Later Development Of Diabetic Nephropathy Research Articles

Development and Validation of a Model for Predicting Diabetic Nephropathy in Chinese People

ObjectiveTo develop a risk model for predicting later development of diabetic nephropathy (DN) in Chinese people with type 2 diabetes mellitus (T2DM) and evaluate its performance with independent validation. MethodsWe used data collected from the project ‘Comprehensive Research on the Prevention and Control of Diabetes’, which was a community-based study conducted by the Jiangsu Center for Disease Control and Prevention in 2013. A total of 11,771 eligible participants were included in our study. The endpoint was a clear diagnosis of DN. Data was divided into two components: a training set for model development and a test set for validation. The Cox proportional hazard regression was used for survival analysis in men and women. The model's performance was evaluated by discrimination and calibration. ResultsThe incidence (cases per 10,000 person-years) of DN was 9.95 (95% CI; 8.66-11.43) in women and 11.28 (95% CI; 9.77-13.03) in men. Factors including diagnosis age, location, body mass index, high-density-lipoprotein cholesterol, creatinine, hypertension, dyslipidemia, retinopathy, diet control, and physical activity were significant in the final model. The model showed high discrimination and good calibration. ConclusionThe risk model for predicting DN in people with T2DM can be used in clinical practice for improving the quality of risk management and intervention.

The risk for diabetic nephropathy is low in young adults in a 17‐year follow‐up from the Diabetes Incidence Study in Sweden (DISS). Older age and higher BMI at diabetes onset can be important risk factors

The main objective of this study was to estimate the occurrence of diabetic nephropathy in a population-based cohort of patients diagnosed with diabetes as young adults (15-34 years). All 794 patients registered 1987-1988 in the Diabetes Incidence Study in Sweden (DISS) were invited to a follow-up study 15-19 years after diagnosis, and 468 (58%) participated. Analysis of islet antibodies was used to classify type of diabetes. After median 17 years of diabetes, 15% of all patients, 14% T1DM and 25% T2DM, were diagnosed with diabetic nephropathy. Ninety-one percent had microalbuminuria and 8.6% macroalbuminuria. Older age at diagnosis (HR 1.05; 95% CI 1.01-1.10 per year) was an independent and a higher BMI at diabetes diagnosis (HR 1.04; 95% CI 1.00-1.09 per 1 kg/m²), a near-significant predictor of development of diabetic nephropathy. Age at onset of diabetes (p = 0.041), BMI (p = 0.012) and HbA1c (p < 0.001) were significant predictors of developing diabetic nephropathy between 9 and 17 years of diabetes. At 17 years of diabetes duration, a high HbA1c level (OR 1.06; 95% CI 1.03-1.08 per 1 mmol/mol increase) and systolic blood pressure (OR 1.08; 95% CI 1.05 1.12 per 1 mmHg increase) were associated with DN. Patients with T2DM diagnosed as young adults seem to have an increased risk to develop diabetic nephropathy compared with those with T1DM. Older age and higher BMI at diagnosis of diabetes were risk markers for development of diabetic nephropathy. In addition, poor glycaemic control but not systolic blood pressure at 9 years of follow-up was a risk marker for later development of diabetic nephropathy.

Serum Uric Acid as a Predictor for Development of Diabetic Nephropathy in Type 1 Diabetes

OBJECTIVEExperimental and clinical studies have suggested that uric acid may contribute to the development of hypertension and kidney disease. Whether uric acid has a causal role in the development of diabetic nephropathy is not known. The objective of the present study is to evaluate uric acid as a predictor of persistent micro- and macroalbuminuria.RESEARCH DESIGN AND METHODSThis prospective observational follow-up study consisted of an inception cohort of 277 patients followed from onset of type 1 diabetes. Of these, 270 patients had blood samples taken at baseline. In seven cases, uric acid could not be determined; therefore, 263 patients (156 men) were available for analysis. Uric acid was measured 3 years after onset of diabetes and before any patient developed microalbuminuria.RESULTSDuring a median follow-up of 18.1 years (range 1.0–21.8), 23 of 263 patients developed persistent macroalbuminuria (urinary albumin excretion rate >300 mg/24 h in at least two of three consecutive samples). In patients with uric acid levels in the highest quartile (>249 μmol/l), the cumulative incidence of persistent macroalbumnuria was 22.3% (95% CI 10.3–34.3) compared with 9.5% (3.8–15.2) in patients with uric acid in the three lower quartiles (log-rank test, P = 0.006). In a Cox proportional hazards model with sex and age as fixed covariates, uric acid was associated with subsequent development of persistent macroalbuminuria (hazard ratio 2.37 [95% CI 1.04–5.37] per 100 μmol/l increase in uric acid level; P = 0.04). Adjustment for confounders did not change the estimate significantly.CONCLUSIONSUric acid level soon after onset of type 1 diabetes is independently associated with risk for later development of diabetic nephropathy.

Differential Effects of Transient Treatment of Spontaneously Hypertensive Rats with Various Antihypertensive Agents on the Subsequent Development of Diabetic Nephropathy

Background/Aims: We have previously shown that treatment of spontaneously hypertensive rats (SHR) with an angiotensin receptor blocker (ARB) during the ‘critical period’ from age 3 to 10 weeks confers protection against L-NAME-induced renal injury later in life. The aim of this study was to examine the effects of transient prepubertal exposure to ARB on the development of nephropathy in streptozotocin-induced diabetic SHR and to compare the results with other antihypertensive agents including a mineralocorticoid receptor antagonist (MR-ant). Methods: Male SHR (n = 43) were transiently treated with candesartan (ARB), potassium canreonate (the active metabolite of the MR-ant spironolactone) or hydralazine (vasodilator) between 3 and 10 weeks of age with untreated rats serving as controls. An additional group was treated continuously with candesartan throughout the study. Rats were injected with streptozotocin to induce diabetes at age 16 weeks and followed until age 8 months. Results: Diabetic control rats showed signs of diabetic nephropathy including albuminuria and mesangial expansion. These changes were significantly suppressed in rats exposed to ARB or MR-ant. Systolic blood pressure was significantly reduced compared to controls in the ARB (transient) and ARB (sustained) groups, but not in the MR-ant or vasodilator groups. Conclusion: Transient prepubertal exposure to ARB or MR-ant, but not vasodilator, confers protection against the later development of diabetic nephropathy and involves blood pressure-independent protective mechanisms.

Glomerular hyperfiltration in non-proteinuric and non-hypertensive Japanese type 2 diabetic patients

Glomerular hyperfiltration (GHF) may be an important factor in the initiation of glomerular damage and in predisposing diabetic patients to the later development of diabetic nephropathy (DN). Previous reports show wide range of prevalence of GHF in type 2 diabetic patients. This cross-sectional study was designed to determine the prevalence of GHF at an early stage of DN in Japanese type 2 diabetic patients and to investigate the relationships between clinical variables and GHF. We measured the glomerular filtration rate (GFR) using the plasma clearance of iohexol in 56 control subjects and 93 type 2 diabetic patients without hypertension or overt proteinuria. We used Altman's method to calculate the age-adjusted 95% reference ranges for GFR from the data of control subjects and classified GHF in type 2 diabetics from the reference ranges. Hyperfiltrators (defined as GFR > mean GFR + 1.96 S.D. of control subjects) was found in 17% patients (16/93). Other 77 patients (83%) were normofiltrators (defined as GFR ≤ mean GFR + 1.96 S.D. of control subjects). GFR values, both in hyperfiltrators and normofiltrators, were 140.5 ± 14.6 and 98.8 ± 14.0 ml/min/1.73 m 2, respectively. Age, sex, BMI, blood pressure, albumin excretion rate, and frequency of microalbuminuria did not differ between the hyperfiltrators and normofiltrators. Fasting plasma glucose and hemoglobin A1c were significantly higher in the hyperfiltrators than the normofiltrators ( P < 0.001 and 0.004, respectively). GHF exists among Japanese type 2 diabetic patients with no evidence of overt proteinuria or hypertension. Glycemic control might be a significant determinant of GHF in these patients.

Effect of dopamine D3 receptor blockade on renal function and glomerular size in diabetic rats

Dopamine D2-like receptors, including D2, D3, and D4 receptors, are involved in the regulation of glomerular hyperfiltration due to diabetes mellitus. These hemodynamic alterations represent a risk factor for the later development of diabetic nephropathy. The aim of the present study was to determine whether the D3 receptor subtype modulates the diabetes-induced increase in glomerular filtration rate (GFR) in rats. Renal function was studied in Sprague-Dawley rats 14 days after induction of a moderate diabetes mellitus (DM) by streptozotocin and in non-diabetic controls (CON). Rats were orally treated either with the peripherally acting, selective dopamine D3 receptor antagonist BSF 135170 (BSF, 10 mg/kg per day for 2 weeks) or with vehicle (VHC). Perfusion-fixed kidneys were used for estimation of glomerular volume. In conscious rats, which were treated with BSF, the DM-induced increase in fluid intake, urinary output, and renal sodium excretion was significantly less pronounced than in the vehicle group (DM-VHC). In the clearance experiments, GFR in CON was about 0.84+/-0.04 ml/min per 100 g body weight. The DM-VHC group presented a significant glomerular hyperfiltration (1.09+/-0.04 ml/min per 100 g body weight). Treatment with BSF significantly lowered GFR towards levels of CON. The estimated glomerular volume was 0.73+/-0.03 x 10(6) microm3 in the CON-VHC group and 0.86+/-0.04 x 10(6) microm3 in the DM-VHC animals. Interestingly, treatment with BSF decreased the glomerular volume in both groups. Irrespective of BSF treatment, kidney wet weight related to body weight was about 36% higher in DM animals compared with CON animals. We conclude that dopamine D3 receptors represent a target for the modulation of diabetes-induced glomerular hyperfiltration. Therefore, the results encourage the testing of the possible beneficial effects of long-term D3 receptor blockade on the development of diabetic nephropathy.

Is low birth weight a risk factor for the development of diabetic nephropathy in patients with type 1 diabetes? A population-based case-control study.

To investigate if low birth weight as a consequence of intrauterine malnutrition is a risk factor for the later development of diabetic nephropathy. In a case-control set-up a group of type 1 diabetic subjects with diabetic nephropathy (n = 51) and a matched control group with normal kidney function (n = 51) were compared. Diabetic nephropathy and normal kidney function were defined as urinary albumin excretion rate above 200 microg min-1 and below 20 microg min-1, respectively. The birth weights were all obtained from the midwives' original records. The patients were identified from a population-based study of chronic diabetic complications in the Funen County, Denmark. Birth weights according to the presence of diabetic nephropathy. The median (10-90 percentile) birth weights were 3,600 g (2,960-4,274) in the group with diabetic nephropathy and 3,600 g (2,880-4,220) in the group without nephropathy, P = 0.52. In the lower quartile of birth weights the median (10-90 percentile) birth weights were 3,000 g (2,780-3,200) in the group with nephropathy versus 2,850 g (2,250-3,175) in the group without nephropathy, P = 0.07. In the upper quartile the median (10-90 percentile) birth weights were 4,225 g (4,000-4,741) in the nephropathy group and 4,000 g in the group without nephropathy, P = 0.13. We found no significant correlation between birth weights and log urinary albumin excretion rate (r = 0.148, P = 0.14) and no difference in the number of patients with nephropathy in the lower versus upper quartiles of birth weights. We found no evidence of low birth weight as a risk factor for the development of diabetic nephropathy.

Effect of Strict Glycemic Control on Renal Hemodynamic Response to Amino Acids and Renal Enlargement in Insulin-Dependent Diabetes Mellitus

Many patients with insulin-dependent diabetes mellitus have an increase in the glomerular filtration rate and renal enlargement early in the course of their disease. Both these changes may be risk factors for the later development of diabetic nephropathy. Their cause is not known, but they could be due to augmented renal responses to the increase in plasma amino acid concentrations that occurs when dietary protein intake is high, a factor known to increase glomerular filtration and renal blood flow in normal subjects. We measured the glomerular filtration rate and renal plasma flow after an overnight fast and during an infusion of amino acids in 12 patients with insulin-dependent diabetes mellitus and 9 normal subjects. The diabetic patients were studied when they were hyperglycemic, when they were euglycemic after an insulin infusion for 36 hours, and after intensive insulin therapy for 3 weeks. Kidney volume was measured by ultrasonography before and after the period of intensive insulin therapy. The glomerular filtration rate and renal plasma flow were normal after fasting when the patients were hyperglycemic (mean [+/- SE] fasting plasma glucose level, 11.5 +/- 0.7 mmol per liter). After the amino acid infusion, these values increased more in the patients (glomerular filtration rate, 2.65 +/- 0.07 ml per second per 1.73 m2 of body-surface area; renal plasma flow, 13.30 +/- 0.68 ml per second per 1.73 m2; P less than 0.05 for both) than in the normal subjects (2.25 +/- 0.08 and 11.20 +/- 0.65 ml per second per 1.73 m2, respectively). The 36-hour infusion of insulin in the diabetic patients did not alter the glomerular filtration rate or renal plasma flow either before or during the amino acid infusion. After three weeks of intensive insulin therapy (fasting plasma glucose level, 5.3 +/- 0.2 mmol per liter), the glomerular filtration rate and renal plasma flow after the amino acid infusion (2.33 +/- 0.03 and 11.30 +/- 0.43 ml per second per 1.73 m2, respectively) were similar to those in the normal subjects. The kidney volumes in the normal subjects and the patients with diabetes were 219 +/- 14 and 312 +/- 14 ml per 1.73 m2, respectively (P less than 0.01); the volume decreased to 267 +/- 22 ml per 1.73 m2 (P less than 0.001) in the diabetic patients after three weeks of intensive insulin therapy, which was not significantly different from the volume in the normal subjects (P = 0.1). Conventionally treated diabetic patients who have normal renal function while fasting have augmented renal hemodynamic responses to increased plasma amino acid concentrations. The concomitant decrease in these hemodynamic responses and in kidney size with strict glycemic control suggests that these phenomena are related and influenced by the metabolic state.

Prevalence of microalbuminuria, arterial hypertension, retinopathy and neuropathy in patients with insulin dependent diabetes.

Diabetic nephropathy is the main cause of the increased morbidity and mortality in patients with insulin dependent diabetes. The prevalence of microalbuminuria was determined in adults with insulin dependent diabetes of five or more years' duration that had started before the age of 41. All eligible patients (n = 982) attending a diabetes clinic were asked to collect a 24 hour urine sample for analysis of albumin excretion by radioimmunoassay; 957 patients complied. Normoalbuminuria was defined as urinary albumin excretion of less than or equal to 30 mg/24 h (n = 562), microalbuminuria as 31-299 mg/24 h (n = 215), and macroalbuminuria as greater than or equal to 300 mg/24 h (n = 180). The prevalence of microalbuminuria and macroalbuminuria was significantly higher in patients whose diabetes had developed before rather than after the age of 20. The prevalence of arterial hypertension increased with increased albuminuria, being 19%, 30%, and 65% in patients with normoalbuminuria, microalbuminuria, and macroalbuminuria respectively. The prevalence of proliferative retinopathy and blindness rose with increasing albuminuria, being 12% and 1.4%, respectively, in patients with normoalbuminuria, 28% and 5.6% in those with microalbuminuria and 58% and 10.6% in those with macroalbuminuria. An abnormal vibratory perception threshold was more common in patients with microalbuminuria (31%) and macroalbuminuria (50%) than in those with normoalbuminuria (21%). This study found a high prevalence (22%) of microalbuminuria, which is predictive of the later development of diabetic nephropathy. Microalbuminuria is also characterised by an increased prevalence of arterial hypertension, proliferative retinopathy, blindness, and peripheral neuropathy. Thus, urinary excretion of albumin should be monitored routinely in patients with insulin dependent diabetes.

Is exercise-induced blood pressure rise predictive of nephropathy in insulin-dependent diabetes?

A follow-up study was performed in 48 male diabetics and 17 age-matched male controls, who in 1963 and 1971 participated in an exercise study to evaluate if the results could predict later development of diabetic nephropathy. The inclusion criteria were: Type I (insulin-dependent) diabetes with age below 40, onset of diabetes before age of 30, duration of diabetes more than 7 years and no proteinuria at the time for the first study. The diabetics demonstrated higher systolic blood pressure (BP) at work but as good physical condition as the controls. Thirteen developed nephropathy after 23 years (range 15-36) of diabetes duration. It was found that exercise-induced, abnormally raised systolic BP was not associated with later development of diabetic nephropathy.

Prevalence of microalbuminuria in children with type 1 (insulin-dependent) diabetes mellitus.

The prevalence of microalbuminuria was determined in children aged 7 to 18 years with Type 1 (insulin-dependent) diabetes of more than 2 years' duration. All patients (n = 102) attending 2 diabetes clinics were asked to collect 2 overnight timed urine samples for albumin analysis by radioimmunoassay. Complete urine collection was obtained in 97 patients (95%). Overnight urinary albumin excretion rates were also measured in 36 healthy children matched for age and sex. Nineteen of the 97 patients (20%) had microalbuminuria, i.e. overnight urinary albumin excretion rates above the upper normal level (14 micrograms/min) in both urine collections. Microalbuminuria was only demonstrated in patients aged greater than or equal to 15 years, prevalence 37% (19/52 patients). Arterial blood pressure was elevated, mean 122/84 +/- 11/9mmHg, in the microalbuminuric group (19 patients) compared to the age-matched normoalbuminuric diabetic group (33 patients), mean 117/74 +/- 10/10mm Hg, p less than 0.001. The prevalence of simplex retinopathy was identical in these two groups, i.e. 25%. Glycosylated haemoglobin was slightly higher in the microalbuminuric patients, p less than 0.10. Our cross-sectional study reveals a high prevalence (37%) of persistent microalbuminuria, a stage highly predictive of later development of diabetic nephropathy, in Type 1 diabetic children aged greater than or equal to 15 years.