Role of glycemic control and blood pressure in the development and progression of nephropathy in elderly Japanese NIDDM patients

Evidential support for garlic supplements against diabetic kidney disease: a preclinical meta-analysis and systematic review

Garlic (Allium sativum L.) is a popular spice that is widely used for food and medicinal purposes and has shown potential effects on diabetic kidney disease (DKD). Nevertheless, systematic preclinical studies are still lacking. In this meta-analysis and systematic review, we evaluated the role and potential mechanisms of action of garlic and its derived components in animal models of DKD. We searched eight databases for relevant studies from the establishment of the databases to December 2022 and updated in April 2023 before the completion of this review. A total of 24 trials were included in the meta-analysis. It provided preliminary evidence that supplementing with garlic could improve the indicators of renal function (BUN, Scr, 24 h urine volume, proteinuria, and KI) and metabolic disorders (BG, insulin, and body weight). Meanwhile, the beneficial effects of garlic and its components in DKD could be related to alleviating oxidative stress, suppressing inflammatory reactions, delaying renal fibrosis, and improving glucose metabolism. Furthermore, time-dose interval analysis exhibited relatively greater effectiveness when garlic products were supplied at doses of 500 mg kg-1 with interventions lasting 8-10 weeks, and garlic components were administered at doses of 45-150 mg kg-1 with interventions lasting 4-10 weeks. This meta-analysis and systematic review highlights for the first time the therapeutic potential of garlic supplementation in animal models of DKD and offers a more thorough evaluation of its effects and mechanisms to establish an evidence-based basis for designing future clinical trials.

Historical review of the diagnosis of prediabetes/intermediate hyperglycemia: Case for the international criteria

In 1997, the ADA recommended an IFG criterion for diagnosing prediabetes/intermediate hyperglycemia of FPG concentrations of 6.1-6.9 mmol/L (110-125 mg/dL). In 2003, they lowered it to 5.6-6.9 mmol/L (100-125 mg/dL) to equalize developing diabetes between IGT and IFG. International organizations accepted the first IFG criterion but not the second. The ADA subsequently recommended HbA1c levels for diagnosing prediabetes/intermediate hyperglycemia of 39-47 mmol/mol (5.7-6.4%) based on a model that utilized the composite risk of developing diabetes and CVD. However, the evidence that the intermediate hyperglycemia that defines prediabetes is independently associated with CVD is weak. Rather, the other risk factors for CVD in the metabolic syndrome are responsible. The WHO opined that prediabetes/intermediate hyperglycemia could not be diagnosed by HbA1c levels but the Canadians and Europeans recommended its diagnosis by values of 42-47 mmol/mol (6.0-6.4%). With the ADA criteria, approximately one-half of people are normal on re-testing, one-third spontaneously revert to normal over time and two-thirds never develop diabetes in their lifetimes. The international criteria for prediabetes/intermediate hyperglycemia increase the risk of developing diabetes and might motivate these individuals to more seriously undertake lifestyle interventions as a preventive measure.

Lipid Accumulation Product is Associated with Urinary Albumin-creatinine Ratio in Chinese Prediabitic Population: A Report from the REACTION Study

BACKGROUND

Lipid accumulation product (LAP) as a powerful marker of visceral obesity is an independent risk factor of chronic kidney disease. The present study attempted to explore the association between LAP and albuminuria in prediabetic individuals.

METHODS

We conducted a cross-sectional study and enrolled 26,529 participants with prediabetes over 40 years old with prediabetes from seven provinces in China. LAP was calculated from waist circumference and fasting triglycerides. Elevated albuminuria was defined by urinary albumin-creatinine ratio (uACR) ≥30 mg/g. Propensity score matching was applied to reduce bias, comparison between LAP and other traditional visceral obesity indices was performed and multiple logistic regression models were conducted to assess the association between LAP and albuminuria in the prediabetic population.

RESULTS

Individuals with uACR ≥30 mg/g were older and had higher BP, BMI, WC, TG, fasting insulin, glycohemoglobin and LAP, as well as lower eGFR and HDL level. Multiple logistic regression analysis showed elevated LAP was associated with increased odds of albuminuria (OR [95%CI]_{Q2 vs Q1} 1.09 [0.94, 1.27], OR [95%CI]_{Q3 vs Q1} 1.13 [0.97, 1.31], OR [95%CI]_{Q4 vs Q1} 1.42 [1.21, 1.67], P for trend=0.018), and superior over waist-to-hip ratio or waist-to-height ratio. Stratification indicated that the prediabetic population with higher LAP level and characterized by female gender, middle age, being overweight, and rise in blood pressure were more likely to have increased uACR.

CONCLUSION

Elevated level of LAP was associated with increased albuminuria in the prediabetic population in China.

Metformin Should Not Be Used to Treat Prediabetes

Based on the results of the Diabetes Prevention Program Outcomes Study (DPPOS), in which metformin significantly decreased the development of diabetes in individuals with baseline fasting plasma glucose (FPG) concentrations of 110-125 vs. 100-109 mg/dL (6.1-6.9 vs. 5.6-6.0 mmol/L) and A1C levels 6.0-6.4% (42-46 mmol/mol) vs. <6.0% and in women with a history of gestational diabetes mellitus, it has been suggested that metformin should be used to treat people with prediabetes. Since the association between prediabetes and cardiovascular disease is due to the associated nonglycemic risk factors in people with prediabetes, not to the slightly increased glycemia, the only reason to treat with metformin is to delay or prevent the development of diabetes. There are three reasons not to do so. First, approximately two-thirds of people with prediabetes do not develop diabetes, even after many years. Second, approximately one-third of people with prediabetes return to normal glucose regulation. Third, people who meet the glycemic criteria for prediabetes are not at risk for the microvascular complications of diabetes and thus metformin treatment will not affect this important outcome. Why put people who are not at risk for the microvascular complications of diabetes on a drug (possibly for the rest of their lives) that has no immediate advantage except to lower subdiabetes glycemia to even lower levels? Rather, individuals at the highest risk for developing diabetes-i.e., those with FPG concentrations of 110-125 mg/dL (6.1-6.9 mmol/L) or A1C levels of 6.0-6.4% (42-46 mmol/mol) or women with a history of gestational diabetes mellitus-should be followed closely and metformin immediately introduced only when they are diagnosed with diabetes.

Sweet dreams: therapeutic insights, targeting imaging and physiologic evidence linking sleep, melatonin and diabetic nephropathy

Melatonin is the main biochronologic molecular mediator of circadian rhythm and sleep. It is also a powerful antioxidant and has roles in other physiologic pathways. Melatonin deficiency is associated with metabolic derangements including glucose and cholesterol dysregulation, hypertension, disordered sleep and even cancer, likely due to altered immunity. Diabetic nephropathy (DN) is a key microvascular complication of both type 1 and 2 diabetes. DN is the end result of a complex combination of metabolic, haemodynamic, oxidative and inflammatory factors. Interestingly, these same factors have been linked to melatonin deficiency. This report will collate in a clinician-oriented fashion the mechanistic link between melatonin deficiency and factors contributing to DN.

Associations of Glycemic Control With Cardiovascular Outcomes Among US Hemodialysis Patients With Diabetes Mellitus

Background

There is a lack of data on the relationship between glycemic control and cardiovascular end points in hemodialysis patients with diabetes mellitus.

Methods and Results

We included adult Medicare‐insured patients with diabetes mellitus who initiated in‐center hemodialysis treatment from 2006 to 2008 and survived for >90 days. Quarterly mean time‐averaged glycated hemoglobin (HbA_1c) values were categorized into <48 mmol/mol (<6.5%) (reference), 48 to <58 mmol/mol (6.5% to <7.5%), 58 to <69 mmol/mol (7.5% to <8.5%), and ≥69 mmol/mol (≥8.5%). Medicare claims were used to identify outcomes of cardiovascular mortality, nonfatal myocardial infarction (MI), fatal or nonfatal MI, stroke, and peripheral arterial disease. We used Cox models as a function of time‐varying exposure to estimate multivariable adjusted hazard ratios and 95%CI for the associations between HbA_1c and time to study outcomes in a cohort of 16 387 eligible patients. Patients with HbA_1c 58 to <69 mmol/mol (7.5% to <8.5%) and ≥69 mmol/mol (≥8.5%) had 16% (CI, 2%, 32%) and 18% (CI, 1%, 37%) higher rates of cardiovascular mortality (P‐trend=0.01) and 16% (CI, 1%, 33%) and 15% (CI, 1%, 32%) higher rates of nonfatal MI (P‐trend=0.05), respectively, compared with those in the reference group. Patients with HbA_1c ≥69 mmol/mol (≥8.5%) had a 20% (CI, 2%, 41%) higher rate of fatal or nonfatal MI (P‐trend=0.02), compared with those in the reference group. HbA_1c was not associated with stroke, peripheral arterial disease, or all‐cause mortality.

Conclusions

Higher HbA_1c levels were significantly associated with higher rates of cardiovascular mortality and MI but not with stroke, peripheral arterial disease, or all‐cause mortality in this large cohort of hemodialysis patients with diabetes mellitus.

Diabetic kidney disease

The kidney is arguably the most important target of microvascular damage in diabetes. A substantial proportion of individuals with diabetes will develop kidney disease owing to their disease and/or other co-morbidity, including hypertension and ageing-related nephron loss. The presence and severity of chronic kidney disease (CKD) identify individuals who are at increased risk of adverse health outcomes and premature mortality. Consequently, preventing and managing CKD in patients with diabetes is now a key aim of their overall management. Intensive management of patients with diabetes includes controlling blood glucose levels and blood pressure as well as blockade of the renin-angiotensin-aldosterone system; these approaches will reduce the incidence of diabetic kidney disease and slow its progression. Indeed, the major decline in the incidence of diabetic kidney disease (DKD) over the past 30 years and improved patient prognosis are largely attributable to improved diabetes care. However, there remains an unmet need for innovative treatment strategies to prevent, arrest, treat and reverse DKD. In this Primer, we summarize what is now known about the molecular pathogenesis of CKD in patients with diabetes and the key pathways and targets implicated in its progression. In addition, we discuss the current evidence for the prevention and management of DKD as well as the many controversies. Finally, we explore the opportunities to develop new interventions through urgently needed investment in dedicated and focused research. For an illustrated summary of this Primer, visit: http://go.nature.com/NKHDzg.

Exercise excess pressure and exercise-induced albuminuria in patients with type 2 diabetes mellitus

Exercise-induced albuminuria is common in patients with type 2 diabetes mellitus (T2DM) in response to maximal exercise, but the response to light-moderate exercise is unclear. Patients with T2DM have abnormal central hemodynamics and greater propensity for exercise hypertension. This study sought to determine the relationship between light-moderate exercise central hemodynamics (including aortic reservoir and excess pressure) and exercise-induced albuminuria. Thirty-nine T2DM (62 ± 9 yr; 49% male) and 39 nondiabetic controls (53 ± 9 yr; 51% male) were examined at rest and during 20 min of light-moderate cycle exercise (30 W; 50 revolutions/min). Albuminuria was assessed by the albumin-creatinine ratio (ACR) at rest and 30 min postexercise. Hemodynamics recorded included brachial and central blood pressure (BP), aortic stiffness, augmented pressure (AP), aortic reservoir pressure, and excess pressure integral (Pexcess). There was no difference in ACR between groups before exercise ( P > 0.05). Exercise induced a significant rise in ACR in T2DM but not controls (1.73 ± 1.43 vs. 0.53 ± 1.0 mg/mol, P = 0.002). All central hemodynamic variables were significantly higher during exercise in T2DM (i.e., Pexcess, systolic BP and AP; P < 0.01 all). In T2DM (but not controls), exercise Pexcess was associated with postexercise ACR ( r = 0.51, P = 0.002), and this relationship was independent of age, sex, body mass index, heart rate, aortic stiffness, antihypertensive medication, and ambulatory daytime systolic BP (β = 0.003, P = 0.003). Light-moderate exercise induced a significant rise in ACR in T2DM, and this was independently associated with Pexcess, a potential marker of vascular dysfunction. These novel findings suggest that Pexcess could be important for appropriate renal function in T2DM.

Updating the natural history of diabetic nephropathy

Diabetic nephropathy (DN) is a major cause of morbidity and mortality in patients with both types of diabetes and the leading cause of end-stage renal disease (ESRD) worldwide. The classical, five-stage natural history of DN, after an initial phase of hyperfiltration, is characterized by a progressive increase of albuminuria from normoalbuminuria to proteinuria, followed by a decline of glomerular filtration rate (GFR). Accumulating evidence indicates that clinical course of DN has changed profoundly, likely as a consequence of changes in treatment. In fact, remission/regression of microalbuminuria is a common feature of both type 1 and 2 diabetes which far outweighs progression to proteinuria. Moreover, GFR loss has been shown to occur independently of albuminuria or even in the absence of it. Nonalbuminuric renal impairment probably represents a different pathway to loss of renal function, which might recognize different pathogenic mechanisms, prognostic implications, and possibly therapeutic measures, as compared with the albuminuric pathway. The nonalbuminuric phenotype might be related to macroangiopathy instead of microangiopathy and/or be the consequence of repeated and/or unresolved episodes of acute kidney injury, even of mild degree. Reduced GFR and albuminuria are both powerful risk factor for cardiovascular events, whereas albuminuria appears to predict death and progression to ESRD better than GFR loss. Finally, it is unclear whether reduced GFR and albuminuria warrant different interventions and whether GFR decline may also regress in response to treatment, as proteinuria does. Further epidemiological, pathologic, pathophysiological, and intervention studies are needed to clarify the distinctive features of nonalbuminuric renal impairment.

Blocking ligand occupancy of the αVβ3 integrin inhibits the development of nephropathy in diabetic pigs

Hyperglycemia stimulates secretion of αVβ3 ligands from vascular cells, including endothelial cells, resulting in activation of the αVβ3 integrin. This study determined whether blocking ligand occupancy of αVβ3 would inhibit the development of diabetic nephropathy. Ten diabetic pigs received an F(ab)2 fragment of an antibody directed against the extracellular domain of the β3-subunit, and 10 received a control IgG F(ab)2 for 18 weeks. Nondiabetic pigs excreted 115 ± 50 μg of protein/mg creatinine compared with control F(ab)2-treated diabetic animals (218 ± 57 μg/mg), whereas diabetic animals treated with the anti-β3 F(ab)2 excreted 119 ± 55 μg/mg (P < .05). Mesangial volume/glomerular volume increased to 21 ± 2.4% in control-treated diabetic animals compared with 14 ± 2.8% (P < .01) in animals treated with active antibody. Diabetic animals treated with control F(ab)2 had significantly less glomerular podocin staining compared with nondiabetic animals, and this decrease was attenuated by treatment with anti-β3 F(ab)2. Glomerular basement membrane thickness was increased in the control, F(ab)2-treated diabetic animals (212 ± 14 nm) compared with nondiabetic animals (170 ± 8.8 nm), but it was unchanged (159.9 ± 16.4 nm) in animals receiving anti-β3 F(ab)2. Podocyte foot process width was greater in control, F(ab)2-treated, animals (502 ± 34 nm) compared with animals treated with the anti-β3 F(ab)2 (357 ± 47 nm, P < .05). Renal β3 tyrosine phosphorylation decreased from 13 934 ± 6437 to 6730 ± 1524 (P < .01) scanning units in the anti-β3-treated group. We conclude that administration of an antibody that inhibits activation of the β3-subunit of αVβ3 that is induced by hyperglycemia attenuates proteinuria and early histologic changes of diabetic nephropathy, suggesting that it may have utility in preventing the progression of this disease complication.

HbA1c and survival in maintenance hemodialysis patients with diabetes in Han Chinese population

BACKGROUND

Previous observational studies using differing methodologies have yielded inconsistent results regarding the association between glycemic control and outcomes in diabetic patients receiving maintenance hemodialysis (MHD). The aim of this study was to investigate the association between HbA1c and survival in diabetic MHD patients in Han Chinese population.

METHODS

A 5-year cohort (October 2007-December 2013) of 236 diabetic MHD patients with HbA1c data was examined for associations between HbA1c and mortality. Death hazard ratios (HR) were estimated using Cox regressions.

RESULTS

Two hundred and thirty-six diabetes patients undergoing MHD in clinics over 5 years were included in our study. Unadjusted survival analyses indicated paradoxically lower death HRs with higher HbA1c values. However, after adjusting for potential confounders (demographics, dialysis vintage, comorbidity, anemia, and inflammation), higher HbA1c values were incrementally associated with higher death risks.

CONCLUSIONS

Poor glycemic control (HbA1c ≥ 8 %) appears to be associated with decreased survival in the general population of diabetic MHD patients. Our study suggests that moderate hyperglycemia increases the risk for all-cause mortality of diabetic MHD patients in Han Chinese population.

Sitagliptin compared with thiazolidinediones as a third-line oral antihyperglycemic agent in type 2 diabetes mellitus

OBJECTIVE

To compare sitagliptin and thiazolidinediones as third-line oral antihyperglycemic agents among ethnic minority patients with poorly controlled type 2 diabetes mellitus.

METHODS

In an open-label, single-arm design, we treated type 2 diabetic patients who had suboptimal diabetes control on maximum tolerated dosages of metformin plus sulfonylureas with the addition of sitagliptin, 100 mg daily, and compared their responses with findings from a historical control group of similar patients treated with rosiglitazone, 8 mg daily, or pioglitazone, 45 mg daily, as their third-line oral agent. Patients were assessed bimonthly, and those who achieved hemoglobin A1c levels less than 7.5% at 4 months continued through 1 year of follow-up.

RESULTS

One hundred eight patients were treated with sitagliptin, and 104 patients constituted the historical control group treated with rosiglitazone or pioglitazone. At baseline, sitagliptin- and thiazolidinedione-treated patients had identical hemoglobin A1c levels (mean ± SD) (9.4 ± 1.8% and 9.4 ± 1.9%, respectively) and similar known diabetes duration (6.7 ± 5.0 years and 7.6 ± 5.8 years, respectively). Hemoglobin A1c was reduced in both groups at 4 months (P<.001), but the reduction was greater with thiazolidinediones than with sitagliptin (-2.0 ± 1.7% vs -1.3 ± 1.8%; P = .006), as was the proportion of patients achieving a hemoglobin A1c level less than 7.5% (62% vs 46%; P = .026). Of all patients achieving a hemoglobin A1c level less than 7.5% at 4 months, the same proportions in each group sustained their hemoglobin A1c level less than 7.5% by 12 months (59% vs 58%). Sitagliptin was well tolerated.

CONCLUSIONS

Among ethnic minority patients with poorly controlled type 2 diabetes while taking maximum tolerated dosages of metformin and sulfonylureas, third-line add-on therapy with a thiazolidinedione controlled hyperglycemia more effectively than sitagliptin after 4 months.

[The risk of diabetic complications in older elderly diabetic patients]

AIM

We examined the risk of the diabetic complications among older elderly diabetic patients.

METHODS

We compared the HbA1c levels of 117 type 2 diabetic patients ≥ 75 years old over a 5-year period, before patients received a diagnosis of diabetic complications, with those of diabetic patients without diabetic complications.

RESULTS

The HbA1c levels of diabetic retinopathy patients were significantly higher than those of patients without diabetic retinopathy (7.9% vs. 6.8%, p<0.01). Similarly, the HbA1c levels of patients with diabetic nephropathy were significantly higher than those of patients without diabetic nephropathy (7.3% vs. 6.7%, p<0.01). The HbA1c levels of diabetic patients with cerebral infarction or ischemic heart disease were also higher than those in diabetic patients without these vascular complications (7.7% vs. 7.0%, p<0.05).

CONCLUSION

The current findings emphasize the importance of careful glycemic control for the prevention of diabetic complications in older elderly patients.

Effect of age and race/ethnicity on HbA1c levels in people without known diabetes mellitus: implications for the diagnosis of diabetes

AIMS

To determine if age and race/ethnicity affect HbA1c levels independent of glycemia.

METHODS

We analyzed 2712 individuals from the NHANES III population 40-74 years old without diabetes history.

RESULTS

HbA1c levels increased by 0.10% per decade in people with NGT and 0.07% in those with IFG and/or IGT, independent of fasting and 2-h glucose on OGTT's. Compared to non-Hispanic whites, HbA1c levels increased by 0.12% (NGT) and 0.10% (IFG/IGT) in Mexican-Americans and 0.21% (NGT) and 0.35% (IFG/IGT) in non-Hispanic blacks, independent of glycemia. At HbA1c levels of >or=6.5%, >or=7.0% and 6.5-6.9%, diabetes diagnosed by current FPG/OGTT criteria occurred in 82%, 94% and 65%, respectively. In non-Hispanic blacks with HbA1c levels of 6.5-6.9%, 68% of those 40-74 years old and 87% of those over 64 years old would not have diabetes by FPG/OGTT criteria. Over 90% of all race/ethnicity groups would have diabetes with HbA1c levels >or=7.0%.

CONCLUSIONS

Because many people, especially older non-Hispanic blacks, with HbA1c levels of 6.5-6.9% would not have diabetes by current FPG/OGTT criteria and clinical retinopathy and nephropathy are very unusual in patients whose HbA1c levels are kept <7.0%; we recommend an HbA1c level of >or=7.0% to diagnose diabetes.

Hyperglycemia alters renal cell responsiveness to pressure in a model of malignant hypertension

OBJECTIVE

Poor glycemic control contributes to development of diabetic nephropathy. However, for a majority of clinical situations, the mechanisms responsible for high glucose-induced aggravation of renal tissue injury are not fully elucidated. We investigated responsiveness to pressure of various renal cell subsets subjected to hyperglycemic environment in an in-vitro model of malignant hypertension.

METHODS

Rat renal mesangium, epithelium and endothelium were exposed to high glucose-containing medium for 10 days and then subjected to high hydrostatic pressure for 1 h to simulate the incidence of malignant hypertension. In some cultures, renin-angiotensin system was experimentally suppressed prior to pressure application. Proliferation, apoptosis, intrarenal p53, H2O2 and angiotensin-II synthesis were subsequently assessed.

RESULTS

By contrast to cultures not exposed to high glucose, in all hyperglycemic cells p53 expression, angiotensin-II synthesis and apoptosis were increased, whereas proliferation depressed, irrespective of pressure enforcement. H2O2 release was enhanced by high pressure per se, and increased further following exposure to high glucose. In all diabetic cultures, inhibition of p53 by a specific inhibitor pifithrin concomitantly significantly decreased apoptosis.

CONCLUSION

Hyperglycemic environment alters responsiveness of renal cells to in-vitro simulation of malignant hypertension. The main consequence of either malignant hypertension or hyperglycemia is exaggerated apoptosis. However, the operating mechanisms differ: Malignant hypertension stimulates renal cell apoptosis via increased angiotensin-II, whereas hyperglycemia elicits apoptosis via augmented p53. By contrast to pressure-induced excessive proliferation of normoglycemic cells, hyperglycemia prohibits elevated proliferation in response to pressure. Angiotensin-II production is maximally augmented by hyperglycemic environment and is not stimulated further by pressure application.

Pro's and con's of the early use of insulin in the management of type 2 diabetes: a clinical evaluation

PURPOSE OF REVIEW

Recently, there have been increasing calls for insulin to be used as the initial treatment of type 2 diabetes, and if not then, soon after its onset. The underlying reason given is that insulin will slow down the apoptosis of pancreatic beta-cells, which is increased in type 2 diabetes. This review will examine the clinical evidence supporting this recommendation.

RECENT FINDINGS

Several observational studies in which newly diagnosed type 2 diabetic patients are intensively treated for a short time with insulin, which is then stopped, have shown that approximately half of these patients retain good control without pharmacological therapy for up to a year. However, HbA1c levels in patients who have to be started on oral antidiabetic drugs are similar to the values in those who do not. HbA1c levels are similar in patients randomized to initial therapy with insulin or oral antidiabetic drug. There is no clinical evidence yet for an effect of insulin on beta-cell apoptosis.

SUMMARY

The primary goal is to achieve and maintain HbA1c levels of less than 7.0%. Given the extra demands on both patients and physicians when starting insulin compared with oral antidiabetic drug and the many subsequent years in which patients have diabetes, the arguments for using insulin initially, or in patients who have achieved the target HbA1c level, are not convincing. However, as soon as oral antidiabetic drug therapy cannot meet this goal, insulin must be introduced.

Detailed treatment algorithms for effective nurse- and pharmacist-directed diabetes care: a personal approach

The purpose of this article is to provide treatment algorithms proven to be effective in meeting the standards of care of the American Diabetes Association to nurses and pharmacists who are given the authority to make independent clinical decisions (under the overall supervision of a physician).

Glycemic control and survival of diabetic hemodialysis patients--importance of lower hemoglobin A1C levels

AIMS

The significance of hemoglobin A1C (HbA1C) on the survival of diabetic hemodialysis patients still remains controversial. We investigated the impact of HbA1C on the survival.

METHODS

A total of 122 diabetic patients on maintenance hemodialysis (age, 59.9+/-11.9 years [mean+/-SD]; hemodialysis duration: 53+/-38 months) were surveyed (survey period: 46+/-19 months).

RESULTS

The cumulative survival of the poor glycemic control group (mean HbA1C of 3-month period > or =6.3%, n=62) was significantly lower than that of the good group (HbA1C<6.3%, n=60), as determined by Kaplan-Meier estimation (P=0.0084, log-rank test). Kaplan-Meier analysis also demonstrated that both cardiovascular and non-cardiovascular mortalities were higher in the poor group than in the good group (P=0.0545 and P=0.0453, respectively). In a multivariate Cox proportional hazard model, the mean HbA1C was a significant predictor of survival (OR 1.260 per 1.0%, 95% CI 1.020-0.579, P=0.0325).

CONCLUSIONS

Poor glycemic control is an independent predictor of poor prognosis in diabetic hemodialysis patients. HbA1C is a clinically useful parameter for identifying the risk for mortality, both for cardiovascular and non-cardiovascular mortality, and that careful management of glycemic control by use of HbA1C is important.

Renal structure as an indicator for development of albuminuria in normo- and microalbuminuric type 2 diabetic patients

Baseline glomerular structure in microalbuminuric (MA) and proteinuric Caucasian type 2 diabetic patients predicted progressive glomerular filtration rate decline while baseline urinary albumin excretion (UAE) did not. Little is known about whether or not renal structure at the early stages of diabetic nephropathy (DN) in type 2 diabetic patients can predict further functional development of DN. Baseline renal structure and function and follow-up data of renal function were examined in 17 type 2 diabetic patients (11 men, 45+/-7 (mean+/-S.D.) years old) with known diabetes duration 11+/-8 years without definable renal disease other than DN. Six patients showed normoalbuminuria (NA), 11 microalbuminuria (MA), and were followed up for 6.4+/-1.8 years after the baseline renal biopsy. Light and electron microscopic morphometric analyses provided quantitative glomerular and tubulointerstitial structural changes. No statistically significant difference was observed in hemoglobin A1c (HbA1c) values or mean blood pressure (MBP) between baseline and follow-up, even though the number of patients placed on antihypertensive drugs increased from 3 to 7. Follow-up UAE was not significantly different from the baseline UAE although 13 of 17 cases showed an increase. Baseline UAE did not correlate with the follow-up UAE or morphometric measures. Glomerular basement membrane width and volume fraction of the mesangium and mesangial matrix positively correlated with follow-up UAE. In NA and MA Japanese type 2 diabetic patients, baseline renal structural measures are more reliable indicators for the development of UAE than baseline UAE.

A1C and survival in maintenance hemodialysis patients

OBJECTIVE

The optimal target for glycemic control has not been established in diabetic dialysis patients.

RESEARCH DESIGN AND METHODS

To address this question, the national database of a large dialysis organization (DaVita) was analyzed via time-dependent survival models with repeated measures.

RESULTS

Of 82,933 patients undergoing maintenance hemodialysis (MHD) in DaVita outpatient clinics over 3 years (July 2001 through June 2004), 23,618 diabetic MHD patients had A1C measurements at least once. Unadjusted survival analyses indicated paradoxically lower death hazard ratios (HRs) with higher A1C values. However, after adjusting for potential confounders (demographics, dialysis vintage, dose, comorbidity, anemia, and surrogates of malnutrition and inflammation), higher A1C values were incrementally associated with higher death risks. Compared with A1C in the 5-6% range, the adjusted all-cause and cardiovascular death HRs for A1C > or = 10% were 1.41 (95% CI 1.25-1.60) and 1.73 (1.44-2.08), respectively (P < 0.001). The incremental increase in death risk for rising A1C values was monotonic and robust in nonanemic patients (hemoglobin > 11.0 g/dl). In subgroup analyses, the association between A1C > 6% and increased death risk was more prominent among younger patients, those who had undergone dialysis for > 2 years, and those with higher protein intake (> 1 g x kg(-1) x day(-1)), blood hemoglobin (> 11 g/dl), or serum ferritin values (> 500 ng/ml).

CONCLUSIONS

In diabetic MHD patients, the apparently counterintuitive association between poor glycemic control and greater survival is explained by such confounders as malnutrition and anemia. All things equal, higher A1C is associated with increased death risk. Lower A1C levels not related to malnutrition or anemia appear to be associated with improved survival in MHD patients.

Development, Worsening, and Improvement of Diabetic Microangiopathy in Older People: Six-Year Prospective Study of Patients Under Intensive Diabetes Control

OBJECTIVES

To examine retinopathy and nephropathy in elderly patients with diabetes mellitus (DM) under intensive multifactorial DM control.

DESIGN

Six-year interventional observation study.

SETTING

Multicenter study including four hospitals.

PARTICIPANTS

Four hundred thirteen elderly (> or = 65) patients with type 2 DM attending each hospital for 1 year or longer; those receiving hemodialysis or with uncured malignancy were excluded.

MEASUREMENTS

Development, worsening, and improvement of retinopathy and nephropathy and respective risk factors.

RESULTS

The mean baseline hemoglobin (HbA1c), blood pressure (BP), and total cholesterol were 6.8%, 137/74 mmHg, and 5.13 mmol/L, respectively. Retinopathy developed in 45 of 168 (27%) patients and, of 63 with nonproliferative retinopathy, worsened and improved in 11 (17%) and 23 (37%), respectively. Nephropathy developed in 53 of 227 (23%) patients and improved in 13 of 51 (25%) having it baseline. The mean change in glomerular filtration rate (DeltaGFR, baseline GFR-GFR at the end of the study period) in those with nephropathy at baseline was 21.5 mL/min. HbA1c was related to development of retinopathy (P=.001, odds ratio (OR)=1.91), and serum creatinine (P=.03, OR=1.02), systolic BP (SBP) (P=.03, OR=1.22), and prior stroke (P=.005, OR=3.21) were related to development of nephropathy. In patients with nephropathy at baseline, SBP (P=.03, Spearman's rho (rho)=0.310), total cholesterol (P=.01, rho=0.361), and low-density lipoprotein cholesterol (P=.03, rho=0.322) were correlated with DeltaGFR.

CONCLUSION

In elderly patients under intensive control for DM, the outcome of microangiopathy is favorable. Modifiable risk factors were hyperglycemia for development of retinopathy and hypertension and hypercholesterolemia for development or worsening of nephropathy; prior stroke was an unmodifiable risk factor for development of nephropathy.

Diabetic nephropathy in the elderly

Renal impairment is frequent in aged diabetic patients, notably with type 2 diabetes. It results from a multifactorial pathogeny, particularly the combined actions of hyperglycaemia, arterial hypertension and ageing. Diabetic nephropathy (DN) is associated with an increased cardiovascular mortality. DN often leads to end stage renal failure (ESRF) which causes specific problems of decision and practical organization of extra-renal epuration in diabetic and aged patients. In the absence of renal biopsy, clinical signs are often insufficient to assess the diabetic origin of a nephropathy in an elderly diabetic patient. Prevention of DN is principally based on tight glycaemic and blood pressure control. The progression of renal lesions can be retarded by strict blood pressure control, notably by blocking of the renin-angiotensin system, if well tolerated in aged patients. It is absolutely necessary to avoid the worsening of renal lesions by potentially nephrotoxic products, notably non steroidal anti-inflammatory drugs (NSAIDs) and iodinated contrast media. At the stage of renal failure, it is important to adapt the antidiabetic treatment, and in the majority of the cases, to switch to insulin when glomerular filtration rate (GFR) is below 30 ml/mn/1.73 m2.

Blood pressure lowering for the prevention and treatment of diabetic kidney disease

The current pandemic of diabetes mellitus will inevitably be followed by an epidemic of chronic kidney disease. It is anticipated that 25-40% of patients with type 1 diabetes and 5-40% of patients with type 2 diabetes will ultimately develop diabetic kidney disease. The control of blood pressure represents a key component for the prevention and management of diabetic nephropathy. There is a strong epidemiological connection between hypertension in diabetes and adverse outcomes in diabetes. Hypertension is closely linked to insulin resistance as part of the 'metabolic syndrome'. Diabetic nephropathy may lead to hypertension through direct actions on renal sodium handling, vascular compliance and vasomotor function. Recent clinical trials also support the utility of blood pressure reduction in the prevention of diabetic kidney disease. In patients with normoalbuminuria, transition to microalbuminuria can be prevented by blood pressure reduction. This action appears to be significant regardless of whether patients have elevated blood pressure or not. The efficacy of ACE inhibition appears to be greater than that achieved by other agents with a similar degree of blood pressure reduction; although large observational studies suggest the risk of microalbuminuria may be reduced by blood pressure reduction, regardless of modality. In patients with established microalbuminuria, ACE inhibitors and angiotensin receptor antagonists (angiotensin receptor blockers [ARBs]) consistently reduce the risk of progression from microalbuminuria to macroalbuminuria, over and above their antihypertensive actions. The clinical utility of combining these strategies remains to be established. In patients with overt nephropathy, blood pressure reduction is associated with reduced urinary albumin excretion and, subsequently, a reduced risk of renal impairment or end stage renal disease. In addition to actions on systemic blood pressure, it is now clear that ACE inhibitors and ARBs also reduce proteinuria in patients with diabetes. This anti-proteinuric activity is distinct from other antihypertensive agents and diuretics. Although there is a clear physiological rationale for blockade of the renin angiotensin system, which is strongly supported by clinical studies, to achieve the optimal lowering of blood pressure, particularly in the setting of established diabetic renal disease, a number of different antihypertensive agents will always be needed. In the end, the choice of agents should be individualised to achieve the maximal tolerated reduction in blood pressure and albuminuria. Ultimately, no matter how it is achieved, so long as it is achieved, renal risk can be reduced by agents that lower blood pressure and albuminuria.

Renal injury: similarities and differences in male and female rats with the metabolic syndrome

The metabolic syndrome is complicated by nephropathy in humans and rats, and males are more affected than females. We hypothesized that female rats had reduced expression of glomerular oxidized low-density lipoprotein (oxLDL) receptor 1 (LOX-1), attendant glomerular oxidant injury, and renal inflammation. Three groups, obese males (OM), obese females (OF), and lean males (LM) of first-generation (F(1)) hybrid rats derived from the Zucker fatty diabetic (ZDF) strain and the spontaneous hypertensive heart failure rat (SHHF/Gmi-fa) were studied from 6 to 41 weeks of age. OM had severe renal oxidant injury and renal failure. Their glomeruli expressed the LOX-1, and exhibited heavier accumulation of the lipid peroxide 4-hydroxynonenal (4-HNE). OM had compromised mitochondrial enzyme function, more renal fibrosis, and vascular leakage. Younger LM, OM, and OF ZS (ZDF/SHHF F(1) hybrid rat) rats, studied from 6 to 16 weeks of age, showed that unutilized renal lipids were comparable in OM and OF, although young OM had worse nephropathy and inflammation. In conclusion, glomerular LOX-1 expression is coupled to deposits of 4-HNE and glomerulosclerosis in OM. We presume that LOX-1 enhances glomerular uptake of oxidized lipids and renal inflammation, causing greater oxidant stress and severe glomerulosclerosis. In OF, renal protection from lipid oxidants appears to be conferred by blunted glomerular LOX-1 expression and renal inflammation.

Enhancing the Predictive Value of Urinary Albumin for Diabetic Nephropathy

Diabetic nephropathy (DN) is a growing cause of ESRD despite widely known recommendations for improved glycemic and BP control. Perhaps earlier identification of patients who have diabetes and are at high risk for DN could reverse these epidemiologic trends. Albumin excretion rate (AER), the mainstay of early detection of DN, is not a sufficiently precise predictor of DN risk. Careful family history, smoking history, consideration of absolute versus categorical AER values, more frequent AER measures, ambulatory BP monitoring, precise GFR measurements, diabetic retinopathy assessments, and plasma lipid levels all can add to predictive accuracy for DN. Thus, although further research in DN biomarkers and predictors is greatly needed, a careful integrated evaluation of currently available parameters can improve our ability to predict DN risk in individual patients.

A discrete-state discrete-time model using indirect observation

This research was motivated by a desire to model the progression of a chronic disease through various disease stages when data are not available to directly estimate all the transition parameters in the model. This is a common occurrence when time and expense make it unfeasible to follow a single cohort to estimate all the transition parameters. One difficulty of developing a model of chronic disease progression from such data is that the available studies often do not include the transitions of interest. For example, in our model of diabetic nephropathy, many clinical studies did not differentiate between patients without nephropathy and those who had microalbuminuria (a pre-clinical stage of nephropathy). Another difficulty was a lack of data to directly estimate parameters of interest. We consider models which can accommodate such difficulties. In this paper we consider the problem of estimating parameters of a discrete-time Markov process when longitudinal data describing the entire process are not available. First, we present a likelihood approach to estimate parameters of a discrete-time Markov model. Next, we use simulation to investigate the finite-sample behaviour of our approach. Finally, we present two examples: a model of diabetic nephropathy and a model of cardiovascular disease in diabetes.

Case management for patients with poorly controlled diabetes: a randomized trial

PURPOSE

To evaluate the effects of a collaborative case management intervention for patients with poorly controlled type 2 diabetes on glycemic control, intermediate cardiovascular outcomes, satisfaction with care, and resource utilization.

METHODS

We conducted a randomized controlled trial at two Department of Veterans Affairs Medical Centers involving 246 veterans with diabetes and baseline hemoglobin A(1C) (HbA(1C)) levels >or=7.5%. Two nurse practitioner case managers worked with patients and their primary care providers, monitoring and coordinating care for the intervention group for 18 months through the use of telephone contacts, collaborative goal setting, and treatment algorithms. Control patients received educational materials and usual care from their primary care providers.

RESULTS

At the conclusion of the study, both case management and control patients remained under poor glycemic control and there was little difference between groups in mean exit HbA(1C) level (9.3% vs. 9.2%; difference = 0.1%; 95% confidence interval: -0.4% to 0.7%; P = 0.65). There was also no evidence that the intervention resulted in improvements in low-density lipoprotein cholesterol level or blood pressure control or greater intensification in medication therapy. However, intervention patients were substantially more satisfied with their diabetes care, with 82% rating their providers as better than average compared with 64% of patients in the control group (P = 0.04).

CONCLUSION

An intervention of collaborative case management did not improve key physiologic outcomes for high-risk patients with type 2 diabetes. The type of patients targeted for intervention, organizational factors, and program structure are likely critical determinants of the effectiveness of case management. Health systems must understand the potential limitations before expending substantial resources on case management, as the expected improvements in outcomes and downstream cost savings may not always be realized.

Microalbuminuria as a marker of cardiovascular and renal risk in type 2 diabetes mellitus: a temporal perspective

Microalbuminuria is a marker for diabetic nephropathy. It also signifies cardiovascular disease, as well as nephropathy, in type 2 diabetes (DM2). Microalbuminuria may precede DM2, occurring with the insulin resistance syndrome and its components, including obesity and hypertension. Other indicators of cardiovascular risk, such as markers of inflammation, are associated with microalbuminuria in populations of patients with and without diabetes. With the rising prevalence of DM2 in minority youth, especially in Native Americans, a marker for future disease risk would allow earlier prevention strategies to be tested. Before microalbuminuria can be used in a prevention strategy, more needs to be known about the mechanism(s) of the association between elevated excretion, its relationship to glucose intolerance, and its relative contribution to cardiovascular and renal disease. These questions are especially applicable as we begin to observe the long-term complications of diabetes in youth.

Treatment of diabetic nephropathy in its early stages

Diabetic nephropathy is one of the most frequent causes of end-stage renal disease (ESRD), and, in recent years, the number of diabetic patients entering renal replacement therapy has dramatically increased. The magnitude of the problem has led to numerous efforts to identify preventive and therapeutic strategies. In normoalbuminuric patients, optimal glycemic control (HbA(1c) lower than 7.5%) plays a fundamental role in the primary prevention of ESRD [weighted mean relative risk reduction (RRR) approximately 37% for metabolic control versus trivial renoprotection for intensive anti-hypertensive therapy or ACE-inhibitors (ACE-I)]. In the microalbuminuric stage, strict glycemic control probably reduces the incidence of overt nephropathy (weighted mean RRR approximately 50%), while blood pressure levels below 130/80 mmHg are recommended according to the average blood pressure levels obtained in various studies. In normotensive patients, ACE-I markedly reduce the development of overt nephropathy almost regardless of blood pressure levels; in hypertensive patients, ACE-I are less clearly active (weighted mean RRR approximately 23% versus other drugs), whereas angiotensin-receptor blockers (ARB) appear strikingly renoprotective. Once overt proteinuria appears, it is uncertain whether glycemic control affects the progression of nephropathy. In type 1 diabetes, various anti-hypertensive treatments, mainly ACE-I, are effective in slowing down the progression of nephropathy; in type 2 diabetes, two recent studies demonstrate that ARB are superior to conventional therapy or calcium channel blockers (CCB). In clinical practice, pharmacological tools are not always used to the best benefit of the patients. Therefore, clinicians and patients need to be educated regarding the renoprotection of drugs inhibiting the renin-angiotensin system (RAS) and the overwhelming importance of achieving target blood pressure.

Insulin resistance, polycystic ovary syndrome, and type 2 diabetes mellitus

OBJECTIVE

To review the definition and prevalence of two insulin resistance (IR)-associated phenotypes, polycystic ovary syndrome (PCOS) and type 2 diabetes mellitus, as well as the risk and nature of their simultaneous presentation.

DESIGN

Review of published literature.

RESULT(S)

Insulin resistance affects between 10% and 25% of the general population. Two common disorders frequently associated with IR are PCOS, affecting 4% to 6% of reproductive-aged women, and type 2 diabetes mellitus, which is observed in about 2% to 6% of similarly aged women. Overall, about 50% to 70% of women with PCOS and 80% to 100% of patients with type 2 diabetes mellitus have variable degrees of IR. Insulin resistance and its secondary hyperinsulinemia appear to underlie many of the endocrine features of PCOS in a large proportion of such patients. The risk of type 2 diabetes mellitus among PCOS patients is 5- to 10-fold higher than normal. In turn, the risk of PCOS among reproductive-aged type 2 diabetes mellitus patients appears to be similarly increased.

CONCLUSION(S)

It remains to be determined whether PCOS and type 2 diabetes mellitus represent no more than different clinical manifestations of the same IR syndrome, with their phenotypic differences due to the presence or absence of a coincidental genetic defect at the level of the ovary or pancreas, respectively, or representing the result of etiologically different subtypes of IR syndromes.

Diagnostic criteria for diabetes revisited: making use of combined criteria

BACKGROUND: Existing cut-offs for fasting plasma glucose (FPG) and post-load glucose (2hPG) criteria are not equivalent in the diagnosis of diabetes and glucose intolerance. Adjusting cut-offs of single measurements have not helped so we undertook this project to see if they could be complementary. METHODS: We performed oral glucose tolerance tests and mean levels of hemoglobin A1c (HbA1c) measurements on 43 patients referred to a diabetes clinic for possible diabetes. Results of single and combined use of the FPG and 2hPG criteria were evaluated against the levels of HbA1c and results re-interpreted in the light of existing reports in the literature. RESULTS: Our results confirm that the FPG and the 2hPG, being specific and sensitive respectively for the presence of glucose intolerance or diabetes, are not equivalent. They are shown to be indeed complementary and a re-definition of diagnostic criteria based on their combined use is proposed. CONCLUSIONS: We conclude that altering single measurement cut-offs for the diagnosis of diabetes and altered glucose tolerance will not result in better outcomes. We present the case for a combined criteria in the diagnosis and definition of diabetes with a FPG>/=7 mmol/L AND 2-hour glucose >/=7.8 mmol/L being used to define diabetes while a FPG<7 mmol/L AND 2-hour glucose <7.8 mmol/L being used to define normality. Discordant values will define impaired glucose tolerance (IGT). This proposal requires prospective evaluation in a large cohort.

Role of blood pressure in the progression of microalbuminuria in elderly Japanese type 2 diabetic patients: a 7-year follow-up study

This 7-year retrospective longitudinal study was carried out in order to clarify the clinical features of elderly type 2 diabetic patients with microalbuminuria. Elderly Japanese type 2 diabetic patients (n = 22; age 50 - 73 years) with microalbuminuria were studied retrospectively. Patients whose urinary albumin excretion rate (UAER) decreased 7 years were considered 'nonprogressors' (n = 8) whereas those whose UAER increased were considered 'progressors' (n = 14). The mean 7-year level of glycosylated haemoglobin (HbA1c) did not differ significantly between non-progressors and progressors but the mean 7-year blood pressure (BP) of progressors (101 +/- 8 mmHg) was significantly higher than that of non-progressors (92 +/- 7 mmHg). In progressors who received no anti-hypertensive drugs, systolic BP was above the BP goal of 130/85 mmHg but mean BP and diastolic BP were below this goal. The results are consistent with the view that hypertension affects the progression of microalbuminuria; raised systolic BP may be a factor in this progression in elderly type 2 diabetic patients.