Association between microalbuminuria and outcome of non-diabetic population aged 40 years and over: The reaction study

AIMS

The goal of this study was to analyze the association between microalbuminuria (MAU) and the outcome of non-diabetic populations among Chinese people.

METHODS

A cohort of 2042 Chinese individuals without diabetes, aged 40 years or older were included. We identified people with impaired fasting glucose and/or impaired glucose tolerance by conducting an oral glucose tolerance test, and then followed them up after 3years. We defined MAU as a urinary albumin-to-creatinine ratio (ACR) exceeding the normal range of 2.5-25mg/mmol (males) or 3.5-35mg/mmol (females).

RESULTS

Among 2042 adults aged 40 years or older in an urban fringe area of Luzhou city (1984 cases were followed up), 262 (12.8%) developed diabetes over 3years. MAU was significantly associated with age, fasting plasma glucose, 2-h glucose, hemoglobin A1c, and triglycerides (P<0.05). Follow-up FBG, 2hPG, TG, and HbA1c levels in the IGR+MAU group were higher than those in other groups (P<0.05). If the relative risk of the isolated normal glucose tolerance (NGT) group progressing to diabetes was set to 1, the risk of progression to diabetes in the NGT+MAU, isolated impaired glucose regulation (IGR), and IGR+MAU groups increased 1.1, 3.9, and 7.5 times, respectively.

CONCLUSIONS

Our study found that MAU is associated with increased risk of diabetes in NGT and IGR populations, especially in the IGR populations, MAU may predict adulthood at very high risk for diabetes.

Higher Blood Urea Nitrogen and Urinary Calcium: New Risk Factors for Diabetes Mellitus in Primary Aldosteronism Patients

Purpose: The aim of the study was to investigate the prevalence and risk factors of diabetes mellitus (DM) in primary aldosteronism (PA) patients. Methods: This case-control study enrolled 259 PA patients in West China Hospital, China from January 2016 to January 2019. Patients were divided into three groups: PA group, PA + impaired fasting glucose (IFG)/impaired glucose tolerance (IGT) group and PA + DM group. Clinical characteristics (like age and sex) and laboratory variables (like plasma aldosterone concentration and plasma renin activity) were compared between three groups. Univariate and multivariate logistic regression analyses were performed to determine risk factors for DM in PA patients. The association of random blood glucose with the above-mentioned factors were also investigated by Pearson correlation analyses. Nomogram model was developed to predict the probability of DM in PA patients. Results: 49 (18.9%) patients were diagnosed with DM and 22 (8.5%) with IFG/IGT in 259 PA patients. Apart from older age, male, higher body mass index, higher triglycerides and lower cholesterol, we found that higher blood urea nitrogen (BUN) and higher 24 h urinary calcium (Ca) might be potential new risk factors for dysglycemia. The nomogram model for DM in PA patients had a good predictive accuracy, with the area under the curve of receiver operating characteristic of 0.839 (95% CI 0.784-0.893). Conclusions: PA patients were more likely to have DM compared with general population. Apart from older age, overweight and dyslipidemia, higher BUN and excessive excretion of urinary Ca may also be the new potential risk factors for DM in PA patients.

Serum and Urinary Selenium Status in Patients with the Pre-diabetes and Diabetes in Northeast China

Homeostasis imbalance of selenium (Se) in diabetes has received great attention. This study investigated serum and urinary Se levels in patients with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), type 1 diabetes (T1D), and type 2 diabetes (T2D) in Northeast Chinese populations. From January 2010 to October 2011, patients with IFG (n = 12), IGT (n = 15), T1D (n = 25), T2D (n = 137), and healthy controls (n = 50) were enrolled in the First Hospital of Jilin University. Se was detected using inductively coupled plasma spectrometer. The serum Se level was dramatically lower in patients with T1D and was significantly higher in IFG subjects, and the urinary Se concentration was markedly lower in IGT and T2D groups. The serum Se levels were positively correlated with serum zinc (Zn) in both IFG and IGT groups, while urinary Se were positively associated with urinary Zn and copper (Cu) in IGT group. The serum Se levels were positively correlated with serum Cu in both T1D and T2D groups, and urinary levels of Se were positively associated with serum zinc and urinary Cu, Zn, calcium (Ca), and magnesium (Mg) and negatively correlated with serum Ca and Mg in T2D group, while the urinary levels of Se were positively correlated with urinary Zn and Mg both in peripheral neuropathy (DPN) and retinopathy (DR) groups. One month of simvastatin therapy reduced serum Se levels. These results suggest the potential role of Se in diabetes should receive attention.

Gender-specific differences of interaction between cadmium exposure and obesity on prediabetes in the NHANES 2007-2012 population

PURPOSE

Data from National Health and Nutrition Examination Survey (NHANES) for the years 2007-2012 were used to evaluate the interactions of cadmium (Cd) exposure with being overweight/obesity on the risk of prediabetes among adults 20 years older.

METHODS

A total of 3552 subjects were included in the analysis. Urinary cadmium levels (UCd) was used as a biomarker for long-term exposure to Cd. Additive interaction was estimated using relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S).

RESULTS

Following covariates adjustments, we found significant associations of UCd with higher prediabetes prevalence, and this association was more apparent in males (Q4 vs Q1: OR = 1.95, 95%CI: 1.34-2.84); while overweight/obesity was associated with prediabetes both in males and in females. Additionally, there was a significant interaction between Cd exposure and being overweight/obesity on prediabetes risk among males (RERI = 1.18, 95% CI: 0.42-1.93; AP = 0.35, 95% CI: 0.12-0.58; S = 2.00, 95% CI: 0.92-4.34).

CONCLUSIONS

Our results suggest that being overweight/obesity may substantially amplify the adverse effects of long-term cadmium exposure on prediabetes risk, and this interaction is more severe in male adults. Further studies are needed to confirm these findings.

Urine levels of 5-aminoimidazole-4-carboxamide riboside (AICAR) in patients with type 2 diabetes

AIMS

5-Aminoimidazole-4-carboxamide riboside (AICAR) is an endogenous activator of AMPK, a central regulator of energy homeostasis. Loss and/or reduction of AMPK signaling plays an important role in the development of insulin resistance in type 2 diabetes. The loss of AMPK in diabetes could be due to a loss of AICAR. The aim of this study was to characterize urine levels of AICAR in diabetes and determine whether an association exists with respect to late complications, e.g., retinopathy, nephropathy and neuropathy.

METHODS

Urine AICAR was measured by liquid chromatography tandem mass spectrometry in 223 patients consisting of 5 healthy controls, 63 patients with pre-diabetes, 29 patients with newly diagnosed type 2 diabetes and 126 patients with long-standing type 2 diabetes. For statistical analyses, nonparametric Kruskal-Wallis test, one-way ANOVA and multivariate regression analysis were performed to investigate the associations of urinary AICAR excretion within different groups and different clinical parameters.

RESULTS

The mean urine AICAR for all 223 patients was 694.7 ± 641.1 ng/ml. There was no significant difference in urine AICAR between the control and patients with diabetes (592.3 ± 345.1 vs. 697.1 ± 646.5 ng/ml). No association between any of the biochemical and/or clinical parameters measured and urine AICAR was found, with the exception of age of patient (R = - 0.34; p < 0.01) and estimated glomerular filtration rate (R = 0.19; p = 0.039). These results were confirmed additionally by linear regression analysis.

CONCLUSIONS

Clinical diabetes is not associated with a change in endogenous AICAR levels. Loss of AICAR may therefore not be a mechanism by which AMPK signaling is reduced in diabetes.

The low levels of bone morphogenic protein-4 and its antagonist noggin in type 2 diabetes

OBJECTIVE

Bone morphogenic protein-4 (BMP-4) is a proinflammatory cytokine which is controlled by BMP-4 antagonists. Our aim was to investigate the levels of BMP-4 and its antagonists, noggin and matrix Gla protein (MGP), in prediabetes and diabetes.

DESIGN

One hundred and forty-two type 2 diabetic, 32 prediabetic, and 58 control subjects participated in this cross-sectional study. BMP-4, noggin, and MGP were measured with the ELISA method.

RESULTS

There was a significant difference between the three groups in relation to sex, hypertension, fasting plasma glucose, HbA1c, lipid profiles, and diastolic blood pressure (p < 0.05). BMP-4 levels were significantly lower in the diabetic group compared to the control group (108.5 and 127.5 ng/mL, respectively, p < 0.001 diabetes vs. control). Noggin levels were significantly lower in the diabetic group compared to the prediabetic and control groups (10.5, 11.5, and 12.0 ng/mL, as median, respectively, p < 0.001; diabetes vs. control, p = 0.002; diabetes vs. prediabetes). BMP-4 was associated significantly with noggin in the entire study population (ß coefficient = 0.796, p < 0.001). Receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve was 0.708 (95% CI 0.551-0.864, p = 0.011) for BMP-4 levels. The optimal cutoff value of BMP-4 for detecting albuminuria was 118.5 ng/mL for which sensitivity was 71.4% and specificity was 66.4%.

CONCLUSIONS

BMP-4 and noggin levels were lower in the diabetic group. High BMP-4 levels were significantly associated with albuminuria. Further studies are warranted to determine the role of BMP-4 in the pathogenic processes underlying albuminuria and hyperglycemia in patients with type 2 diabetes.

Association of sodium intake with insulin resistance in Korean children and adolescents: the Korea National Health and Nutrition Examination Survey 2010

BACKGROUND

This study aimed to evaluate the relationship between sodium intake and insulin resistance indices.

METHODS

A total of 718 Korean children and adolescents (411 boys) aged 10-18 years who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) were included in the study. The urinary sodium to urinary creatinine ratio was used as a surrogate for sodium intake. The homeostatic model assessment of insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI) were used as indices of insulin resistance.

RESULTS

The mean urinary sodium to urinary creatinine ratio was 11.34 in males and 10.17 in females. The urinary sodium to urinary creatinine ratio was significantly positively correlated with HOMA-IR (r=0.165, p<0.001) and inversely correlated with QUICKI (r=-0.181, p<0.001) in Pearson's correlation analyses. In a multivariate linear regression analysis, the urinary sodium to urinary creatinine ratio was independently and significantly positively associated with HOMA-IR (β=0.073, p=0.018) and significantly inversely associated with QUICKI (β=-0.080, p=0.007) after adjustment for possible confounders. HOMA-IR was independently and significantly positively associated with the urinary sodium to urinary creatinine ratio (β=0.087, p=0.018), whereas QUICKI was independently and significantly negatively associated with the urinary sodium to urinary creatinine ratio (β=-0.097, p=0.009) after controlling for confounders.

CONCLUSIONS

Our results suggest that sodium intake, as estimated by the urinary sodium to urinary creatinine ratio, may be independently associated with insulin resistance in children and adolescents.

Higher Protein Intake Is Not Associated with Decreased Kidney Function in Pre-Diabetic Older Adults Following a One-Year Intervention-A Preview Sub-Study

Concerns about detrimental renal effects of a high-protein intake have been raised due to an induced glomerular hyperfiltration, since this may accelerate the progression of kidney disease. The aim of this sub-study was to assess the effect of a higher intake of protein on kidney function in pre-diabetic men and women, aged 55 years and older. Analyses were based on baseline and one-year data in a sub-group of 310 participants included in the PREVIEW project (PREVention of diabetes through lifestyle Intervention and population studies in Europe and around the World). Protein intake was estimated from four-day dietary records and 24-hour urinary urea excretion. We used linear regression to assess the association between protein intake after one year of intervention and kidney function markers: creatinine clearance, estimated glomerular filtration rate (eGFR), urinary albumin/creatinine ratio (ACR), urinary urea/creatinine ratio (UCR), serum creatinine, and serum urea before and after adjustments for potential confounders. A higher protein intake was associated with a significant increase in UCR (p = 0.03) and serum urea (p = 0.05) after one year. There were no associations between increased protein intake and creatinine clearance, eGFR, ACR, or serum creatinine. We found no indication of impaired kidney function after one year with a higher protein intake in pre-diabetic older adults.

Usefulness of urinary glucose excretion after oral glucose tolerance testing to detect insulin secretion failure before the onset of diabetes mellitus

Sodium-glucose cotransporter 2 inhibitors are commonly used to promote urinary glucose excretion (UGE). However, it remains unclear how UGE reflects glucose metabolism in the natural history of diabetes. Thus, we retrospectively reviewed the prediabetes medical records of 64 patients who had undergone 75-g oral glucose tolerance testing (OGTT) with measurements of UGE at 0 min, 60 min, and 120 min. The mean age and glycated hemoglobin levels were 46 ± 10 years and 5.6 ± 0.3%, respectively. The median UGE (60 min + 120 min) value was 16.8 mg ([interquartile range]: [10.5-150.0 mg]). Thus, we categorized 16 patients as having high UGE (≥150.0 mg) and 48 patients as having low UGE (<150.0 mg). As compared with the low UGE group, the high UGE group exhibited a significantly lower median insulinogenic index (0.23 [0.12-0.35] vs. 0.56 [0.31-1.06], p = 0.001) and homeostasis model assessment of β-cell function value (46 [26-67] vs. 66 [41-85], p = 0.028). The log-transformed insulinogenic index exhibited a significant inverse association with log-transformed UGE (60 min + 120 min) (r = -0.50, p < 0.001). The association between higher UGE and lower insulinogenic index was also observed in a subgroup analysis of patients with plasma glucose levels of ≥160 mg/dL during the OGTT. Therefore, UGE measurements after OGTT may provide a useful clinical marker for detecting insulin secretion failure and advancing preventive and therapeutic interventions among populations with a high risk of developing diabetes.

Urine Albumin-to-Creatinine Ratio: A Marker of Early Endothelial Dysfunction in Youth

CONTEXT

The urine albumin-to-creatinine ratio (UACR) is a useful predictor of cardiovascular (CV) events in adults. Its relationship to vascular function in children is not clear.

OBJECTIVE

We investigated whether UACR was related to insulin resistance and endothelial function, a marker of subclinical atherosclerosis, in adolescents across the spectrum of glucose regulation.

PARTICIPANTS

Participants were 58 adolescents: 13 normal weight (NW), 25 overweight with normal glucose tolerance (OW-NGT), and 20 overweight with prediabetes (OW-PreD).

INTERVENTIONS

Interventions included oral glucose tolerance test, hyperinsulinemic-euglycemic clamp with determination of insulin sensitivity (IS), endothelial function assessment by peripheral arterial tonometry determination of the reactive hyperemia index (RHI), body composition (dual-energy x-ray absorptiometry), and abdominal fat distribution (magnetic resonance imaging).

PRIMARY OUTCOME MEASURE

Fasting UACR was determined.

RESULTS

The 3 groups did not differ with respect to age, sex, or Tanner stage. The NW group had significantly lower percent body fat, higher IS (10.4 ± 0.9, 3.5 ± 0.6, and 2.1 ± 0.2 mg/kg/min per μU/mL; P < .001), and higher RHI (1.84 ± 0.1, 1.56 ± 0.1, and 1.56 ± 0.1, P = .04) than the OW-NGT and OW-PreD groups, respectively. lnUACR was related to percent body fat (r = 0.4, P = .001), RHI (r = -0.33, p = .01), and IS (r = -0.27, P = .043). In multiple regression analysis with lnUACR as the dependent variable and RHI, percent body fat, age, sex, race, systolic blood pressure, cholesterol, glycated hemoglobin, and IS as independent variables, RHI (β = -0.3, P = .045) and sex (β = 0.31, P = .06) contributed to the variance in UACR (R(2) = 0.35, P = .02).

CONCLUSIONS

UACR is an early marker of endothelial dysfunction in youth, independent of glycemia. Endothelial dysfunction may mediate the link between obesity-related insulin resistance and early microalbuminuria.

Relationship between dyslipidemia and albuminuria in prediabetic adults: the Korea National Health and Nutrition Examination Survey 2011-2012

This study aimed to estimate the relationship between various lipid abnormalities and albuminuria in Korean prediabetic adults. Data obtained from the Korea National Health and Nutrition Examination Survey (KNHANES) 2011-2012 were analyzed. The study consisted of 4,811 subjects in the normal glucose group and 3,872 in the prediabetic group. Prediabetes was defined by the fasting plasma glucose or hemoglobin A1c level. Albuminuria was defined as a urine albumin to creatinine ratio (UACR) ≥30 mg/g. Various parameters of dyslipidemia were assessed. No differences were observed in the prevalence of lipid abnormalities in prediabetic men with different values of UACR. Prediabetic women with increased urinary albumin excretion showed a significantly higher prevalence of lipid abnormalities. The proportion of mixed dyslipidemia was significantly higher in prediabetic women with albuminuria. Higher levels of total cholesterol, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), and TC to HDL-C ratio, TG to HDL-C ratio, and LDL-C to HDL-C ratio were significantly associated with increased risk of albuminuria in prediabetic women.

CONCLUSIONS

Several lipid abnormalities were significantly associated with the increased risk of albuminuria in prediabetic women. Hence, screening for lipid abnormalities may be helpful for identification of risk for albuminuria in prediabetic subjects.

Urinary type IV collagen is related to left ventricular diastolic function and brain natriuretic peptide in hypertensive patients with prediabetes

AIM

Urinary type IV collagen is an early biomarker of diabetic nephropathy. Concomitant prediabetes (the early stage of diabetes) was associated with left ventricular (LV) diastolic dysfunction and increased brain natriuretic peptide (BNP) in hypertensive patients. We hypothesized that urinary type IV collagen may be related to these cardiac dysfunctions.

METHODS

We studied hypertensive patients with early prediabetes (HbA1c <5.7% and fasting glucose >110, n=18), those with prediabetes (HbA1c 5.7-6.4, n=98), and those with diabetes (HbA1c>6.5 or on diabetes medications, n=92). The participants underwent echocardiography to assess left atrial volume/body surface area (BSA) and the ratio of early mitral flow velocity to mitral annular velocity (E/e'). Left ventricular diastolic dysfunction (LVDD) was defined if patients had E/e'≥15, or E/e'=9-14 accompanied by left atrial volume/BSA≥32ml/mm(2). Urinary samples were collected for type IV collagen and albumin, and blood samples were taken for BNP and HbA1c.

RESULTS

Urinary type IV collagen and albumin increased in parallel with the deterioration of glycemic status. In hypertensive patients with prediabetes, subjects with LVDD had higher levels of BNP and urinary type IV collagen than those without LVDD. In contrast, in hypertensive patients with diabetes, subjects with LVDD had higher urinary albumin and BNP than those without LVDD. Urinary type IV collagen correlated positively with BNP in hypertensive patients with prediabetes, whereas it correlated with HbA1c in those with diabetes.

CONCLUSIONS

In hypertensive patients with prediabetes, urinary type IV collagen was associated with LV diastolic dysfunction and BNP.

Screening for type 2 diabetes and pre-diabetes in general practice: a descriptive study of Maltese practices

OBJECTIVE

The aim of this research study was to ascertain the awareness of Maltese family doctors to the prevalence and significance of impaired glucose regulation and early diagnosis of type 2 diabetes and whether practices were influenced by employment status, post-graduate training in diabetes or years since graduation.

METHODS

A specially constructed questionnaire was distributed by mail to all the 298 family doctors listed as Specialists in Family Medicine in the Maltese Medical Council register. Participants had to be practising family medicine in Malta. Results were analysed using SPSS 20.0 aiming for a significance criterion of 0.05 and a power of 80%.

RESULTS

Valid replies were received from 154 GPs (51.7%). 93.2% claimed to offer their patients some form of screening. Screening levels reached up to 95.9% in the presence of specific risk factors (e.g., high previous HbA1c levels) but fell to between 46.2% and 58.7% in patients over 50, the physically inactive and those who suffer from polycystic ovarian syndrome. Screening using capillary glucose is widespread (70.8%) as opposed to the oral glucose tolerance test (23.4%). Results also show a high use of urinalysis in screening (53.2%) and a paradoxical lack of use of HbA1c in screening by young doctors and by those with recent extra training in diabetes.

CONCLUSIONS

The need for a structured screening programme in Malta and its viability need to be evaluated by further studies. Educational support to GPs together with logistic support for GPs needs to be improved.

Relationship between urinary bisphenol A levels and prediabetes among subjects free of diabetes

Bisphenol A (BPA) is a high volume production chemical used in the manufacture of polycarbonate plastics and epoxy resins. Recent experimental studies have suggested that BPA affects glucose metabolism through diverse mechanisms including insulin resistance, pancreatic β-cell dysfunction, adipogenesis, inflammation and oxidative stress. Prediabetes is a stage earlier in the hyperglycemia continuum associated with increased future risk of developing diabetes. Therefore, we examined the association between BPA exposure and prediabetes among subjects free of diabetes. We examined the association between urinary BPA levels and prediabetes in 3,516 subjects from the National Health and Nutritional Examination Survey 2003-2008. Urinary BPA levels were examined in tertiles. Prediabetes was defined as fasting glucose concentration 100-125 mg/dL or 2-h glucose concentration of 140-199 mg/dL or an A1C value of 5.7-6.4 %. Overall, we observed a positive association between higher levels of urinary BPA and prediabetes, independent of potential confounders including body mass index, alcohol intake, blood pressure and serum cholesterol levels. Compared to tertile 1 (referent), the multivariate-adjusted odds ratio (95 % confidence interval) of prediabetes associated with tertile 3 of BPA was 1.34 (1.03-1.73), p-trend = 0.02. In subgroup analysis, this association was stronger among women and obese subjects. Higher urinary BPA levels are found to be associated with prediabetes independent of traditional diabetes risk factors. Future prospective studies are needed to confirm or disprove this finding.

Associations of serum and urinary magnesium with the pre-diabetes, diabetes and diabetic complications in the Chinese Northeast population

The effect of magnesium (Mg) deficiency on the prevalence of diabetes and diabetic complications has received a great attention. The present study investigated the association of Mg level in the serum or urine of the patients, lived in the Northeast areas of China, with either pre-diabetes or diabetes with and without complications. From January 2010 to October 2011, patients with type 1 diabetes (T1D, n = 25), type 2 diabetes (T2D, n = 137), impaired fasting glucose (IFG, n = 12) or impaired glucose tolerance (IGT, n = 15), and age/gender matched control (n = 50) were enrolled in the First Hospital of Jilin University. In T2D group, there were 24, 34, and 50 patients with nephropathy, retinopathy or peripheral neuropathy. Serum Mg levels in the patients with IGT, IFG, T2D, and T1D were significantly lower than that of control. The urinary Mg levels were significantly increased only in T2D and T1D patients compared to control. There was no difference for these two changes among T2D with and without complications; In addition, there was a significantly positive correlation of serum Mg levels with serum Ca levels only in T2D patients, and also a significantly positive correlation of urinary Mg levels with urinary Ca levels in control, IGT patients, and T2D patients. Simvastatin treatment in T2D patients selectively reduced serum Ca levels and urinary Mg levels. These results suggest that the potential impact of Mg deficiency on metabolic syndrome, diabetes and diabetic complications needs to be received special attention.

Urinary N-acetyl-β-D-glucosaminidase levels are positively correlated with 2-hr plasma glucose levels during oral glucose tolerance testing in prediabetes

BACKGROUND

Urinary N-acetyl-β-D-glucosaminidase (NAG) excretion is increased in patients with impaired glucose tolerance (IGT). This study investigated when during the oral glucose tolerance test (OGTT) the plasma glucose, urine glucose, and insulin levels correlate most strongly with urinary N-acetyl-β-d-glucosaminidase (NAG) levels in prediabetic subjects.

METHODS

The OGTT was administered to 80 subjects who had not yet received a diagnosis of diabetes mellitus (DM) and in whom HbA1c levels were ≤6.8% and fasting plasma glucose levels were <7.0 mmol/l. Forty-two subjects had normal glucose tolerance (NGT), 31 had impaired glucose tolerance (IGT), and 7 had DM according to World Health Organization criteria. Serum levels of cystatin C, the estimated glomerular filtration rate, the urinary albumin-to-creatinine (Cr) ratio, urinary and serum β2-microglobulin, and urinary NAG were measured as markers of renal function.

RESULTS

NAG levels were significantly higher in subjects with DM and in subjects with IGT than in subjects with NGT. No significant associations were observed between glycemic status and other markers of renal function. Multiple linear regression analysis showed that the NAG level was positively correlated with plasma glucose levels at 120 min of the OGTT and was associated with the glycemic status of prediabetic patients.

CONCLUSION

These results suggest that postprandial hyperglycemia is an independent factor that causes renal tubular damage in prediabetes patients.

Elevated cystatin C concentration and progression to pre-diabetes: the Western New York study

OBJECTIVE

We conducted a nested case-control investigation to examine whether elevated baseline concentrations of cystatin C predicted progression from normoglycemia to pre-diabetes over 6 years of follow-up from the Western New York Health Study.

RESEARCH DESIGN AND METHODS

In 2002-2004, 1,455 participants from the Western New York Health Study, who were free of type 2 diabetes and known cardiovascular disease at baseline (1996-2001), were reexamined. An incident case of pre-diabetes was defined as an individual with fasting glucose < 100 mg/dl at the baseline examination and > or = 100 and < or = 125 mg/dl at the follow-up examination, thereby eliminating individuals with prevalent pre-diabetics. All case patients (n = 91) were matched 1:3 to control participants based on sex, race/ethnicity, and year of study enrollment. All control subjects had fasting glucose levels < 100 mg/dl at both baseline and follow-up examinations. Cystatin C concentrations and the urinary albumin-to-creatinine ratio were measured from frozen (-196 degrees C) baseline blood and urine samples. Serum creatinine concentrations were available from the baseline examination only.

RESULTS

Multivariate conditional logistic regression analyses adjusted for age, baseline glucose level, homeostasis model assessment of insulin resistance, BMI, hypertension, estimated glomerular filtration rate, cigarette smoking, and alcohol use revealed a significantly increased risk of progression to pre-diabetes among those with elevated baseline concentrations of cystatin C (odds ratio 3.28 [95% CI 1.43-7.54]) (upper quintile versus the remainder). Results of secondary analyses that considered high-sensitivity C-reactive protein, interleukin-6, E-selectin, or soluble intercellular adhesion molecule-1 did not alter these results.

CONCLUSIONS

These results suggest that cystatin C was associated with a threefold excess risk of progression to pre-diabetes in this population.

Is microalbuminuria part of the prediabetic state? The Mexico City Diabetes Study

Microalbuminuria is associated with increased cardiovascular mortality in both diabetic and non-diabetic subjects. A number of studies have indicated that insulin resistance, increased blood pressure and dyslipidaemia precede the onset of clinical diabetes. We examined various correlates of microalbuminuria in 1,298 non-diabetic subjects who participated in the Mexico City Diabetes Study, a population-based study of diabetes and cardiovascular risk factors. Both parental history of diabetes and impaired glucose tolerance were significantly associated with microalbuminuria. These results were not explained by differences in age or blood pressure between subjects with or without a parental history of diabetes or impaired glucose tolerance. In addition, subjects with microalbuminuria had increased 2-h insulin and triglyceride concentrations, a higher prevalence of hypertension, and decreased high density lipoprotein cholesterol concentrations relative to subjects without microalbuminuria. These results that microalbuminuria may be a feature of the prediabetic state.

Albuminuria in type 2 (non-insulin-dependent) diabetes mellitus and impaired glucose tolerance in Pima Indians

The prevalence of abnormal urinary albumin excretion, defined by a urine albumin to creatinine ratio greater than or equal to 30 mg/g (approximately equivalent to an albumin excretion rate of greater than or equal to 30 mg/24 h), was determined in 2728 Pima Indians aged greater than or equal to 15 years from the Gila River Indian Community in Arizona, a population with a high prevalence of Type 2 (non-insulin-dependent) diabetes mellitus. Excessive albumin excretion was present in 8% of subjects with normal glucose tolerance, 15% of those with impaired glucose tolerance, and 47% of subjects with diabetes. The intermediate prevalence of abnormal albuminuria in those with impaired glucose tolerance suggests that hyperglycaemia even at levels below those diagnostic of diabetes is associated with renal abnormalities in some subjects and that these abnormalities may precede the onset of diabetes. Abnormal albuminuria at levels not reliably detected by the usual dipstick methods was commonly observed in Pima Indians with diabetes, even those with diabetes of recent onset. Associations were found with age, duration of diabetes, level of glycaemia, blood pressure, and treatment with insulin.

[Importance of glycosuria in pregnant women as a risk factor in relation to diabetes mellitus]

The diabetic type of glucose tolerance tests was revealed in 16% of the women with glycosuria during pregnancy and in 8% of the women of control group without any other risk factors in respect to diabetes mellitus. The results of remote follow up over the women of the both groups are presented. Glycosuria during pregnancy should not be considered prognostically unfavourable in case of normal glucose tolerance test results; pathogenesis of such glycosuria during pregnancy was not associated with insulin insufficiency. Glycosuria during pregnancy served as an indication of the glucose tolerance test for the purpose of timely detection of latent diabetes.

Urinary excretion of n-hexanedioic and n-octanedioic acid in juvenile diabetics with ketonuria

Urine samples from patients with newly diagnosed juvenile diabetes and predibetic coma or ketonuria, but no acid-base disturbances in the blood, have been analyzed for dicarboxylic acids by combined gas-liquid chromatography and mass spectrometry.

The precomatose patients excreted up to 210 and 38 μg./1 mg. of creatinine, respectively, of n-hexanedioic and n-octanedioic acid. The excretion was almost normalized within a few hours by insulin treatment. Nonacidotic patients with ketonuria excreted 9.2 ± 5.1 mg./24 hr. of n-hexanedioic acid, and some also excreted slightly increased amounts of n-octanedioic acid. All patients excreted normal amounts of 3-methylhexanedioic acid, which was unaffected by insulin treatment.

Our findings direct attention to a metabolic pathway which may be of importance in the pathogenesis of ketosis in diabetes mellitus, namely the formation of short-chain dicarboxylic acids (for instance, intermediates of the tricarboxylic acid cycle) by ω-oxidation of fatty acids followed by β-oxidations of the dicarboxylic acids thus formed.