Prediabetes defined by the International Expert Committee as a risk for development of glomerular hyperfiltration

Association between the number of teeth and incident pre-diabetes among middle-aged adults with periodontal disease: a retrospective cohort analysis of Japanese claims data

OBJECTIVES

To investigate the association between the number of teeth and the new onset of pre-diabetes.

DESIGN

Retrospective cohort study.

SETTING

The National Database of Health Insurance Claims and Specific Health Checkups of Japan, which holds information from both the yearly health check-up programme known as the 'Specific Health Checkup' and health insurance claims data.

PARTICIPANTS

1 098 371 normoglycaemic subjects who participated in the Specific Health Checkup programme every year from fiscal year (FY) 2015 to FY 2018 and had dental insurance claims data with a diagnosis of periodontal disease during FY 2016.

OUTCOME MEASURES

Incidence of pre-diabetes or diabetes observed at the Specific Health Checkup during FY 2018.

RESULTS

Among the participants, 1 77 908 subjects developed pre-diabetes, and 579 developed diabetes at the check-up during the subsequent follow-up year. Compared with the subjects with 26-28 teeth, those with 20-25, 15-19 or 1-14 teeth were associated with an increased likelihood of developing pre-diabetes or diabetes onset with adjusted ORs of 1.03 (95% CI: 1.02 to 1.05), 1.06 (1.03 to 1.09) and 1.07 (1.04 to 1.11), respectively. No clear modifications were observed for age, sex, body mass index or current smoking.

CONCLUSIONS

Having fewer teeth was associated with a higher incidence of pre-diabetes. Due to the limitations of this study, however, causality remains undetermined.

Sex-specific association of body mass index and fatty liver index with prevalence of renal hyperfiltration: a cross sectional study using Japanese health check-up data

BACKGROUND

The relationship between obesity and nonalcoholic fatty liver disease and renal hyperfiltration is controversial. This study aimed to assess the correlations of body mass index and fatty liver index, respectively, with renal hyperfiltration in non-diabetic subjects, considering age, sex, and body surface area.

METHODS

This cross-sectional study assessed the Japanese health check-up data (FY2018) of 62,379 non-diabetic individuals from a health insurance database. Renal hyperfiltration is the ≥ 95th percentile of estimated glomerular filtration rate (derived by Chronic Kidney Disease Epidemiology Collaboration formula) by gender and age in healthy subjects. After adjusting for potential confounders, multiple logistic regression models were applied to evaluate the correlation of renal hyperfiltration with body mass index categories and fatty liver index (10 equal parts).

RESULTS

A negative and positive correlation, respectively, were noted when the body mass index was < 21 and ≥ 30 in women; however, a positive correlation was noted for BMI < 18.5 and ≥ 30 in men. Renal hyperfiltration prevalence increased when fatty liver index increased for both sexes; the cutoff value for fatty liver index was 14.7 for women and 30.4 for men.

CONCLUSIONS

Body mass index and renal hyperfiltration correlated linearly in women; however, in men, the correlation was U-shaped; therefore, differing by sex. However, fatty liver index correlated linearly with renal hyperfiltration in both sexes. Non-alcoholic fatty liver disease might be associated with renal hyperfiltration; Fatty liver index is a simple marker that can be obtained from health check-ups. Since a high fatty liver index correlated with renal hyperfiltration, it may be beneficial to monitor the renal function in such a population.

Insulin Resistance is Associated with Clinical Manifestations of Diabetic Kidney Disease (Glomerular Hyperfiltration, Albuminuria, and Kidney Function Decline)

Clinical features of diabetic kidney disease include glomerular hyperfiltration, albuminuria, and kidney function decline towards End-Stage Kidney Disease (ESKD). There are presently neither specific markers of kidney involvement in patients with diabetes nor strong predictors of rapid progression to ESKD. Serum-creatinine-based equations used to estimate glomerular filtration rate are notoriously unreliable in patients with diabetes. Early kidney function decline, reduced glomerular filtration rate, and proteinuria contribute to identifying diabetic patients at higher risk for rapid kidney function decline. Unlike proteinuria, the elevation of urinary albumin excretion in the range of microalbuminuria is frequently transient in patients with diabetes and does not always predict progression towards ESKD. Although the rate of progression of kidney function decline is usually accelerated in the presence of proteinuria, histological lesions of diabetes and ESKD may occur with normal urinary albumin excretion. No substantial reduction in the rate of ESKD associated with diabetes has been observed during the last decades despite intensified glycemic control and reno-protective strategies, indicating that existing therapies do not target underlying pathogenic mechanisms of kidney function decline. Very long-term effects of sodium-glucose transporters- 2 inhibitors and glucagon-like peptide-1 analogs remain to be defined. In patients with diabetes, glucagon secretion is typically elevated and induces insulin resistance. Insulin resistance is consistently and strongly associated with clinical manifestations of diabetic kidney disease, suggesting that reduced insulin sensitivity participates in the pathogenesis of the disease and may represent a therapeutic objective. Amelioration of insulin sensitivity in patients with diabetes is associated with cardioprotective and kidney-protective effects.

Development of glomerular hyperfiltration, a multiphasic phenomenon

The trajectory of glomerular filtration rate (GFR) in relation to glomerular hyperfiltration (GHF) has been unknown. It was evaluated retrospectively in 23,982 GHF-free health examinees who were followed for 2-10 yr (mean: 5.1 yr). GFR was estimated by the serum creatinine concentration, and GHF was defined as age- and sex-specific estimated GFR (eGFR) ≥ 95% of the Japanese general population. The temporal profile of eGFR was plotted in a GHF-centered way, which was fitted to a random coefficient linear mixed model. Of the 23,982 subjects, 797 and 23,185 subjects developed or did not develop GHF, respectively, so that they were termed as the GHF₍₊₎ and GHF_(-) groups. At baseline, median eGFR was significantly elevated in the GHF₍₊₎ group compared with in the GHF_(-) group: 94.1 versus 77.3 mL/min/1.73 m² (P < 0.001). Elevation of basal eGFR lasted for a mean (SD) of 3.3 (1.9) yr in the GHF₍₊₎ group; mean eGFR then rose to the GHF range, which was 108.5 mL/min/1.73 m². The eGFR decline after the peak was steeper in the GHF₍₊₎ group than in the GHF_(-) group: -0.984 versus -0.497 mL/min/1.73 m²/yr (P < 0.001). Baseline eGFR, but no other variable, well predicted incident GHF, with an area under the receiver operating characteristic curve of 0.87 (95% confidence interval: 0.86-0.88). In conclusion, GHF occurs as a chronic, multiphasic phenomenon: initially with a sustained GFR elevation for years, followed by a GFR surge to the GHF range, which was accompanied by accelerated GFR declining.

An evaluation of preterm kidney size and function over the first two years of life

BACKGROUND

We carried out a study to determine the impact of prematurity on kidney development in the first 2 years of life.

METHODS

In this prospective study, extremely preterm neonates (gestation < 28 weeks) were recruited and underwent assessments at 6, 12, and 24 months of age. A cohort of neonates born term were also recruited and followed up for 24 months. The primary outcomes measured in this study were total kidney volume (TKV) and estimated glomerular filtration rate (eGFR); albuminuria and blood pressure measurements (all provided as mean (standard deviation)) were the secondary outcomes.

RESULTS

Fifty-three premature and 31 term neonates (control) were recruited. At the age of 24 months (corrected age), infants born preterm had significantly smaller TKV (56.1 (9.4) vs. 64.8 (10.2) mL; P = 0.006). There was no difference in eGFR. These preterm infants were smaller (11.25 (1.53) vs. 12.9 (1.8) kg; P = 0.002) and shorter (83.8 (3.0) vs. 86.3 (3.4) cm; P = 0.02) when compared with the control group. At 6, 12, and 18 months respectively, preterm infants had, relative to their height, significantly smaller kidney volumes (0.54 (0.1) vs. 0.59 (0.1) mL/cm, P = 0.05; 0.61 (0.1) vs.0.71 (0.1) mL/cm, P = 0.003; and 0.67 (0.1) vs.0.76 (0.1) mL/cm, P = 0.006).

CONCLUSIONS

Relative to body length, TKV in premature infants is smaller. Since length reflects adult body proportions more accurately than BSA, TKV to height ratio may be a more important measure in the child. Despite smaller TKV (and therefore fewer nephrons), infants born prematurely achieve similar eGFRs in the first 24 months of life, probably due to single-nephron hyperfiltration.

High levels of fasting glucose and glycosylated hemoglobin values are associated with hyperfiltration in a Spanish prediabetes cohort. The PREDAPS Study

AIM

This study aimed to investigate whether different levels of fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) in prediabetes are associated with hyperfiltration.

METHODS

A prospective cohort of 2,022 individuals aged 30-74 years took part in the PREDAPS Study. One cohort of 1,184 participants with prediabetes and another cohort of 838 participants with normal FPG and normal HbA1c were followed for 5 years. Hyperfiltration was defined as an estimated glomerular filtration rate (eGFR) above the age- and gender-specific 95th percentile for healthy control participants, while hypofiltration was defined as an eGFR below the 5th percentile. The prevalence of hyperfiltration was compared for different levels of prediabetes: level 1 of prediabetes: FPG <100 mg/dL plus HbA1c 5.7-6.0% or FPG 100-109 mg/dL plus HbA1c < 5.7%; level 2 of prediabetes: FPG <100 mg/dL plus HbA1c 6.1-6.4% or FPG 100-109 mg/dL plus HbA1c 5.7-6.0% or FPG 110-125 mg/dL plus HbA1c <5.7% and level 3 of prediabetes: FPG 100-109 mg/dL plus HbA1c 6.1-6.4% or FPG 110-125 mg/dL plus HbA1c 5.7-6.4%.

RESULTS

The participants with hyperfiltration were significantly younger, had a higher percentage of active smokers, and lower levels of hemoglobin and less use of ACEIs or ARBs. Only level 3 prediabetes based on FPG 100-109 mg/dL plus HbA1c 6.1-6.4% or FPG 110-125 mg/dL plus HbA1c 5.7-6.4% had a significantly higher odds ratio (OR) of hyperfiltration (OR 1.69 (1.05-2.74); P < 0.001) compared with no prediabetes (FPG < 100 mg/dL and HbA1c < 5.7%) after adjustment for different factors. The odds ratios for different levels of HbA1c alone in prediabetes increased progressively, but not significantly.

CONCLUSIONS

Level 3 of prediabetes based on FPG 100-109 mg/dL plus HbA1c 6.1-6.4% or FPG 110-125 mg/dL plus HbA1c 5.7-6.4% had a significantly higher OR of hyperfiltration compared with participants without prediabetes.