forename: Emi
authors.initials: E
authors.lastname: Morita
authors.forename: Sayo
authors.initials: S
authors.lastname: Kawai
authors.forename: Guang
authors.initials: G
authors.lastname: Yin
authors.forename: Noriyo
authors.initials: N
authors.lastname: Ozawa
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Furuta
authors.forename: Erina
authors.initials: E
authors.lastname: Koyama
authors.forename: Rumi
authors.initials: R
authors.lastname: Tsuchiya
authors.forename: Noriko
authors.initials: N
authors.lastname: Kouno
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hamajima
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D005215:Fasting / Q000097:blood*; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate / Q000502:physiology*; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007678:Kidney Glomerulus / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D015995:Prevalence; D012189:Retrospective Studies; D011795:Surveys and Questionnaires
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin